@article{EL2013,
  author = {Gregor Engels AND Markus Luckey},
  title = {Editorial},
  journal = {Computer Science - Research and Development},
  year = {2013},
  volume = {28},
  number = {1},
  pages = {1--2},
  month = {Januar},
  note = {Organ der Fachbereiche Softwaretechnik, Datenbanken und Informationssysteme der Gesellschaft f{\"u}r Informatik e.V. (GI)}
}

@article{traceability,
  author = {Elke Bouillon AND Baris G{\"u}ldali AND Andrea Herrmann AND Thorsten Keuler AND Daniel Moldt AND Matthias Riebisch},
  title = {Leichtgewichtige Traceability im agilen Entwicklungsprozess am Beispiel von Scrum},
  journal = {Softwaretechnik-Trends},
  year = {2013},
  volume = {33},
  number = {1},
  pages = {29-30}
}

@article{gg12,
  author = {Silke Geisen AND Baris G{\"u}ldali},
  title = {Agiles Testen in Scrum -- Testtypen und Abl{\"a}ufe},
  journal = {OBJEKTspektrum (Online Themenspecials)},
  year = {2012},
  number = {Agility/2012},
  pages = {1-4},
  month = {Oktober},
  abstract = {Mittlerweile sind viele Unternehmen dazu {\"u}bergegangen, ihre Software \glqq{}agil\grqq{} zu entwickeln. Die damit verbundenen Erwartungen sind vor allem ein fr{\"u}hes Kundenfeedback sowie eine k{\"u}rzere \glqq{}Time-to-Market\grqq{} durch entsprechend schnelle Release-Zyklen. Hinter den Kulissen finden sich jedoch oftmals Probleme, sodass die erwarteten Vorteile agiler Softwareentwicklung nicht oder nur teilweise zum Tragen kommen. Gr{\"u}nde daf{\"u}r liegen selten an technischen H{\"u}rden, sondern oftmals in einer zu oberfl{\"a}chlichen Interpretation der Philosophie von agiler Softwareentwicklung und den damit zusammenh{\"a}ngenden Kernzielen: Planung und Analyse auf ein sinnvolles Ma{\ss} zu reduzieren und zugleich unn{\"o}tige Arbeiten zu vermeiden. Was sinnvoll und was unn{\"o}tig ist, stellt dabei eine der wesentlichen Herausforderungen dar.}
}

@article{DEK-2012,
  author = {Uwe Dumslaff AND Gregor Engels AND Marion Kremer},
  title = {IT ist nicht gleich IT: Ein Pl{\"a}doyer f{\"u}r eine situationsbezogene Softwareentwicklung},
  journal = {OBJEKTspektrum},
  year = {2012},
  number = {Nr. 5},
  pages = {52 - 57},
  month = {September},
  note = {Fachzeitschrift TroisdorfCapgemini}
}

@article{Christ2012,
  author = {Fabian Christ AND Benjamin Nagel AND Reto Bachman-Gm{\"u}r AND Rupert Westenthaler},
  title = {Semantisches Content Management},
  journal = {JavaMagazin},
  year = {2012},
  volume = {8},
  pages = {96--100},
  month = {August}
}

@article{luckey_jvlc12,
  author = {Markus Luckey AND Martin Erwig AND Gregor Engels},
  title = {Systematic Evolution of Model-Based Spreadsheet Applications},
  journal = {Journal of Visual Languages and Computing},
  year = {2012},
  volume = {23},
  number = {5},
  pages = {267-286},
  month = {Oct}
}

@article{EW2012,
  author = {Gregor Engels AND Jon Whittle},
  title = {Ten years of software and systems modeling},
  journal = {Software and Systems Modeling},
  year = {2012},
  volume = {11},
  number = {4},
  pages = {467--470},
  month = {October},
  note = {Softw Syst. Model (2012) 11:467-470}
}

@article{GerthSoSym11,
  author = {Christian Gerth AND Jochen K{\"u}ster AND Markus Luckey AND Gregor Engels},
  title = {Detection and Resolution of Conflicting Change Operations in Version Management of Process Models},
  journal = {Software and Systems Modeling},
  year = {2011},
  pages = {1-19},
  month = {December},
  abstract = {Version management of process models requires that different versions of process models are integrated by applying change operations. Conflict detection between individually applied change operations and conflict resolution support are integral parts of version management. For conflict detection it is utterly important to compute a precise set of conflicts, since the minimization of the number of detected conflicts also reduces the overhead for merging different process model versions. As not every syntactic conflict leads to a conflict when taking into account model semantics, a computation of conflicts solely on the syntax leads to an unnecessary high number of conflicts. Moreover, even the set of precisely computed conflicts can be extensive and their resolution means a significant workload for a user. As a consequence, adequate support is required that guides a user through the resolution process and suggests possible resolution strategies for individual conflicts. In this paper, we introduce the notion of syntactic and semantic conflicts for change operations of process models. We provide a method how to efficiently compute conflicts precisely, using a term formalization of process models and consider the subsequent resolution of the detected conflicts based on different strategies. Using this approach, we can significantly reduce the number of overall conflicts and reduce the amount of work for the user when resolving conflicts.}
}

@article{gjmnw10,
  author = {Stephan Wei{\ss}leder AND Baris G{\"u}ldali AND Michael Mlynarski AND Arne-Michael T{\"o}rsel AND David Farag{'o} AND Florian Prester AND Mario Winter},
  title = {Modellbasiertes Testen: Hype oder Realit{\"a}t?},
  journal = {OBJEKTspektrum},
  year = {2011},
  number = {6},
  pages = {59-65},
  month = {Oktober},
  abstract = {Manuelle Testerstellung verursacht hohe Kosten. Im Vergleich dazu bietet modellbasiertes Testen gro{\ss}e Vorteile hinsichtlich Testautomatisierung, fr{\"u}her Fehlerfindung, Erh{\"o}hung der Testabdeckung, effizienten Testentwurfs und besserer R{\"u}ckverfolgbarkeit. Die Einf{\"u}hrung des modellbasierten Testens ist jedoch mit Investitionen verbunden, f{\"u}r die die Rendite h{\"a}ufig unklar erscheint. Dabei finden sich in der Literatur bereits etliche Erfahrungsberichte zur erfolg­reichen Einf{\"u}hrung von modellbasiertem Testen in unterschiedlichen Anwendungsdom{\"a}nen. In diesem Artikel pr{\"a}sentieren wir einen {\"U}berblick {\"u}ber einige dieser Erfahrungsberichte.}
}

@article{gfse11,
  author = {Baris G{\"u}ldali AND Holger Funke AND Stefan Sauer AND Gregor Engels},
  title = {TORC: test plan optimization by requirements clustering},
  journal = {Software Quality Journal},
  year = {2011},
  pages = {1-29},
  note = {10.1007/s11219-011-9149-4},
  abstract = {Acceptance testing is a time-consuming task for complex software systems that have to fulfill a large number of requirements. To reduce this effort, we have developed a widely automated method for deriving test plans from requirements that are expressed in natural language. It consists of three stages: annotation, clustering, and test plan specification. The general idea is to exploit redundancies and implicit relationships in requirements specifications. Multi-viewpoint techniques based on RM-ODP (Reference Model for Open Distributed Processing) are employed for specifying the requirements. We then use linguistic analysis techniques, requirements clustering algorithms, and pattern-based requirements collection to reduce the total effort of testing against the requirements specification. In particular, we use linguistic analysis for extracting and annotating the actor, process and object of a requirements statement. During clustering, a similarity function is computed as a measure for the overlap of requirements. In the test plan specification stage, our approach provides capabilities for semi-automatically deriving test plans and acceptance criteria from the clustered informal textual requirements. Two patterns are applied to compute a suitable order of test activities. The generated test plans consist of a sequence of test steps and asserts that are executed or checked in the given order. We also present the supporting prototype tool TORC, which is available open source. For the evaluation of the approach, we have conducted a case study in the field of acceptance testing of a national electronic identification system. In summary, we report on lessons learned how linguistic analysis and clustering techniques can help testers in understanding the relations between requirements and for improving test planning.}
}

@article{SE2010,
  author = {Christian Soltenborn AND Gregor Engels},
  title = {Using Rule Overriding to Improve Reusability and Understandability of Dynamic Meta Modeling Specifications},
  journal = {Journal of Visual Languages and Computing},
  year = {2011},
  volume = {22},
  number = {3},
  pages = {233--250},
  abstract = {Dynamic Meta Modeling (DMM) is a visual semantics specification technique targeted at languages based on a metamodel. A DMM specification consists of a runtime metamodel and operational rules which describe how instances of the runtime metamodel change over time. A known deficiency of the DMM approach is that it does not support the refinement of a DMM specification, e.g., in the case of defining the semantics for a refined and extended domain-specific language (DSL). Up to now, DMM specifications could only be reused by adding or removing DMM rules.In this paper, we enhance DMM such that DMM rules can override other DMM rules, similar to a method being overridden in a subclass, and we show how rule overriding can be realized with the graph transformation tool GROOVE. We argue that rule overriding does not only have positive impact on reusability, but also improves the intuitive understandability of DMM semantics specifications.}
}

@article{Späth2010,
  author = {Michael Mlynarski AND Melanie Sp{\"a}th},
  title = {Agiles Testen in Gro{\ss}projekten mit TDD und Testaspekten: Beobachtungen und erste Erfahrungen},
  journal = {Softwaretechnik-Trends},
  year = {2010},
  volume = {30},
  number = {3},
  pages = {1--5}
}

@article{JurMly2010,
  author = {Marian Jureczko AND Michael Mlynarski},
  title = {Automated acceptance testing tools for web applications using Test-Driven Development},
  journal = {Electrical Review},
  year = {2010},
  volume = {86},
  pages = {198--202},
  month = {September},
  abstract = {In the last years the software engineering community pays a strong interest in agile development methods. Those methods place software testing for example the Test-Driven Development method as an important task of the development process. Agile projects rely on good test automation tools. In this paper we evaluate five test automation tools for their usage in acceptance testing for web applications using Test-Driven Development. }
}

@article{GEArtic09,
  author = {Gregor Engels},
  title = {Guest Editorial to the Special Section on MODELS 2007},
  journal = {Software \& Systems Modeling},
  year = {2010},
  volume = {9},
  number = {1},
  pages = {5--6},
  month = {Januar}
}

@article{gjmnw10,
  author = {Baris G{\"u}ldali AND Stefan Jungmayr AND Michael Mlynarski AND Stefan Neumann AND Mario Winter},
  title = {Starthilfe f{\"u}r modellbasiertes Testen},
  journal = {OBJEKTspektrum},
  year = {2010},
  number = {3},
  pages = {63-69},
  month = {April},
  abstract = {Modellbasiertes Testen ist eine Technik, die durch den Einsatz von abstrakten Modellen und geeigneten Algorithmen bestimmte manuelle Aktivit{\"a}ten, wie z. B. das Testdesign, unterst{\"u}tzt. Die Einf{\"u}hrung von modellbasiertem Testen hat das Potenzial, die Test{\"u}berdeckung durch die automatische Generierung von Testf{\"a}llen zu erh{\"o}hen und somit das Vertrauen in die Software zu steigern. Den Einsparungen von manuellen Testaktivit{\"a}ten steht aber der Zusatzaufwand f{\"u}r die Erstellung der Modelle gegen{\"u}ber. Projekt- und Testmanager stehen also vor der Frage, ob modellbasiertes Testen in ihrer konkreten Testorganisation eine sinnvolle Investition darstellt. Dieser Artikel erkl{\"a}rt die wesentlichen Begriffe zum Thema modellbasiertes Testen und gibt Entscheidungstr{\"a}gern eine heuristische Entscheidungshilfe an die Hand.}
}

@article{bgm2010,
  author = {Dominik Beulen AND Baris G{\"u}ldali AND Michael Mlynarski},
  title = {Tabellarischer Vergleich der Prozessmodellef{\"u}r modellbasiertes Testen aus Managementsicht},
  journal = {Softwaretechnik-Trends},
  year = {2010},
  volume = {30},
  number = {2},
  pages = {6-9},
  month = {Mai},
  abstract = {In dieser Publikation zeigen wir, wie die unterschiedlichen Prozessmodelle aus Managementsicht miteinander verglichen werden k{\"o}nnen. Daf{\"u}r stellen wir basierend auf die Literatur Vergleichskriterien auf. Unser Ziel ist es, mit Hilfe von objektiven Kriterien eine Vergleichbarkeit von MBT-Prozessmodellen zu erm{\"o}glichen. Den Testmanagern geben wir ein Hilfsmittel in die Hand, mit dem sie einsch{\"a}tzen k{\"o}nnen, mit welchen Aufw{\"a}nden sie bei der Auswahl eines Prozessmodells rechnen k{\"o}nnen. Da die Einf{\"u}hrung neuer Verfahren vom Reifegrad eines Prozesses abh{\"a}ngt, adressieren wir bei dem Vergleich auch den f{\"u}r die Prozessmodelle ben{\"o}tigten Reifegrad des Testprozesses nach Test Process Improvement (TPI) und die ben{\"o}tigten Mo-dellierungskenntnisse des Testteams, die mit Hilfe von Modeling Maturity Levels (MML) gemessen werden k{\"o}nnen. }
}

@article{lgg2010,
  author = {Renate L{\"o}ffler AND Baris G{\"u}ldali AND Silke Geisen},
  title = {Towards Model-based Acceptance Testing for Scrum},
  journal = {Softwaretechnik-Trends},
  year = {2010},
  volume = {30},
  number = {3},
  pages = {9--12},
  month = {August},
  abstract = {In agile processes like Scrum, strong customer involve-ment requires techniques to support requirements anal-ysis and acceptance testing. Additionally, test automa-tion is crucial, as incremental development and contin-uous integration need high efforts for testing. To copewith these challenges, we propose a model-based tech-nique for documenting customer's requirements usingtest models. These can be used by the developers asrequirements specification and by the testers for accep-tance testing. We use light-weight and easy-to-learnmodeling languages. Based on the test models, we gen-erate test scripts for FitNesse and Selenium, which arewell-known test tools in the agile community.}
}

@article{EGGRR09,
  author = {Gregor Engels AND Michael Goedicke AND Ursula Goltz AND Andreas Rausch AND Ralf H. Reussner},
  title = {Design for Future -- Legacy-Probleme von morgen vermeidbar?},
  journal = {Informatik-Spektrum},
  year = {2009},
  volume = {32},
  number = {5},
  pages = {393--397},
  month = {Oktober}
}

@article{es09,
  author = {Michael Spijkerman AND Tobias Eckardt},
  title = {Modellbasiertes Testen auf Basis des fundamentalen Testprozesses},
  journal = {Softwaretechnik-Trends},
  year = {2009},
  volume = {29},
  number = {4},
  month = {November},
  abstract = {Modellbasiertes Testen (MBT) spielt eine immer gr{\"o}{\ss}ere Rolle, um den Testentwurf w{\"a}hrend eines Testprozesses zu systematisieren. Vorgehensmodelle im Hinblick auf Modellbildung, Testfallspezifikation, Generierung der Testf{\"a}lle undTestdurchf{\"u}hrung sind vorhanden (vgl. [2], [4], [5], [7]). Der fundamentale Testprozess (FTP) von Spillner und Linz [6] bietet eine gesamtheitliche Sicht, von der Planung bis zumAbschluss der Testaktivit{\"a}ten. Er nimmt jedoch nicht explizit Bezug auf MBT. Es ist nicht klar welche Aspekte zu ber{\"u}cksichtigen sind, wenn modellbasiertes Testen in Kombinationmit dem FTP angewendet werden soll. In diesem Artikel wird ein erster Schritt hin zu einem modellbasierten Testprozess vorgestellt, der sich an dem FTP orientiert.}
}

@article{HFKV08,
  author = {Rainer Hauser AND Michael Friess AND Jochen K{\"u}ster AND Jussi Vanhatalo},
  title = {An Incremental Approach to the Analysis and Transformation of Workflows Using Region Trees},
  journal = {Transactions on Systems, Men, and Cybernetics},
  year = {2008},
  volume = {38},
  number = {3},
  pages = {347--359},
  month = {May},
  abstract = {The analysis of workflows in terms of structural correctness is important for ensuring the quality of workflow models. Typically, this analysis is only one step in a larger development process, followed by further transformation steps that lead from high-level models to more refined models until the workflow can finally be deployed on the underlying workflow engine of the production system. For practical and scalable applications, both analysis and transformation of workflows must be integrated to allow incremental changes of larger workflows. In this paper, we introduce the concept of a region tree (RT) for workflow models that can be used as the central data structure for both workflow analysis and workflow transformation. An RT is similar to a program structure tree and imposes a hierarchy of regions as an overlay structure onto the workflow model. It allows an incremental approach to the analysis and transformation of workflows, and thereby, significantly reduces the overhead because individual regions can be dealt with separately. The RT is built using a set of region-growing rules. The set of rules presented here is shown to be correct and complete in the sense that a workflow is region-reducible as defined through these rules if and only if it is semantically sound.}
}

@article{egs08,
  author = {Baris G{\"u}ldali AND Stefan Sauer AND Gregor Engels},
  title = {Formalisierung der funktionalen Anforderungen mit visuellen Kontrakten und deren Einsatz f{\"u}r modellbasiertes Testen},
  journal = {Softwaretechnik-Trends},
  year = {2008},
  volume = {28},
  number = {3},
  pages = {12-16},
  month = {August},
  abstract = {Wir haben in diesem Beitrag einen Ansatz zurFormalisierung der UML-Anwendungsfallsbeschreibungenvorgestellt, um Anwendungsf{\"a}lleeffektiv f{\"u}r Testzwecke einsetzen zu k{\"o}nnen.Dabei werden die textuellen Beschreibungen derVor- und Nachbedingungen mit visuellen Kontraktenformalisiert. Die visuellen Kontrakte beschreibendie {\"A}nderungen bez{\"u}glich der fachlichenDaten nach der Ausf{\"u}hrung des Anwendungsfalls.Mit visuellen Kontrakten k{\"o}nnenw{\"a}hrend der Testfallspezifikation Testeingabengeneriert und w{\"a}hrend der Testausf{\"u}hrung Testausgaben{\"u}berpr{\"u}ft werden. F{\"u}r visuelle Kontraktewurden Werkzeuge entwickelt, die dieEinbindung der visuellen Kontrakte in den Entwicklungs-und Testprozess erm{\"o}glichen.}
}

@article{Ehrig,
  author = {Karsten Ehrig AND Jochen K{\"u}ster AND Gabriele Taentzer},
  title = {Generating Instance Models from Meta Models},
  journal = {Software and Systems Modeling},
  year = {2008},
  volume = {8},
  number = {4},
  pages = {479-500},
  month = {July},
  abstract = {Meta modeling is a wide-spread technique to define visual languages, with the UML being the most prominent one. Despite several advantages of meta modeling such as ease of use, the meta modeling approach has one disadvantage: it is not constructive, i.e., it does not offer a direct means of generating instances of the language. This disadvantage poses a severe limitation for certain applications. For example, when developing model transformations, it is desirable to have enough valid instance models available for large-scale testing. Producing such a large set by hand is tedious. In the related problem of compiler testing, a string grammar together with a simple generation algorithm is typically used to produce words of the language automatically. In this paper, we introduce instance-generating graph grammars for creating instances of meta models, thereby overcoming the main deficit of the meta modeling approach for defining languages.}
}

@article{EngVo08,
  author = {Gregor Engels AND Markus Vo{\ss}},
  title = {Quasar Enterprise},
  journal = {Informatik-Spektrum},
  year = {2008},
  volume = {31},
  number = {6},
  pages = {548--555},
  abstract = {Die Gestaltung und Weiterentwicklung gro{\ss}er Anwendungslandschaften gilt heutzutage als eine der gr{\"o}{\ss}ten Herausforderungen in der Softwaretechnik. Als L{\"o}sungsansatz wurde in den letzten Jahren vielfach das Paradigma einer serviceorientierten Architektur (SOA) diskutiert und insbesondere durch herstellerspezifische Technologien unterst{\"u}tzt. Dieser Beitrag widmet sich einer h{\"a}ufig vernachl{\"a}ssigten methodischen Herangehensweise und stellt mit Quasar Enterprise einen strukturierten und in der Praxis erprobten L{\"o}sungsansatz vor. Insbesondere werden konkrete Verfahrensbausteine f{\"u}r eine durchg{\"a}ngige Methode vorgestellt, die einem Architekten helfen, eine auf das zu unterst{\"u}tzende Gesch{\"a}ft ausgerichtete Anwendungslandschaft zu entwickeln und zu warten. Wesentliche Charakteristika von Quasar Enterprise sind der konsequente Einsatz einer serviceorientierten Herangehensweise, die Verwendung eines Architektur-Frameworks als Strukturierungsgrundlage und die Aufbereitung der Methode in Form von 20 Verfahrensbausteinen.}
}

@article{ESS2008,
  author = {Gregor Engels AND Stefan Sauer AND Christian Soltenborn},
  title = {Unternehmensweit verstehen -- unternehmensweit entwickeln: Von der Modellierungssprache zur Softwareentwicklungsmethode},
  journal = {Informatik-Spektrum},
  year = {2008},
  volume = {31},
  number = {5},
  pages = {451--459},
  month = {October},
  abstract = {Sollen wir UML 1.4, UML 2.0 oder eine ganz andere Modellierungssprache f{\"u}r unsere Softwareentwicklung einsetzen? Der folgende Beitrag zeigt, dass bei der Festlegung einer unternehmensweiten Entwicklungsmethode nicht die Frage nach der Modellierungssprache im Vordergrund stehen sollte. Viel entscheidender f{\"u}r den Erfolg von Softwareentwicklungsprojekten in einem Unternehmen ist ein einheitliches Verst{\"a}ndnis der Entwicklungskonzepte und -artefakte sowie ihrer Beziehungen untereinander. Eine Einigung {\"u}ber ein unternehmensweites Dom{\"a}nenmodell der Softwareentwicklungskonzepte sollte deshalb vor der Auswahl von Modellierungssprachen, eines konkreten Vorgehensmodells und geeigneter Werkzeuge erfolgen.}
}

@article{Bals2007,
  author = {Jan-Christopher Bals AND Fabian Christ AND Gregor Engels AND Stefan Sauer},
  title = {Software-Qualit{\"a}t - {\"u}berall! - Excel-lente Software},
  journal = {Forschungsforum Paderborn},
  year = {2007},
  volume = {10},
  pages = {56--60},
  month = {January}
}

@article{Heckel2007,
  author = {Reiko Heckel AND Alexey Cherchago},
  title = {Structural and Behavioural Compatibility of Graphical Service Specifications},
  journal = {Logic and Algebraic Programming},
  year = {2007},
  volume = {70},
  number = {1},
  pages = {15--33},
  month = {January},
  abstract = {The ability of applications to dynamically discover required services is a key motivation for Web Services. However, this aspect is not entirely supported by current Web Services standards. It is our objective to develop a formal approach, allowing the automation of the discovery process. The approach is based on the matching of interface specifications of the required and provided services. In the present paper, we establish an integral notion of structural and behavioural compatibility of service specifications. While structural information is represented by operation declarations, behavioural descriptions are provided by contracts expressed as graph transformation rules with positive and negative application conditions. The integration of structural and behavioural descriptions is facilitated by typed and parameterised graph transformation systems, augmenting the rule-based description of behaviour by a type graph and operation declarations representing the structural aspect. The matching relation taking into account this combination is called parameterised substitution morphism. We show that substitution morphisms satisfy the semantic requirement inherent in its name: the substitutability of abstract operations by (calls to) concrete ones.}
}

@article{Kuester2006,
  author = {Jochen K{\"u}ster},
  title = {Definition and Validation of Model Transformations},
  journal = {Software and Systems Modeling},
  year = {2006},
  volume = {5},
  number = {3},
  pages = {233--259},
  month = {September},
  abstract = {With model transformations becoming more widely used, there is an increasing need for approaches focussing on a systematic development of model transformations. Although a number of approaches for specifying model transformations exist, none of them focusses on systematically validating model transformations with respect to termination and confluence. Termination and confluence ensure that a model transformation always produces a unique result. Also called functionality, these properties are important requirements for practical applications of model transformations. In this paper, we introduce our approach to model transformation. Using and extending results from the theory of graph transformation, we investigate termination and confluence properties of model transformations specified in our approach. We establish a set of criteria for termination and confluence to be checked at design time by static analysis of the transformation rules and the underlying metamodels. Moreover, the criteria are formulated in such a way that they require less experience with the theory of graph transformation. Our concepts are illustrated by a running example of a model tranformation from statecharts to the process algebra Communicating Sequential Processes.}
}

@article{Heckel2006,
  author = {Reiko Heckel AND Marc Lohmann},
  title = {Model-Driven Development of Reactive Information Systems: From Graph Transformation Rules to JML Contracts},
  journal = {International Journal on Software Tools for Technology Transfer (STTT)},
  year = {2006},
  volume = {9},
  number = {2},
  pages = {193--207},
  month = {August},
  abstract = {The model-driven architecture focuses on the evolution and integration of applications across heterogeneous platforms by means of generating implementations from platform-independent models. Most of the existing realizations of this idea are limited to static models. We propose a model-driven approach to the development of reactive information systems, like dynamic Web pages or Web services, modeling their typical request-query-update-response pattern by means of graph transformation rules. Rather than generating executable code from these models we focus on the verification of the consistency between different sub-models and an implementation that may have been produced manually. The main technical tool for achieving this goal is a mapping of graph transformation rules to contracts expressed in the Java Modeling Language.}
}

@article{HRI05,
  author = {Zille Huma AND Muhammad Rehman AND Nadeem Iftikhar},
  title = {An Ontology-Based Framework for Semi-Automatic Schema Integration},
  journal = {Journal of Computer Science and Technology},
  year = {2005},
  volume = {20},
  number = {6},
  pages = {788--796},
  month = {November},
  abstract = {Currently, schema integration frameworks use approaches like rule-based, machine learning, etc. This paper presents an ontology-based wrapper-mediator framework that uses both the rule-based and machine learning strategies at the same time. The proposed framework uses global and local ontologies for resolving syntactic and semantic heterogeneity, and XML for interoperability. The concepts in the candidate schemas are merged on the basis of the similarity coefficient, which is calculated using the defined rules and the prior mappings stored in the case-base.}
}

@article{Hausmann2005,
  author = {Jan Hendrik Hausmann AND Reiko Heckel AND Marc Lohmann},
  title = {Model-based development of Web service descriptions enabling a precise matching concept},
  journal = {International Journal of Web Services Research},
  year = {2005},
  volume = {2},
  number = {2},
  pages = {67--85},
  month = {April-June},
  abstract = {Web services are software components that can be discovered and employed at runtime using the Internet. Conflicting requirements towards the nature of these services can be identified. From a business perspective, Web services promise to enable the formation of ad-hoc cooperations on a global scale. From a technical perspective, a high degree of standardization and rigorous specifications are required to enable the automated integration of Web services. A suitable technology for Web services has to mediate these needs for flexibility and stability. To be usable in practice, this technology has to be aligned to standard software engineering practice to allow for a seamless development of Web service enabled components. In this paper, we introduce a new approach to the description of Web services. It is a visual approach based on the use of software models and graph transformations and allows for the flexible description of innovative services while providing a precise matching concept. A methodology enabling the seamless development of such Web service descriptions in the context of a standard model-based development approach is presented.}
}

@article{Doberkat2005,
  author = {Ernst-Erich Doberkat AND Gregor Engels AND Jan Hendrik Hausmann AND Marc Lohmann AND J{\"o}rg Pleumann AND Jens Schr{\"o}der},
  title = {Software Engineering and eLearning: The MuSofT Project},
  journal = {e-learning and education (eleed) Journal},
  year = {2005},
  volume = {2},
  month = {Dezember},
  abstract = {eLearning supports the education in certain disciplines. Here, we report about novel eLearning concepts, techniques, and tools to support education in Software Engineering, a subdiscipline of computer science. We call this "Software Engineering eLearning". On the other side, software support is a substantial prerequisite for eLearning in any discipline. Thus, Software Engineering techniques have to be applied to develop and maintain those software systems. We call this "eLearning Software Engineering". Both aspects have been investigated in a large joint, BMBF-funded research project, termed MuSofT (Multimedia in Software Engineering). The main results are summarized in this paper.}
}

@article{Baresi2005,
  author = {Luciano Baresi AND Reiko Heckel AND Sebastian Th{\"o}ne AND D{'a}niel Varr{'o}},
  title = {Style-Based Modeling and Refinement of Service-Oriented Architectures},
  journal = {Software and Systems Modeling},
  year = {2005},
  volume = {5},
  number = {2},
  pages = {187-207},
  abstract = {Service-oriented architectures (SOA) provide a flexible and dynamic platform for implementing business solutions. In this paper, we address the modeling of such architectures by refining business-oriented architectures, which abstract from technology aspects, into service-oriented ones, focusing on the ability of dynamic reconfiguration (binding to new services at run-time) typical for SOA. The refinement is based on conceptual models of the platforms involved as architectural styles, formalized by graph transformation systems. Based on a refinement relation between abstract and platform-specific styles we investigate how to realize business-specific scenarios on the SOA platform by automatically deriving refined, SOA-specific reconfiguration scenarios.}
}

@article{HHS04SoSym,
  author = {Jan Hendrik Hausmann AND Reiko Heckel AND Stefan Sauer},
  title = {Dynamic Meta Modeling with Time: Specifying the Semantics of Multimedia Sequence Diagrams},
  journal = {Software and Systems Modeling},
  year = {2004},
  volume = {3},
  number = {3},
  pages = {181--193},
  month = {August},
  abstract = {UML offers different diagram types to model behavior and dynamics of software systems. In some domains like embedded real-time systems or multimedia systems, it is necessary to include specifications of time since the correctness of these applications depends on the fulfillment of temporal requirements in addition to functional requirements. UML thus already incorporates language features to model time and temporal constraints. Such model elements must have an equivalent in the semantic domain. We have proposed Dynamic Meta Modeling (DMM) as a means for the specification of the formal operational semantics of UML models by applying graph transformation to the meta modeling of dynamic behavior. Within this paper, we extend this approach to also account for time by building on timed graph transformations. We apply these concepts to the domain of multimedia application modeling in which we adopt UML sequence diagrams. The DMM rules with time then specify an interpreter that can be used to analyze or test a model of multimedia sequence diagrams.}
}

@article{Engels2003a,
  author = {Gregor Engels AND Jan Hendrik Hausmann AND Marc Lohmann},
  title = {eLearning-Plattformen f{\"u}r die Hochschule: Bedarfsgerechte Bestimmung der Anforderungen},
  journal = {ForschungsForum Paderborn},
  year = {2003},
  volume = {6},
  pages = {44--47},
  month = {January},
  abstract = {Der Einfluss neuer Technologien auf die Art wie wir Lehren und Lernen wird seit einigen Jahren unter dem Begriff eLearning diskutiert. Auch an den Hochschulen gibt es Bemhungen, eLearning-Konzepte zu etablieren. Dabei versprechen so genannte eLearning-Plattformen ein integriertes und reibungsloses Zusammenarbeiten aller Beteiligten am eLearning zu ermglichen. Der Einsatz einer so zentralen Software in einem System wie der Hochschule ist ein komplexes Problem, fr dessen Bewltigung die Softwaretechnik, ein Fachgebiet der Informatik, Methoden und Sprachen bereitstellt. Zentrale Idee dabei ist es, von existierenden Strukturen und den Bedrfnissen der Anwender auszugehen. In diesem Beitrag wird beschrieben, wie die Analyse von Hochschulstrukturen und Prozessen der Planung des Einsatzes von eLearning-Plattformen dient.}
}

@article{Mehner2003,
  author = {Katharina Mehner},
  title = {Zur Performanz der {\"U}berwachung von Methodenaufrufen mit der Java Platform Debugger Architecture (JPDA)},
  journal = {Java Spektrum},
  year = {2003},
  volume = {6},
  month = {November/ December},
  abstract = {Die Java Plattform Debugger Architecture (JPDA) bietet komfortable Schnittstellen f{\"u}r die {\"U}berwachung von laufenden Java-Programmen. Mit der JPDA k{\"o}nnen Debugger, Tracing- und Monitoring-Werkzeuge implementiert werden. Der Laufzeit-Overhead durch die JPDA ist nicht unerheblich, aber er kann durch Wahl der Schnittstellen und weiterer Parameter beeinflusst werden. Hier wird der Laufzeit-Overhead f{\"u}r die {\"U}berwachung von Methodenaufrufen gemessen, wie sie in Tracing- und Monitoring-Werkzeugen vorkommt.}
}

@article{CHM02a,
  author = {Andrea Corradini AND Reiko Heckel AND Ugo Montanari},
  title = {Compositional SOS and Beyond: A Coalgebraic View of Open Systems},
  journal = {Theoretical Computer Science},
  year = {2002},
  volume = {280},
  number = {1-2},
  pages = {163--192},
  month = {May},
  abstract = {In this paper we address the issue of providing a structured coalgebra presentation of transition systems with algebraic structure on states determined by an equational specification . More precisely, we aim at representing such systems as coalgebras for an endofunctor on the category of-algebras. The systems we consider are specified by using arbitrary SOS rules, which in general do not guarantee that bisimilarity is a congruence. We first show that the structured coalgebra representation...}
}

@article{HLEO02,
  author = {Reiko Heckel AND Merc{'e} Llabr{'e}s AND Hartmut Ehrig AND Fernando Orejas},
  title = {Concurrency and Loose Semantics of Open Graph Transformation Systems},
  journal = {Mathematical Structures in Computer Science},
  year = {2002},
  volume = {12},
  number = {4},
  pages = {349--376},
  month = {August},
  abstract = {Graph transitions represent an extension of the DPO approach to graph transformation for the specification of reactive systems. In this paper, we develop the theory of concurrency for graph transitions. In particular, we prove a local Church--Rosser theorem and define a notion of shift-equivalence that allows us to represent both intra-concurrency (within the specified subsystem) and inter-concurrency (between subsystem and environment). Via an implementation of transitions in terms of DPO transformations with context rules, a second, more restrictive notion of equivalence is defined that captures, in addition, the extra-concurrency (between operations of the environment). As a running example and motivation, we show how the concepts of this paper provide a formal model for distributed information systems. }
}

@article{EngelsKG2002c,
  author = {Gregor Engels AND Jochen K{\"u}ster AND Luuk Groenewegen},
  title = {Consistent Interaction of Software Components},
  journal = {Transactions of the SDPS: Journal of Integrated Design \& Process Science},
  year = {2002},
  volume = {6},
  number = {4},
  pages = {2--22},
  month = {December},
  abstract = {Constructing complex software systems by integrating different software components isa promising and challenging approach. With the functionality of software components given by models it is possible to ensure consistency of such models before implementation in order to successfully build the system. Models consisting of different submodels, the absence of an overall formal semantics and the numerous possibilities of employing models requires the development of techniques ensuring the consistency. In this paper, we discuss the issue of consistency of models made up of different submodels proposing a concept for the management of consistency. Consistency management relies on a consistency concept and a process for ensuring consistency of models. We introduce a consistency concept for software components modeled in the Unified Modeling Language (UML) and devise suitable consistency checks. On this basis, we propose a process how to locate and resolve inconsistencies, thus ensuring the consistency of models and by that the consistency of componentbased systems derived from those models.}
}

@article{dhk02scp,
  author = {Ralph Depke AND Reiko Heckel AND Jochen K{\"u}ster},
  title = {Formal Agent-Oriented Modeling with Graph Transformation},
  journal = {Science of Computer Programming},
  year = {2002},
  volume = {44},
  pages = {229--252},
  abstract = {For the generic specification of protocols, goals, or workflows, many approaches to agentoriented modeling provide a concept of role. Roles abstract from the concrete agents involved in an interaction. They provide means for the evolution of agents and serve as components of agent design. Despite the wide-spread usage of roles in agent-oriented modeling, a systematic analysis of the different aspects and properties of this concept is still missing. In this paper, we perform such an analysis and identify requirements for a general role concept. We develop such a role concept for a modeling approach based on the UML and graph transformation systems and exemplify its use for the specification (and application) of protocols. Finally, we provide a run-time semantics for roles based on concepts from the theory of graph transformation.}
}

@article{Doberkat2002,
  author = {Ernst-Erich Doberkat AND Gregor Engels},
  title = {MuSofT - Multimedia in der Softwaretechnik},
  journal = {Informatik Forschung und Entwicklung},
  year = {2002},
  volume = {1},
  number = {17},
  pages = {41--44},
  month = {Februar},
  abstract = {Im BMBF-Verbundprojekt MuSofT werden multimediale Lehrmaterialienf{\"u}r die Lehre der Softwaretechnik entwickelt. Neben den inhaltliche Aspekten sind dieDistribution und die Lizenzierung der erstellten Lehrmaterialien wichtige Themakomplexe,um die Nachhaltigkeit des Projektes zu erh{\"o}hen. In diesem Papier stellen wirdie in MuSofT gew{\"a}hlten L{\"o}sungen einer Open-Content-Lizenz sowie eines Portalszur Distribution der entwickelten Materialien vor.}
}

@article{CGH01tcs,
  author = {Andrea Corradini AND Martin Gro{\ss}e-Rhode AND Reiko Heckel},
  title = {A Coalgebraic presentation of structured transition systems},
  journal = {Theoretical Computer Science},
  year = {2001},
  volume = {260},
  number = {1-2},
  pages = {27--55},
  month = {May},
  abstract = {This paper relates labelled transition systems and coalgebras with the motivation of comparing and combining their complementary contributions to the theory of concurrent systems. The well-known mismatch between these two notions concerning the morphisms is resolved by extending the coalgebraic framework by lax cohomomorphisms.Enriching both labelled transition systems and coalgebras with algebraic structure for an algebraic specification, the correspondence is lost again. This motivates the introduction of lax coalgebras, where the coalgebra structure is given by a lax homomorphism. The resulting category of lax coalgebras and lax cohomomorphisms for a suitable endofunctor is shown to be isomorphic to the category of structured transition systems, where both states and transitions form algebras.The framework is also presented on a more abstract categorical level using monads and comonads, extending the bialgebraic approach introduced by Turi and Plotkin.}
}

@article{PJE+00,
  author = {Julia Padberg AND Lars Jansen AND Hartmut Ehrig AND E. Schnieder AND Reiko Heckel},
  title = {Cooperability in Train Control Systems: Specification of Scenarios using Open Nets},
  journal = {Transactions of the Society for Design and Process Science},
  year = {2001},
  volume = {5},
  number = {1},
  pages = {3--21},
  abstract = {We consider the area of train control systems like the European Train Control Systems (ETCS) where several different scenarios are considered and related software components must cooper-ate effectively in order to achieve the desired system behavior. In order to specify operational behavior of ETCS high-level Petri net techniques have been identified as one of the most ade-quate formal specification techniques according to the state of the art. Petri nets can be used to describe scenarios that represent the required operational behavior of the controlled system. Unfortunately, Petri nets in the usual sense are not fully adequate to model such scenarios and to achieve cooperability. This is caused by the lack of Petri nets to interact with the environment. Thus Petri nets fail to provide a suitable notion for cooperability between different components of a system. The new notion of open nets, developed within the research group ``Petri Net Tech-nology'', is most promising as a conceptual and formal technique for these kinds of problems. In this paper we study a simplified version of a railway level crossing control system. There are a few number of basic scenarios represented by interaction diagrams, which are modeled by open nets, called scenario nets. The cooperability of system components is ensured by suit-able integration and composition techniques for open nets. These techniques provide a basis for cooperability in train control systems in general, especially for problems in the area of ETCS.}
}

@article{HEWC01,
  author = {Reiko Heckel AND Hartmut Ehrig AND Uwe Wolter AND Andrea Corradini},
  title = {Double Pullback Transitions and Coalgebraic Loose Semantics for Graph Transformation Systems},
  journal = {Applied Categorical Structures},
  year = {2001},
  volume = {9},
  number = {1},
  pages = {83--110},
  month = {January},
  abstract = {The aim of this paper is an extension of the theory of graph transformation systems in order to make them suitable for the specification of reactive systems. For this purpose two main extensions of the algebraic theory of graph transformations are proposed. Firstly, graph transitions are introduced as a loose interpretation of graph productions, defined using a double pullback construction in contrast to classical graph derivations based on double-pushouts. Two characterisation results relate ...}
}

@article{Engels2001,
  author = {Gregor Engels AND Jens Gaulke AND Stefan Sauer},
  title = {Modelle f{\"u}r automobile Software - Objektorientierte Modellierung von eingebetteten, interaktiven Softwaresystemen im Automobil},
  journal = {Forschungsforum Paderborn},
  year = {2001},
  volume = {4},
  pages = {24--29},
  month = {January},
  abstract = {Wie in allen technischen Ger{\"a}ten werden auch im Automobil immer mehr Funktionen durch Softwaresysteme realisiert bzw. gesteuert. Bei einer Entwicklung derartiger Softwaresysteme wird im Rahmen eines ingenieurm{\"a}{\ss}igen Entwicklungsprozesses zun{\"a}chst ein Modell erstellt. Hierzu muss eine Modellierungssprache zur Verf{\"u}gung stehen, die den Modellierer ad{\"a}quat bei der Erstellung des Modells unterst{\"u}tzt und ein einheitliches Verst{\"a}ndnis des Modells erm{\"o}glicht. }
}

@article{DHK01ijseke,
  author = {Ralph Depke AND Reiko Heckel AND Jochen K{\"u}ster},
  title = {Roles in Agent-Oriented Modeling},
  journal = {International Journal of Software Engineering and Knowledge Engineering},
  year = {2001},
  volume = {11},
  number = {3},
  pages = {281--302},
  abstract = {In this paper, we perform such an analysis and identify requirements for a general role concept. We develop such a role concept for a modeling approach based on the UML and graph transformation systems and exemplify its use for the specification (and application) of protocols. Finally, we provide a run-time semantics for roles based on concepts from the theory of graph transformation.}
}

@article{DHKL00,
  author = {Ralph Depke AND Reiko Heckel AND Jochen K{\"u}ster AND Matthew Langham},
  title = {Agenten im Auftrag des Bankkunden},
  journal = {Geldinstitute},
  year = {2000},
  volume = {31},
  number = {1-2},
  pages = {32--33},
  month = {Februar }
}

@article{HE00,
  author = {Gregor Engels AND Reiko Heckel},
  title = {Graph Transformation and Visual Modeling Techniques},
  journal = {Bulletin of the EATCS},
  year = {2000},
  number = {71},
  pages = {186--202},
  month = {June},
  abstract = {In order to provide semantic support for visual modeling techniques, new techniques have to be developed which help us to narrow the conceptual gap between graph-based visual modeling techniques like the UML and established methodologies of programming language semantics almost exclusively based on trees and terms. Concepts and results from the area of graph transformation can be used both as a basis for high-level rule-based visual languages, and as semantic domain for visual modeling techniques focusing on the structural and behavioral aspects of today's software systems. Moreover, graph transformation can provide the necessary technology in order to develop the graph-based counterparts of the denotational, operational, or algebraic semantics paradigms in the field of programming languages.In this paper, we substantiate these claims by examples of the use of graph transformation as visual modeling notion, semantic domain, and for the semantics of diagram languages.}
}

@article{CH00eatcs,
  author = {Andrea Corradini AND Reiko Heckel},
  title = {Graph Transformation and Visual Modeling Techniques: Workshop Summary and HowTo},
  journal = {Bulletin of the EATCS},
  year = {2000},
  number = {72},
  pages = {69--76},
  month = {October},
  abstract = {In order to provide semantic support for visual modeling techniques, new techniques have to be developed which help us to narrow the conceptual gap between graph-based visual modeling techniques like the UML and established methodologies of programming language semantics almost exclusively based on trees and terms. Concepts and results from the area of graph transformation can be used both as a basis for high-level rule-based visual languages, and as semantic domain for visual modeling techniques focusing on the structural and behavioral aspects of today's software systems. Moreover, graph transformation can provide the necessary technology in order to develop the graph-based counterparts of the denotational, operational, or algebraic semantics paradigms in the field of programming languages.In this paper, we substantiate these claims by examples of the use of graph transformation as visual modeling notion, semantic domain, and for the semantics of diagram languages.}
}

@article{Depke1999,
  author = {Ralph Depke AND Gregor Engels AND Katharina Mehner AND Stefan Sauer AND Annika Wagner},
  title = {Ein Vorgehensmodell f{\"u}r die Multimedia-Entwicklung mit Autorensystemen},
  journal = {Informatik Forschung und Entwicklung},
  year = {1999},
  volume = {14},
  number = {2},
  pages = {83--94},
  month = {June},
  abstract = {Multimedia-Anwendungen sind interaktive Softwaresysteme und verlangen als solche, mit softwaretechnischen Methoden erstellt zu werden. Sie werden heutzutage in der Regel mit Hilfe von Autorensystemen entwickelt, die eine Ad-hoc-Entwicklung auf Implementierungsniveau unterst{\"u}tzen. Hierdurch und wegen des Fehlens etablierter Vorgehensmodelle f{\"u}r die Multimedia-Softwareentwicklung reduziert sich der Multimedia-Entwicklungsproze{\ss} auf die Implementierungsphase. Dies f{\"u}hrt zu den in der Softwaretechnik bekannten Problemen wie mangelnder Konzeption und fehlender Dokumentation. Wir stellen in diesem Beitrag ein Vorgehensmodell f{\"u}r die Entwicklung von Multimedia-Anwendungen vor, in dessen Mittelpunkt eine Analyse- und Entwurfsphase im Hinblick auf eine Implementierung der Multimedia-Anwendung mit einem Autorensystem stehen. Ausgehend von einem frameworkbasierten Analysemodell der Anwendung und einem Modell der Realisierungsm{\"o}glichkeiten mit einem konkreten Autorensystem wird systematisch ein Implementierungsmodell auf Instanzebene abgeleitet, das als Eingabe f{\"u}r das Autorensystem verwendet wird. Das postulierte Vorgehensmodell wird exemplarisch f{\"u}r das Autorensystem Director am Beispiel der Dom{\"a}ne multimedialer Lehr-/Lernanwendungen erl{\"a}utert.}
}

@article{Cherchago1999,
  author = {Alexey Cherchago AND V. Finaev},
  title = {Formalization of the development process for a software-hardware reflexodiagnostic tool},
  journal = {Scientific bulletin of Academy of Information Technologies in Education, Science and Balneology},
  year = {1999},
  volume = {3}
}

@article{Andries1999,
  author = {Marc Andries AND Gregor Engels AND Annegret Habel AND Berthold Hoffmann AND Hans-J{\"o}rg Kreowski AND Sabine Kuske AND Detlef Plump AND Andy Sch{\"u}rr AND Gabriele Taentzer},
  title = {Graph Transformation for Specification and Programming},
  journal = {Science of Computer Programming},
  year = {1999},
  volume = {34},
  number = {1},
  pages = {1--54},
  month = {April },
  abstract = {The framework of graph transformation combines the potentials and advantages of both, graphs and rules, to a single computational paradigm. In this paper we present some recent developments in applying graph transformations as a rule-based framework for the specification and development of systems, languages, and tools. After reviewing the basic features of graph transformation, we discuss a selection of applications, including the evaluation of functional expressions, the specification of an interactive graphical tool, an example specification of abstract data types, and the definition of a visual database query language. The case studies indicate the need for suitable structuring principles which are independent of a particular graph transformation approach. To this end, we present the concept of a transformation unit, which allows systematic and structured specifications and programming based on graph transformation.}
}

@article{EHTE97b,
  author = {Gregor Engels AND Reiko Heckel AND Gabriele Taentzer AND Hartmut Ehrig},
  title = {A Combined Reference Model- and View-Based Approach to System Specification},
  journal = {Int. Journal of Software and Knowledge Engeneering},
  year = {1997},
  volume = {7},
  number = {4},
  pages = {457--477},
  month = {December},
  abstract = {The idea of a combined reference model- and view-based specification approach has been proposed recently in the software engineering community. In this paper we present a specification technique based on graph transformations which supports such a development approach. The use of graphs and graph transformations allows to satisfy the general requirements of an intuitive understanding and the integration of static and dynamic aspects on a well-defined and sound semantical base. On this background, formal notions of view and view relation are developed and the behaviour of views is described by a loose semantics. View relations are shown to preserve the behaviour of views. Moreover, we define a construction for the automatic integration of views which assumes that the dependencies between different views are described by a reference model. The views and the reference model are kept consistent manually, which is the task of a model manager. In case of more than two views more general scenarios are developed and discussed. We are able to show that the automatic view integration is compatible with the loose semantics, i.e., the behaviour of the system model is exactly the integration of the behaviours of the views. All concepts and results are illustrated at the well-known example of a banking system.}
}

@article{Engels97a,
  author = {Gregor Engels AND Hans J{\"u}rgen Schneider},
  title = {Guest Editors' Introduction},
  journal = {International Journal on Software Engineering and Knowledge Engineering (IJSEKE)},
  year = {1997},
  volume = {7},
  number = {4},
  pages = {397--400},
  month = {December },
  note = {},
  abstract = {Guest Editors Introduction}
}

@article{Andries1996,
  author = {Marc Andries AND Gregor Engels},
  title = {A Hybrid Query Language for the Extended Entity Relationship Model},
  journal = {Journal of Visual Languages and Computing},
  year = {1996},
  volume = {7},
  number = {3},
  pages = {321--352},
  month = {September},
  abstract = {We present the hybrid query language HQL/EER for an Extended Entity-Relationship model. As its main characteristic, this language allows a user to usebothgraphical and textual elements in the formulation of one and the same query. We demonstrate the look-and-feel of this query language by means of examples, and show how syntax and semantics of this language are formally defined using programmed graph rewriting systems. Although we present the language in the context of the EER model, the concept of hybrid languages is applicable in the context of other database models as well. We illustrate this claim by discussing a prototype implementation of a Hybrid Query Tool based on an object-oriented approach, namely the Object Modeling Technique (OMT).}
}

@article{HHT96,
  author = {Annegret Habel AND Reiko Heckel AND Gabriele Taentzer},
  title = {Graph Grammars with Negative Application Conditions},
  journal = {Fundamenta Informaticae},
  year = {1996},
  volume = {26},
  number = {3,4},
  pages = {287--313},
  month = {June},
  abstract = {In each graph-grammar approach it is defined how and under which conditions graph productions can be applied to a given graph in order to obtain a derived graph. The conditions under which productions can be applied are called application conditions. Although the generative power of most of the known general graph-grammar approaches is sufficient to generate any recursively enumerable set of graphs, it is often convenient to have specific application conditions for each production. Such application conditions, on the one hand, include context conditions like the existence or non-existence of nodes, edges, or certain subgraphs in the given graph as well as embedding restrictions concerning the morphisms from the left-hand side of the production to the given graph. In this paper, the concept of application conditions introduced by Ehrig and Habel is restricted to contextual conditions, especially negative ones. In addition to the general concept, we state local confluence and the Parallelism Theorem for derivations with application conditions. Finally we study context-free graph grammars with application conditions with respect to their generative power.}
}

@article{HCEL96,
  author = {Reiko Heckel AND Andrea Corradini AND Hartmut Ehrig AND Michael L{\"o}we},
  title = {Horizontal and Vertical Structuring of Typed Graph Transformation Systems},
  journal = {Mathematical Structures in Computer Science},
  year = {1996},
  volume = {6},
  number = {6},
  pages = {613--648}
}

@article{Loehr-Richter1994,
  author = {Perdita L{\"o}hr-Richter AND Gregor Engels},
  title = {Visuelles Spezifizieren von komplexen Aktionen auf Datenbankstrukturen},
  journal = {GI-Datenbank Rundbrief},
  year = {1994},
  volume = {13},
  pages = {33--35},
  month = {March}
}

@article{EngelsLNSS1992,
  author = {Gregor Engels AND Claus Lewerentz AND Manfred Nagl AND Wilhelm Sch{\"a}fer AND Andy Sch{\"u}rr},
  title = {Building Integrated Software Development Environments, Part I: Tool Specification},
  journal = {ACM Transactions on Software Engineering and Methodology (TOSEM)},
  year = {1992},
  volume = {1},
  number = {2},
  pages = {135--167},
  month = {April},
  abstract = {The conceptual modeling approach of the IPSEN (Integrated Project Support Environment) project for building highly integrated environments is based on using attributed graphs to model and implement arbitrary object structures, in particular all kinds of software documents and their relationships. A language based on graph grammars, called PROGRESS (Programmed Graph REwriting SyStems), and a suitable method for the application of this language, called graph grammar engineering, have been developed over the last ten years. This language and method are being extensively used for specifying the complex graph structures of internal document representations as well as for specifying the functionality of all tools (editors, browsers, analyzers, debuggers) working on these internal representations. This paper explains the language and the method for applying the language based on a pragmatic nontrivial example of a software production process and its corresponding documents. In particular, it is shown why and how a graph grammar-based strongly typed language is perfectly suitable to formally specify highly integrated software tools. In addition, it is shown that the implementation of these tools (i.e., an environment composed of these tools) is systematically being derived from the formal specifications.}
}

@article{Engels1992a,
  author = {Gregor Engels AND Martin Gogolla AND Uwe Hohenstein AND Klaus H{\"u}lsmann AND Perdita L{\"o}hr-Richter AND Gunter Saake AND Hans-Dietrich Ehrich},
  title = {Conceptual Modelling of Database Applications Using an Extended ER Model},
  journal = {Data \& Knowledge Engineering},
  year = {1992},
  volume = {9},
  number = {2},
  pages = {157--204},
  month = {December},
  abstract = {In this paper, we motivate and present a data model for conceptual design of structural and behavioural aspects of databases. We follow an object centered design paradigm in the spirit of semantic data models. The specification of structural aspects is divided into modelling of object structures and modelling of data types used for describing object properties. The specification of object structures is based on an Extended Entity--Relationship (EER) model. The specification of behavioural aspects is divided into the modelling of admissible database state evolutions by means of temporal integrity constraints and the formulation of database (trans)actions. The central link for integrating these design components is a descriptive logic--based query language for the EER model. The logic part of this language is the basis for static constraints and descriptive action specifications by means of pre- and postconditions. A temporal extension of this logic is the specification language for temporal integrity constraints. We emphasize that the various aspects of a database application are specified using several appropriate, but yet compatible formalisms, which are integrated by a unifying common semantic.}
}

@article{Hohenstein1992,
  author = {Uwe Hohenstein AND Gregor Engels},
  title = {SQL/EER - Syntax and Semantics of an Entity-Relationship-Based Query Language},
  journal = {Information Systems},
  year = {1992},
  volume = {17},
  number = {3},
  pages = {209--242},
  abstract = {This paper presents the high-level query language SQL/EER for an extended Entity-Relationship model (EER model). SQL/EER directly supports all the concepts of the EER model and takes into account well-known features that are integral part of contemporary query languages, e.g. arithmetic and aggregate functions. In contrast to usual descriptions of query languages, we give SQL/EER a complete formal specification of syntax and sematics. This syntax is defined by using an attribute grammar which fixes the context-free structure and the context-sensitive rules. The operational semantics is defined by formally translating SQL/EER queries into queries of an existing, semantically well-defined calculus. The attribute grammar is extended to cover this translation, too.The query language SQL/EER is used in a database design environment. In this context, the formal specification of its syntax and the semantics has been used to implement a syntax-directed editor and a query interpreter for SQL/EER.}
}

@article{Engels1983,
  author = {Gregor Engels AND Udo Pletat AND Hans-Dietrich Ehrich},
  title = {An Operational Semantics for Specifications of Abstract Data Types with Error Handling},
  journal = {Acta Informatica},
  year = {1983},
  volume = {9},
  number = {3},
  pages = {235--254},
  abstract = {A new approach to an operational treatment of errors and exceptions in specifications of abstract data types is presented. Considering a specification as a term rewriting system, we define an operational semantics and give conditions that are sufficient for its well-definedness (Church-Rosser property). Also, we give conditions that are sufficient for the termination of reduction strategies, respecting the specified error and exception handling.}
}

@article{Engels1983a,
  author = {Gregor Engels AND Rupert Gall AND Manfred Nagl AND Wilhelm Sch{\"a}fer},
  title = {Software Specification Using Graph Grammars},
  journal = {Computing},
  year = {1983},
  volume = {31},
  number = {4},
  pages = {317--346},
  month = {December},
  abstract = {The following paper,demonstrates that programmed sequential graph grammars can be used in a systematic proceeding to specify tbe changes of high level intermediate data structures arising in a programming support environment, in which all tools work in an incremental and syntax-driven mode. In this paper we lay stress upon the way to get the specification rather than on the result of this process. Therefore, we give here some approach to "specification engineering" using graph grammars. This approach is influenced by the syntactical definition of the underlying language for Programming in the Small, the module concept etc. to be supported on one side but also by the idea of the user interface.}
}

@book{KEHNPSW-2012,
  author = {Marion Kremer AND Gregor Engels AND Alexander Hofmann AND J{\"o}rg Hohwiller AND Oliver E. Nandico AND Thomas N{\"o}tzold AND Karl Prott AND Diethelm Schlegel AND Andreas Seidl AND Thomas Wolf},
  title = {Quasar 3.0 - A Situational Approach to Software Engineering},
  publisher = {Capgemini CSD Research, Offenbach 2012},
  year = {2012},
  month = {Juni}
}

@book{Engels2008,
  author = {Gregor Engels AND Andreas Hess AND Bernhard Humm AND Oliver Juwig AND Marc Lohmann AND Jan-Peter Richter AND Markus Vo{\ss} AND Johannes Willkomm},
  title = {Quasar Enterprise: Anwendungslandschaften serviceorientiert gestalten},
  publisher = {dpunkt-Verlag},
  year = {2008},
  address = {M{\"u}nchen},
  month = {M{\"a}rz},
  abstract = {IT-Anwendungslandschaften in Unternehmen sind komplexe {\"u}ber Jahre gewachsene Gebilde. Sie architektonisch zu gestalten und nachhaltig zu entwickeln braucht eine eigene Technologie jenseits der klassischen Softwaretechnik. Der Ansatz serviceorientierter Architekturen (SOA) ist ein wichtiges Instrument, reicht aber alleine nicht aus.In Quasar Enterprise haben Experten des Softwareunternehmens sd\&m eine durchg{\"a}ngige Architekturmethodik f{\"u}r die serviceorientierte Gestaltung von Anwendungslandschaften zusammengetragen, die Erfahrungen aus Dutzenden von Beratungs-, Integrations- und gro{\ss}en Softwareprojekten widerspiegelt. Das Besondere an Quasar Enterprise ist die Sammlung sehr konkreter Methoden, Regeln, Referenzarchitekturen und Muster f{\"u}r die Gestaltung - ausgehend von der Architektur des Gesch{\"a}fts, {\"u}ber die logische Strukturierung der IT in Services und Dom{\"a}nen, bis hin zu physischen Komponenten und Schnittstellen inkl. deren Kopplung {\"u}ber technische Integrationsplattformen.Teil I beschreibt ein fiktives, aber realistisches Projekt aus der Sicht eines IT-Architekten. Der Leser schaut ihm bei seiner Arbeit {\"u}ber die Schulter und erlangt dabei ein intuitives Verst{\"a}ndnis der Artefakte und Verfahrensbausteine von Quasar Enterprise. Das Vorgehen im Projekt erlebt er dabei beispielhaft.Teil II vertieft das Erlernte systematisch. Die Grundlagen f{\"u}r Anwendungslandschaften und SOA werden eingef{\"u}hrt und dann Schritt f{\"u}r Schritt Begriffe, Zusammenh{\"a}nge und Vorgehensbausteine erl{\"a}utert. Die Beziehungen zwischen Architekturentscheidungen und Qualit{\"a}tszielen werden transparent gemacht und Verweise auf weiterf{\"u}hrende Literatur gegeben. Das Buch richtet sich an alle, die etwas {\"u}ber Anwendungslandschaften und SOA in der Praxis wissen wollen. Prim{\"a}re Zielgruppe sind IT-Architekten, erfahrene Softwareingenieure und Berater. }
}

@book{Doberkat00,
  editor = {E.-E. Doberkat, G. Engels, M. Grauer, H. L. Grob, U. Kelter, W. Leidhold, V. Nienhaus},
  title = {Multimedia in der wirtschaftswissenschaftlichen Lehre - Erfahrungsbericht},
  publisher = {LIT Verlag},
  year = {2000},
  address = {M{\"u}nster},
  pages = {317},
  abstract = {GeleitwortZu welchem Zweck f{\"o}rdert das Land Nordrhein-Westfalen Multimediaprojekte f{\"u}r die Hochschullehre?Inzwischen hat es sich herumgesprochen, dass die Computerunterst{\"u}tzung nicht nur den Zugriff auf Wissen und Information dramatisch ver{\"a}ndern wird, sondern in Zukunft auch das Lernen selbst und die Gestaltung der Lernprozesse. Wird im gleichen Ma{\ss}e, wie Information weltweit {\"u}ber Netz zugriffsf{\"a}hig wird, auch \glqq{}Lernen\grqq{} zugriffsf{\"a}hig? H{\"a}lt die industrielle Arbeitsteilung Einzug auch in das Feld der Hochschullehre? Wird sich die Lehre vom Ort ihrer Entstehung, der Hochschule, verselbstst{\"a}ndigen? Werden Weiterbildungseinrichtungen die Zweit- und Drittvermarktung {\"u}bernehmen oder ganze Teile der jetzigen Lehraufgaben der Hochschulen ersetzen? Wird damit die r{\"a}umliche Einbindung der Hochschullehre in den Ort Hochschule derartig aufgel{\"o}st, dass Hochschulen - jedenfalls viele von ihnen - ihren Charakter verlieren oder sehr {\"a}ndern? Wird die kulturell-nationale Einbindung von Lehre unter dem Druck der Globalisierung und mit dem Mittel der Virtualit{\"a}t {\"u}berfl{\"u}ssig? Werden Studierende, wo auch immer sie sind, k{\"u}nftig von vornherein Angebote in der lingua franca Englisch bevorzugen, und wenn sie dies tun, warum nicht gleich ein angels{\"a}chsisches Original?Seit der Erfindung des Buchdrucks hat keine technische Innovation ein solches Potenzial zur Ver{\"a}nderung von Lernprozessen und zur Ver{\"a}nderung der Institutionen des Lernens gehabt wie die vernetzte Computerunterst{\"u}tzung. Diese Potenziale entwickeln sich mit einer vergleichsweise gro{\ss}en Geschwindigkeit. Diese Geschwindigkeit ist lange Zeit untersch{\"a}tzt worden. Daher wird zurzeit der Blick gerne Richtung USA gerichtet. Scheinbar ist dort alles weiter. Alte und neue Einrichtungen spezialisieren sich in diesem Feld.Testet man ab, in Bezug auf welche Anwendungen und welchen Nutzen die Entwicklung dort rascher bew{\"a}ltigt sein soll, relativiert sich das Bild. Vermarktbare Weiterbildung wird dort st{\"a}rker als bei uns schon mit Multimedialit{\"a}t und Netzverteilung verbunden. Allerdings ist der Standard daf{\"u}r, was Multimedialit{\"a}t oder Virtualit{\"a}t ist, nicht in jedem Fall beeindruckend. Konzepte f{\"u}r ganze Hochschulen, die soweit umgesetzt sind, dass Anlass zur Sorge in Bezug auf ein Gef{\"a}lle zwischen den USA und uns best{\"u}nde, sind z.Zt. so (noch) nicht zu sehen.Trotzdem, die konkurrenzhafte Globalisierung erfasst auch unsere Hochschulen. Der Nachteil, den man heute noch nicht hat, kann morgen schon Wirklichkeit sein. Vor diesem Hintergrund gibt es mehrere Felder, in denen das Land Nordrhein-Westfalen das gemeinsame Engagement von Land und Hochschulen f{\"u}r wesentlich h{\"a}lt:* Kein Student sollte die Hochschule verlassen - gleich in welchem Fach - ohne sich in der Nutzung der computerunterst{\"u}tzten Informationsangebote und eines computerunterst{\"u}tzten Lerner-Arbeitsplatzes auszukennen.* Jede Hochschule muss sich das Ziel setzen, in einem {\"u}berschaubaren Zeitraum eine vern{\"u}nftige integrierte technische Unterst{\"u}tzung f{\"u}r den Gesamtkomplex des Informationsmanagements und des Lernens zu realisieren. Diese Plattform soll hochschulfreundlich den wirklichen Abl{\"a}ufen folgen und m{\"o}glichst {\"u}berschaubare Kosten f{\"u}r den Support und die Erneuerung verursachen.* In allen F{\"a}chern sollten die Hochschulen so schnell wie m{\"o}glich die Vorteile multimedial unterst{\"u}tzten Lernens fachlich realisieren.F{\"u}r diese Seite, den Content, gibt es sowohl im Land Nordrhein-Westfalen als auch bundesweit entsprechende Programme, um Lernsoftware, die hochschul{\"u}bergreifend einsetzbar ist, zu entwickeln. Es braucht aber mehr: Um in einer Hochschule eine lebendige und sinnvolle Nutzung des Computers f{\"u}r den Lehrbetrieb zu erm{\"o}glichen, sollte die ganze Flut an Informationen, an grauer Literatur, an hand-outs, an Folien, an Dingen, die man nur ein Semester braucht oder die in mehreren Semestern wachsen, an disziplin{\"a}r entstehenden Papieren, aber auch an Ergebnissen interdisziplin{\"a}rer Zusammenarbeit f{\"u}r die Lehre in einer integrierten nutzerfreundlichen Technik zur Verf{\"u}gung stehen. Ziel muss sein, dass der Studierende ohne Medienbruch seinen eigenen \glqq{}virtuellen Schreibtisch\grqq{} im Hochschulnetz hat. Und Ziel muss es auch sein, dass Hochschullehrer ohne \glqq{}Sklaven\grqq{} (Hiwi aus der Informatik) ihre Inhalte ins Netz bekommen. Auch die Kompetenz im virtuellen berufsbegleitenden Studium, die die Universit{\"a}t in Hagen als traditionell einzige Fernuniversit{\"a}t im deutschsprachigen Raum auf dem Hintergrund gewachsenen Betreuungs-Know-hows hat, sollte kooperativ allen Hochschulen zugute kommen k{\"o}nnen.Diese Ziele vor Augen hat das MSWWF zusammen mit der Landesrektorenkonferenz den Universit{\"a}tsverbund Multimedia (UVM) als standort{\"u}bergreifendes Kompetenznetzwerk ins Leben gerufen. Hier wurde vor drei Jahren das \glqq{}Leitprojekt Wirtschaftswissenschaften\grqq{} ausgeschrieben. Die Idee war, dass in den Wirtschaftswissenschaften schon ausreichend viele Ans{\"a}tze f{\"u}r breitere Kooperationen zu sehen waren und es sich gleichzeitig um ein Massenfach handelt, dessen {\"U}berlastprobleme zur Nutzung von Multimedia als Mittel der Verbesserung der Qualit{\"a}t der Lehre geradezu herausfordern. Ziel war auch, {\"u}ber den technischen Bereich hinaus die Gespr{\"a}chsm{\"o}glichkeiten {\"u}ber Arbeitsteilungen und wechselseitiges, erg{\"a}nzendes und kooperatives Nutzen zu entwickeln und zu verbessern. Der Weg der letzten Jahre war f{\"u}r alle Beteiligten nicht ohne M{\"u}hen. Denn die Hochschullehre, so war es immer {\"u}bereinstimmende Interpretation, geh{\"o}rt zu den vornehmen Bereichen der Wissenschaftsfreiheit, d.h. jeder einzelne Hochschullehrer verantwortet seine Lehre individuell und etwaige Abstimmung bezieht sich nur auf die Erf{\"u}llung der Studienordnung, des notwendigen semesterweisen Angebotes und {\"a}hnlicher Rahmensetzungen und erfolgt jeweils an der eigenen Hochschule im eigenen Fach.Noch einmal zur{\"u}ck zu den USA. Dort wird prognostiziert, dass der Bildungsmarkt der Markt der Zukunft ist - und zwar schon kurzfristig. Das Vordringen der nur durch Geldstr{\"o}me gesteuerten Marktmechanismen in Bereiche, deren Entwicklung eben noch konsensual durch gesellschaftliche Willensbildung gepr{\"a}gt wurden, hat schon in anderen Bereichen verbl{\"u}fft. Wir sollten daher nicht naiv sein und die eigene Aneignung der Potentiale virtueller Lernumgebungen nicht vers{\"a}umen. Entscheidend wird die F{\"a}higkeit unserer Hochschulen sein, eine Neujustierung zu leisten zwischen der multimedial standardisierbaren Lehre einerseits und dem diskursiven, er{\"o}rternden, forschungsorientierten Input des individuellen Hochschullehrers andererseits. Daran, wie gut es gelingt, mit den neuen Konzepten zu {\"u}berzeugen, wird sich entscheiden, wie weit die Hochschule der Zukunft der Hochschule, die wir kennen, noch gleichen wird. Nur wer mitspielt, kann mitpr{\"a}gen.D{\"u}sseldorf, im Februar 2000Monika KrammeMinisterium f{\"u}r Schule und Weiterbildung, Wissenschaft und Forschung }
}

@book{EEKHandbook1999,
  editor = {H. Ehrig, G. Engels, H.-J. Kreowski},
  title = {Handbook of Graph Grammars and Computing by Graph Transformations, Volume 2: Applications, Languages and Tools},
  publisher = {World Scientific Publishing Company},
  year = {1999},
  address = {London},
  month = {October},
  abstract = {Graph grammars originated in the late 60s, motivated by considerations about pattern recognition and compiler construction. Since then, the list of areas which have interacted with the development of graph grammars has grown quite impressively. Besides the aforementioned areas, it includes software specification and development, VLSI layout schemes, database design, modeling of concurrent systems, massively parallel computer architectures, logic programming, computer animation, developmental biology, music composition, visual languages, and many others.The area of graph grammars and graph transformations generalizes formal language theory based on strings and the theory of term rewriting based on trees. As a matter of fact, within the area of graph grammars, graph transformation is considered as a fundamental computation paradigm where computation includes specification, programming, and implementation. Over the last three decades, graph grammars have developed at a steady pace into a theoretically attractive and important-for-applications research field.Volume 2 of the indispensable Handbook of Graph Grammars and Computing by Graph Transformations considers applications to functional languages, visual and object-oriented languages, software engineering, mechanical engineering, chemical process engineering, and images. It also presents implemented specification languages and tools, and structuring and modularization concepts for specification languages. The contributions have been written in a tutorial/survey style by the top experts in the corresponding areas. This volume is accompanied by a CD-Rom containing implementations of specification environments based on graph transformation systems, and tools whose implementation is based on the use of graph transformation systems. }
}

@book{Engels1989,
  author = {Gregor Engels AND Wilhelm Sch{\"a}fer},
  title = {Programmentwicklungsumgebungen: Konzepte und Realisierung},
  publisher = {Teubner},
  year = {1989},
  address = {Stuttgart}
}

@inproceedings{wachsmuth:2013a,
  author = {Henning Wachsmuth AND Mirko Rose AND Gregor Engels},
  title = {Automatic Pipeline Construction for Real-Time Annotation},
  booktitle = {Proceedings of the 14th International Conference on Intelligent Text Processing and Computational Linguistics},
  year = {2013},
  editor = {Alexander Gelbukh},
  pages = {38-49},
  publisher = {Springer},
  address = {Samos, Greece},
  month = {March},
  abstract = {Many annotation tasks in computational linguistics are tackled with manually constructed pipelines of algorithms. In real-time tasks where information needs are stated and addressed ad-hoc, however, manual construction is infeasible. This paper presents an artificial intelligence approach to automatically construct annotation pipelines for given information needs and quality prioritizations. Based on an abstract ontological model, we use partial order planning to select a pipeline's algorithms and informed search to obtain an efficient pipeline schedule. We realized the approach as an expert system on top of Apache UIMA, which offers evidence that pipelines can be constructed ad-hoc in near-zero time.},
  series = {LNCS},
  volume = {7816}
}

@inproceedings{bruBecEng2013-1,
  author = {Frank Br{\"u}seke AND Steffen Becker AND Gregor Engels},
  title = {Decision Support via Automated Metric Comparison for the Palladio-based Performance Blame Analysis},
  booktitle = {Proceedings of the 4th ACM/SPEC International Conference on Performance Engineering (ICPE 2013), Prague (Czech Republic)},
  year = {2013},
  publisher = {to be published},
  note = {to be published},
  abstract = {When developing component-based systems, we incorporate third-party black-box components. For each component, performance contracts have been specified by their developers. If errors occur within the system built from these components, it is very important to find out whether components violate their performance contracts or whether the composition itself is faulty. This task is called performance blame analysis. In our previous work we presented a performance blame analysis approach that blames components based on a comparison of response time values from testing to values derived from the performance contract. In that approach, the system architect needs to manually assess if the test data series shows faster or slower response times than the data derived from the contract. This is laborious as the system architect has to do this for each component operation. In this paper we present an automated comparison of each pair of data series as decision support. In contrast to our work, other approaches do not achieve fully automated decision support, because they do not incorporate sophisticated contracts. We exemplify our performance blame analysis including the automated decision support using the "Common Component Modeling Example" (CoCoME) benchmark.}
}

@inproceedings{acml_seams13,
  author = {Markus Luckey AND Gregor Engels},
  title = {High-­Quality Specification of Self-­Adaptive Software Systems},
  booktitle = {Proceeding of the 8th international symposium on Software engineering for adaptive and self-managing systems},
  year = {2013},
  publisher = {ACM (to appear)},
  address = {New York, NY, USA},
  month = {May},
  series = {SEAMS '13}
}

@inproceedings{SGENH2013,
  author = {Claudia Schumacher AND Baris G{\"u}ldali AND Gregor Engels AND Markus Niehammer AND Matthias Hamburg},
  title = {Modellbasierte Bewertung von Testprozessen nach TPI NEXT® mit Gesch{\"a}ftsprozess-Mustern},
  booktitle = {Software Engineering 2013},
  year = {2013},
  editor = {Stefan Kowalewski, Bernhard Rumpe},
  pages = {331--344},
  organization = {GI},
  month = {M{\"a}rz},
  note = {Fachtagung des GI-FachbereichsSoftwaretechnik26. Februar - 1. M{\"a}rz 2013AachenProceedings},
  abstract = {Die Qualit{\"a}t eines zu entwickelnden Softwareprodukts wird entscheidend durch die Qualit{\"a}t des zugeh{\"o}rigen Textprozesses beeinflusst. Das TPI(R)- Modell ist ein Referenzmodell zur Bewertung der Qualit{\"a}t des Testprozesses, das mittels Kontrollpunkten den Reifegrad von Testaktivit{\"a}ten bestimmt.},
  series = {LNI},
  volume = {P-213}
}

@inproceedings{GE2013,
  author = {Gregor Engels},
  title = {On-the-Fly Computing - Das Entwicklungs- und Betriebsparadigma f{\"u}r Softwaresysteme der Zukunft},
  booktitle = {Software Engineering 2013},
  year = {2013},
  editor = {Stefan Kowalewski, Bernhard Rumpe},
  pages = {17--18},
  month = {M{\"a}rz},
  note = {eingeladener VortragFachtagung des GI-Fachbereichs Softwaretechnik26. Februar - 1. M{\"a}rz 2013AachenProceedings},
  journal = {LNI},
  series = {LNI},
  volume = {P-213}
}

@inproceedings{qosa_13,
  author = {Matthias Becker AND Markus Luckey AND Steffen Becker},
  title = {Performance Analysis of Self-Adaptive Systems for Requirements Validation at Design-Time},
  booktitle = {Ninth International ACM Sigsoft Conference on the Quality of Software Architectures},
  year = {2013},
  publisher = {ACM (to appear)},
  address = {New York, NY, USA},
  series = {QoSA 2013}
}

@inproceedings{sitis12,
  author = {Stefan B{\"o}ttcher AND Dennis Bokermann AND Rita Hartel},
  title = {Generalizing and Improving SQL/XML Query Evaluation},
  booktitle = {Proceedings of the 8th International Conference on Signal Image Technology and Internet Systems (SITIS-2012), Sorrento, Italy},
  year = {2012}
}

@inproceedings{qosa12,
  author = {Matthias Becker AND Markus Luckey AND Steffen Becker},
  title = {Model-driven Performance Engineering of Self-Adaptive Systems: A Survey},
  booktitle = {Proceedings of the International Conference on Quality of Software Architecture},
  year = {2012},
  publisher = {ACM},
  address = {New York, NY, USA},
  series = {QoSA'12}
}

@inproceedings{wachsmuth:2012,
  author = {Henning Wachsmuth AND Benno Stein},
  title = {Optimal Scheduling of Information Extraction Algorithms},
  booktitle = {Proceedings of the 24th International Conference on Computational Linguistics: Posters},
  year = {2012},
  pages = {1281--1290},
  publisher = {The COLING 2012 Organizing Committee},
  address = {Mumbai, India},
  abstract = {Most research on run-time efficiency in information extraction is of empirical nature. This paper analyzes the efficiency of information extraction pipelines from a theoretical point of view in order to explain empirical findings. We argue that information extraction can, at its heart, be viewed as a relevance filtering task whose efficiency traces back to the run-times and selectivities of the employed algorithms. To better understand the intricate behavior of information extraction pipelines, we develop a sequence model for scheduling a pipeline's algorithms. In theory, the most efficient schedule corresponds to the Viterbi path through this model and can hence be found by dynamic programming. For real-time applications, it might be too expensive to compute all run-times and selectivities beforehand. However, our model implies the benchmarks of filtering tasks and illustrates that the optimal schedule depends on the distribution of relevant information in the input texts. We give formal and experimental evidence where necessary.}
}

@inproceedings{Models2012,
  author = {Zille Huma AND Christian Gerth AND Gregor Engels AND Oliver Juwig},
  title = {Towards an Automatic Service Discovery for UML-based Rich Service Descriptions},
  booktitle = {Proceedings of the ACM/IEEE 15th International Conference on Model Driven Engineering Languages and Systems (MODELS'12)},
  year = {2012},
  pages = {709-725},
  publisher = {Springer-Verlag},
  address = {Berlin/Heidelberg},
  abstract = {Service-oriented computing (SOC) promises to solve many issues in the area of distributed software development, e.g. the realization of the loose coupling pattern in practice through service discovery and invocation. For this purpose, service descriptions must comprise structural as well as behavioral information of the services otherwise an accurate service discovery is not possible. We addressed this issue in our previous paper and proposed a UML-based rich service description language (RSDL) providing comprehensive notations to specify service requests and offers.However, the automatic matching of service requests and offers specified in a RSDL for the purpose of service discovery is a complex task, due to multifaceted heterogeneity of the service partners. This heterogeneity includes the use of different underlying ontologies or different levels of granularity in the specification itself resulting in complex mappings between service requests and offers. In this paper, we present an automatic matching mechanism for service requests and offers specified in a RSDL that overcomes the underlying heterogeneity of the service partners.},
  series = {LNCS},
  volume = {7590}
}

@inproceedings{Christ2011a,
  author = {Fabian Christ AND Benjamin Nagel},
  title = {A Reference Architecture for Semantic Content Management Systems},
  booktitle = {Proceeding of the Enterprise Modelling and Information Systems Architectures Workshop 2011 (EMISA'11), Hamburg (Germany)},
  year = {2011},
  editor = {M. N{\"u}ttgens, O. Thomas, B. Weber},
  pages = {135--148},
  publisher = {GI},
  abstract = {Content Management Systems (CMS) lack the ability of managing semantic information that is part of the content stored in a CMS. On the other hand, a lot of research has been done in the field of Information Extraction (IE) and Information Retrieval (IR), respectively. Additionally, the vision of the Semantic Web yields to new software components that make semantic technology usable for application developers. In this paper, we combine IE/IR concepts with the technologies of the Semantic Web and propose a new family of CMS, called Semantic CMS (SCMS), with advanced semantic capabilities. We provide a reference architecture for SCMS and prove its value along two implementations. One implementation was created as part of the Interactive Knowledge Stack research project and another one in a one-year student project exploring the design of an SCMS for the software engineering domain.},
  series = {LNI},
  volume = {P-190}
}

@inproceedings{adaptcases_seams11,
  author = {Markus Luckey AND Benjamin Nagel AND Christian Gerth AND Gregor Engels},
  title = {Adapt Cases: Extending Use Cases for Adaptive Systems},
  booktitle = {Proceeding of the 6th international symposium on Software engineering for adaptive and self-managing systems},
  year = {2011},
  pages = {30--39},
  publisher = {ACM},
  address = {New York, NY, USA},
  month = {May},
  abstract = {Adaptivity is prevalent in today's software. Mobile devices self-adapt to available network connections, washing machines adapt to the amount of laundry, etc. Current approaches for engineering such systems facilitate the specification of adaptivity in the analysis and the technical design. However, the modeling of platform independent models for adaptivity in the logical design phase remains rather neglected causing a gap between the analysis and the technical design phase. To overcome this situation, we propose an approach called Adapt Cases. Adapt Cases allow the explicit modeling of adaptivity with dedicated means, enabling adaptivity to gather attention early in the software engineering process. Since our approach is based on use cases it is easy adoptable in new and even running projects that use the UML as a specification language, and additionally, can be easily incorporated into model-based development environments. },
  series = {SEAMS '11}
}

@inproceedings{wachsmuth2011b,
  author = {Henning Wachsmuth AND Kathrin Bujna},
  title = {Back to the Roots of Genres: Text Classification by Language Function},
  booktitle = {Proceedings of the 5th International Joint Conference on Natural Language Processing},
  year = {2011},
  pages = {632-640},
  publisher = {AFNLP},
  address = {Chiang Mai, Thailand},
  abstract = {The term "genre" covers different aspects of both texts and documents, and it has led to many classification schemes. This makes different approaches to genre identification incomparable and the task itself unclear. We introduce the linguistically motivated text classification task language function analysis, LFA, which focuses on one well-defined aspect of genres. The aim of LFA is to determine whether a text is predominantly expressive, appellative, or informative. LFA can be used in search and mining applications to efficiently filter documents of interest. Our approach to LFA relies on fast machine learning classifiers with features from different research areas. We evaluate this approach on a new corpus with 4,806 product texts from two domains. Within one domain, we correctly classify up to 82\% of the texts, but differences in feature distribution limit accuracy on out-of-domain data.}
}

@inproceedings{bokermann2011,
  author = {Stefan B{\"o}ttcher AND Dennis Bokermann AND Rita Hartel},
  title = {Computing Compressed XML Data from Relational Databases},
  booktitle = {Proceedings of the 28th British National Conference on Databases (BNCOD-2011), Manchester, Great Britain},
  year = {2011},
  pages = {209--220},
  publisher = {Springer (Berlin/Heidelberg)},
  abstract = {SQL/XML allows generating an XML document as the result of a query that is evaluated on relational data. This facilitates companies sharing their relational data in form of XML documents with other companies or with a marketplace, but significantly increases the exchanged data volume. To reduce both the volume of the exchanged data by exchanging compressed XML and the time needed for compression, we propose an approach that allows preparation of a compressed XML document as the answer to an SQL/XML query directly, i.e., without the need to create the XML document first and compress it afterwards. Our evaluation has shown that generating the compressed document directly is in most cases faster than generating the uncompressed XML document and compressing it, and in some cases it is even faster than the generation of the uncompressed XML document alone. As our approach of generating compressed XML requires only SQL support from the underlying database system, a second advantage is that it can be used for the generation of compressed XML even for database systems that do not (yet) support SQL/XML (like MySQL). },
  series = {LNCS},
  volume = {7051}
}

@inproceedings{wachsmuth2011a,
  author = {Henning Wachsmuth AND Benno Stein AND Gregor Engels},
  title = {Constructing Efficient Information Extraction Pipelines},
  booktitle = {Proceedings of the 20th ACM Conference on Information and Knowledge Management},
  year = {2011},
  pages = {2237-2240},
  publisher = {ACM},
  address = {Glasgow, Scotland},
  month = {October},
  abstract = {Information Extraction (IE) pipelines analyze text through several stages. The pipeline's algorithms determine both its effectiveness and its run-time efficiency. In real-world tasks, however, IE pipelines often fail acceptable run-times because they analyze too much task-irrelevant text. This raises two interesting questions: 1) How much "efficiency potential" depends on the scheduling of a pipeline's algorithms? 2) Is it possible to devise a reliable method to construct efficient IE pipelines?Both questions are addressed in this paper. In particular, we show how to optimize the run-time efficiency of IE pipelines under a given set of algorithms. We evaluate pipelines for three algorithm sets on an industrially relevant task: the extraction of market forecasts from news articles. Using a system-independent measure, we demonstrate that efficiency gains of up to one order of magnitude are possible without compromising a pipeline's original effectiveness.}
}

@inproceedings{Soltenborn2010,
  author = {Nils Bandener AND Christian Soltenborn AND Gregor Engels},
  title = {Extending DMM Behavior Specifications for Visual Execution and Debugging},
  booktitle = {Proceedings of the 3rd International Conference on Software Language Engineering (SLE 2010)},
  year = {2011},
  editor = {B. Malloy, S. Staab, M. van den Brand},
  pages = {357--376},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Dynamic Meta Modeling (DMM) is a visual semantics specification technique targeted at behavioral languages equipped with a metamodel defining the language's abstract syntax. Given a model and a DMM specifification, a transition system can be computed which represents the semantics of that model. It allows for the investigation of the model's behavior, e.g. for the sake of understanding the model's semantics or to verify that certain requirements are fufilled. However, due to a number of reasons such as tooling and the size of the resulting transition systems, the manual inspection of the resulting transition system is cumbersome.One solution would be a visualisation of the model's behavior using animated concrete syntax. In this paper, we show how we have enhanced DMM such that visual execution and debugging can be added to a language in a simple manner.},
  series = {LNCS},
  volume = {6563}
}

@inproceedings{Christ2011,
  author = {Fabian Christ AND Jan-Christopher Bals},
  title = {Kompatibilit{\"a}tsanalyse bei Evolution framework-basierter Anwendungen},
  booktitle = {Proceedings of the 3rd Design for Future Workshop held at the Software Engineering 2011 Conference (SE2011), Karlsruhe (Germany)},
  year = {2011},
  editor = {R. Reussner, A. Pretschner, S. J{\"a}hnichen},
  pages = {29--40},
  publisher = {GI},
  abstract = {Die Entwicklung betrieblicher Informationssysteme basiert auf dem Einsatz von Frameworks. Diese bieten ein hohes Ma{\ss} an Wiederverwendung und sind flexibel anpassbar. Mit der Evolution der eingesetzten Frameworks unabh{\"a}ngig von der Anwendung entsteht die Notwendigkeit, Frameworks durch neuere Versionen zu ersetzen, um Fehler zu beheben oder neue Funktionen benutzen zu k{\"o}nnen. Etwaige Inkompatibilit{\"a}ten neuer Versionen erfordern Anpassungen an der Anwendung. In der Praxis entsteht das Problem, dass die erforderlichen Anpassungen schwierig zu bestimmen sind. In dieser Arbeit zeigen wir einen Ansatz zur automatischen Kompatibilit{\"a}tsanalyse bei der Evolution framework-basierter Anwendungen.},
  series = {LNI},
  volume = {P-184}
}

@inproceedings{KGE-Caise11,
  author = {Lial Khaluf AND Christian Gerth AND Gregor Engels},
  title = {Pattern-Based Modeling and Formalizing of Business Process Quality Constraints},
  booktitle = {Proceedings of the 23rd International Conference on Advanced Information System Engineering (CAiSE'11)},
  year = {2011},
  editor = {H. Mouratidis and C. Rolland},
  pages = {521-535},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {The quality of business processes can be checked by verifying theircompliance with specific quality constraints. These constraints represent a set of required temporal and logical relationships between different steps of business processes.Quality constraints are usually formulated as informal texts, which makes themdifficult to be verified, when business processes become complex. One way tosolve this problem is by automating the verification of quality constraints onbusiness processes by applying model checking. To apply model checking, bothbusiness processes and quality constraints have to be formalized. In this paper,we define a new visual language for modeling quality constraints and we providea pattern-based translation for quality constraint models into Computation TreeLogic formulas.},
  series = {LNCS},
  volume = {6741}
}

@inproceedings{GerthSCC11,
  author = {Christian Gerth AND Markus Luckey AND Jochen K{\"u}ster AND Gregor Engels},
  title = {Precise Mappings between Business Process Models in Versioning Scenarios},
  booktitle = {Proceedings of the IEEE 8th International Conference on Services Computing (SCC'11)},
  year = {2011},
  pages = {218-225},
  publisher = {IEEE Computer Society},
  abstract = {In the development process of service-oriented systems, business process models are used at different levels. Typically, high-level business process models that describe business requirements and needs are stepwise refined to the IT level by different business modelers and software architects. As a result, different process model versions must be compared and merged by means of model version control. An important prerequisite for process model version control is an elaborated matching approach that results in precise mappings between different process model versions. The challenge of such an approach is to deal with syntactically different process models that are semantically equivalent. For that purpose, matching techniques must consider the semantics of process modeling languages. In this paper, we present a matching approach for process models in a versioning scenario. Based on a term formalization of process models, we enable an efficient and effective way to match syntactically different but semantically equivalent process models resulting in precise mappings.}
}

@inproceedings{quaasy_poster11,
  author = {Markus Luckey AND Christian Gerth AND Christian Soltenborn AND Gregor Engels},
  title = {QUAASY - QUality Assurance of Adaptive SYstems},
  booktitle = {Proceedings of the 8th International Conference on Autonomic Computing (ICAC'11)},
  year = {2011},
  publisher = {ACM},
  month = {June},
  abstract = {The emerging approach to tackle the increasing complexity of today's software systems is the use of self-adaptation techniques. Modeling and implementing adaptivity features is a burdensome and error-prone task that potentially results in erroneous system models. As a consequence, quality analysis and assurance must be considered early in the development of self-adaptive systems.We propose a quality assurance approach for self-adaptive systems in terms of an integrated modeling and analysis approach, which helps identifying errors in modeled self-adaptive systems early in the design process. We employ a modeling language for self-adaptive systems including adaptation rules and formally define their semantics. Given the language and its formal semantics, we formulate quality properties, such as fairness of the specified adaptation rule system. These quality properties are verified using a model checking approach.}
}

@inproceedings{HPRSSE-2011,
  author = {Marianne Heinemann AND Markus Palme AND Andreas Rothmann AND Frank Salger AND J{\"u}rgen Sch{\"o}nke AND Gregor Engels},
  title = {Selektionswerkzeug zur Auswahl projektspezifischer Vorgehensstrategien},
  booktitle = {Software Engineering 2011},
  year = {2011},
  editor = {R. Reussner, M. Grund, A. Oberweis, W. Tichy},
  pages = {33--36},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  month = {Februar},
  series = {Lecture Notes in Informatics},
  volume = {P-183}
}

@inproceedings{GE2011,
  author = {Gregor Engels},
  title = {Services aus der Cloud = Fahren im Nebel? Wie minimiere ich die Risiken und erreiche hohe Qualit{\"a}t?},
  booktitle = {Proceedings der 41. Jahrestagung der Gesellschaft f{\"u}r Informatik - Informatik 2011},
  year = {2011},
  editor = {H.-U. Hei{\ss}, P. Pepper, H. Schlingloff, J. Schneider},
  publisher = {GI},
  month = {Oktober},
  note = {Informatik schafft Communities4.-7. Oktober 2011Berlin},
  abstract = {Der Kostendruck einerseits und die Verf{\"u}gbarkeit des Internets andererseits f{\"u}hren dazu, dass Softwaresysteme auf Services aus der Cloud zur{\"u}ckgreifen (m{\"u}ssen bzw. k{\"o}nnen). Dies gilt f{\"u}r alle Anwendungsbereiche und somit insbesondere auch f{\"u}r die Software im Auto. Aber wie sorge ich daf{\"u}r, dass die Services aus der Cloud zu meinem Softwaresystem passen und die Anforderungen erf{\"u}llen? Der Vortrag diskutiert aktuelle Ans{\"a}tze der konstruktiven und analytischen Qualit{\"a}tssicherung, um durch Ma{\ss}nahmen sowohl zur Entwicklungs- als auch Laufzeit eine hohe Qualit{\"a}t beim Einsatz von Services aus der Cloud zu erzielen. Insbesondere wird {\"u}ber aktuelle Arbeiten im neuen DFG Sonderforschungsbereich 901 "On-the-Fly Computing" berichtet.},
  series = {LNI},
  volume = {192}
}

@inproceedings{EK2011,
  author = {Gregor Engels AND Marion Kremer},
  title = {Situational Software Engineering: Ein Rahmenwerk f{\"u}r eine situationsgerechte Auswahl von Entwicklungsmethoden und Vorgehensmodellen},
  booktitle = {Proceedings der41. Jahrestagung der Gesellschaft f{\"u}r Informatik - Informatik 2011;},
  year = {2011},
  editor = {H.-U. Hei{\ss}, P. Pepper, H. Schlingloff, J. Schneider},
  publisher = {GI},
  month = {Oktober},
  note = {Informatik schafft Communities4.-7. Oktober 2011Berlin},
  abstract = {Industrielle Softwareentwicklung unterliegt einem stetig steigenden Kosten-, Zeit- und Qualit{\"a}tsdruck, der einen effektiven, effizienten und wirtschaftlichen Einsatz der zur Verf{\"u}gung stehenden Ressourcen bei IT Dienstleistern erfordert. In diesem Beitrag berichten wir {\"u}ber industrielle Erfahrungen bei der Entwicklung eines Rahmenwerks, um f{\"u}r ein aktuelles Softwareprojekt im Sinne eines Situational Software Engineering eine situationsgerechte Auswahl und Kombination von Methoden und Vorgehensmodellbausteinen zu bestimmen. Es werden konkrete Kriterien angegeben, anhand deren Methodenb{\"u}ndel f{\"u}r Systemklassen geschn{\"u}rt werden k{\"o}nnen.},
  series = {LNI},
  volume = {192}
}

@inproceedings{Christ2010,
  author = {Fabian Christ AND Jan-Christopher Bals AND Gregor Engels AND Christian Gerth AND Markus Luckey},
  title = {A Generic Meta-Model-based Approach for Specifying Framework Functionality and Usage},
  booktitle = {Proceedings of the 48th International Conference on Objects, Models, Components and Patterns (TOOLS'10), M{'a}laga (Spain)},
  year = {2010},
  editor = {J. Vitek},
  pages = {21--40},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {June},
  abstract = {Enterprise software development is based on the usage of frameworks. However, well-established concepts to specify framework functionality and how to use it can hardly be found. As consequence, there are poor framework documentations. Various problems arise from this, e.g. a high effort for learning a framework and therefore the need of framework specialists. Existing framework description languages (FDL) focus on parts of the problem but do not cover all aspects of specifying framework functionality and usage. In this paper, we present a generic approach for specifying all aspects of framework functionality and usage. We collected requirements to identify relevant aspects and defined a generic meta-model for FDLs. The generic meta-model is the base for defining concrete FDLs while guaranteeing that all relevant framework aspects are covered. Particularly, due to its generic character, parts of the meta-model representing specific framework aspects can be instantiated by existing or newly defined languages.},
  journal = {LNCS},
  series = {LNCS},
  volume = {6141}
}

@inproceedings{ES10,
  author = {Gregor Engels AND Stefan Sauer},
  title = {A Meta-Method for Defining Software Engineering Methods},
  booktitle = {Graph Transformations and Model-Driven Engineering},
  year = {2010},
  editor = {G. Engels, C. Lewerentz, W. Sch{\"a}fer, A. Sch{\"u}rr, B. Westfechtel},
  pages = {411--440},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  journal = {LNCS},
  series = {LNCS},
  volume = {5765}
}

@inproceedings{SEH10,
  author = {Frank Salger AND Gregor Engels AND Alexander Hofmann},
  title = {Assessments in Global Software Development: A Tailorable Framework for Industrial Projects},
  booktitle = {Proceedings ACM/IEEE 32nd International Conference on Software Engineering, Software Engineering in Practice Track, Cape Town, South Africa (ICSE'10)},
  year = {2010},
  editor = {W. Visser, I. Kr{\"u}ger},
  pages = {29--38},
  publisher = {ACM New York, NY, USA},
  month = {May},
  abstract = {Assessments are an effective technique for software quality assurance. As global software development (GSD) becomes the standard, an assessment framework must be flexible to support different sourcing and shoring models. Although much work exists on inspections and reviews, an assessment framework which addresses these challenges is missing. We present a systematic yet flexible assessment framework. The paper contributes: i) The description of our assessment framework which addresses four challenges: Appropriateness of a software requirements specification (SRS), viability of software architectures and SRS, wholeness of work packages, and compliance of results with predefined quality objectives. ii) A detailed explanation how the assessment framework can be tailored to support offshore and outsourcing scenarios. This paper describes the result of a two years research initiative at Capgemini sd\&m and serves the practitioner to implement assessment frameworks according to his needs. We also discuss open research questions of high relevance for the software industry.},
  volume = {2}
}

@inproceedings{HE10,
  author = {Marianne Heinemann AND Gregor Engels},
  title = {Auswahl projektspezifischer Vorgehensstrategien},
  booktitle = {Integration von Vorgehensmodellen und Projektmanagement},
  year = {2010},
  editor = {O. Linssen, T. Greb, M. Kuhrmann, D. Lange, R. H{\"o}hn},
  pages = {132--142},
  publisher = {Shaker Verlag},
  month = {April}
}

@inproceedings{Huck2010,
  author = {Wilfried Huck AND Alexej Alakbarov AND Gitta Domik AND Rafael Radkowski AND Roswitha T{\"o}lke AND Ann-Cathrin Mikus AND Silke Geisen},
  title = {Computergest{\"u}tzte traumatherapeutische Behandlungsm{\"o}glichkeiten bei Verkehrsunfallopfern von Kinder und Jugendlichen},
  booktitle = {12. Jahrestagung der Deutschsprachigen Gesellschaft f{\"u}r Psychotraumatologie (DeGPT)},
  year = {2010},
  address = {G{\"o}ttingen},
  month = {March}
}

@inproceedings{GerthSCC10,
  author = {Christian Gerth AND Markus Luckey AND Jochen K{\"u}ster AND Gregor Engels},
  title = {Detection of Semantically Equivalent Fragments for Business Process Model Change Management},
  booktitle = {Proceedings of the IEEE 7th International Conference on Services Computing (SCC'10)},
  year = {2010},
  pages = {57--64},
  publisher = {IEEE Computer Society},
  note = {Best Student Paper of SCC 2010.},
  abstract = {Modern business process modeling environments support distributed development by means of model version control, i. e., comparison and merging of two different model versions. This is a challenging task since most modeling languages support an almost arbitrary creation of process models. Thus, in multi-developer environments, process models or parts of them are often syntactically very different but semantically equivalent. Hence, the comparison of business process models must be performed on a semantic level rather then on a syntactic level. For the domain of business process modeling, this problem is yet unsolved.This paper describes an approach that allows the semantic comparison of different business process models using a normal form. For that purpose, the process models are fully automatically translated into process model terms and normalized using a term rewriting system. The resulting normal forms can be efficiently compared and easily be used for reconciliation. Our approach enables the semantic comparison of business process models ignoring syntactic redundancies.}
}

@inproceedings{KuesterGE10,
  author = {Jochen K{\"u}ster AND Christian Gerth AND Gregor Engels},
  title = {Dynamic Computation of Change Operations in Version Management of Business Process Models},
  booktitle = {Proceedings of the 6th European Conference on Modelling Foundations and Applications (ECMFA'10)},
  year = {2010},
  editor = {T. K{\"u}hne, B. Selic},
  pages = {201--216},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {June},
  abstract = {Version management of business process models requires that changescan be resolved by applying change operations. In order to give a user maximalfreedom concerning the application order of change operations, position parameters of change operations must be computed dynamically during change resolution. In such an approach, change operations with computed position parameters must be applicable on the model and dependencies and conflicts of change operations must be taken into account because otherwise invalid models can be constructed. In this paper, we study the concept of partially specified change operations where parameters are computed dynamically. We provide a formalization for partially specified change operations using graph transformation and provide a concept for their applicability. Based on this, we study potential dependencies and conflicts of change operations and show how these can be taken into account within change resolution. Using our approach, a user can resolve changes of business process models without being unnecessarily restricted to a certain order.},
  series = {LNCS},
  volume = {6138}
}

@inproceedings{wachsmuth2010a,
  author = {Henning Wachsmuth AND Peter Prettenhofer AND Benno Stein},
  title = {Efficient Statement Identification for Automatic Market Forecasting},
  booktitle = {Proceedings of the 23rd International Conference on Computational Linguistics},
  year = {2010},
  pages = {1128-1136},
  publisher = {ACM},
  address = {Beijing, China},
  month = {August},
  abstract = {Strategic business decision making involves the analysis of market forecasts. Today, the identification and aggregation of relevant market statements is done by human experts, often by analyzing documents from the World Wide Web. We present an efficient information extraction chain to automate this complex natural language processing task and show results for the identification part. Based on time and money extraction, we identify sentences that represent statements on revenue using support vector classification. We provide a corpus with German online news articles, in which more than 2,000 such sentences were annotated by domain experts from the industry. On the test data, our identification algorithm achieves overall precision and recall of 0.86 and 0.87, respectively.}
}

@inproceedings{HDE10,
  author = {Marianne Heinemann AND Bettina Duwe AND Gregor Engels},
  title = {Enriching RUP with key success factors for large-scale custom software development projects},
  booktitle = {Software \& Systems Engineering Essentials (SEE) 2010},
  year = {2010},
  editor = {M. Sihling, A. Rausch, J. Friedrich, M. Kuhrmann},
  pages = {37--56},
  publisher = {Technische Universit{\"a}t M{\"u}nchen},
  month = {Mai},
  abstract = {Capgemini sd\&m has a long-standing experience in executing custom software development (CSD) projects with a special focus on large-scale and rightshore projects, where resources are distributed over different locations in Germany, Poland (nearshoring) or India (farshoring).For many years, that experience was brought together in a proprietary life cycle model for CSD projects. However, this proprietary life cycle model was not based on an existing industrial standard and therefore was difficult to communicate to clients as well as to employees with other cultural background.Besides the proprietary life cycle model, Capgemini sd\&m has developed its software engineering methodology named QUASAR that focuses on the special requirements for Enterprise Architecture and Custom Software Development projects. With having enhanced QUASAR at fast pace in the last years, it became important to not only update the life cycle model, but to additionally integrate the software engineering methodology.With the continuously increasing trend to software industrialization and thus the growing demand for standardization, the goal was to build on a standard life cycle model and integrate the key factors of our successful software engineering methodology QUASAR.2 ApproachTo unify the understanding of our software engineering processes and work products, we defined an ontology of relevant software engineering notions as the basis for all further actions.The RUP disciplines have been validated, and we found a need to extend and detail them in order to reflect the special requirements of custom software development.Next step was to validate the work products. A fine-grained artifact model has been developed that elaborates the artifact hierarchy based on a categorization for different artifact types. The result is a comprehensive catalogue of artifacts for all software engineering disciplines. We identified the critical artifacts and defined relevant in- and output artifacts for each discipline.In parallel to the development of the artifact model, we commenced the life cycle model evolution. We identified the key success factors of our traditional approach and substantiated RUP to explicitly reflect them.We elaborated our life cycle model based on the three dimensions results, time and tasks, the latter being reflected by the RUP concepts of phases, disciplines and activities. The results dimension was one elementary pillar within our traditional model: We work with a concept of stages that coarsely define, to which degree the system has been built. The explicit definition of development stages allows parallelized work and thus a quicker project execution.The approach to build a development stage is iterative, where cycling through the development activities occurs by component and includes testing and software integration. The resulting step-by-step integration of software from early on is seen as a further success factor within our traditional life cycle model and as such has been transferred to the new model.The bridging element between the life cycle model and the software engineering methodology is a new kind of milestone that is not foreseen by RUP: the discipline milestone. These milestones define the to-be status of critical artifacts at special points in time for each discipline and based on our development stages.The resulting life cycle model is called ``Quasar project incremental'' and is meant to be our standard life cycle model for large-scale and rightshore projects.3 Evaluation``Quasar project incremental'' combines the standard RUP approach with our traditional key success factors for custom software development. Furthermore, it integrates project management with our software engineering methodology hence providing a comprehensive model of interaction of those two levels within one project that practically helps to communicate.In the meantime, ``Quasar project incremental'' has been deployed in several custom software development projects. Concrete samples and a critical evaluation will be given in the presentation.},
  series = {TUM-I1009}
}

@inproceedings{SEE10Erf,
  author = {Frank Br{\"u}seke AND Yavuz Sancar AND Enes Yigitbas},
  title = {Erfolgsfaktoren von Testprozessbewertungsmodellen},
  booktitle = {Proceedings of the Conference on Software \& Systems Engineering Essentials 2010 (SEE 2010), K{\"o}ln (Germany)},
  year = {2010},
  editor = {M. Sihling, A. Rausch, J. Friedrich, M. Kuhrmann},
  pages = {277-298},
  publisher = {Technische Universit{\"a}t M{\"u}nchen}
}

@inproceedings{SEE10ERW,
  author = {Yavuz Sancar AND Claudia Schumacher},
  title = {Erweiterung des TPI-Modells zur Reifegradbewertung unter Ber{\"u}cksichtigung von projekteigenen Anforderungen},
  booktitle = {Proceedings of the Conference on Software \& Systems Engineering Essentials 2010 (SEE 2010), K{\"o}ln (Germany)},
  year = {2010},
  editor = {M. Sihling, A. Rausch, J. Friedrich, M. Kuhrmann},
  pages = {299-314},
  publisher = {Technische Universit{\"a}t M{\"u}nchen}
}

@inproceedings{HKRSSW2010,
  author = {Mathias H{\"u}lsbusch AND Barbara K{\"o}nig AND Arend Rensink AND Maria Semenyak AND Christian Soltenborn AND Heike Wehrheim},
  title = {Full Semantics Preservation in Model Transformation - A Comparison of Proof Techniques},
  booktitle = {Proceedings of the 8th International Conference on Integrated Formal Methods (IFM 2010)},
  year = {2010},
  editor = {D. M{'e}ry, S. Merz},
  pages = {183--198},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Model transformation is a prime technique in modern, model-driven software design. One of the most challenging issues is to show that the semantics of the models is not affected by the transformation. So far, there is hardly any research into this issue, in particular in those cases where the source and target languages are different.In this paper, we are using two different state-of-the-art proof techniques (explicit bisimulation construction versus borrowed contexts) to show bisimilarity preservation of a given model transformation between two simple (self-defined) languages, both of which are equipped with a graph transformation-based operational semantics. The contrast between these proof techniques is interesting because they are based on different model transformation strategies: triple graph grammars versus in situ transformation.We proceed to compare the proofs and discuss scalability to a more realistic setting.},
  series = {LNCS},
  volume = {6396}
}

@inproceedings{ELSSW210,
  author = {Gregor Engels AND Claus Lewerentz AND Wilhelm Sch{\"a}fer AND Andy Sch{\"u}rr AND Bernhard Westfechtel},
  title = {Graph Transformations and Model-Driven Engineering: The Merits of Manfred Nagl},
  booktitle = {Graph Transformations and Model-Driven Engineering},
  year = {2010},
  editor = {G. Engels, C. Lewerentz, W. Sch{\"a}fer, A. Sch{\"u}rr, B. Westfechtel},
  pages = {1--5},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  journal = {LNCS},
  series = {LNCS},
  volume = {5765}
}

@inproceedings{Mlynarski2010a,
  author = {Michael Mlynarski},
  title = {Holistic Model-Based Testing for Business Information Systems},
  booktitle = {Proceedings of 3rd International Conference on Software Testing, Verification and Validation},
  year = {2010},
  pages = {327--330},
  publisher = {IEEE Computer Society},
  month = {April},
  abstract = {Growing complexity of today's software development requires new and better techniques in software testing. A promising one seems to be model-based testing. The goal is to automatically generate test artefacts from models, improve test coverage and guarantee traceability. Typical problems are missing reuse of design models and test case explosion. Our research work aims to find a solution for the mentioned problems in the area of UML and Business Information Systems. We use model transformations to automatically generate test models from manually annotated design models using a holistic view. In this paper we define and justify the research problem and present first results.}
}

@inproceedings{ES10,
  author = {Gregor Engels AND Frank Salger},
  title = {Knowledge Transfer in Global Software Development - Leveraging Acceptance Test Case Specifications},
  booktitle = {In Proceedings of the ACM/IEEE 32nd International Conference on Software Engineering (ICSE), New Ideas and Emergent Results program, May 2010, Cape Town (South Africa)},
  year = {2010},
  pages = {211--214},
  publisher = {ACM New York, NY, USA},
  abstract = {Effective knowledge transfer (KT) is always important in software development projects, but crucial in global software development (GSD). Two challenges arise: First, reviews of the software requirements specification (SRS) are indispensable, but not always effective. Second, using knowledge representations that support KT from customers to developers is paramount. However, 'classical' SRS often don't support SRS comprehension of all stakeholders. We address these two challenges with a new approach that exploits the multi-fold power of a acceptance test case specifications (ATC-Specs): 1) A specific two-stage test-based review technique is used. We argue that these two-stage reviews of ATC-Specs increase the quality of the ATC-Specs and the SRS. 2) Additionally to the SRS, ATC-Specs are delivered to the offshore team, bridging the mental models of different stakeholders, and thus effectively transferring knowledge. We provide preliminary evidence of the validity of our approach based on a commercial GSD project at Capgemini sd\&m.}
}

@inproceedings{VMBPSH10,
  author = {Jan Van den Bergh AND Gerrit Meixner AND Kai Breiner AND Andreas Pleu{\ss} AND Stefan Sauer AND Heinrich Hussmann},
  title = {Model-driven Development of Advanced User Interfaces},
  booktitle = {Proc. 28th International Conference on Human Factors in Computing Systems (CHI 2010)},
  year = {2010},
  pages = {4429--4432},
  publisher = {ACM},
  address = {Atlanta, Georgia, USA,},
  month = {April},
  abstract = {The workshop on model-driven development of advanced user interfaces will be a forum of multidisciplinary discussion on how to integrate model driven development with the often more informal methodologies used in user-centered design. Starting point of the discussion will be the tools, models, methods and experiences of the workshop participants.},
  series = {Extended Abstracts Volume}
}

@inproceedings{GerthModels10,
  author = {Christian Gerth AND Jochen K{\"u}ster AND Markus Luckey AND Gregor Engels},
  title = {Precise Detection of Conflicting Change Operations using Process Model Terms},
  booktitle = {Proceedings of the ACM/IEEE 13th International Conference on Model Driven Engineering Languages and Systems (MODELS'10)},
  year = {2010},
  editor = {D.C. Petriu, N. Rouquette, and {\O}. Haugen},
  pages = {93--107},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  note = {ACM Distinguished Paper Award MODELS 2010.},
  abstract = {Version management of process models requires that changes can be resolved by applying change operations. Conflict detection is an important part of version management and the minimization of the number of detected conflicts also reduces the overhead when resolving changes. As not every syntactic conflict leads to a conflict when taking into account model semantics, a computationof conflicts solely on the syntax leads to an unnecessary high number of conflicts. In this paper, we introduce the notion of syntactic and semantic conflicts for change operations of process models. We provide a method how to efficiently compute conflicts, using a term formalization of process models. Using this approach, we can significantly reduce the number of overall conflicts and thereby reduce the amount of work for the user when resolvingconflicts.},
  series = {LNCS},
  volume = {6395}
}

@inproceedings{SheetDiff10,
  author = {Chris Chambers AND Martin Erwig AND Markus Luckey},
  title = {SheetDiff: A Tool for Identifying Changes in Spreadsheets},
  booktitle = {Proceedings of the 26th IEEE Symposium on Visual Languages and Human-Centric Computing 2010 (VL/HCC 2010)},
  year = {2010},
  editor = {Chr. Hundhausen, E. Pietriga, P. Diaz, M. B. Rosson},
  pages = {85--92},
  organization = {IEEE Computer Society},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {September},
  abstract = {Most spreadsheets, like other software, change over time. A frequentlyoccurring scenario is the repeated reuse and adaptation of spreadsheets fromone project to another. If several versions of one spreadsheet forgrading/budgeting/etc. have accumulated, it is often not obvious which one tochoose for the next project. In situations like these, an understanding of howtwo versions of a spreadsheet differ is crucial to make aninformed choice. Other scenarios are the reconciliation of two spreadsheetscreated by different users, generalizing different spreadsheets into a commontemplate, or simply understanding and documenting the evolution of aspreadsheet over time.In this paper we present a method for identifying the changes between twospreadsheets with the explicit goal of presenting them to users in a conciseform. We have implemented a prototype system, called SheetDiff, and testedthe approach on several different spreadsheet pairs. As our evaluations willshow, this system works reliably in practice. Moreover, we have comparedSheetDiff to similar systems that are commercially available. An importantdifference is that while all these other tools distribute the changerepresentation over two spreadsheets, our system displays all changes in thecontext of one spreadsheet, which results in a more compact representation.}
}

@inproceedings{gs10,
  author = {Baris G{\"u}ldali AND Stefan Sauer},
  title = {Transfer of Testing Research from University to Industry: An Experience Report},
  booktitle = {online Proc. of International TestIstanbul Conference 2010 (URL: www.testistanbul.org/presentations.html)},
  year = {2010},
  publisher = {Turkish Testing Board},
  month = {May},
  abstract = {Software Quality Lab (s-lab) is an open multi-private-public partnership institute for knowledge and technology transfer. In s-lab, partners from industrial software development closely cooperate with research groups of the University of Paderborn. Together with partners from industry, s-lab develops and evaluates constructive and analytical methods and tools of software engineering for obtaining high-quality software. Testing plays an important role in analytical quality assurance within s-lab's activities. Thereby our main focus lies on the development of testing methods, test automation tools and test management concepts for the individual needs of the industrial partners. Because of the different requirements of the university and the industry; the cooperation involves some challenges, e.g. defining projects aiming at the commercial interests of the industry and addressing interesting research questions.In this paper, we give an overview of testing activities in s-lab and address targets and challenges of the cooperative work between industry and university. We also summarize the lessons learned during the numerous testing projects especially in the domain of business information systems.}
}

@inproceedings{vdmWuebb2010,
  author = {Thomas von der Ma{\ss}en AND Andreas W{\"u}bbeke},
  title = {Verteiltes Testen heterogener Systemlandschaften},
  booktitle = {Proceedings of Software Engineering 2010 (SE2010)},
  year = {2010},
  editor = {G. Engels, M. Luckey, W. Sch{\"a}fer},
  pages = {17--18},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  series = {Lecture Notes in Informatics},
  volume = {P-159}
}

@inproceedings{Baumann2009,
  author = {Andrea Baumann AND Gregor Engels AND Alexander Hofmann AND Stefan Sauer AND Johannes Willkomm},
  title = {A Holistic Software Engineering Method for Service-Oriented Application Landscape Development},
  booktitle = {Proceedings of the First NAF Academy Working Conference on Practice-Driven Research on Enterprise Transformation (PRET 2009), Amsterdam (The Netherlands)},
  year = {2009},
  pages = {1--17},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Enterprises are transforming into enterprises which follow from a business as well as from an IT perspective a service-oriented paradigm. This change towards service-oriented enterprise and IT architectures has to be reflected in the methodologies of developing whole application landscapes as well as individual applications. Quasar (Quality Software Architecture) has been developed as the standard architecture and development method of Capgemini sd\&m for individual applications. For the development of service-oriented enterprise application landscapes, Quasar Enterprise has been designed. Both Quasar and Quasar Enterprise are integrated with each other within a holistic software engineering method to seamlessly cover the full development lifecycle of service-oriented application landscapes, from business modeling and service design to actual software development. In this paper, we illustrate how a company-wide ontology of development artifacts serves as the key feature for integrating both methods.},
  series = {Lecture Notes in Business Information Processing},
  volume = {28}
}

@inproceedings{SchatXACT09,
  author = {Tim Schattkowsky AND Tao Xie},
  title = {A UML Framework for IP-XACT-based IP Management},
  booktitle = {Proceedings of the conference on Design Automation and Test in Europe (DATE 2009), Nice (France)},
  year = {2009},
  pages = {238--243},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA}
}

@inproceedings{ECMDA-09,
  author = {Jochen K{\"u}ster AND Christian Gerth AND Gregor Engels},
  title = {Dependent and Conflicting Change Operations of Process Models},
  booktitle = {Proceedings of the 5th European Conference on Model-Driven Architecture Foundations and Applications (ECMDA-FA'09)},
  year = {2009},
  pages = {158--173},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Version management of models is common for structural diagrams such as class diagrams but still challenging for behavioral models such as process models. For process models, conflicts of change operations are difficult to resolve because often dependencies to other change operations exist. As a consequence, conflicts and dependencies between change operations must be computed and shown to the user who can then take them into account while creating a consolidated version. In this paper, we introduce the concepts of dependencies and conflicts of change operations for process models and provide a method how to compute them. We then discuss different possibilities for resolving conflicts. Using our approach it is possible to enable version management of process models with minimal manual intervention of the user.},
  series = {LNCS},
  volume = {5562}
}

@inproceedings{wuebb2009,
  author = {Martin Assmann AND Gregor Engels AND Thomas von der Ma{\ss}en AND Andreas W{\"u}bbeke},
  title = {Identifying Software Product Line Component Services},
  booktitle = {Proceedings of International Conference on Evaluation of Novel Approaches to Software Engineering (ENASE 09)},
  year = {2009},
  editor = {S. Jablonski, L. Maciaszek},
  pages = {45--56},
  abstract = {Software Product Line (SPL) development provides the possibility of reusing common parts in similar software products. However the SPL approach does not centrally improve the maintenance of software products of a Software Product Line. This paper presents an approach for reducing maintenance costs of SPL products by using the concept Software as a Service. The SPL-SaaS approach was developed with the experiences of arvato services integrating the software product line concept since years. It shows up the advantageous and disadvantageous characteristics of components that play a role for the concept combination. To be able to identify adequate components, criteria for the identification of software components suitable for the approach are derived from these characteristics. Furthermore the requirements of the potential service users are examined and categorized concerning their effects on the system architecture. Special requirements of customers often lead to architectural constraints that are not compatible with the approach. If both, the criteria are met and the architectural constraints are compatible, the SPL-SaaS approach can be applied to a component. The whole approach is applied on an example of arvato services}
}

@inproceedings{Soltenborn2009b,
  author = {Gregor Engels AND Daniela Fisseler AND Christian Soltenborn},
  title = {Improving Reusability of Dynamic Meta Modeling Specifications with Rule Overriding},
  booktitle = {Proceedings of the 2009 IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC 2009), Corvallis, Oregon (USA)},
  year = {2009},
  editor = {R. DeLine, M. Minas, M. Erwig},
  pages = {39--46},
  publisher = {IEEE Computer Society},
  address = {Piscataway, NJ (USA)},
  note = {Best Paper of VL/HCC 2009.},
  abstract = {Dynamic Meta Modeling (DMM) is a visual semantics specification technique targeted at languages equipped with a metamodel. In DMM, the metamodel of a language is mapped into a runtime metamodel able to express runtime states of instances of that language. In addition, graph transformation rules are defined which describe how these runtime states change in time. Given an instance of the runtime metamodel and a set of rules typed over that metamodel, a transition system can be computed which represents the semantics of the model instance under investigation.To be easily understandable by language engineers, DMM resembles a couple of well-known object-oriented concepts. Part of this is the fact that a DMM rule has many similarities to a method in an object-oriented language.In this paper, we enhance DMM such that DMM rules can "override" other DMM rules, similar to a method being overridden in a subclass. We argue that this does not only have positive impact on reusability of DMM specifications, but also improves the intuitive understandability of DMM rules.}
}

@inproceedings{EngSaSa09,
  author = {Frank Salger AND Stefan Sauer AND Gregor Engels},
  title = {Integrated Specification and Quality Assurance for Large Business Information Systems},
  booktitle = {Proceedings of the 2nd India Software Engineering Conference (ISEC'09)},
  year = {2009},
  pages = {129--130},
  publisher = {ACM Press},
  address = {New York, NY, USA}
}

@inproceedings{GerthModels09,
  author = {Christian Gerth AND Jochen K{\"u}ster AND Gregor Engels},
  title = {Language-Independent Change Management of Process Models},
  booktitle = {Proceedings of the ACM/IEEE 12th International Conference on Model Driven Engineering Languages and Systems (MODELS'09). Denver (CO, USA)},
  year = {2009},
  editor = {A. Sch{\"u}rr, B. Selic},
  pages = {152--166},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {In model-driven development approaches, process models are used at different levels of abstraction and are described by different languages. Similar to other software artifacts, process models are developed in team environments and underlie constant change. This requires reusable techniques for the detection of changes between different process models and the computation of dependencies and conflicts between changes. In this paper, we propose a framework for the construction of process model change management solutions that provides generic techniques for the detection of differences and the computation of dependencies and conflicts between changes. The framework contains an abstract representation for process models that serves as a common denominator for different process models. In addition, we show how the framework is instantiated exemplarily for BPMN.},
  series = {LNCS},
  volume = {5795 }
}

@inproceedings{VRW09,
  author = {Hendrik Voigt AND Thomas Ruhroth AND Heike Wehrheim},
  title = {Measure, diagnose, refactor: A formal quality cycle for software models},
  booktitle = {35th EUROMICRO Conference on Software Engineering and Advanced Applications (SEAA)},
  year = {2009},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA}
}

@inproceedings{DBLP:conf/iui/MeixnerGBHPSB09,
  author = {Gerrit Meixner AND Daniel G{\"o}rlich AND Kai Breiner AND Heinrich Hu{\ss}mann AND Andreas Pleu{\ss} AND Stefan Sauer AND Jan Van den Bergh},
  title = {Model Driven Development of Advanced User Interfaces 2009},
  booktitle = {Proceedings of the 2009 International Conference on Intelligent User Interfaces},
  year = {2009},
  editor = {Cristina Conati and Mathias Bauer and Nuria Oliver and Daniel S. Weld},
  pages = {503-504},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {October}
}

@inproceedings{seaa09/mde,
  author = {Baris G{\"u}ldali AND Michael Mlynarski AND Andreas W{\"u}bbeke AND Gregor Engels},
  title = {Model-Based System Testing Using Visual Contracts},
  booktitle = {Proceedings of Euromicro SEAA Conference 2009, Special Session on ``Model Driven Engineering''},
  year = {2009},
  pages = {121-124},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {In system testing the system under test (SUT) is tested against high-level requirements which are captured at early phases of the development process. Logical test cases developed from these requirements must be translated to executable test cases by augmenting them with implementation details. If manually done these activities are error-prone and tedious. In this paper we introduce a model-based approach for system testing where we generate first logical test cases from use case diagrams which are partially formalized by visual contracts, and then we transform these to executable test cases using model transformation. We derive model transformation rules from the design decisions of developers.}
}

@inproceedings{gse+09,
  author = {Baris G{\"u}ldali AND Holger Funke AND Michael Jahnich AND Stefan Sauer AND Gregor Engels},
  title = {Semi-automated Test Planning for e-ID Systems by Using Requirements Clustering},
  booktitle = {24th IEEE/ACM International Conference on Automated SoftwareEngineering (ASE 2009), 16-20 November 2009, Auckland, New Zeland},
  year = {2009},
  pages = {29-39},
  abstract = {In acceptance testing, customer requirements as specified in system specifications have to be tested for their successful implementation. This is a time-consuming task due to inherent system complexity and thus a large number of requirements. In order to reduce efforts in acceptance testing, we introduce a novel approach that exploits redundancies and implicit relations in requirements specifications, which are based on multi-viewpoint techniques, in our case the reference model for open distributed processing (RM-ODP). It deploys requirements clustering and linguistic analysis techniques for reducing the total number of test cases. We report on concrete experiences with this approach within joint R\&D work of the Software Quality Lab (s-lab) of the University of Paderborn and HJP Consulting, an international consulting company, specialized in planning, procurement and acceptance testing of national electronic identification (e-ID) systems. The paper is concluded with an overview on the current tool support especially for automated detection of the redundancies and implicit relations in requirements. Also the future work on the tool support for the overall test specification process is discussed. }
}

@inproceedings{EGPS09,
  author = {Gregor Engels AND Silke Geisen AND Stefan Sauer AND Olaf Port},
  title = {Sicherstellen der Betrachtung von nicht-funktionalen Anforderungen in SCRUM-Prozessen durch Etablierung von Feedback},
  booktitle = {Informatik 2009 - Im Focus das Leben},
  year = {2009},
  editor = {S. Fischer, E. Maehle, R. Reischuk},
  pages = {458},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  series = {Lecture Notes in Informatics},
  volume = {154}
}

@inproceedings{Ass09,
  author = {Martin Assmann AND Markus Haack AND Hendrik Scheider AND Nico vom Hagen AND Roger Zacharias},
  title = {SOA-Business Case},
  booktitle = {Transform IT: Optimale Gesch{\"a}ftsprozesse durch eine transformierende IT},
  year = {2009},
  editor = {F. Keuper, K. Hamidian, E. Verwaayen, T. Kalinowski},
  pages = {97--126},
  publisher = {Gabler},
  address = {Wiesbaden, Deutschland}
}

@inproceedings{Soltenborn2009a,
  author = {Christian Soltenborn AND Gregor Engels},
  title = {Towards Test-Driven Semantics Specification},
  booktitle = {Proceedings of the 12th International Conference on Model Driven Engineering Languages and Systems (MODELS 2009), Denver, Colorado (USA)},
  year = {2009},
  editor = {A. Sch{\"u}rr, B. Selic},
  pages = {378--392},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Behavioral models are getting more and more important within the software development cycle. To get the most use out of them, their behavior should be defined formally. As a result, many approaches exist which aim at specifying formal semantics for behavioral languages (e.g., Dynamic Meta Modeling (DMM), Semantic Anchoring). Most of these approaches give rise to a formal semantics which can e.g. be used to check the quality of a particular language instance, for instance using model checking techniques.However, if the semantics specification itself contains errors, it is more or less useless, since one cannot rely on the analysis results. Therefore, the language engineer must make sure that the semantics he develops is of the highest quality possible. To help the language engineer to achieve that goal, we propose a test-driven semantics specification process: the semantics of the language under consideration is first informally demonstrated using example models, which will then be used as test cases during the actual semantics specification process. In this paper, we present this approach using the already mentioned specification language DMM.},
  series = {LNCS},
  volume = {5795}
}

@inproceedings{KKIO09,
  author = {Michael Mlynarski AND Marian Jureczko},
  title = {Zautomatyzowane testy akceptacyjne dla aplikacji internetowych w programowaniu sterowanym testami},
  booktitle = {Proceedings of Krajowa Konferencja In{\.z}ynierii Oprogramowania 2009},
  year = {2009},
  editor = {W. D\k{a}browski, A. Stasiak},
  pages = {294--305},
  publisher = {Wydawnictwo Komunikacji i \L\k{a}czno{'s}ci},
  abstract = {Rozdzia{\l} prezentuje analiz\k{e} por{'o}wnawcz\k{a} wybranych, darmowych narz\k{e}dzi umo{\.z}liwiaj\k{a}cych tworzenie zautomatyzowanych funkcjonalnych test{'o}w akceptacyjnych, czyli Fitnesse, STF, JFCUnit oraz Selenium. Badana jest mo{\.z}liwo{'s}ć stosowania tych narz\k{e}dzi do testowania aplikacji internetowych wytwarzanych w procesie opieraj\k{a}cym si\k{e} o podej{'s}cie programowania przez testy. Aplikacje internetowe s\k{a} bardzo specyficzn\k{a} grup\k{a} aplikacji. Do ich uruchomienia potrzeba serwera aplikacji. W zwi\k{a}zku z tym nie ka{\.z}da aplikacja nadaje si\k{e} do przeprowadzania na nich test{'o}w akceptacyjnych. Dodatkowe komplikacje pojawiaj\k{a} si\k{e}, je{\.z}eli wymagać, aby testy powsta{\l}y przed napisaniem kodu {'z}r{'o}d{\l}owego, co ma miejsce w przypadku programowaniu przez testy.},
  series = {Od modelu do wdro{\.z}enia: kierunki badań i zastosowań in{\.z}ynierii oprogramowania},
  volume = {3}
}

@inproceedings{Engels08-1,
  author = {Gregor Engels AND Andreas Hess AND Bernhard Humm AND Oliver Juwig AND Marc Lohmann AND Jan-Peter Richter AND Markus Vo{\ss} AND Johannes Willkomm},
  title = {A Method for Engineering a true Service-Oriented Architecture},
  booktitle = {Proceedings of the Tenth International Conference on Enterprise Information Systems (ICEIS 2008), Barcelona (Spain)},
  year = {2008},
  editor = {J. Cordeiro, J. Filipe},
  pages = {272--281},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {June },
  note = {10th International Conference on Enterprise Information Systems (ICEIS 2008)},
  volume = {ISAS-2}
}

@inproceedings{VoigtR08,
  author = {Hendrik Voigt AND Thomas Ruhroth},
  title = {A Quality Circle Tool for Software Models},
  booktitle = {Proceedings of the 27th International Conference on Conceptual Modeling (ER 2008), Barcelona, Spain},
  year = {2008},
  editor = {Q. Li, S. Spaccapietra, E. Yu, A. Oliv{'e}},
  pages = {526--527},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  abstract = {The quality management of software models is an important issue. As a preparative task, the quality circle requires quality planning. After that a software model can repeat the sequence: quality measurement, quality analysis, and quality improvement. Until now, existing tools lack support for all these activities at once. Therefore, we developed and implemented concepts that provide the full quality circle for software models. The considered models are mainly represented in the syntax of UML class and statechart diagrams and their semantics are formally defined. The formal semantics of the considered software models allows us to improve them while preserving their external behavior.},
  series = {LNCS},
  volume = {5231}
}

@inproceedings{Engels08,
  author = {Gregor Engels AND Baris G{\"u}ldali AND Christian Soltenborn AND Heike Wehrheim},
  title = {Assuring Consistency of Business Process Models and Web Services using Visual Contracts},
  booktitle = {Proceedings of the 3rd International Symposium on Applications of Graph Transformation with Industrial Relevance (AGTIVE 2007), Kassel (Germany)},
  year = {2008},
  editor = {A. Sch{\"u}rr, M. Nagl, A. Z{\"u}ndorf},
  pages = {17--31},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  abstract = {Business process models describe workflows by a set of actions together with their ordering. When implementing business processes within a service-oriented architecture, these actions are mapped to existing IT (web) services, which are then to be executed in the order specified by the business process. However, the execution of a web service can require certain preconditions to be fulfilled. These might not hold at the time of execution specified in the business process model: it can be inconsistent with the web service specification.In this paper we propose a technique for checking consistency of process models with web service specifications. To this end, both are equipped with a formal semantics (in terms of graph transformations). We show how to use an existing model checker for graph transformation systems to carry out the consistency check.},
  series = {LNCS},
  volume = {5088}
}

@inproceedings{Koehler07,
  author = {Jana Koehler AND Thomas Gschwind AND Jochen K{\"u}ster AND Cesare Pautasso AND Ksenia Ryndina AND Jussi Vanhatalo AND Hagen V{\"o}lzer},
  title = {Combining Quality Assurance and Model Transformations in Business-Driven Development},
  booktitle = {Proceedings of the 3rd International Symposium on Applications of Graph Transformations with Industrial Relevance 2007 (AGTIVE '07), Kassel (Germany)},
  year = {2008},
  pages = {1--16},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Business-driven development is a methodology for developing IT solutions that directly satisfy business requirements. At its core are business processes, which are usually modeled by combining graphical and textual notations. During business-driven development, business process models are taken to the IT level, where they are implemented in a Service-Oriented Architecture. A major challenge in business-driven development is the semantic gap between models captured at the business and the IT level. Model transformations play a major role in bridging this gap.This paper presents a transformation framework for IBM WebSphere Business Modeler that enables programmers to quickly develop in-place model transformations, which are then made available to users of this tool. They address various user needs such as quickly correcting modeling errors, refining a process model, or applying a number of refactoring operations. Transformations are combined with quality assurance techniques, which help users to preserve or improve the correctness of their business process models when applying transformations.},
  series = {LNCS},
  volume = {5088}
}

@inproceedings{Comp08,
  author = {Frank Salger AND Marcel Bennicke AND Gregor Engels AND Claus Lewerentz},
  title = {Comprehensive Architecture Evaluation and Management in Large Software-Systems},
  booktitle = {Quality of Software Architectures. Models and Architectures},
  year = {2008},
  editor = {S. Becker, F. Plasil, R. Reussner},
  pages = {205--219},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  abstract = {The architecture of a software system is both a success and a failure factor. Taking the wrong architectural decisions may break a project, since such errors are often systematic and affect cross-cutting aspects of the system to be built. Moreover, software projects get more and more challenging due to the rising complexity and dynamics of business processes, large team size and distributed development. As the software architecture is the common platform for many project activities, it constitutes a critical success factor. Thus, a comprehensive method for evaluating a software architecture and propagating important properties of it downstream to code is needed. At sd\&m, we designed a comprehensive architecture evaluation and management framework in order to satisfy these needs. In this paper, we derive a list of requirements, such a framework should fulfill. We then present the components of our architecture evaluation method and demonstrate, how it fulfills these requirements.},
  journal = {LNCS},
  series = {LNCS},
  volume = {5281}
}

@inproceedings{DetKGFE08,
  author = {Jochen K{\"u}ster AND Christian Gerth AND Alexander F{\"o}rster AND Gregor Engels},
  title = {Detecting and Resolving Process Model Differences in the Absence of a Change Log},
  booktitle = {Proceedings of the 6th International Conference on Business Process Management (BPM'08)},
  year = {2008},
  editor = {M. Dumas, M. Reichert, M.-C. Shan},
  pages = {244--260},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Business-driven development favors the construction of process models at different abstraction levels and by different people. As a consequence, there is a demand for consolidating different versions of process models by detecting and resolving differences. Existing approaches rely on the existence of a change log which logs the changes when changing a process model. However, in several scenarios such a change log does not exist and differences must be identified by comparing process models before and after changes have been made. In this paper, we present our approach to detecting and resolving differences between process models, in the absence of a change log. It is based on computing differences and deriving change operations for resolving differences, thereby providing a foundation for variant and version management in these cases.},
  series = {LNCS},
  volume = {5240}
}

@inproceedings{VE08-2,
  author = {Hendrik Voigt AND Gregor Engels},
  title = {Ein verfeinerter GQM-Ansatz zur Qualit{\"a}tsbewertung von Software-Modellen},
  booktitle = {Proceedings of Software-Qualit{\"a}tsmodellierung und -bewertung (SQMB '08), M{\"u}nchen, Germany},
  year = {2008},
  editor = {S. Wagner, M. Broy, F. Deissenboeck, J. M{\"u}nch, P. Liggesmeyer},
  pages = {39--46},
  publisher = {Technische Universit{\"a}t M{\"u}nchen},
  abstract = {Wir stellen einen Qualit{\"a}tsmanagementansatz zur Bewertung von Software-Modellen vor. Unser Ansatz basiert auf der Goal Question Metric (GQM). Wir verfeinern GQM und f{\"u}gen wichtige Konzepte und Aktivit{\"a}ten hinzu, um auf diese Weise die Besonderheiten bei der Qualit{\"a}tsbewertung von Software-Modellen ber{\"u}cksichtigen zu k{\"o}nnen. Dabei konzentrieren wir uns insbesondere auf den Kontext eines Software-Modells als entscheidenden Einflussfaktor f{\"u}r die Dokumentation von Informationsbed{\"u}rfnissen, Qualit{\"a}tsverst{\"a}ndnis, Messung und Analyse. Aktuell wird eine Werkzeugunterst{\"u}tzung f{\"u}r die Eclipse Plattform entwickelt, damit unser Qualit{\"a}tsmanagementansatz evaluiert und wirtschaftlich eingesetzt werden kann.}
}

@inproceedings{Engels08-2,
  author = {Gregor Engels AND Anneke Kleppe AND Arend Rensink AND Maria Semenyak AND Christian Soltenborn AND Heike Wehrheim},
  title = {From UML Activities to TAAL - Towards Behaviour-Preserving Model Transformations},
  booktitle = {Proceedings of the 4th European Conference on Model Driven Architecture - Foundations and Applications (ECMDA-FA 2008), Berlin (Germany)},
  year = {2008},
  editor = {I. Schieferdecker, A. Hartman},
  pages = {95--109},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {July},
  abstract = {Model transformations support a model-driven design by providing an automatic translation of abstract models into more concrete ones, and eventually program code. Crucial to a successful application of model transformations is their correctness, in the sense that the meaning (semantics) of the models is preserved. This is especially important if the models not only describe the structure but also the intended behaviour of the systems. Reasoning about and showing correctness is, however, often impossible as the source and target models typically lack a precise definition of their semantics.In this paper, we take a first step towards provably correct behavioural model transformations. In particular, we develop transformations from UML Activities (which are visual models) to programs in TAAL, which is a textual Java-like programming language. Both languages come equipped with formal behavioural semantics, which, moreover, have the same semantic domain. This sets the stage for showing correctness, which in this case comes down to showing that the behaviour of every (well-formed) UML Activity coincides with that of the corresponding TAAL program, in a well-defined sense.},
  series = {LNCS},
  volume = {5095}
}

@inproceedings{VE08-1,
  author = {Hendrik Voigt AND Gregor Engels},
  title = {Kontextsensitive Qualit{\"a}tsplanung f{\"u}r Software-Modelle},
  booktitle = {Proceedings of Modellierung (2008), Berlin (Germany)},
  year = {2008},
  editor = {T. K{\"u}hne, W. Reisig, F. Steimann},
  pages = {165--180},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  month = {March},
  abstract = {Der Goal Question Metric (GQM) Ansatz stellt eine allgemeine Qualit{\"a}tsmanagementstrategie dar und ber{\"u}cksichtigt infolgedessen nicht die Besonderheiten von Software-Modellen. Wir haben eine kontextsensitive Qualit{\"a}tsplanung f{\"u}r Software- Modelle entwickelt, die den GQM-Ansatz auf die Qualit{\"a}tsplanung von Software- Modellen zuschneidet und um Konzepte und Aktivit{\"a}ten erweitert. Dabei konzentrieren wir uns auf den Kontext eines Software-Modells als entscheidenden Einflussfaktor f{\"u}r die Dokumentation von Informationsbed{\"u}rfnissen, Qualit{\"a}tsverst{\"a}ndnis und Messung. Unser Ansatz zur Qualit{\"a}tsplanung besteht aus einem Metamodell zur Formulierung relevanter Inhalte und einem Prozess, der als Leitfaden bei der Planung dient.},
  series = {Lecture Notes in Informatics},
  volume = {127}
}

@inproceedings{WJMK08,
  author = {Michael Wahler AND Jochen K{\"u}ster},
  title = {Predicting Coupling of Object-Centric Business Process Implementations},
  booktitle = {Proceedings of the 6th International Conference on Business Process Management},
  year = {2008},
  pages = {148--163},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {September},
  abstract = {Object-centric approaches for business process implementation distribute process logic among several interacting components, each representing a life cycle of an object. One of the challenges is to manage the component coupling, because highly-coupled components are difficult to distribute, maintain and adapt. Existing techniques that derive a component for each object that changes state in a given process do not consider component interdependencies and run the risk of producing components that are highly coupled. To make coupling explicit and manageable during component identification, we propose an approach for computing the expected coupling of an object-centric implementation for a given process model prior to actually deriving this implementation.},
  series = {LNCS},
  volume = {5240}
}

@inproceedings{Informatiktage2008,
  author = {Michael Mlynarski},
  title = {Qualit{\"a}tssicherung im Business Process Modeling durch automatische Ableitung visueller Kontrakte aus heterogenen UML-Modellen},
  booktitle = {Informatiktage 2008. Fachwissenschaftlicher Informatik-Kongress, 14. und 15. M{\"a}rz 2008, B-IT Bonn-Aachen International Center for Information Technology in Bonn},
  year = {2008},
  pages = {87-90},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  series = {Lecture Notes in Informatics}
}

@inproceedings{VGE08,
  author = {Hendrik Voigt AND Baris G{\"u}ldali AND Gregor Engels},
  title = {Quality Plans for Measuring the Testability of Models},
  booktitle = {Proceedings of the 11th International Conference on Quality Engineering in Software Technology (CONQUEST 2008), Potsdam (Germany)},
  year = {2008},
  editor = {I. Schieferdecker, S. Goericke},
  pages = {353--370},
  publisher = {dpunkt.verlag},
  abstract = {For models used in model-based testing, the evaluation of their testability is an important issue. Existing approaches lack some relevant aspects for a systematic and comprehensive evaluation. Either they do (1) not consider the context of software models, (2) not offer a systematic process for selecting and developing right measurements, (3) not define a consistent and common quality understanding, or (4) not distinct between objective and subjective measurements.We present a novel quality management approach for the evaluation of software models in general that considers all these aspects in an integrated way. Our approach is based on a combination of the Goal Question Metric (GQM) and quality models. We demonstrate our approach by systematically developing a short quality plan for measuring the testability of software models.}
}

@inproceedings{DBLP:conf/se/EngelsV08,
  author = {Gregor Engels AND Markus Vo{\ss}},
  title = {Quasar Enterprise - Anwendungslandschaften serviceorientiert gestalten},
  booktitle = {Software Engineering 2008. Fachtagung des GI-Fachbereichs Softwaretechnik},
  year = {2008},
  editor = {K. Herrmann, B. Bruegge},
  pages = {24--27},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  month = {February },
  series = {Lecture Notes in Informatics},
  volume = {121}
}

@inproceedings{Frohnhoff08,
  author = {Stephan Frohnhoff AND Gregor Engels},
  title = {Revised Use Case Point Method - Effort Estimation in Development Projects for Business Applications},
  booktitle = {Setting Quality Standards, Proceedings of the 11th International Conference on Quality Engineering in Software Technology (CONQUEST 2008), Potsdam (Germany)},
  year = {2008},
  editor = {I. Schieferdecker, S. Goericke},
  pages = {15--32},
  publisher = {dpunkt Verlag},
  abstract = {Rapid and precise effort estimation of software development projects is crucial in ITindustry. In a case study, the Use Case Point (UCP) method was applied to 15 commercialsoftware development projects. The estimated efforts were compared with the incurredproject efforts. We measured a standard deviation of 42 \%. This is not acceptablefor industrial usage. Therefore, we propose appropriate improvements of the UseCase Point method leading to significantly higher estimation accuracy with only 20 \%standard deviation. The contribution of this paper is a detailed description of the improvedUse Case Point method.}
}

@inproceedings{AssEDOC08,
  author = {Martin Assmann AND Gregor Engels},
  title = {Service-Oriented Enterprise Architectures: Evolution of Concepts and Methods},
  booktitle = {Proc. of the 12th IEEE International Enterprise Distributed Object Computing Conference 2008 (EDOC 08), Munich (Germany)},
  year = {2008},
  pages = {xxxiv--xliii},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {September},
  abstract = {This paper depicts the evolution of enterprise architectures to their today often used service-oriented form and presents a state-of-the-art development process for this kind of architecture. The development process covers both the development of business architecture as well as the appropriate software architecture. While showing up a possible form of further evolution of enterprise architectures, we identify the major challenges for future development methods of enterprise architectures.}
}

@inproceedings{Wuebbeke2008,
  author = {Andreas W{\"u}bbeke},
  title = {Towards an Efficient Reuse of Test Cases for Software Product Lines},
  booktitle = {Proceedings of the 12th International Software Product Line Conference (SPLC 2008), Limerick (Ireland)},
  year = {2008},
  editor = {S. Thiel, K. Pohl},
  pages = {361--368},
  publisher = {Lero},
  address = {Limerick},
  month = {September},
  abstract = {Testing is a creative, complex and often time consuming task of the development process of a software system. If the basis of this process is the development-paradigm Software Product Line (SPL) the complexity is extended by the dimension variability. This variability is the basic principle for an effective and efficient reuse in all disciplines and their dimensions of the development process. To support this reuse in an optimal way product line specific concepts and approaches are necessary. This contribution presents the state the art in testing Software Product Lines and derives current challenges on an efficient design of executable test cases in this context.},
  volume = {2}
}

@inproceedings{AssmannEcsa08,
  author = {Martin Assmann AND Gregor Engels},
  title = {Transition to Service-Oriented Enterprise Architecture},
  booktitle = {Proceedings of the Second European Conference on Software Architecture (ECSA 2008), Paphos (Cyprus)},
  year = {2008},
  editor = {R. Morrison, D. Balasubramaniam, K. E. Falkner},
  pages = {346--349},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {September},
  abstract = {Enterprise Architecture (EA) has undergone many changes since the IT has found its way into enterprises. At the moment the Service-Oriented Architecture (SOA) is being hyped but has also gained some importance. Implementing SOA can have many implications for an enterprise, depending on how visionary the implemented architecture is. This paper provides the description of an enterprise architecture that is fully-fledged concerning service-orientation and points out the architectural challenges that have to be mastered with future research results.},
  series = {LNCS},
  volume = {5292}
}

@inproceedings{Schattkowsky2007a,
  author = {Tim Schattkowsky AND Gregor Engels AND Alexander F{\"o}rster},
  title = {A Model-Based Approach for Platform-Independent Binary Components with Precise Timing and Fine-Grained Concurrency},
  booktitle = {Proceedings of the 40th Annual Hawaii International Conference on System Sciences (HICSS 2007)},
  year = {2007},
  pages = {286ff.},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {Fine grained concurrency and accurate timing can be essential for embedded hardware and software systems. These requirements should be reflected in the specification and must be consistently enforced by the actual implementation. Automated synthesis of the implementation from such specifications appears to be a straightforward way to ensure this consistency. However, especially for software systems this is quite difficult, since software lacks the inherent timing and concurrency of a hardware system. Still, the same timing and concurrency requirements have to be fulfilled. Thus, we introduce a UML-based design approach that supports the synthesis of embedded hardware or software systems from essentially the same abstract specification. Our approach provides explicit support for specifying fine grained concurrency and microsecond accurate timing. In our approach, these properties must be ensured by the automatically derived implementation. Since this is especially hard to achieve for software systems, this paper focuses on execution on software platforms. For this, we introduce our UML Virtual Machine (UVM). It enables the direct execution of binary encoded system specifications and enforces the desired timing and concurrency. As a result, our approach enables the creation of binary encoded portable concurrent time-accurate software components.}
}

@inproceedings{Engels2007a,
  author = {Gregor Engels AND Christian Soltenborn AND Heike Wehrheim},
  title = {Analysis of UML Activities Using Dynamic Meta Modeling},
  booktitle = {Proceedings of the conference on Formal Methods for Open Object-based Distributed Systems (FMOODS 2006), Oslo (Norway)},
  year = {2007},
  editor = {M. M. Bosangue, E. Broch Johnsen},
  pages = {76--90},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {June},
  abstract = {Dynamic Meta Modeling (DMM) is a universal approach to defining semantics for languages syntactically grounded on meta models. DMM has been designed with the aim of getting highly understandable yet precise semantic models which in particular allow for a formal analysis. In this paper, we exemplify this by showing how DMM can be used to give a semantics to and define an associated analysis technique for UML Activities.},
  series = {LNCS},
  volume = {4468}
}

@inproceedings{Bals07,
  author = {Jan-Christopher Bals AND Fabian Christ AND Gregor Engels AND Martin Erwig},
  title = {ClassSheets - model-based, object-oriented design of spreadsheet applications},
  booktitle = {Proceedings of the TOOLS Europe Conference (TOOLS 2007), Z{\"u}rich (Swiss)},
  year = {2007},
  pages = {383--398},
  publisher = {Journal of Object Technology},
  month = {October },
  abstract = {Using spreadsheets is the preferred method to calculate, display or store anything that fits into a table-like structure. They are often used by end users to create applications. But they have one critical drawback - they are very error-prone.To reduce the error-proneness, we purpose a new way of object-oriented modeling of spreadsheets prior to using them. These spreadsheet models, termed ClassSheets, are used to generate concrete spreadsheets on the instance level.By this approach sources of errors are reduced and spreadsheet applications are easier to understand. },
  journal = {Journal of Object Technology},
  volume = {6}
}

@inproceedings{Sauer2007,
  author = {Stefan Sauer AND Gregor Engels},
  title = {Easy Model-Driven Development of Multimedia User Interfaces with GuiBuilder},
  booktitle = {Proceeding of the 4th International Conference on Universal Access in Human-Computer Interaction (UAHCI, as Part of HCI International, 2007), Beijing (China)},
  year = {2007},
  editor = {C. Stephanidis},
  pages = {537--546},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  note = {Journal:Universal Access in HCI, Part IBook:HCI (5)},
  abstract = {GUI builder tools are widely used in practice to develop the user interface of software systems. Typically they are visual programming tools that support direct-manipulative assembling of the user interface components. We have developed the tool GuiBuilder which follows a model-driven approach to the development of graphical (multimedia) user interfaces. This allows a meta-design approach where user interface developers as well as prospective users of the system are supported in modelling the desired functionality of the GUI on a high level of abstraction that is easy to understand for all involved stakeholders. The model consists of compositional presentation diagrams to model the structure of the user interface and hierarchical statechart diagrams to model its behaviour. GuiBuilder then supports the transformation of the model to Java, i.e., the generation of a working user interface and the simulation of the modelled behaviour. Interactive sessions with the user interface can be recorded and replayed.},
  series = {LNCS},
  volume = {4554}
}

@inproceedings{KusterRG07,
  author = {Jochen K{\"u}ster AND Ksenia Ryndina AND Harald Gall},
  title = {Generation of Business Process Models for Object Life Cycle Compliance},
  booktitle = {Proceedings of the conference on Business Process Management (BPM 2007), Brisbane (Australia)},
  year = {2007},
  editor = {G. Alonso, P. Dadam, M. Rosemann},
  pages = {165--181},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October },
  abstract = {Business process models usually capture data exchanged between tasks in terms of objects. These objects are commonly standardized using reference data models that prescribe, among other things, allowed object states. Allowed state transitions can be modeled as object life cycles that require compliance of business processes. In this paper, we first establish a notion of compliance of a business process model with an object life cycle. We then propose a technique for generating a compliant business process model from a set of given reference object life cycles.},
  journal = {Proceedings 5th International Conference on Business Process Management},
  series = {LNCS},
  volume = {4714}
}

@inproceedings{Ryndina2007,
  author = {Ksenia Ryndina AND Jochen K{\"u}ster AND Harald Gall},
  title = {Generation of Business Process Models for Object Life Cycle Compliance},
  booktitle = {Proceedings of the BPM Demonstration Program (satellite event of the 5th International Conference on Business Process Management (BPM 2007)), Brisbane (Australia)},
  year = {2007},
  editor = {G. Alonso, P. Dadam, M. Rosemann},
  pages = {165--181},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October },
  abstract = {Business process models usually capture data exchanged between tasks in terms of objects. These objects are commonly standardizedusing reference data models that prescribe, among other things, allowed object states. Allowed state transitions can be modeled as object life cycles that require compliance of business processes. In this paper, we first establish a notion of compliance of a business process model with an object life cycle. We then propose a technique for generating a compliant business process model from a set of given reference object life cycles.},
  series = {LNCS},
  volume = {4714/2007}
}

@inproceedings{Kuester07-1,
  author = {Jochen K{\"u}ster AND Ksenia Ryndina AND Harald Gall},
  title = {Improving Inconsistency Resolution with Side-effect Evaluation and Costs},
  booktitle = {Proceedings of the ACM/IEEE 10th International Conference on Model Driven Engineering Languages and Systems (MODELS 2007), Nashville, TN (USA)},
  year = {2007},
  editor = {G. Engels, B. Opdyke, D. C. Schmidt, F. Weil},
  pages = {136--150},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October },
  journal = {ACM/IEEE 10th International Conference on Model Driven Engineering Languages and Systems},
  volume = {4735}
}

@inproceedings{EC-TEL2007,
  author = {Michael Mlynarski AND Knut Hinkelmann AND Johannes Magenheim AND Tobias Nelkner AND Wolfgang Reinhardt AND Kai Holzweissig},
  title = {KnowledgeBus - An Architecture to Support Intelligent and Flexible Knowledge Management},
  booktitle = {Creating New Learning Experiences on a Global Scale, Second European Conference on Technology Enhanced Learning, EC-TEL 2007, Crete, Greece, September 17-20, 2007},
  year = {2007},
  pages = {487-492},
  publisher = {Springer},
  address = {Berlin/Heidelberg}
}

@inproceedings{Pleuss2007,
  author = {Andreas Pleu{\ss} AND Jan Van den Bergh AND Stefan Sauer AND Heinrich Hu{\ss}mann AND Alexander B{\"o}dcher},
  title = {Model Driven Development of Advanced User Interfaces (MDDAUI) - MDDAUI'06 Workshop Report},
  booktitle = {MoDELS 2006 Workshops},
  year = {2007},
  editor = {T. K{\"u}hne},
  pages = {101--105},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {This paper reports on the 2nd Workshop on Model Driven Development of Advanced User Interfaces (MDDAUI'06) held on October 2nd, 2006 at the MoDELS'06 conference in Genova, Italy. It briefly describes the workshop topic and provides a short overview on the workshop structure. In the main part it introduces the four topics discussed in the workshop's afternoon sessions and summarizes the discussion results.},
  series = {LNCS},
  volume = {4364}
}

@inproceedings{Zimmermann07,
  author = {Olaf Zimmermann AND Thomas Gschwind AND Jochen K{\"u}ster AND Frank Leymann AND Nelly Schuster},
  title = {Reusable Architectural Decision Models for Enterprise Application Development},
  booktitle = {Proceedings the conference on Quality of Software-Architectures (QoSA 2007), Medford, MA (USA)},
  year = {2007},
  pages = {15--32},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {July},
  abstract = {In enterprise application development and other software construction projects, a critical success factor is to make sound architectural decisions. Text templates and tool support for capturing architectural decisions exist, but have failed to reach broad adoption so far. One of the inhibitors we perceived on large-scale industry projects is that architectural decision capturing is regarded as a retrospective and therefore unwelcome documentation task which does not provide any benefit during the original design work. A major problem of such a retrospective approach is that the decision rationale is not available to decision makers when they identify, make, and enforce decisions. Often a large, possibly distributed, community of decision makers is involved in these three steps. In this paper, we propose a new conceptual framework for proactive decision identification, decision maker collaboration, and decision enforcement. Based on a meta model capturing reuse and collaboration aspects explicitly, our framework instantiates decision models from requirements models and reusable decision templates. These templates capture knowledge gained on other projects employing the same architectural style. As an exemplary application of these concepts to service-oriented architecture shows, reusable architectural decision models can speed up the decision identification and improve the quality of thedecision making. Reusable architectural decision models can also simplify the exchange of architecture design rationale within and between project teams, and expose decision outcome as model transformation parameters in model-driven software development.}
}

@inproceedings{Wachsmuth2007,
  author = {Stephan Arens AND Alexander Buss AND Helena Deck AND Miroslaw Dynia AND Matthias Fischer AND Holger Hagedorn AND Peter Isaak AND Jaroslaw Kutylowski AND Friedhelm Meyer auf der Heide AND Viktor Nesterow AND Adrian Ogiermann AND Boris Stobbe AND Thomas Storm AND Henning Wachsmuth},
  title = {Smart Teams: Simulating Large Robotic Swarms in Vast Environments},
  booktitle = {Proceedings of the 4th International Symposium on Autonomous Minirobots for Research and Edutainment},
  year = {2007},
  pages = {215--222},
  publisher = {Heinz Nixdorf Institut, University of Paderborn},
  address = {Buenos Aires, Argentina},
  month = {October},
  abstract = {We consider the problem of exploring an unknown environment using a swarm of autonomous robots with collective behavior emerging from their local rules. Each robot has only a very restricted view on the environment which makes cooperation difficult. We introduce a software system which is capable of simulating a large number of such robots (e.g. 1000) on highly complex terrains with millions of obstacles. Its main purpose is to easily integrate and evaluate any kind of algorithm for controlling the robot behavior. The simulation may be observed in real-time via a visualization that displays both the individual and the collective progress of the robots. We present the system design, its main features and underlying concepts.}
}

@inproceedings{Hess2007,
  author = {Andreas Hess AND Bernhard Humm AND Markus Vo{\ss} AND Gregor Engels},
  title = {Structuring Software Cities - A Multidimensional Approach},
  booktitle = {Proceedings of the 11th IEEE International Enterprise Distributed Object Computing Conference (EDOC 2007)},
  year = {2007},
  pages = {122--129},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {Software cities alias application landscapes of large enterprises comprise tens or even hundreds of IT applications. Structuring software cities into domains is an important task of enterprise architects. The quality of the resulting domain model is crucial for the success of enterprise architecture management and an important tool for the governance of the development of an enterprise's application landscape. This paper presents a novel method for constructing domain models based on business services, business objects, and business dimensions. The method has been validated in numerous industrial projects. }
}

@inproceedings{Forster2007,
  author = {Alexander F{\"o}rster AND Gregor Engels AND Tim Schattkowsky AND Ragnhild Van Der Straeten},
  title = {Verification of Business Process Quality Constraints Based on Visual Process Patterns},
  booktitle = {Proceedings of the First Joint IEEE/IFIP Symposium on Theoretical Aspects of Software Engineering (TASE 2007), Shanghai (China)},
  year = {2007},
  pages = {197--208},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {Business processes usually have to consider certain constraints like domain specific and quality requirements. The automated formal verification of these constraints is desirable, but requires the user to provide an unambiguous formal specification. In particular since the notations for business process modeling are usually visual flow-oriented languages, the notational gap to the languages usually employed for the formal specification of constraints, e.g., temporal logic, is significant and hard to bridge. Thus, our approach relies on UML Activities as a single language for the specification of both business processes and the corresponding constraints. For the expression of such constraints, we have provided a process pattern definition language based on specialized Activities. In this paper, we describe how model checking can be employed for formal verification of business processes against such patterns. For this, we present an automated transformation of the business process and the corresponding patterns into a transition system and temporal logic, respectively.}
}

@inproceedings{Informatiktage2007,
  author = {Michael Mlynarski AND Tobias Nelkner AND Wolfgang Reinhardt},
  title = {Vom Informations- zum Wissensmanagement: Der Knowledge Bus als flexibler L{\"o}sungsansatz},
  booktitle = {Informatiktage 2007: Fachwissenschaftlicher Informatik-Kongress, 30. und 31. M{\"a}rz 2007, B-IT Bonn-Aachen International Center for Information Technology Bonn},
  year = {2007},
  pages = {99--102}
}

@inproceedings{FoersterVLHCC06,
  author = {Alexander F{\"o}rster AND Tim Schattkowsky AND Gregor Engels AND Ragnhild Van Der Straeten},
  title = {A Pattern-driven Development Process for Quality Standard-conforming Business Process Models},
  booktitle = {IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC 2006), Brighton (UK)},
  year = {2006},
  pages = {135--142},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  journal = {In Proc.}
}

@inproceedings{Hauser2006,
  author = {Rainer Hauser AND Michael Friess AND Jochen K{\"u}ster AND Jussi Vanhatalo},
  title = {Combining Analysis of Unstructured Workflows with Transformation to Structured Workflows},
  booktitle = {Proceedings of the 10th IEEE International Enterprise Distributed Object Computing Conference (EDOC 2006)},
  year = {2006},
  pages = {129--140},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {October },
  abstract = {Analysis of workflows in terms of structural correctness is important for ensuring the quality of workflow models. Typically, this analysis is only one step in a larger development process, followed by further transformation steps that lead from high-level models to more refined models until the workflow can finally be deployed on the underlying workflow engine of the production system. For practical and scalable applications, analysis and transformations of workflows must both be integrated to allow incremental changes of larger workflows. In this paper, we introduce the concept of a region tree for workflow models that can be used as the central data structure for both workflow analysis and workflow transformation. A region tree is similar to a program structure tree and imposes a hierarchy of regions onto the workflow model. It allows an incremental approach to analysis and transformation of workflows and thereby significantly reduces the overhead because individual regions can be dealt with separately. }
}

@inproceedings{Loeser2006,
  author = {Christoph Loeser AND Gunnar Schomaker AND Matthias Schubert AND Tim Schattkowsky},
  title = {Fairness Considerations in Replication and Placement Strategies for large Documents in heterogeneous Content Delivery Networks},
  booktitle = {Proceedings of the 5th International Conference on Networking (ICN 2006), Morne (Mauritius)},
  year = {2006},
  pages = {105},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {In previous publications there have been several proposals regarding replica generation and placement of readonly content in content distribution networks or P2P overlays. Within this paper, we extend approaches for heterogeneous placement scenarios described in prior publications. Therefore we presume heterogeneous server peers' bandwidth, HD capacity, and movie popularities. Within our scenario, movie documents are replicated and placed onto server peers with respect to the predicted popularity values. Thus, each document aims to gain fair networks resources according to its popularity. Besides different heuristics for placement and replication strategies we present simulation results for these techniques in hierarchical overlay networks. These algorithms base on predicted popularity values of each document. }
}

@inproceedings{Ehrig2006,
  author = {Karsten Ehrig AND Gabriele Taentzer AND Jochen K{\"u}ster AND Jessica Winkelmann},
  title = {Generating Instance Models from Meta Models},
  booktitle = {Proceedings of the conference on Formal Methods for Open Object-Based Distributed Systems (FMOODS 2006), Bologna (Italy)},
  year = {2006},
  pages = {156--170},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {June},
  abstract = {Meta modeling is a wide-spread technique to define visual languages, with the UML being the most prominent one. Despite several advantages of meta modeling such as ease of use, the meta modeling approach has one disadvantage: It is not constructive i. e. it does not offer a direct means of generating instances of the language. This disadvantage poses a severe limitation for certain applications. For example, when developing model transformations, it is desirable to have enough valid instance models available for large-scale testing. Producing such a large set by hand is tedious. In the related problem of compiler testing, a string grammar together with a simple generation algorithm is typically used to produce words of the language automatically. In this paper, we introduce instance-generating graph grammars for creating instances of meta models, thereby overcoming the main deficit of the meta modeling approach for defining languages.},
  series = {LNCS},
  volume = {4037/2006}
}

@inproceedings{Engels2006d,
  author = {Gregor Engels AND Baris G{\"u}ldali AND Oliver Juwig AND Marc Lohmann AND Jan-Peter Richter},
  title = {Industrielle Fallstudie: Einsatz visueller Kontrakte in serviceorientierten Architekturen},
  booktitle = {Proceedings of the conference on Software Enginneering, Fachtagung des GI Fachbereichs Softwaretechnik (SE 2006), Leipzig (Germany)},
  year = {2006},
  editor = {B. Biel, M. Book, V. Gruhn},
  pages = {111--122},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  month = {March},
  note = {Software Enginneering 2006, Fachtagung des GI Fachbereichs Softwaretechnik},
  abstract = {Serviceorientierte Architekturen (SOA) erlauben eine schnelle und kosteneffiziente Bereitstellung unterschiedlicher Funktionalit{\"a}ten zur Unterst{\"u}tzung der Gesch{\"a}ftsprozesse eines Unternehmens. Dazu werden fachliche Funktionalit{\"a}ten in Form von Enterprise Services zur Verf{\"u}gung gestellt. Die hohe Zahl von Enterprise Services erfordert eine geeignete semantische Beschreibung zu deren effizienten Verwaltung. Zur semantischen Beschreibung von Enterprise Services sowie zur Formulierung von Suchanfragen ist an der Universit{\"a}t Paderborn die Methode der visuellen Kontrakte entwickelt worden. Das Papier stellt die Ergebnisse der ersten Phase einer umfangreichen industriellen Fallstudie zur Evaluation der praktischen Anwendbarkeit visueller Kontrakte im Kontext einer SOA vor.},
  series = {Lecture Notes in Informatics},
  volume = {79}
}

@inproceedings{Engels2006f,
  author = {Gregor Engels AND Marc Lohmann AND Stefan Sauer AND Reiko Heckel},
  title = {Model-Driven Monitoring: An Application of Graph Transformation for Design by Contract},
  booktitle = {Proceedings of the 3rd International Conference on Graph Transformation (ICGT 2006), Natal (Brazil)},
  year = {2006},
  editor = {A. Corradini, H. Ehrig, U. Montanari, L. Ribeiro, G. Rozenberg},
  pages = {336--350},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {The model-driven development (MDD) approach for constructing software systems advocates a stepwise refinement and transformation process starting from high-level models to concrete program code. In contrast to numerous research efforts that try to generate executable function code from models, we propose a novel approach termed model-driven monitoring. Here, models are used to specify minimal requirements and are transformed into assertions on the code level for monitoring hand-coded programs during execution.We show how well-understood results from the graph transformation community can be deployed to support this model-driven monitoring approach. In particular, models in the form of visual contracts are defined by graph transitions with loose semantics, while the automatic transformation from models to JML assertions on the code level is defined by strict graph transformation rules. Both aspects are supported and realized by a dedicated Eclipse plug-in.},
  series = {LNCS},
  volume = {4178}
}

@inproceedings{Lohmann2006a,
  author = {Marc Lohmann AND Gregor Engels AND Stefan Sauer},
  title = {Model-driven Monitoring: Generating Assertions from Visual Contracts},
  booktitle = {Proceedings of the 21st IEEE International Conference on Automated Software Engineering (ASE 06), Tokyo (Japan)},
  year = {2006},
  pages = {355--356},
  publisher = {IEEE Computer Society},
  address = {Los Alamitos, CA, USA},
  abstract = {The Visual Contract Workbench is a tool that supports model-driven development of software systems by lifting the Design by Contract idea, which is usually used at the code level, to the model level. It uses visual contracts for graphically specifying the pre- and post-conditions of an operation. Java classes with JML (Java Modeling Language) assertions are generated from visual contracts to facilitate automatic monitoring of the correctness of the programmer's implementation.}
}

@inproceedings{Schattkowsky2006d,
  author = {Tim Schattkowsky AND Alexander F{\"o}rster AND Christoph Loeser},
  title = {Secure Storage for Physically Exposed Web- and Application Servers},
  booktitle = {Proceedings of the 5th International Conference on Networking (ICN 2006), Morne (Mauritius)},
  year = {2006},
  pages = {86},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA}
}

@inproceedings{Engels2006e,
  author = {Gregor Engels AND Jan Hendrik Hausmann AND Marc Lohmann AND Stefan Sauer},
  title = {Teaching UML Is Teaching Software Engineering Is Teaching Abstraction},
  booktitle = {Proceedings of the Satellite Events at the MoDELS 2005 Conference, Montego Bay (Jamaica)},
  year = {2006},
  editor = {J.-M. Bruel},
  pages = {306--319},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  note = {Proceedings of the workshopt on Satellite Events at the MoDELS 2005 Conference (MoDELS 2005 International Workshops OCLWS, MoDeVA, MARTES, AOM, MTiP, WiSME, MODAUI, NfC, MDD, WUsCAM, Montego Bay, Jamaica)},
  abstract = {As the Unified Modeling Language (UML) has by now seen widespread and successful use in the software industry and academia alike, it has also found its way into many computer science curricula. An outstanding advantage of teaching UML is that it enables an illustration of many crucial concepts of software engineering, far beyond its concrete notation. Most important among these concepts is that of abstraction. We present a course design which demonstrates the use of UML as a vehicle for teaching such core concepts of software engineering. Multimedia elements and tools help to efficiently convey the courses message to the students.},
  series = {LNCS},
  volume = {3844 / 2006}
}

@inproceedings{Schattkowsky2006c,
  author = {Tim Schattkowsky AND Jan Hendrik Hausmann AND Gregor Engels},
  title = {Using UML Activities for System-on-Chip Design and Synthesis},
  booktitle = {Proceedings of the International Conference on Model Driven Engineering Languages and Systems (MoDELS 2006), Genova (Italy)},
  year = {2006},
  editor = {O. Nierstrasz, J. Whittle, D. Harel, G. Reggio},
  pages = {737--752},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {The continuous advances in manufacturing Integrated Circuits (ICs) enable complete systems on a single chip. However, the design effort for such System-on-Chip (SoC) solutions is significant. The productivity of the design teams currently lags behind the advances in manufacturing and this design productivity gap is still widening. One important reason is the lack of abstraction in traditional Hardware Description Languages (HDLs) like VHDL. The UML provides more abstract concepts for modeling behavior that can also be employed for hardware design. In particular, the new UML Activity semantics fit nicely with the inherent data flow in hardware systems. Therefore, we introduce a UML-based design approach for complete SoC specification. Our approach enables generation of complete synthesizable HDL code. The equivalent hardware can be automatically generated using the existing tools chains. As an example, we outline Handel-C code generation for an MP3 decoder design.},
  series = {LNCS},
  volume = {4199/2006}
}

@inproceedings{DBLP:conf/uml/PleussBSH05,
  author = {Andreas Pleu{\ss} AND Jan Van den Bergh AND Stefan Sauer AND Heinrich Hu{\ss}mann},
  title = {Workshop Report: Model Driven Development of Advanced User Interfaces (MDDAUI)},
  booktitle = {Satellite Events at the MoDELS 2005 Conference, MoDELS 2005 International Workshops, Doctoral Symposium, Educators Symposium, Revised Selected Papers, Montego Bay (Jamaica)},
  year = {2006},
  editor = {J. M. Bruel},
  pages = {182--190},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {This paper reports about the workshop Model Driven Development of Advanced User Interfaces (MDDAUI) which was held on October 2nd, 2005 at the MoDELS/UML 2005 conference in Montego Bay, Jamaica. We introduce the topic of the workshop and give an overview about the workshop's structure. Then we summarize the accepted contributions and finally we provide an overview about the workshop discussion and its results.It is intended to provide a follow-up event of this workshop in the next year.},
  series = {LNCS},
  volume = {3844}
}

@inproceedings{Schattkowsky2005d,
  author = {Tim Schattkowsky AND Alexander F{\"o}rster},
  title = {A Generic Component Framework for High Performance Locally Concurrent Computing Based on UML 2.0 Activities},
  booktitle = {Proceedings of the 12th IEEE International Conference and Workshops on the Engineering of Computer-Based Systems (ECBS 2005)},
  year = {2005},
  pages = {3--10},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {Software support for multiple hardware threads like the Pentium 4's hyperthreading technology or the upcoming multi-core desktop processors is required even for traditional single processor domains like home and office systems. Although the modeling of concurrent systems is already quite advanced, the current engineering practice usually does not yield highly concurrent applications without significant extra efforts due to several limitations of most methods for concurrent systems design. Unlike other methods, we consider the problem as a deployment problem where the software components need to be deployed on different multiple execution units depending on the system configuration. To overcome this, we present a component model and design approach based on the execution semantics of UML 2.0 Activities that enables the efficient design and construction of software applications with increased inherent concurrency and scalability for multi-processor platforms. The application of the approach and its benefits are demonstrated in a real world Web server example. },
  journal = {In Proc. 12th Annual IEEE International Conference and Workshop on the Engineering of Computer Based Systems (ECBS)}
}

@inproceedings{Belli2005,
  author = {Fevzi Belli AND Baris G{\"u}ldali},
  title = {A holistic approach to test-driven model checking},
  booktitle = {Proceedings of the conference on Innovations in Applied Artificial Intelligence and Expert Systems (IEA/AIE 2005), Bari (Italy)},
  year = {2005},
  pages = {321--331},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  note = {IEA/AIE'2005: Proceedings of the 18th international conference on Innovations in Applied Artificial Intelligence and Expert Systems},
  abstract = {Testing is the most common validation method in the software industry. It entails the execution of the software system in the real environment. Nevertheless, testing is a cost-intensive process. Because of its conceptual simplicity the combination of formal methods and test methods has been widely advocated. Model checking belongs to the promising candidates for this marriage. The present paper modifies and extends the existing approaches in that, after the test case generation, a model checking step supports the manual test process. Based on the holistic approach to specification-based construction of test suites, this paper proposes to generate test cases to cover both the specification model and its complement. This helps also to clearly differentiate the correct system outputs from the faulty ones as the test cases based on the specification are to succeed the test, and the ones based on the complement of the specification are to fail. Thus, the approach handles the oracle problem in an effective manner.},
  series = {LNCS}
}

@inproceedings{Schattkowsky2005e,
  author = {Tim Schattkowsky AND Wolfgang M{\"u}ller AND Achim Rettberg},
  title = {A Model-Based Approach for Executable Specifications on Reconfigurable Hardware},
  booktitle = {Proceedings of the conference on Design, Automation and Test in Europe (DATE 2005), Munich (Germany)},
  year = {2005},
  pages = {692--697},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {UML 2.0 provides a rich set of diagrams for systems documentation and specification. Much effort has been undertaken to employ different aspects of UML for multiple domains, mainly in the area of software systems. Considering the area of electronic design automation, however, we currently see only very few approaches which investigate UML for hardware design and hardware/software co-design. We present an approach for executable UML closing the gap from system specification to its model-based execution on reconfigurable hardware. For this purpose, we present our abstract execution platform (AEP), which is based on a virtual machine running an executable UML subset for embedded software and reconfigurable hardware. This subset combines UML 2.0 classes, state-machines and sequence diagrams for a complete system specification. We describe how these binary encoded UML specifications can be directly executed and give the implementation of such a virtual machine on a Virtex II FPGA. Finally, we present evaluation results comparing the AEP implementation with C code on a C167 microcontroller.},
  journal = {Design, Automation and Test in Europe, 2005. Proceedings}
}

@inproceedings{Schattkowsky05,
  author = {Tim Schattkowsky AND Wolfgang M{\"u}ller},
  title = {A UML Virtual Machine for Embedded Systems},
  booktitle = {Proceedings of the International Conference on Information Systems - New Generations (ISNG 2005), Las Vegas, NV (USA)},
  year = {2005},
  month = {April}
}

@inproceedings{Foerster2005,
  author = {Alexander F{\"o}rster AND Gregor Engels AND Tim Schattkowsky},
  title = {Activity Diagram Patterns for Modeling Quality Constraints in Business Processes},
  booktitle = {Proceedings of the 8th International Conference on Model Driven Engineering Languages and Systems (MoDELS 2005), Montego Bay (Jamaica)},
  year = {2005},
  editor = {L. C. Briand, C. Williams},
  pages = {2--16},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  series = {LNCS},
  volume = {3713}
}

@inproceedings{Guo2005,
  author = {Ping Guo AND Gregor Engels AND Reiko Heckel},
  title = {Architectural Style - Based Modeling and Simulation of Complex Software Systems},
  booktitle = {Proceedings of the 12th Asia-Pacific Software Engineering Conference (APSEC 2005), Taipei (Taiwan)},
  year = {2005},
  pages = {367--374},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {December},
  abstract = {The design and development of complex software systems is a difficult task, and it is not easy to ensure the quality of a developed software. The paper presents an architectural style-based approach to specifying and analyzing complex software systems. The approach is developed based on UML-like meta models and graph transformation techniques to support sound methodological principals, formal analysis and refinement. The approach is illustrated through the specification and simulation of architectural styles of mobile computing middleware, where three abstract levels of architectural styles are defined in order to decrease the complexity brought by mobility.}
}

@inproceedings{Engels2005d,
  author = {Gregor Engels AND Martin Erwig},
  title = {ClassSheets: automatic generation of spreadsheet applications from object-oriented specifications},
  booktitle = {Proceedings of the 20th IEEE/ACM International Conference on Automated Software Engineering (ASE 2005), Long Beach, CA (USA)},
  year = {2005},
  pages = {124--133},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {November},
  abstract = {Spreadsheets are widely used in all kinds of business applications.Numerous studies have shown that they contain manyerrors that sometimes have dramatic impacts. One reasonfor this situation is the low-level, cell-oriented developmentprocess of spreadsheets.We improve this process by introducing and formalizinga higher-level object-oriented model termed ClassSheet.While still following the tabular look-and-feel of spreadsheets,ClassSheets allow the developer to express explicitlybusiness object structures within a spreadsheet, whichis achieved by integrating concepts from the UML (UnifiedModeling Language). A stepwise automatic transformationprocess generates a spreadsheet application that is consistentwith the ClassSheet model. Thus, by deploying theformal underpinning of ClassSheets, a large variety of errorscan be prevented that occur in many existing spreadsheetapplications today.The presented ClassSheet approach links spreadsheet applicationsto the object-oriented modeling world and advocatesan automatic model-driven development process forspreadsheet applications of high quality.}
}

@inproceedings{Schattkowsky2005c,
  author = {Tim Schattkowsky},
  title = {Discovery and Routing in the HEN Heterogeneous Peer-to-Peer Network},
  booktitle = {Proceedings of the 4th International Conference on Networking (ICN 2005), Reunion Island (France)},
  year = {2005},
  editor = {P. Lorenz, P. Dini},
  pages = {653--661},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Network infrastructures are nowadays getting more and more complex as security considerations and technical needs like network address translation are blocking traffic and protocols in IP-based networks. Applications in such networks should transparently overcome these limitations. Examples for such applications range from simple chat clients to collaborative work environments spanning different enterprises with different heterogeneous network infrastructure and different security policies, e.g., different firewalls with different configurations. Overlay networks are a convenient way to overcome this problem. In many cases, diverse barriers like multiple facing firewalls would require significant user knowledge to establish a connection. Self-organizing peer-to-peer networks appear to be a convenient solution, but contemporary systems still have limitations in overcoming connectivity problems in heterogeneous networks. Thus, we introduce a self-organizing peer-to-peer infrastructure that overcomes these issues by transparently interconnecting networks with different protocols and address schemes.},
  series = {LNCS},
  volume = {3421}
}

@inproceedings{Mahajan2005,
  author = {Kiran Mahajan AND Christoph Laroque AND Wilhelm Dangelmaier AND Christian Soltenborn AND Michael Kortenjan AND Daniel Kuntze},
  title = {d$^{3}$FACT insight: A motion planning algorithm for material flow simulations in virtual environments},
  booktitle = {Proceedings of the conference on Simulation and Visualization (SimViS 2005), Magedeburg (Germany)},
  year = {2005},
  editor = {T Schulze, G. Horton, B. Preim, S. Schlechtweg},
  pages = {115--126},
  publisher = {SCS European Publishing House},
  address = {Erlangen},
  abstract = {Visualization has always played an important role in the analysis of material flow simulations. These days, commercial software is available to visualize such systems. Using these software, the user has to model and parameterize the simulation and finally view the simulation in a virtual environment. After analyzing the system, typically he might wish to carry out changes in the layout, parameters, etc of the simulation model which also includes determining new motion paths for objects like forklifts, automated guided vehicles, etc. This paper presents a motion planning algorithm which automatically determines the paths for such objects depending on the new model layout without colliding with other objects of the virtual factory. First the motivation is presented in a case study form to emphasize drawbacks of existing software. Then the algorithm is described on the highest level followed by details of the methodology. The paper concludes with future research and conclusions.},
  volume = {1}
}

@inproceedings{Lohmann2005,
  author = {Marc Lohmann AND Stefan Sauer AND Gregor Engels},
  title = {Executable Visual Contracts},
  booktitle = {Proceedings of the IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC 2005)},
  year = {2005},
  editor = {M. Erwig, A. Sch{\"u}rr},
  pages = {63--70},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {Design by Contract (DbC) is widely acknowledged to be a powerful technique for creating reliable software. DbC allows developers to specify the behavior of an operation precisely by pre- and post-conditions. Existing DbC approaches predominantly use textual representations of contracts to annotate the actual program code with assertions. In the Unified Modeling Language (UML), the textual Object Constraint Languages (OCL) supports the specification of pre- arid post-conditions by constraining the model elements that occur in UML diagrams. However; textual specifications in OCL can become complex and cumbersome, especially for software developers who are typically not used to OCL. In this paper, we propose to specify the pre- and post-conditions of an operation visually by a pair of UML object diagrams (visual Contract). We define a mapping of visual contracts into Java classes that are annotated with behavioral interface specifications in the Java Modeling Language (JML). The mapping supports testing the correctness of the implementation against the specification using JML tools, which include a runtime assertion checker. Thus we make the visual contracts executable.}
}

@inproceedings{Stoerrle05,
  author = {Harald St{\"o}rrle AND Jan Hendrik Hausmann},
  title = {Towards a Formal Semantics of UML 2.0 Activities},
  booktitle = {Software Engineering},
  year = {2005},
  editor = {P. Liggesmeyer, K. Pohl, M. Goedicke},
  pages = {117--128},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  abstract = {The new version 2.0 of the Unified Modeling Language (UML) was targetedat improving expressiveness and semantic precision. These developments areparticularly evident in activity diagrams which have not only acquired many new features,but a completely new metamodel and semantic foundation. The UML containssome hints that Petri-nets are the inspirational source for the new semantics. In thispaper we will investigate how strong the alignment of UML's activity diagrams toPetri-nets really is. We start by providing a mapping of the basic elements of activitydiagrams to Petri-nets and discuss the problems arising when trying to extend thisapproach to some of the advanced features of activity diagrams, namely exceptions,traverse-to-completion, and streaming. This examination raises several syntactic andsemantic questions concerning activities. We conclude that for basic activities, theanalogy works pretty well, but for higher-level constructs, no such intuitive connectionexists.},
  series = {Lecture Notes in Informatics},
  volume = {64}
}

@inproceedings{Schattkowsky2005b,
  author = {Tim Schattkowsky AND Wolfgang M{\"u}ller},
  title = {Transformation of UML StateMachines for Direct Execution},
  booktitle = {Proceedings of the IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC 2005), Dallas, TX (USA)},
  year = {2005},
  pages = {117--124},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {September },
  abstract = {Executable UML models are nowadays gaining interest in embedded systems design. This domain is strongly devoted to the modeling of reactive behavior using StateChart variants. In this context, the direct execution of UML State Machines is an interesting alternative to native code generation approaches since it significantly increases portability. However, fully featured UML 2.0 State Machines may contain a broad set of features with complex execution semantics that differ significantly from other StateChart variants. This makes their direct execution complex and inefficient. In this paper, we demonstrate how such State Machines can be represented using a small subset of the UML State Machine features that enables efficient execution. We describe the necessary model transformations in terms of graph transformations and discuss the underlying semantics and implications for execution. }
}

@inproceedings{Schattkowsky2005f,
  author = {Tim Schattkowsky},
  title = {UML 2.0 - Overview and Perspectives in SoC Design},
  booktitle = {Proceedings of the conference on Design, Automation and Test in Europe (DATE 2005), Munich (Germany)},
  year = {2005},
  pages = {832--833},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {The design productivity gap requires more efficient design methods. Software systems have faced the same challenge and seem to have mastered it with the introduction of more abstract design methods. The UML has become the standard for software systems modeling and thus the foundation of new design methods. Although the UML is defined as a general purpose modeling language, its application to hardware and hardware/software codesign is very limited. In order to successfully apply the UML in these fields, it is essential to understand its capabilities and to map it to a new domain.},
  volume = {2}
}

@inproceedings{Eden04,
  author = {Jonas Eden AND Matthias Weber AND Mark-Oliver Reiser AND Thomas Wierczoch AND Ulrich Freund AND Orazio Gurrieri AND Jochen K{\"u}ster AND Henrik L{\"o}nn AND J{\"o}rn Migge},
  title = {An Architecture Description Language for Developing Automotive ECU-Software},
  booktitle = {Proceedings of the 14th International Symposium and 4th European Systems Engineering Conference (INCOSE 2004), Toulouse (France)},
  year = {2004},
  pages = {101-112},
  month = {June},
  abstract = {The significance of embedded software systems in the automotive domain has increased dramatically during the last ten years. In contrast, today's development methods and tools applied in the automotive industry are limited in many ways. They are each restricted to certain stages of development and therefore several approaches need to be used simultaneously, they are not interoperable and most of them are not tailored to the specific needs of the automotive domain. In this paper we present an Architecture Description Language called EAST ADL that seeks to capture all information needed during development, from early analysis to implementation and evolution and meets specific automotive requirements such as support for automatic code generation in the context of common automotive hardware.}
}

@inproceedings{Heckel2004c,
  author = {Reiko Heckel AND Alexey Cherchago},
  title = {Application of Graph Transformation for Automating Web Service Discovery},
  booktitle = {Proceedings of the seminar on Language Engineering for Model-Driven Software Development (2003), Dagstuhl (Germany)},
  year = {2004},
  editor = {J. Bezivin, R. Heckel},
  publisher = {Internationales Begegnungs- und Forschungszentrum f{\"u}r Informatik (IBFI)},
  address = {Dagstuhl, Germany},
  month = {March},
  abstract = {The paper represents current achievements of an ongoing research that aims to develop a formal approach supporting an automatic selection of a Web service sought by a requestor. The approach is based on the matching the requestor's requirements for a "useful" service against the service description offered by the provider. We focus on the checking behavioral compatibility between operation contracts specifying pre-conditions and effects of required and provided operations. Graph transformation rules with positive application conditions are proposed as a visual formal notation for contracts. The desired dependence between requestor and provider contracts is determined by the semantic compatibility relation and syntactic matching procedure that is sound w.r.t. this relation. },
  series = {Dagstuhl Seminar Proceedings}
}

@inproceedings{Böttcher04,
  author = {Stefan B{\"o}ttcher AND Sven Groppe AND Tim Schattkowsky},
  title = {Automated Data and Service Mapping for Integrated Electronic Markets},
  booktitle = {Proceedings of the 8th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2004), Orlando, FL (USA)},
  year = {2004}
}

@inproceedings{Heckel2004,
  author = {Reiko Heckel AND Ping Guo},
  title = {Conceptual Modeling of Styles For Mobile Systems: A layered approach based on graph transformation},
  booktitle = {Proceedings of the conference on Mobile Information Systems (MOBIS 2004), Oslo (Norway)},
  year = {2004},
  editor = {E. Lawrence, B. Pernici, J. Krogstie},
  pages = {65--79},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {When designing a mobile application, we have to be aware of the properties and facilities of the target platform. At a conceptual level, this platform can be specified by a style, defining the structures and operations available to applications. In this paper, we use a UML-like meta model for the structural aspect and graph transformation rules over its instances to specify the dynamics of a style of mobile systems. The model is layered to separate clearly the software from the hardware and the geographic view of the system.},
  series = {IFIP - International Federation for Information Processing},
  volume = {158}
}

@inproceedings{Schattkowsky04,
  author = {Tim Schattkowsky},
  title = {Direct Execution of UML 2.0 Sequence Diagrams},
  booktitle = {Proceedings of the 10th International Conference on Information Systems Analysis and Synthesis (ISAS 2004), Orlando, FL (USA)},
  year = {2004},
  month = {August}
}

@inproceedings{Schattkowsky04-1,
  author = {Tim Schattkowsky},
  title = {Efficient Execution of UML State Machines on a Virtual Machine},
  booktitle = {Proceedings of the conference on Systemics, Cybernetics and Informatics (SCI 2004), Orlando, FL (USA)},
  year = {2004},
  month = {July},
  note = {Proc. 8th World Multi-Conference on Systemics, Cybernetics and Informatics, Orlando, FL, USA, 2004}
}

@inproceedings{Engels04,
  author = {Gregor Engels AND Stefan Sauer},
  title = {Guest Editors' Introduction},
  booktitle = {International Journal of Software Engineering and Knowledge Engineering (IJSEKE)},
  year = {2004},
  editor = {G. Engels, S. Sauer},
  pages = {543--544},
  publisher = {World Scientific Publishing},
  month = {December},
  volume = {14}
}

@inproceedings{Schattkowsky2004a,
  author = {Tim Schattkowsky AND Wolfgang M{\"u}ller},
  title = {Model-Based Design of Embedded Systems},
  booktitle = {Proceedings of the 7th IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (ISORC 2004), Vienna (Austria)},
  year = {2004},
  editor = {J. Gustafsson, T. Aoki, I. Lee},
  pages = {121--128},
  publisher = {IEEE Computer Society},
  address = {Los Alamitos, CA, USA},
  note = {12-14 May 2004}
}

@inproceedings{Hausmann2004,
  author = {Jan Hendrik Hausmann AND Reiko Heckel AND Marc Lohmann},
  title = {Model-based Discovery of Web Services},
  booktitle = {Proceedings of the IEEE International Conference on Web Services (ICWS 2004)},
  year = {2004},
  pages = {324--331},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {July},
  abstract = {Web Services are software components that can be discovered and employed at runtime using the Internet. Conflicting requirements towards the nature of these services can be identified. From a business perspective, Web Services promise to enable the formation of ad-hoc cooperation's on a global scale. From a technical perspective, a high degree of standardization and rigorous specifications are required to enable the automated integration of Web Services. A suitable technology for Web Services has to mediate these needs for flexibility and stability. In this paper, a new approach to the description of Web Service semantics is introduced. It is a visual approach based on the use of software models and graph transformations and allows for the description of innovative services while providing a precise matching concept. An implementation using current standards and tools is available.}
}

@inproceedings{Schattkowsky2004d,
  author = {Tim Schattkowsky AND Wolfgang M{\"u}ller},
  title = {Model-Based Specification and Execution of Embedded Real-Time Systems},
  booktitle = {Proceedings of the conference on Design Automation and Test in Europe (DATE 2004), Paris, France},
  year = {2004},
  pages = {1392--1393},
  publisher = {IEEE Computer Society},
  address = {Los Alamitos, CA, USA},
  month = {February },
  abstract = {This paper proposes a methodology for an executable UML 2.0 subset based on State Transition Diagrams (STDs) and Sequence Diagrams (SD) that covers interrupts, exceptions, and timeouts. In this a UML Virtual Machine (UVM) as the run-time environment for complete executable specifications based on that executable UML subset. Such specifications are compiled to binary programs consisting of data structures (STDs) and bytecode (SDs).},
  volume = {2}
}

@inproceedings{Guo2004,
  author = {Ping Guo AND Reiko Heckel},
  title = {Modeling and Simulation of Context-Aware Mobile Systems},
  booktitle = {Proceedings of the 19th IEEE international conference on Automated software engineering (ASE 2004)},
  year = {2004},
  pages = {430--433},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {This paper presents an approach for analysis, design and simulation of mobile systems. The approach is developed based on UML-like meta models and graph transformation techniques to support sound methodological principals, formal analysis and refinement. With conceptual and concrete level of modeling and simulation, the approach could support application development and the development of new mobile platforms.}
}

@inproceedings{Schattkowsky2004b,
  author = {Tim Schattkowsky AND Christoph Loeser AND Wolfgang M{\"u}ller},
  title = {Peer-To-Peer Technology for Interconnecting Web Services in Heterogeneous Networks},
  booktitle = {Proceedings of the 18th International Conference on Advanced Information Networking and Applications (AINA 2004), Fukuoka (Japan)},
  year = {2004},
  editor = {L. Barolli},
  pages = {611-616},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {April},
  abstract = {The interconnection of software components is a keyto enabling collaborative work. However, technologydifferences and security barriers like firewalls oftenhinder establishing collaborative infrastructures betweenenterprises or even within a single enterprise. Weintroduce a peer-to-peer based network infrastructurethat transparently overcomes these problems using relayand routing mechanisms as well as different underlyingtransport protocols. We discuss the application of thistechnology to interconnect Web Services. }
}

@inproceedings{Schattkowsky2004c,
  author = {Tim Schattkowsky AND Christoph Loeser AND Wolfgang M{\"u}ller},
  title = {Peer-to-Peer-based Web Services for Collaborative Engineering Environments},
  booktitle = {Proceedings of the International Conference on Networking (ICN 2004), Guadeloupe (France)},
  year = {2004},
  publisher = {IEEE Computer Society},
  address = {Los Alamitos, CA, USA},
  month = {March},
  abstract = {The Internet connects different enterprises to allow collaborative work, sharing of resources or just the integration of remotely supplied and possibly commercial services. However, different enterprises usually have different heterogeneous network infrastructure and different security policies, e.g., different firewalls with different configurations. The latter often imposes severe challenges to establish a real collaborative engineering infrastructure with distributed tool environments as well as secure exchange of design data and documents over different Intranets. We introduce ANTS (Advanced Network Transport Service) as a peer-to-peer based infrastructure, which can be applied to seamlessly integrate tools and interconnect them as Web Services in order to overcome connectivity problems between highly protected intranets. ANTS is supports relay and routing as well as different underlying transport protocols like TCP, HTTP(R) to transmit data across heterogeneous networks. The transport mechanism itself can be accessed as a Web Service using SOAP calls to the same server. This enables us to have a unified security solution for both the transport service and all other services hosted by the server. We currently apply in industrial projects to interconnect distributed design teams for secure exchange of design data and documents between different Intranets.}
}

@inproceedings{Guo2004a,
  author = {Ping Guo AND Reiko Heckel},
  title = {Simulation and Testing of Mobile Computing Systems using Fujaba},
  booktitle = {Proceedings of the 2nd International Fujaba Days (2004), Darmstadt (Germany)},
  year = {2004},
  address = {Darmstadt, Germany},
  month = {September},
  abstract = {The paper presents an approach for analysis, modeling and validation of mobile information systems with the tool support of Fujaba. The approach is developed based on UML-like meta models and graph transformation techniques to support sound methodological principals, normal analysis and refinement. With conceptual and concrete level of modeling and simulation, the approach could support application development and the development of new mobile platforms. The approach also provides automatic analysis, validation and behavior consistency check with the support of Fujaba.}
}

@inproceedings{Belli2004,
  author = {Fevzi Belli AND Baris G{\"u}ldali},
  title = {Software Testing via Model Checking},
  booktitle = {Proceedings of the conference on Computer and Information Sciences (ISCIS 2004), Kemer-Antalya (Turkey)},
  year = {2004},
  editor = {C. Aykanat, T. Dayar, I. Korpeoglu},
  pages = {907--916},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Testing is a necessary, but costly process for user-centric quality control. Moreover, testing is not comprehensive enough to completely detect faults. Many formal methods have been proposed to avoid the drawbacks of testing, e.g., model checking that can be automatically carried out. This paper presents an approach that (i) generates test cases from the specification and (ii) transfers the specification-oriented testing process to model checking. Thus, the approach combines the advantages of testing and model checking assuming the availability of (i) a model that specifies the expected, desirable system behavior as required by the user and (ii) a second model that describes the system behavior as observed. The first model is complemented in also specifying the undesirable system properties. The approach analyzes both these specification models to generate test cases that are then converted into temporal logic formulae to be model checked on the second model.},
  series = {LNCS},
  volume = {3280}
}

@inproceedings{Cherchago2004,
  author = {Alexey Cherchago AND Reiko Heckel},
  title = {Specification Matching of Web Services Using Conditional Graph Transformation Rules},
  booktitle = {Proceedings of the conference on Graph Transformation (ICGT 2004), Rome (Italy)},
  year = {2004},
  editor = {H.Ehrig, G. Engels, F. Parisi-Presicce, G. Rozenberg},
  pages = {304--318},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  note = {Graph Transformations},
  abstract = {The ability of applications to dynamically discover required services is a key problem for Web Services. However, this aspect is not adequately supported by current Web Services standards. It is our objective to develop a formal approach allowing the automation of the discovery process. The approach is based on the matching of requestors requirements for a useful service against service descriptions. In the present paper, we concentrate on behavioral compatibility. This amounts to check a relation between provided and required operations described via operation contracts. Graph transformation rules with positive and negative application conditions are proposed as a visual formal notation for contract specification. We establish the desired semantic relation between requestor and provider and prove the soundness and completeness of a syntactic notion of matching w.r.t. this relation.},
  series = {LNCS},
  volume = {3256 / 2004}
}

@inproceedings{Baresi2004,
  author = {Luciano Baresi AND Reiko Heckel AND Sebastian Th{\"o}ne AND D{'a}niel Varr{'o}},
  title = {Style-Based Refinement of Dynamic Software Architectures},
  booktitle = {Proceedings of the conference on Software Architecture (WICSA 2004), Oslo (Norway)},
  year = {2004},
  pages = {155--166},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  note = {12-15 June 2004},
  abstract = {In this paper, we address the correct refinement of abstract architectural models into more platformspecific representations. We consider the challenging case of dynamic architectures which can perform runtime reconfigurations. For this purpose, the underlying platform has to provide the necessary reconfiguration mechanisms. To conceptually model such platforms including provided reconfiguration mechanisms, we use architectural styles formalized by graph transformation rules. Based on formal refinement relations between abstract and platform-specific styles, we can then investigate how to realize business-specific scenarios on a certain platform by automatically deriving refined, platform-specific reconfiguration scenarios.}
}

@inproceedings{Schattkowsky03,
  author = {Tim Schattkowsky},
  title = {A Model-based Approach for Dynamic Tool Integration},
  booktitle = {Proceedings of the conference on Systemics, Cybernetics and Informatics (SCI 2003), Orlando, FL (USA)},
  year = {2003},
  month = {June },
  note = {In Proc. 7th Multi-Conference on Systemics, Cybernetics and Informatics}
}

@inproceedings{Kostienko2003,
  author = {Tomasz Kostienko AND Wolfgang M{\"u}ller AND Adam Pawlak AND Tim Schattkowsky},
  title = {An advanced infrastructure for collaborative engineering in electronic design automation},
  booktitle = {Proceedings of the 10th International Conference on Concurrent Engineering (ISPE CE 2003), Madeira, Portugal},
  year = {2003},
  pages = {703--710},
  publisher = {A. A. Balkema Publishers},
  month = {July },
  abstract = {Engineering collaboration gets its new global dimension with the omnipotent access to Internet.Engineers have severe requirements concerning: security of design data, quality of net connections, easiness of collaboration, etc. This article presents visions and middleware architecture to establish pan-European collaborative engineering infrastructure and its application in the field of Electronic Design Automation (EDA).We present a transparent infrastructure to engineers to enable their Internet-based collaboration during the design of complex electronic systems. In this context, we introduce an advanced collaborative infrastructure (ACI) for distance spanning, tool integration, and administration as well as open interfaces for XML-based data exchange. ACI constitutes a backbone for our collaborative research and engineering studies by fostering a combination of most recent plug-and-play technologies and secure, peer-to-peer data transfer with XMLbased tool integration. ACI and its deployments have been developed with the EU project E-Colleg (IST-1999-11746).}
}

@inproceedings{Kuster2003,
  author = {Jochen K{\"u}ster AND Gregor Engels},
  title = {Consistency Management within Model-Based Object-Oriented Development of Components},
  booktitle = {Proceedings of the conference on Formal Methods for Components and Objects (FMCO 2003), Leiden (Netherlands)},
  year = {2003},
  editor = {F. S. de Boer and M. M. Bonsangue and S. Graf and W. P. de Roever},
  pages = {157-176},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  abstract = {The Unified Modeling Language (UML) favors the construction of models composed of several submodels, modeling the system components under development at different levels of abstraction and from different viewpoints. Currently, consistency of object-oriented models expressed in the UML is not defined in the UML language specification. This allows the construction of inconsistent UML models. Defining consistency of UML models is complicated by the fact that UML models are applied differently, depending on the application domain and development process. As a consequence, a form of consistency management is required that allows the software engineer to define, establish and manage consistency, tailored specifically to the development context. In recent years, we have developed a general methodology and tool support to overcome this problem. The methodology is based on a thorough study of the notion of consistency and has led to a generic definition of the notion of consistency. Our methodology itself aims at a step-wise systematic construction of a consistency management process, by providing a number of activities to be performed by the software engineer. It is complemented by a tool called Consistency Workbench which supports the software engineer in performing the methodology. In this paper, we provide an overview and summary of our approach.},
  series = {LNCS},
  volume = {3188}
}

@inproceedings{KusterHE03,
  author = {Jochen K{\"u}ster AND Reiko Heckel AND Gregor Engels},
  title = {Defining and Validating Transformations of UML Models},
  booktitle = {Proceedings of the conference on Human Centric Computing Languages and Environments (HCC 2003), Auckland (New Zealand)},
  year = {2003},
  pages = {145--152},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {With the success of the UML, the ability of transforming models into programs or formal specifications becomes a key to automated code generation or verification in the software development process. In this paper, we describe a concept for specifying model transformations by means of graph transformation rules on the UML meta model. In order to validate the termination and uniqueness of such transformations, we derive a number of sufficient criteria from basic results of the theory of graph transformation. This ensures that the rules can be executed automatically while, at the same time, providing a high-level visual model of the transformation.}
}

@inproceedings{Mueller03,
  author = {Wolfgang Mueller AND Tim Schattkowsky AND Heinz-Josef Eikerling AND Jan Wegner},
  title = {Dynamic Tool Integration in Heterogeneous Computer Networks},
  booktitle = {Proceedings of the conference on Design Automation and Test in Europe (DATE 2003), Munich (Germany)},
  year = {2003},
  pages = {946-951},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {March},
  abstract = {Tool installation and automation of administrative tasks in heterogeneous computer networks becomes of increasing importance with the availability of complex heterogeneous computer networks. This article introduces a new approach for dynamic network tool management, i.e., TRMS. A variant of TRMS using SNMP - a well established standard for network administrationis outlined and illustrated by the application of the integration and management of design tools for Printed Circuit Boards (PCBs). }
}

@inproceedings{Engels2003d,
  author = {Gregor Engels AND Stefan Sauer AND Bettina Neu},
  title = {Integrating software engineering and user-centred design for multimedia software developments},
  booktitle = {Proceedings of the conference on Human-Centric Computing Languages and Environments (HCC 2003), Auckland (New Zealand)},
  year = {2003},
  pages = {254--256},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {October },
  abstract = {The object-oriented modeling of interactive multimedia applications in the OMMMA approach is designed to enable multimedia software developers to create comprehensive analysis and design models of multimedia software. For development of highly usable multimedia applications, this approach must be embedded in a more holistic development process that takes a user-oriented perspective on multimedia software development. In this paper, we elaborate on the differences between usercentred design activities and object-oriented software design activities and outline their integration in a comprehensive development process.}
}

@inproceedings{Engels2003c,
  author = {Gregor Engels AND Jochen K{\"u}ster AND Reiko Heckel AND Marc Lohmann},
  title = {Model Based Verification and Validation of Properties},
  booktitle = {Proceedings of the conference on Uniform Approaches to Graphical Process Specification Techniques (UNIGRA 2003, Satellite Event of the ETAPS 2003), Warsaw (Poland)},
  year = {2003},
  editor = {R. Bardohl, H. Ehrig},
  pages = {1--18},
  publisher = {Elsevier},
  month = {June},
  abstract = {One of the key issues in software development, like in all engineering problems, is to ensure that the product delivered meets its specification. Verification and validation are well-established techniques for ensuring the quality of a product within the overall software development lifecycle. With models being expressed in the Unified Modeling Language, the application of verification and validation is complicated. Firstly, concerning verification, a UML model is typically not the input language of a verification tool. Secondly, with regards to validation, a UML model is also not directly executable. In this paper, we show how verification and validation can be achieved for UML models. Within our approach, graph transformation techniques are applied for automated translation of UML models into a language understood by a verification tool or directly into an implementation. By the use of such semantic-preserving transformations, both verification and validation can be lifted up to the model level, allowing for a seamless integration of verification and validation into a UML-based development process.},
  series = {Electronic Notes in Theoretical Computer Science},
  volume = {82}
}

@inproceedings{HeVo2003,
  author = {Hendrik Voigt AND Reiko Heckel},
  title = {Model-Based Development of Executable Business Processes for Web Services},
  booktitle = {Proceedings of Lectures on Concurrency and Petri Nets, Advances in Petri Nets (ACPN 2003), Eichst{\"a}tt, Germany},
  year = {2003},
  editor = {J. Desel, W. Reisig, G. Rozenberg},
  pages = {559--584},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {September},
  abstract = {In order to implement business processes, the composition of simpler services provided by different independent participants requires a high degree of standardization and flexibility. For this purpose, platform-independent XML-based languages like the Business Process Execution Language for Web Services (BPEL4WS) are suitable. XML documents are in fact human readable, but in general they are hard to produce and to understand by business experts which are, however, most qualified for defining business processes. We present a model-based development method based on an intuitive and adequate modelling notation, an automatic transformation of process models to their XML-based encoding, and techniques to analyze processes. In this context the Unified Modeling Language (UML) as standard notation for modelling software, graph transformation as meta language for defining model transformations, and a semantic interpretation of process models in terms of Communicating Sequential Processes (CSP) are used.},
  volume = {3098}
}

@inproceedings{Heckel2003e,
  author = {Reiko Heckel AND Marc Lohmann},
  title = {Model-Based Development of Web Applications Using Graphical Reaction Rules},
  booktitle = {Proceedings of the 6th International Conference on Fundamental Approaches to Software Engineering (FASE 2003), Warsaw (Poland)},
  year = {2003},
  editor = {M. Pezz{'e}},
  pages = {170--183},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {The OMG's Model-Driven Architecture focusses on the evolution and integration of applications across heterogeneous middleware platforms. Presently available instances of this idea are mostly limited to static models. We propose a model-driven approach to the development of web-enabled applications, seen as reactive information systems on an HTTP-based communication platform, which covers both static and dynamic aspects. To support the separate change of both platform and functionality we separate at model and implementation level the platform-independent application logic from classes specific to technologies like HTML or SOAP. We discuss a notion of consistency between models at different abstraction levels based on a concept of graphical reaction rules, i.e., graph transformation rules which integrate data state transformation and reactive behavior.},
  series = {LNCS},
  volume = {2621}
}

@inproceedings{Baresi2003,
  author = {Luciano Baresi AND Reiko Heckel AND Sebastian Th{\"o}ne AND D{'a}niel Varr{'o}},
  title = {Modeling and validation of service-oriented architectures: application vs. style},
  booktitle = {Proceedings of the European Software Engineering Conference and ACM SIGSOFT Symposium on the Foundations of Software Engineering (ESEC/FSE 2003), Helsinki (Finland)},
  year = {2003},
  pages = {68--77},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {September},
  abstract = {Most applications developed today rely on a given middleware platform which governs the interaction between components, the access to resources, etc. To decide, which platform is suitable for a given application (or more generally, to understand the interaction between application and platform), we propose UML models of both the architectural style of the platform and the application scenario. Based on a formal interpretation of these as graphs and graph transformation systems, we are able to validate the consistency between platform and application. We exemplify the approach for platforms realizing the service-oriented architectural style and a supply chain management system as application scenario. Besides, we demonstrate the potential of model checking for graph transformation systems for answering the above consistency question.}
}

@inproceedings{Alfert2003,
  author = {Klaus Alfert AND Ernst-Erich Doberkat AND Gregor Engels AND Marc Lohmann AND Johannes Magenheim AND Andy Sch{\"u}rr},
  title = {MuSofT: Multimedia in der Softwaretechnik},
  booktitle = {Proceedings of the conference on Software Engineering im Unterricht der Hochschulen (SEUH 2003), Berlin (Germany)},
  year = {2003},
  editor = {J. Siedersleben, D. Weber-Wulff},
  pages = {70--80},
  publisher = {dpunkt Verlag},
  address = {Heidelberg},
  month = {February},
  note = {SEUH 8 - Software Engineering im Unterricht der Hochschulen, Berlin 2003},
  abstract = {Im BMBF-Verbundprojekt MuSofT werden multimediale Lehrmaterialien f{\"u}r die Lehre der Softwaretechnik entwickelt. In diesem Papier stellen wir die Bem{\"u}hungen innerhalb von MuSofT vor, eine qualitativ hochwertige und nachhaltige Entwicklung von Lernobjekten zu realisieren. Wir legen den Fo-kus dabei auf die didaktischen Grundannahmen, die inhaltliche und stilisti-sche Abstimmung zwischen den Materialien sowie die gleichf{\"o}rmige Be-schreibung der Materialien durch Metadaten, die eine effektive Recherche des Materials innerhalb des MuSofT-Portals erm{\"o}glichen.}
}

@inproceedings{Engels03,
  author = {Gregor Engels AND Klaus Alfert AND Ernst-Erich Doberkat},
  title = {MuSofT: Multimedia in der SoftwareTechnik},
  booktitle = {Proceeding of the 1. e-Learning Fachtagung Informatik (DeLFI 2003), Garching bei M{\"u}nchen (Germany)},
  year = {2003},
  editor = {A. Bode, J. Desel, S. Ratmayer, M. Wessner},
  pages = {115-119},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  month = {September },
  series = {Lecture Notes in Informatics},
  volume = {37}
}

@inproceedings{Lohmann2003,
  author = {Marc Lohmann AND Stefan Sauer AND Tim Schattkowsky},
  title = {ProGUM-Web: Tool Support for Model-Based Development of Web Applications},
  booktitle = {Proceedings of the 6th International Conference on the Unified Modeling Language (UML 2003), San Francisco, CA (USA)},
  year = {2003},
  editor = {P. Stevens, J. Whittle, G. Booch},
  pages = {101--105},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {ProGUM-Web is a tool that supports model-based development of Web applications using an extension of UML. It accounts for the characteristics of Web applications and their specific development. Code templates are generated from the model for both graphic designers and software developers. These code templates can iteratively and independently be advanced and are re-integrated within ProGUM-Web. Prototypes of Web applications can automatically be generated throughout the development.},
  series = {LNCS},
  volume = {2863}
}

@inproceedings{Engels2003b,
  author = {Gregor Engels AND Reiko Heckel AND Jochen K{\"u}ster},
  title = {The Consistency Workbench: A Tool for Consistency Management in UML-based Development},
  booktitle = {Proceedings of the 6th International Conference on The Unified Modeling Language: Modeling Languages and Applications (UML 2003), San Francisco, CA (USA)},
  year = {2003},
  editor = {P. Stevens, J. Whittle, G. Booch},
  pages = {356--359},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {With the Unified Modeling Language becoming applied indiverse contexts, the ability of defining and checking customized consistencyconditions is gaining increasing importance. In this paper, weintroduce the Consistency Workbench for defining and establishing consistencyin a UML-based development process.},
  series = {LNCS},
  volume = {2863}
}

@inproceedings{HKTV03,
  author = {Reiko Heckel AND Jochen K{\"u}ster AND Sebastian Th{\"o}ne AND Hendrik Voigt},
  title = {Towards Consistency of Web Service Architectures},
  booktitle = {Proceedings of the 7th World Multiconference on Systemics, Cybernetics, and Informatics (SCI 2003), Orlando, FL (USA)},
  year = {2003},
  month = {July},
  abstract = {Web services are self-descriptive software components which can automatically be discovered and engaged, together with other web components, to complete tasks over the Internet. The integration of Web services entails consistency problems which can best be solved at the level of models. In this paper, we discuss an approach to model-based consistency management for component-based architectures and its application to Web service architectures.}
}

@inproceedings{Hausmann2003,
  author = {Jan Hendrik Hausmann AND Stuart Kent},
  title = {Visualizing model mappings in UML},
  booktitle = {Proceedings of the ACM symposium on Software visualization (SOFTVIS 2003), San Diego, CA (USA)},
  year = {2003},
  pages = {169--178},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  abstract = {software development, it is essential that these mappings are defined precisely and automated as far as possible: they form the basis for generation of code and other models from a model, for reconciliation and management of consistency between models, and even for the definition of modeling languages themselves. A standard way of defining software modeling languages is metamodeling, which involves the construction of an object model of the syntax and, optionally, semantics of the language, using the diagrammatic syntax of the Unified Modeling Language (UML). This paper proposes an extension to UML for expressing mappings between models using diagrams, and illustrates how the extension can be used in metamodeling. The extension is inspired by mathematical relations and corrects a deficiency in the concept of association in class diagrams. The notation of object diagrams is also extended to allow particular instances of a relation to be presented.}
}

@inproceedings{Heckel02,
  author = {Reiko Heckel AND Mourad Chouikha},
  title = {Compositional Control Synthesis for Discrete Event Systems: An Approach based on Open Petri Nets},
  booktitle = {Proceedings of the conference on Integrated Design \& Process Technology (IDPT 2002), Pasadena, CA (USA)},
  year = {2002},
  pages = {63-77},
  publisher = {Society of Design and Process Science},
  address = {Grandview, TX, USA},
  month = {June},
  note = {Sixth World Conference on Integrated Design \& Process Technology (IDPT 2002)},
  abstract = {Open nets are place-transition Petri nets with interfaces, which support a notion of composition and a corresponding compositional interpretation of the concurrent behaviour of nets. The control synthesis problem of generating a controller for a given plant from an abstract specification of the controller's behaviour can be formulated in terms of open nets bymodelling the plant as an open net whose interfaces correspond to the sensors and actuators of the controller and specifying the desired behaviour as a set of processes for this net. Then, the problem consists in synthesising a controller net which, when composed with the net modelling the plant, leads to the specified restriction of the plant's processes.Based on this observation, which provides an abstraction of the actual synthesis algorithm, we study the problem of generating controllers consisting of several components. In particular, we analyse requirements for the logic used for specifying the controller in order to allow for a compositional, component-wise synthesis.}
}

@inproceedings{Heckel2002,
  author = {Reiko Heckel AND Jochen K{\"u}ster AND Gabriele Taentzer},
  title = {Confluence of Typed Attributed Graph Transformation Systems},
  booktitle = {Proceedings of the First International Conference on Graph Transformation (ICGT 2002), Barcelona (Spain)},
  year = {2002},
  editor = {A. Corradini, H.-J. Kreowski},
  pages = {161--176},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October },
  abstract = {The issue of confluence is of major importance for the successful application of attributed graph transformation, such as automated translation of UML models into semantic domains. Whereas termination is undecidable in general and must be established by carefully designing the rules, local confluence can be shown for term rewriting and graph rewriting using the concept of critical pairs. In this paper, we discuss typed attributed graph transformation using a new simplified notion of attribution. For this kind of attributed graph transformation systems we establish a definition of critical pairs and prove a critical pair lemma, stating that local confluence follows from confluence of all critical pairs.}
}

@inproceedings{Engels02a,
  author = {Gregor Engels AND Reiko Heckel AND Jochen K{\"u}ster AND Luuk Groenewegen},
  title = {Consistency-Preserving Model Evolution through Transformations},
  booktitle = {Proceedings of the 5th International Conference on The Unified Modeling Language (UML 2002), Dresden (Germany)},
  year = {2002},
  editor = {J.-M. J{'e}z{'e}quel, H. Hussmann, S. Cook},
  pages = {212--226},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {Oktober},
  series = {LNCS},
  volume = {2460}
}

@inproceedings{Engels2002e,
  author = {Gregor Engels AND Jochen K{\"u}ster AND Luuk Groenewegen},
  title = {Consistent Interaction Of Software Components},
  booktitle = {Proceedings of the conference on Integrated Design and Process Technology (IDPT 2002), Pasadena, CA (USA)},
  year = {2002},
  pages = {2--22},
  publisher = {IOS Press},
  month = {June },
  abstract = {Constructing complex software systems by integrating different software components is a promising and challenging approach. With the functionality of software components given by models it is possible to ensure consistency of such models before implementation in order to successfully build the system. Models consisting of different submodels, the absence of an overall formal semantics and the numerous possibilities of employing models requires the development of techniques ensuring the consistency. In this paper, we discuss the issue of consistency of models made up of different submodels proposing a concept for the management of consistency. Consistency management relies on a consistency concept and a process for ensuring consistency of models. We introduce a consistency concept for software components modeled in the Unified Modeling Language (UML) and devise suitable consistency checks. On this basis, we propose a process how to locate and resolve inconsistencies, thus ensuring the consistency of models and by that the consistency of component-based systems derived from those models.},
  journal = {Journal of Integrated Design \& Process Science},
  volume = {6}
}

@inproceedings{Hausmann2002,
  author = {Jan Hendrik Hausmann AND Reiko Heckel AND Gabriele Taentzer},
  title = {Detecting conflicting functional requirements in a use case driven approach: A static analysis technique based on graph transformation},
  booktitle = {Proceedings of the 24th International Conference on Software Engineering (ICSE 2002), Orlando, FL (USA)},
  year = {2002},
  pages = {105--155 },
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {Mai},
  abstract = {In object-oriented software development, requirements of different stakeholders are often manifested in use case models which complement the static domain model by dynamic and functional requirements. In the course of development, these requirements are analyzed and integrated to produce a consistent overall requirements specification. Iterations of the model may be triggered by conflicts between requirements of different parties.However, due to the diversity, incompleteness, and informal nature, in particular of functional and dynamic requirements, such conflicts are difficult to find. Formal approaches to requirements engineering, often based on logic, attack these problems, but require highly specialized experts to write and reason about such specifications.In this paper, we propose a formal interpretation of use case models consisting of UML use case, activity, and collaboration diagrams. The formalization, which is based on concepts from the theory of graph transformation, allows to make precise the notions of conflict and dependency between functional requirements expressed by different use cases. Then, use case models can be statically analyzed, and conflicts or dependencies detected by the analysis can be communicated to the modeler by annotating the model.An implementation of the static analysis within a graph transformation tool is presented.}
}

@inproceedings{Tchertchago2002,
  author = {Alexey Cherchago},
  title = {Formal Semantics for a UML fragment using UML/OCL metamodeling},
  booktitle = {Proceedings of the 6th IASTED International Conference on Software Engineering and Applications (SEA 2002), Cambridge, MA (USA)},
  year = {2002},
  publisher = {ACTA Press},
  abstract = {This paper studies the definition of formal semantics for a fragment of the Unified Modeling Language (UML) that covers some static and dynamic UML concepts. The idea of the considered methodological approach is based on the formalization of an information system in order to use this model as a semantic reference structure. Metamodels for abstract syntax and a set of constraints for static semantics of metaclasses are provided for this fragment. The development of an integrated model enables to incorporate metamodels for class and statechart diagrams with semantic reference model and, thus, to determine semantic relationship between them. We use the Object Constraint Language (OCL) as an expression language to describe a set of well-formedness rules and semantic constraints for considered models. Practical experiments with the USE tool are carried out to analyse and justify constraints.}
}

@inproceedings{Gyapay2002,
  author = {Szilvia Gyapay AND Reiko Heckel AND D{'a}niel Varr{'o}},
  title = {Graph Transformation with Time: Causality and Logical Clocks},
  booktitle = {Proceedings of the First International Conference on Graph Transformation (ICGT 2002), Barcelona (Spain)},
  year = {2002},
  editor = {A. Corradini, H.-J. Kreowski},
  pages = {120--134},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  abstract = {Following TER nets, an approach to the modelling of time in high-level Petri nets, we propose a model of time within (attributed) graph transformation systems where logical clocks are represented as distinguished node attributes. Corresponding axioms for the time model in TER nets are generalised to graph transformation systems and semantic variations are discussed. They are summarised by a general theorem ensuring the consistency of temporal order and casual dependencies. The resulting notions of typed graph transformation with time specialise the algebraic doublepushout (DPO) approach to typed graph transformation. In particular, the concurrency theory of the DPO approach can be used in the transfer of the basic theory of TER nets. 1.},
  series = {LNCS},
  volume = {2505}
}

@inproceedings{Mehner2002,
  author = {Katharina Mehner},
  title = {JaVis: A UML-Based Visualization and Debugging Environment for Concurrent Java Programs},
  booktitle = {Proceedings of the International Seminar on Software Visualization, Dagstuhl (Germany)},
  year = {2002},
  editor = {S. Diehl},
  pages = {163--175},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {May },
  abstract = {Debugging concurrent Java programs is a difficult task because of multiple control flows and inherent nondeterminism. It requires techniques not provided by traditional debuggers such as tracing, visualization, and automated error analysis. Therefore, we have developed the JaVis environment for visualizing and debugging concurrent Java programs. The information about a running program is collected by tracing. The Unified Modeling Language (UML) is used for the visualization of traces. Traces are automatically analyzed for deadlocks. The tracingis implemented usingthe Java Debug Interface (JDI) of the Java Platform Debugger Architecture. The visualization is integrated into the UML CASE tool Together.},
  series = {LNCS},
  volume = {2269}
}

@inproceedings{Depke2002,
  author = {Ralph Depke AND Gregor Engels AND Matthew Langham AND Bj{\"o}rn L{\"u}tkemeier AND Sebastian Th{\"o}ne},
  title = {Process-Oriented, Consistent Integration of Software Components},
  booktitle = {Proceedings of the conference on Prolonging Software Life: Development and Redevelopment (COMPSAC 2002), Oxford (England)},
  year = {2002},
  pages = {13--18},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {August},
  note = {COMPSAC '02: Proceedings of the 26th International Computer Software and Applications Conference on Prolonging Software Life: Development and Redevelopment},
  abstract = {The integration of software components becomes a more and more important issue in software engineering. Process-oriented approaches should provide automated information processes. Therefore, the software components have to be integrated in a consistent way, i.e., their export interfaces have to be respected by the importing components. Furthermore, the type system of component interfaces has to support a tunable degree of freedom. This allows the insertion of components with interfaces of restricted but sufficient degree of compatibility. In this paper, we develop a concept for consistent and flexible integration of components. We present a process modeling language that combines UML and XML in order to support consistent, flexible, and executable processes. Finally, we provide a formalization of the proposed component type system.}
}

@inproceedings{Schattkowsky2002,
  author = {Tim Schattkowsky AND Marc Lohmann},
  title = {Rapid Development of Modular Dynamic Web Sites Using UML},
  booktitle = {Proceedings of the 5th International Conference on The Unified Modeling Language (UML 2002), Dresden (Germany)},
  year = {2002},
  pages = {336--350},
  publisher = {Springer},
  address = {London, UK},
  abstract = {Development of dynamic Web sites is often performed by teams consisting of graphic designers and software developers. Communication between these different team members has to be supported with a simple modeling approach that considers their different academical backgrounds. Dynamic Web sites can contain multiple modules that may reappear on different pages. Reuse of both business logic and visual design modules would be desirable. Furthermore, a considerable amount of time is usually consumed by the implementation of data flows that are already defined in the model. Rapid development is enabled by providing roundtrip engineering capabilities with support for automatic code generation. We propose a simple subset of the UML adapted to the problem domain by means of stereotypes as well as a strategy for generating code templates from such models. These templates are tailored to the tasks of each team member. This enables parallel work and automated reintegration of results.},
  series = {LNCS}
}

@inproceedings{Engels2002f,
  author = {Gregor Engels AND Jan Hendrik Hausmann AND Reiko Heckel AND Stefan Sauer},
  title = {Testing the Consistency of Dynamic UML Diagrams},
  booktitle = {Proceedings of the Sixth International Conference on Integrated Design and Process Technology (IDPT 2002), Pasadena, CA (USA)},
  year = {2002},
  month = {June},
  note = {Pasadena, CA, USA}
}

@inproceedings{Baresi2002,
  author = {Luciano Baresi AND Reiko Heckel},
  title = {Tutorial Introduction to Graph Transformation: A Software Engineering Perspective},
  booktitle = {Proceedings of the 1st International Conference on Graph Transformation (ICGT 2002), Barcelona (Spain)},
  year = {2002},
  editor = {A. Corradini, H. Ehrig, H.-J. Kreowski, G. Rozenberg},
  pages = {402--429},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October },
  series = {LNCS},
  volume = {2505}
}

@inproceedings{EngelsKGH2001b,
  author = {Gregor Engels AND Jochen K{\"u}ster AND Luuk Groenewegen AND Reiko Heckel},
  title = {A methodology for specifying and analyzing consistency of object-oriented behavioral models},
  booktitle = {Proceedings of the 8th European Software Engineering Conference (ESEC 2001) and 9th ACM SIGSOFT Symposium on the Foundations of Software Engineering (FSE-9), Vienna (Austria)},
  year = {2001},
  editor = {V. Gruhn},
  pages = {186--195},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {September },
  abstract = {Object-oriented modeling favors the modeling of object behavior from different viewpoints and the successive refinement of behavioral models in the development process. This gives rise to consistency problems of behavioral models. The absence of a formal semantics for UML models and the numerous possibilities of employing behavioral models within the development process lead to the rise of a number of different consistency notions. In this paper, w e discuss the issue of consistency of behavioral models in the UML and present a general methodology how consistency problems can be dealt with. According to the methodology, those aspects of the models relevant to the consistency are mapped to a semantic domain in which precise consistency tests can be formulated. The choice of the semantic domain and the definition of consistency conditions can be used to construct different consistency notions. We show the applicability of our methodology by giving an example of a concrete consistency problem of concurrent object-oriented models.},
  volume = {26}
}

@inproceedings{Baldan2001,
  author = {Paolo Baldan AND Andrea Corradini AND Hartmut Ehrig AND Reiko Heckel},
  title = {Compositional Modeling of Reactive Systems Using Open Nets},
  booktitle = {Proceedings of the conference on Concurrency Theory (CONCUR 2001), Aalborg (Denmark)},
  year = {2001},
  editor = {K. G. Larsen, M. Nielsen},
  pages = {502--518},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {August },
  abstract = {In order to model the behaviour of open concurrent systems by means of Petri nets, we introduce open Petri nets, a generalization of the ordinary model where some places, designated as open, represent an interface of the system towards the environment. Besides generalizing the token game to reflect this extension, we define a truly concurrent semantics for open nets by extending the Goltz-Reisig process semantics of Petri nets.We introduce a composition operation over open nets, characterized as a pushout in the corresponding category, suitable to model both interaction through open places and synchronization of transitions. The process semantics is shown to be compositional with respect to such composition operation. Technically, our result is similar to the amalgamation theorem for data-types in the framework of algebraic specifications. A possible application field of the proposed constructions and results is the modeling of interorganizational workflows, recently studied in the literature. This is illustrated by a running example.},
  series = {LNCS},
  volume = {2154}
}

@inproceedings{Kuster2001,
  author = {Jochen K{\"u}ster AND Joachim Stroop},
  title = {Consistent Design of Embedded Real-Time Systems with UML-RT},
  booktitle = {Proceedings of the conference on Object-Oriented Real-Time Distributed Computing (ISORC 2001), Magdeburg (Germany)},
  year = {2001},
  pages = {31-40},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {May},
  abstract = {Modeling embedded real-time systems consisting of different components with UML-RT leads to a design model using various diagrams. Sequence diagrams describe possible interactions between system components and may be annotated with specific real-time constraints. Statechart diagrams are used for describing each component's behavior. In order to be able to get a consistent model, a consistency concept for different diagram types is needed that takes into account real-time constraints. In this paper, a consistency concept for sequence diagrams and state-chart diagrams is presented which focuses on the establishment of timing constraints. Our consistency concept distinguishes between syntactical, semantic and real-time consistency and takes into account the influence of processor allocation and scheduling. Using the consistency concept we describe a method for ensuring the consistency based on worst case execution time analysis of statecharts and schedulability analysis of tasks, thereby enabling a precise answer of the question of consistency.}
}

@inproceedings{HE01,
  author = {Reiko Heckel AND Gregor Engels},
  title = {Graph Transformation as a Meta Language for Dynamic Modeling and Model Evolution},
  booktitle = {Proceeding of International Special Session on Formal Foundations of Software Evolution (FFSE 2001, co-located with the Conference on Software Maintenance and Reengineering), Lisbon (Portugal)},
  year = {2001},
  editor = {T. Mens, M. Wermelinger},
  pages = {42-47},
  publisher = {Universidade Nova de Lisboa},
  address = {Lisbon}
}

@inproceedings{Depke2001,
  author = {Ralph Depke AND Reiko Heckel AND Jochen K{\"u}ster},
  title = {Improving the Agent-Oriented Modeling Process with Roles},
  booktitle = {Proceedings of the Fifth International Conference on Autonomous Agents (AGENTS 2001), Montreal (Canada)},
  year = {2001},
  pages = {640-647},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {Juni},
  abstract = {The agent-oriented modeling process is divided in a typicalsequence of activities, i.e., requirements specification,analysis, and design. The requirements are specified by descriptionsof the system's functionality and by exemplaryscenarios of essential interactions. In analysis the system'sstructure is captured and mandatory behavior of agents isprescribed. The design model describes system behavior bymeans of local operations. The problem arises how the transitionbetween these different stages of the modeling processcan be performed. In this paper, we introduce a conceptof roles in order to support the transition in a systematicway and thereby improving the agent-oriented modeling process.}
}

@inproceedings{Depke01,
  author = {Ralph Depke AND Reiko Heckel},
  title = {Modellierung von Prozessen mit UML und Realisierung durch eine Internet-Agentenplattform},
  booktitle = {Proceedings of the 9. Kolloquium Software-Entwicklung f{\"u}r Internet und Intranet, Ostfildern (Germany)},
  year = {2001},
  publisher = {Technische Akademie Esslingen},
  month = {September},
  abstract = {Workflow management systems provide a facility to execute processes, i.e., workflows by interpretation of process descriptions. The use of process descriptions allows the flexible specification of behavior in a problem oriented way. A system can evolve by just changing the process descriptions. These characteristics are useful not only for workflow management systems but also for general information systems. It has been shown that the activity diagrams of theUnified Modeling Language (UML) can be used for process or workflow descriptions. In a recent project, activity diagrams have been used for specifying complete workflow models that are executed within an agent based workflow management system. Software agents provide advantages that make them useful for the realization of workflow management systems. Such an agent based workflow execution platform has been developed by use of present technology for web information systems. Especially, the eXtensible Markup Language (XML) has been used extensively because it is flexible and it is inherently able to homogenize different kinds of data processing activities within a system.}
}

@inproceedings{Hec01,
  author = {Reiko Heckel},
  title = {Open Petri Nets as Semantic Model for Business Process Integration},
  booktitle = {Proceedings of the 2nd International Colloquium on Petri Net Technologies for Modelling Communication Based Systems},
  year = {2001},
  editor = {H. Ehrig, W. Reisig, H. Weber},
  pages = {129--134},
  publisher = {DFG Research Group "Petri Net Technology"},
  month = {September},
  abstract = {One important application of Petri nets is thespecification of workflows. Such a specification is needed, for example, when interoperability of theworkflows is an issue, which is frequently the case when business processes of different organizations shall be integrated.A workflow net is a Petri netsatisfying some structural constraints, like the existence of one initial and one final place, and a corresponding soundness condition.An interorganizational workflow is modeled as a set of such workflow nets connected through additional places for asynchronous communication and synchronization requirements on transitions.In this contribution we interpret an interorganizational workflow as acomposition of open nets. This allows us to project processes of the overall net to open processes of the local nets and,vice versa, to deduce the globalbehavior from the behavior of the components.Such a compositional uunderstanding of workflows can be used to simulate and test local workflow nets in an unknown environment, and it provides the semantic justification for reusable components.}
}

@inproceedings{Lütkemeier01,
  author = {Bj{\"o}rn L{\"u}tkemeier AND Sebastian Th{\"o}ne},
  title = {Prozessorientierte Integration von Softwarekomponenten durch XML-basierte Workflow-Modelle},
  booktitle = {Proceedings of the Fachwissenschaftlicher Informatik-Kongress (Informatiktage 2001), Bad Schussenried (Germany)},
  year = {2001},
  publisher = {Konradin-Verlag},
  month = {November}
}

@inproceedings{Engels2001a,
  author = {Gregor Engels AND Reiko Heckel AND Jochen K{\"u}ster},
  title = {Rule-Based Specification of Behavioral Consistency Based on the UML Meta-model},
  booktitle = {Proceedings of the conference on The Unified Modeling Language, Modeling Languages, Concepts, and Tools (UML 2001), Toronto (Canada)},
  year = {2001},
  editor = {M. Gogolla, C. Kobryn},
  pages = {272--287},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  abstract = {Object-oriented modeling favors the modeling of object behavior from different viewpoints and at different levels of abstraction. This gives rise to consistency problems between overlapping or semantically related submodels.The absence of a formal semantics for the UML and the numerous ways of employing the language within the development process lead to a number of different consistency notions. Therefore, general meta-level techniques are required for specifying, analyzing, and communicating consistency constraints. In this paper, we discuss theissue of consistency of behavioral models in the UML and present techniques for specifying and analyzing consistency. Using meta-model rules we transform elements of UML models into a semantic domain. Then, consistency constraints can by specified and validated using the language and the tools of the semantic domain. This general methodology is exemplified by the problem of protocol statechart inheritance.},
  volume = {2185}
}

@inproceedings{Heckel2001b,
  author = {Reiko Heckel AND Stefan Sauer},
  title = {Strengthening UML Collaboration Diagrams by State Transformations},
  booktitle = {Proceedings of the 4th International Conference on Fundamental Approaches to Software Engineering (FASE 2001), Genova (Italy)},
  year = {2001},
  editor = {H. Humann},
  pages = {109--123},
  publisher = {Springer},
  address = {London, UK},
  month = {April},
  abstract = {Collaboration diagrams as described in the official UML documents specify patterns of system structure and interaction. In this paper, we propose their use for specifying, in addition, pre/postconditions and state transformations of operations and scenarios. This conceptual idea is formalized by means of graph transformation systems and graph process, thereby integrating the state transformation with the structural and the interaction aspect.},
  series = {LNCS},
  volume = {2029}
}

@inproceedings{Kuester01,
  author = {Jochen K{\"u}ster},
  title = {Towards Behavior Consistent Modeling in UML-RT},
  booktitle = {Proceedings of the Forum on Design Languages (FDL'01)},
  year = {2001},
  address = {Lyon, France},
  month = {September}
}

@inproceedings{Hausmann2001,
  author = {Jan Hendrik Hausmann AND Reiko Heckel AND Stefan Sauer},
  title = {Towards Dynamic Meta Modeling of UML Extensions: An Extensible Semantics for UML Sequence Diagrams},
  booktitle = {Proceedings of the IEEE Symposia on Human Centric Computing Languages and Environments (HCC 2001), Stresa (Italy)},
  year = {2001},
  pages = {80--87},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {September},
  abstract = {The Unified Modeling Language (UML) still lacks a formal and commonly agreed specification of its semantics that also accounts for UML's built-in semantic variation points and extension mechanisms. The semantics specification of such extensions must be formally integrated and consistent with the standard UML semantics without changing the latter. Feasible semantics approaches must thus allow advanced UML modelers to define domain-specific language extensions in a precise, yet usable manner. We have proposed dynamic meta modeling for specifying operational semantics of UML behavioral diagrams based on UML collaboration diagrams that are interpreted as graph transformation rules. Herein we show how this approach can be advanced to specify the semantics of UML extensions. As a case study we specify the operational semantics of UML sequence diagrams and extend this specification to include features for modeling multimedia applications.}
}

@inproceedings{Flake2001,
  author = {Christian Geiger AND Stephan Flake AND Jochen K{\"u}ster},
  title = {Towards UML-based Analysis and Design of Multi-Agent Systems},
  booktitle = {Proceedings of International NAISO Symposium on Information Science Innovations in Engineering of Natural and Artificial Intelligent Systems (ENAIS 2001), Dubai (United Arab Emirates)},
  year = {2001}
}

@inproceedings{Sauer2001,
  author = {Stefan Sauer AND Gregor Engels},
  title = {UML-based Behavior Specification of Interactive Multimedia Applications},
  booktitle = {Proceedings of the IEEE Symposia on Human Centric Computing Languages and Environments (HCC 2001), Stresa (Italy)},
  year = {2001},
  pages = {248--255},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {September},
  note = {Best Paper of HCC 2001.},
  abstract = {Availability of precise, yet usable modeling languages is essential to the construction of multimedia systems based on software engineering principles and methods. Although several languages have been proposed for the specification of isolated multimedia system aspects, there not yet exists an integrated modeling language that adequately supports multimedia software development in practice. We propose an extension of the Unified Modeling Language (UML) for the integrated specification of multimedia systems based on an object-oriented development method. Since integration of co-existing timed procedural and interactive behavior is at the heart of multimedia systems, we focus on UML-based specification of behavior in this paper. In addition, we outline how these behavioral aspects are to be integrated with media, presentation, and software architecture modeling to achieve a coherent and consistent model.}
}

@inproceedings{Hausmann2001a,
  author = {Jan Hendrik Hausmann AND Reiko Heckel},
  title = {Use Cases as views: A formal approach to Requirements engineering in the Unified Process},
  booktitle = {Proceedings of the GI/OCG-Jahrestagung on Wirtschaft und Wissenschaft in der Network Economy - Visionen und Wirklichkeit (2001), Wien ({\"O}sterreich)},
  year = {2001},
  editor = {K.Bauknecht, W. Brauer, Th. A. M{\"u}ck},
  pages = {595--599},
  publisher = {{\"O}sterreichische Computer Gesellschaft},
  address = {Wien ({\"O}sterreich)},
  month = {September},
  abstract = {In Requirements Engineering structural and functionalrequirements for a new software system are gathered, analyzed,and manifested. Unfortunately the connection betweenthese aspects gets lost in the standard object orientedmethodology and has to be re-established later on.Not only is this tedious work but the detection of conflictsand inconsistencies in early phases is hindered by the separationof static and dynamic aspects. We propose the useof graph transformations to specify the connection betweenthese aspects. Based on what we call an integratedbusiness model, consistency analysis at the requirementsmodel level becomes possible.Keywords: UML, Unified Process, functional specifications,integrated business model, graph transformation1 IntroductionAt the beginning of each software development there areseveral ideas or visions of what the system to be buildshould achieve. The techniques developed in the area ofrequirements engineering are concerned with gathering,structuring and integrating these different ideas for thenew system. It is the goal of this process to achieve aset of reasonable and consistent requirements for the furtherdevelopment process. The main problem is the detectionand resolution of inconsistencies and conflicts betweencompeting requirements. The application of formalmethods and notations promises to support this task byenabling automated analysis. Although multiple formalmethods have been proposed by scientists (see e.g. [7] fora survey), the standard methodologies in object orientedsoftware engineering still use very informal and imprecisetechniques in this phase of the development process.In particular, what is missing is a coupling between thestructural (data) description (captured in class diagrams)and the behavior of the system (captured in activity anduse case diagrams). In this paper we will show how to improvethis situation by giving use cases a precise description,thus achieving a coupling of the dynamic and staticparts of the model. This allows to apply formal techniquesof consistency analysis.The paper is organized as follows: Section 2 givesan introduction to the requirements analysis phase in theUnified Process (UP) and points out some weak points ofthis approach. We will advance the basic ideas presentedin the UP by further elaborating the ideas of a businessmodel and formalizing their notion in Section 3. Section 4introduces use case diagrams and their new role in thecontext of the integrated business model. Section 5 extendsthe notion of views to structure the whole requirementsmodel and the concluding Section 6 gives perspectivestoward further work on this topic.},
  volume = {1}
}

@inproceedings{Cherchago00,
  author = {Alexey Cherchago AND N. Alexandrova},
  title = {A Model of a Physician's Decision-Making Process using Electropunctural Methods of Diagnostics},
  booktitle = {Proceedings of the All-Russia Students, Young Scientists and Specialists Scientific and Technical Conference on Biotechnical, Medical and Environmental Systems and Complexes (Ryazan, Russia)},
  year = {2000}
}

@inproceedings{Hausmann2000,
  author = {Gregor Engels AND Jan Hendrik Hausmann AND Reiko Heckel AND Stefan Sauer},
  title = {Dynamic Meta-Modeling: A Graphical Approach to the Operational Semantics of Behavioral Diagrams in UML},
  booktitle = {Proceedings of the 3rd international conference on the Unified Modeling Language (UML 2000), York (UK)},
  year = {2000},
  editor = {A. Evans, S. Kent, B. Selic},
  pages = {323--337},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  note = {Third International Conference},
  abstract = {In this paper, dynamic meta modeling is proposed as a new approach to the operational semantics of behavioral UML diagrams. The dynamic meta model extends the well-known static meta model by a speci.cation of the system's dynamics by means of collaboration diagrams. In this way, it is possible to de.ne the behavior of UML diagrams within UML.The conceptual idea is inherited from Plotkin's structured operational semantics (SOS) paradigm, a style of semantics speci.cation for concurrent programming languages and process calculi: Collaboration diagrams are used as deduction rules to specify a goal-oriented interpreter for the language. The approach is exemplified using a fragment of UML statechart and object diagrams.Formally, collaboration diagrams are interpreted as graph transformation rules. In this way, dynamic UML semantics can be both mathematically rigorous so as to enable formal specifications and proofs and, due to the use of UML notation, understandable without prior knowledge of heavy mathematic machinery. Thus, it can be used as a reference by tool developers, teachers, and advanced users.},
  series = {LNCS},
  volume = {1939}
}

@inproceedings{Depke02,
  author = {Ralph Depke AND Matthew Langham AND Bj{\"o}rn L{\"u}tkemeier AND Sebastian Th{\"o}ne},
  title = {Ein Konzept zur Generierung von XSL-Transformationen und dessen Anwendung bei Bankselbstbedienungssystemen},
  booktitle = {Proceedings of the Net.ObjectDays (2000), Erfurt (Germany)},
  year = {2000},
  month = {October },
  abstract = {Die Transformation von XML-Dokumenten mit XSLTRegeln ist von gro{\ss}er praktischer Relevanz. Der Aufwand f{\"u}r die Erstellung der Regeln w{\"a}chst allerdings mit der Gr{\"o}{\ss}e der ineinander zu {\"u}berf{\"u}hrenden Dokumentformate und der Komplexit{\"a}t der Transformation. Mit der wachsenden Menge von Regeln wird die {\"U}bersetzung auch immer weniger nachvollziehbar. Die in diesem Artikel vorgeschlagene Spezifikation von XSLTransformationen und die nachfolgende Generierung von XSLT-Regeln vereinfacht die Erstellung von {\"U}bersetzern und bildet gleichfalls eine besser verst{\"a}ndliche Dokumentation der {\"U}bersetzungsvorschrift. Die praktische Relevanz des Verfahrens zeigt sich zum Beispiel bei der Konvertierung von Austauschformaten in Bankselbstbedienungssystemen.}
}

@inproceedings{Thoene00,
  author = {Sebastian Th{\"o}ne},
  title = {Entwicklung eines {\"U}bersetzers von Nachrichtenaustauschformaten f{\"u}r Bankselbstbedienungssysteme in XML-Formate},
  booktitle = {Proceedings of the Informatiktage 2000, Bad Schussenried (Germany)},
  year = {2000},
  editor = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
  publisher = {Konradin-Verlag},
  address = {Leinfelden - Echterdingen},
  month = {October },
  abstract = {Banken verwenden heute noch {\"u}berwiegend bin{\"a}re Nachrichtenaustauschformate zwischen Bankselbstbedienungssystemen und zentralen Rechnern, aber aufgrund zahlreicher Vorteile sollen in Zukunft XML-basierte Formate eingesetzt werden. Damit entsteht das Problem der {\"U}bersetzung zwischen bin{\"a}ren und XML-Formaten. Da unterschiedliche Ausgangsformate in ein einheitliches Zielformat {\"u}bersetzt werden sollen, m{\"u}ssen entstehende XML-Zwischenformate in das Zielformat umgesetzt werden. Daraus entsteht die interessante Frage, wie Transformationen von XML-Dokumenten spezifiziert und erzeugt werden k{\"o}nnen.In der Arbeit wurde ein Konzept zur L{\"o}sung der praxisbezogenen Problemstellung entwickelt. Ziel der Arbeit war vor allem, Vorschl{\"a}ge f{\"u}r die {\"U}bersetzung von bin{\"a}ren Formaten in XML-Dokumente und f{\"u}r die Transformation von XML-Dokumenten zu erarbeiten. Im Anschlu{\ss} sollten die Konzepte in eine Implementierung umgesetzt werden.F{\"u}r die Umwandlung von bin{\"a}ren Austauschformaten in Bankselbstbedienungssystemen wurde ein leicht erweiterbarer {\"U}bersetzer in ein XML-Zwischenformat entwickelt. F{\"u}r die Umwandlung in das XML-Zielformat wurde ein Konzept entwickelt, XML-Dokumente durch XSL-Transformationen umzustrukturieren. Derartige Transformationen werden nach einer neu entwickelten Methode in neuartigen XML-Dokumenten spezifiziert. Aus den Spezifikationsdokumenten werden XSLT-Regeln generiert, die von vorhandenen XSLT-Prozessoren f{\"u}r die Transformation von XML-Dokumenten verwendet werden. Das vorgeschlagene Konzept wurde implementiert und damit die gestellte Aufgabe vollst{\"a}ndig gel{\"o}st.}
}

@inproceedings{Engels01,
  author = {Gregor Engels AND Reiko Heckel},
  title = {Graph Transformation as a Conceptual and Formal Framework for System Modeling and Model Evolution},
  booktitle = {Proceedings of the 27th International Colloquium on Automata, Languages and Programming (ICALP 2000), Geneva (Switzerland)},
  year = {2000},
  pages = {127-150},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {July},
  series = {LNCS},
  volume = {1853}
}

@inproceedings{Hausmann2000a,
  author = {Jan Hendrik Hausmann},
  title = {Graphtransitionsregeln zur Beschreibung der Semantik von UML},
  booktitle = {Proceedings of the Informatiktage 2000, Bad Schussenried (Germany)},
  year = {2000},
  pages = {103--107},
  publisher = {Konradin Verlag},
  address = {Leinfelden - Echterdingen},
  month = {Dezember},
  abstract = {In dieser Arbeit soll gezeigt werden, da{\ss} es m{\"o}glich ist, das Konzept von SOS-Regeln, die zur Semantikbeschreibungvon textuell notierten Programmiersprachen dienen, auf die graphische ModellierungsspracheUML zu {\"u}bertragen. Es entstehen dabei Graphtransitionsregeln, die geeignet sind, die Semantik von UMLpr{\"a}zise zu spezifizieren.}
}

@inproceedings{Depke2000a,
  author = {Ralph Depke AND Reiko Heckel AND Jochen K{\"u}ster},
  title = {Integrating visual modeling of agent-based and object-oriented systems},
  booktitle = {Proceedings of the conference on Autonomous agents (AGENTS 2000), Barcelona (Spain)},
  year = {2000},
  pages = {82--83},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {June},
  abstract = {A concept of roles is introduced for a more fine-grained modeling of objects' and agents' structure and behavior. As requirement specification, global graph transformation rules determine the overall effect of the interaction among agents and objects while abstracting form the communication involved. On the design level they describe local autonomous operations by which agents may react to changes in their environment.}
}

@inproceedings{Lohmann2000,
  author = {Marc Lohmann AND Annika Wagner},
  title = {Konzeption eines XML-f{\"a}higen Mailtools},
  booktitle = {Proceedings of Net.Object Days 2000, Erfurt (Germany)},
  year = {2000},
  abstract = {In dieser Arbeit wird ein Konzept vorgestellt, wie XML eingesetzt werden kann, um inhaltlich strukturierte Nachrichten, wie sie etwa einem ausgef{\"u}llten Formular entsprechen, mit einem Mailtool zu versenden. Damit sollen einerseits die M{\"o}glichkeiten einer automatischen Weiterverarbeitung der Nachrichten verbessert werden. Andererseits wird durch den Einsatz von Formularen bei der elektronischen Kommunikation angestrebt, die papierbasierte Kommunikation noch st{\"a}rker als bisher m{\"o}glich in den Hintergrund zu dr{\"a}ngen.}
}

@inproceedings{Engels2000e,
  author = {Gregor Engels AND Luuk Groenewegen},
  title = {Object-Oriented Modeling - A Roadmap},
  booktitle = {Proceedings of the Conference on The Future of Software Engineering - Special Track at 22nd International Conference on Software Engineering (ICSE 2000), Limerick (Ireland)},
  year = {2000},
  editor = {A. Finkelstein},
  pages = {103--116},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  month = {June },
  abstract = {Object-oriented modeling has become the de-facto standard in the early phases of a software development process during the last decade. The current state-of-the-art is dominated by the existence of the Unified Modeling Language (UML), the development of which has been initiated and pushed by industry.This paper presents a list of requirements for an ideal object-oriented modeling language and compares it with the achievements of UML and other object-oriented modeling approaches. This forms the base for the discussion of a roadmap for object-oriented modeling, which is structured according to a classification scheme of six different themes, which are language-, model- orprocess-related, respectively.}
}

@inproceedings{Engels2000c,
  author = {Gregor Engels AND Reiko Heckel AND Stefan Sauer},
  title = {UML - A Universal Modeling Language?},
  booktitle = {Proceedings of the 21st International Conference on Application and Theory of Petri Nets (ICATPN 2000), Aarhus (Denmark)},
  year = {2000},
  editor = {M. Nielsen, D. Simpson},
  pages = {24--38},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {June},
  abstract = {Abstract. The Unified Modeling Language (UML) is the de facto industrial standard of an object-oriented modeling language. It consists of several sublanguages which are suited to model structural and behavioral aspects of a software system. The UML was developed as a general-purpose language together with intrinsic features to extend the UML towards problem domain-specific profiles. The paper illustrates the language features of the UML and its adaptation mechanisms. As a conclusion, we show that the UML or an appropriate, to be defined core UML, respectively, may serve as a universal base of an object-oriented modeling language. But this core has to be adapted according to problem domain-specific requirements to yield an expressive and intuitive modeling language for a certain problem domain.},
  series = {LNCS},
  volume = {1825}
}

@inproceedings{Mehner2000,
  author = {Katharina Mehner AND Annika Wagner},
  title = {Visualizing the Synchronization of Java-Threads with UML},
  booktitle = {Proceedings of the IEEE International Symposium on Visual Languages (VL 2000), Seattle (Washington)},
  year = {2000},
  pages = {199--206},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  month = {September },
  abstract = {Concurrent programming is a complex task, even with modern languages such as Java who provide language-based support for multithreading and synchronization. In addition to typical errors from sequential programming concurrent programming is prone to security and lifeness errors, which are difficult to detect due to the inherent nondeterminism in concurrent programs. While debugging is still mainly based on textual representations, we think that the use of visual languages can ease program comprehension. Once a synchronization error is detected, e.g. during testing, the error situation shall be visualized to analyze the reason for the error. With UML being a major visual modeling language for object oriented software development we decide to base our visualization on it and present how to visualize program traces with UML sequence and collaboration diagrams. We focus on the visualization of the synchronization of threads. For this purpose, we extend UML to model the runtime mechanisms of the Java language constructs for synchronization.}
}

@inproceedings{Gadducci1999,
  author = {Fabio Gadducci AND Reiko Heckel AND Merc{'e} Llabr{'e}s},
  title = {A Bi-Categorical Axiomatisation of Concurrent Graph Rewriting},
  booktitle = {Proceedings of the 8th Conference on Category Theory and Computer Science (CTCS 1999), Edinburgh (UK)},
  year = {1999},
  editor = {M. Hofmann, D. Pavlovic, P. Rosolini},
  pages = {80--100},
  publisher = {Elsevier},
  month = {September },
  abstract = {In this paper the concurrent semantics of double-pushout (DPO) graph rewriting, which is classically defined in terms of shift-equivalence classes of graph derivations, is axiomatised via the construction of a free monoidal bi-category. In contrast to a previous attempt based on 2-categories, the use of bi-categories allows to define rewriting on concrete graphs. Thus, the problem of composition of isomorphism classes of rewriting sequences is avoided. Moreover, as a first step towards the recovery of the full expressive power of the formalism via a purely algebraic description, the concept of disconnected rules is introduced, i.e., rules whose interface graphs are made of disconnected nodes and edges only. It is proved that, under reasonable assumptions, rewriting via disconnected rules enjoys similar concurrency properties like in the classical approach.},
  series = {Electronic Notes in Theoretical Computer Science},
  volume = {29}
}

@inproceedings{Cherchago99,
  author = {Alexey Cherchago},
  title = {Application of the Structured Analysis and Design Technique (SADT) Methodology for the Medical Information Systems Development},
  booktitle = {Proceedings of the All-Russia Students', Young Scientists' and Specialists' Scientific and Technical Conference "New Information Technologies in Scientific Researches and in Education" (Ryazan, Russia)},
  year = {1999}
}

@inproceedings{Sauer1999a,
  author = {Stefan Sauer AND Gregor Engels},
  title = {Extending UML for Modeling of Multimedia Applications},
  booktitle = {Proceedings of the IEEE Symposium on Visual Languages (VL 1999), Tokyo (Japan)},
  year = {1999},
  editor = {M. Hirakawa, P. Mussio},
  pages = {80--87},
  publisher = {IEEE Computer Society},
  address = {Tokyo, Japan},
  note = {Awarded at the VL/HCC 2010 as the most influential VL/HCC paper of the last decade.},
  abstract = {An analysis of how visual modeling of structure and dynamic behavior of a multimedia application differs from modeling conventional software yields that aspects of the graphical user interface and time-dynamic behavior ought to be integral parts of a coherent multimedia application model. In this sense, we extend the model-view-controller paradigm towards multimedia.As a result, we present OMMMA-L, a visual Language for the Object-Oriented Modeling of MultiMedia Applications that is based on the Unified Modeling Language (UML). The structural and behavioral diagram types of UML have been analyzed and are adapted and extended according to multimedia application characteristics.A presentation diagram is introduced and integrated to adequately describe the visual presentation. In addition to explaining the different diagram types, we also give pragmatic guidelines on how to deploy and combine the various diagrams.}
}

@inproceedings{Engels1999c,
  author = {Gregor Engels AND Ralph Depke AND Christoph Borowski},
  title = {Konzeption und objektorientierte Realisierung einer internet-basierten Datenbankanwendung},
  booktitle = {Kolloquium Software-Entwicklung - Methoden, Werkzeuge, Erfahrungen},
  year = {1999},
  editor = {H. J. Scheibl},
  pages = {531--540},
  publisher = {Technische Akademie Esslingen},
  address = {Ostfildern},
  month = {September},
  abstract = {Today e-commerce applications use web browsers as an uniform user interface and they rely on databases as datasources. Different technologies exist for database access: common gateway interface (CGI), Java and its databaseinterface java database connectivity (JDBC), proprietary approaches of database vendors, etc. We present criteria forthe selection of an appropriate solution and we successivly apply them in our application development process.Throughout the development process of internet based database applications object oriented techniques can be used.The unified modeling language (UML) is used for requirement analysis and design of the application and theimplementation proceeds with the programming language Java. The transition from the object oriented modelinglanguage UML to the object oriented programming language Java succeeds smoothly. We report on our experience withthe modeling tool Rational Rose 98 of Rational, Inc. We use Java and JDBC to implement a seminar reservation systemthat can be regarded as a small e-commerce application.},
  volume = {8}
}

@inproceedings{Hec99,
  author = {Reiko Heckel},
  title = {Modeling Agent-Based Systems with Graph Transformation and UML},
  booktitle = {Proceedings of the Dagstuhl-Seminar 99451 on Rigorous Analysis and Design for Software Intensive Systems},
  year = {1999}
}

@inproceedings{Deugo1999,
  author = {Dwight Deugo AND Jochen K{\"u}ster AND Franz Oppacher AND Ingo von Otte},
  title = {Patterns as a Means for Intelligent Software Engineering},
  booktitle = {Proceedings of the conference on Artificial Intelligence (IC-AI 1999) Las Vegas, Nevada (USA)},
  year = {1999},
  editor = {H. R. Arabnia},
  pages = {605-611},
  publisher = {CSREA Press},
  abstract = {In this paper, we make a case for the development of intelligent software engineering patterns. Patterns have proven extremely useful to the object-oriented programming community. However, of the large amount of pattern research, little effort has been devoted to developing intelligent software engineering patterns. We wish to correct this situation. We believe, for example, that the ongoing success of agent systems depends on the development of sound software engineering principles for them. Patterns are a recognized means to this end, and one that we wish to promote.},
  journal = {Proceedings International Conference of Artificial Intelligence (IC-AI)},
  volume = {2}
}

@inproceedings{Corradini1999b,
  author = {Andrea Corradini AND Reiko Heckel AND Ugo Montanari},
  title = {Tile Transition Systems as Structured Coalgebras},
  booktitle = {Proceedings of the 12th International Symposium on Fundamentals of Computation Theory (FCT '99)},
  year = {1999},
  editor = {G. Ciobanu and G. Paun},
  pages = {13--38},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {The aim of this paper is to investigate the relation between two models of concurrent systems: tile rewrite systems and coalgebras. Tiles are rewrite rules with side effects which are endowed with operations of parallel and sequential composition and synchronization. Their models can be described as monoidal double categories. Coalgebras can be considered, in a suitable mathematical setting, as dual to algebras. They can be used as models of dynamical systems with hidden states in order to study concepts of observational equivalence and bisimilarity in a more general setting. In order to capture in the coalgebraic presentation the algebraic structure given by the composition operations on tiles, coalgebras have to be endowed with an algebraic structure as well. This leads to the concept of structured coalgebras, i.e., coalgebras for an endofunctor on a category of algebras. However, structured coalgebras are more restrictive than tile models. Those models which can be presented as structured coalgebras are characterized by the so-called horizontal decomposition property, which, intuitively, requires that the behavior is compositional in the sense that all transitions from complex states can be derived by composing transitions out of component states.},
  series = {LNCS},
  volume = {1684}
}

@inproceedings{EngelsHSW1999,
  author = {Gregor Engels AND Roland H{\"u}cking AND Stefan Sauer AND Annika Wagner},
  title = {UML Collaboration Diagrams and Their Transformation to Java},
  booktitle = {Proceddings of The Unified Modeling Language: Beyond the Standard, Second International Conference (UML 99), Fort Collins, Colorado, USA},
  year = {1999},
  editor = {R. France, B. Rumpe},
  pages = {473--488},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {October},
  series = {LNCS},
  volume = {1723}
}

@inproceedings{Cherchago98,
  author = {Alexey Cherchago},
  title = {A generalized schema of a decision-making process of a SCENAR-therapeutist},
  booktitle = {Proceedings of the Scientific and Technical Conference on Medical Information Systems (MIS 1998), Taganrog (Russia)},
  year = {1998}
}

@inproceedings{Heckel1998a,
  author = {Reiko Heckel},
  title = {Compositional Verification of Reactive Systems Specified by Graph Transformation},
  booktitle = {Proceedgins of the First International Conference on Fundamental Approaches to Software Engineering (FASE 1998), Lisbon (Portugal)},
  year = {1998},
  pages = {138--153},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {A loose semantics for graph transformation rules which has been developed recently is used in this paper for the compositional verification of specifications. The main conceptual tool here is the notion of view , that is, an incomplete specification describing only a certain aspect of the overall system. A view anticipates the (potential) behavior of the complete system by its loose semantics. This ensures that properties of the view are inherited by the complete system.Based on this result one may verify temporal properties by decomposing a specification into several views, analyzing them separately, and deriving the desired property from properties shown for the views.},
  series = {LNCS},
  volume = {1382}
}

@inproceedings{Depke1998,
  author = {Ralph Depke AND Gregor Engels AND Katharina Mehner AND Stefan Sauer AND Annika Wagner},
  title = {Ein Ansatz zur Verbesserung des Entwicklungsprozesses von Multimedia-Anwendungen},
  booktitle = {Proceedings of the GI-Fachtagung on Softwaretechnik (1998), Paderborn (Germany)},
  year = {1998},
  pages = {12--19},
  publisher = {GI},
  month = {September },
  journal = {Softwaretechnik-Trends},
  volume = {18}
}

@inproceedings{Didrich1998,
  author = {Klaus Didrich AND Annika Wagner},
  title = {Integration of Single Pushout Transformation and Functional Programming},
  booktitle = {Proceedings of the World Conference on Integrated Design and Process Technology (IDPT 1998), Berlin (Germany)},
  year = {1998},
  editor = {M.M. Tarik, J. Tanaka, K. Itoh, M. Goedicke, W. Rossack, H. Ehrig, F. Kurfess},
  pages = {65-73},
  publisher = {Society for Design and Process Science},
  volume = {4}
}

@inproceedings{Padberg1998,
  author = {Julia Padberg AND Lars Jansen AND Reiko Heckel AND Hartmut Ehrig},
  title = {Interoperability in Train Control Systems: Specification of Scenarios Using Open Nets},
  booktitle = {Proceedings of the conference on Integrated Design and Process Technology (IDPT 1998), Berlin (Germany)},
  year = {1998},
  pages = {17--28},
  publisher = {Society for Design and Process Science},
  month = {October},
  abstract = {We consider the area of train control systems like the European Train Control Systems ETCS where several different scenarios are considered and accordant software components must interoperate effectively in order to achieve the desired system behaviour. In order to specify corresponding problems for ETCS high-level Petri net techniques have been identified as one of the most adequate formal specification technique according to the state of the art. Unfortunately, Petri nets in the usual sense are not fully adequate to model such scenarios and to achieve interoperability. The new notion of open nets, developed within the DFG-Research Group Petri Net Technology, is most promising as a conceptual and formal technique for these kinds of problems. In this paper we study a simplified version of a railway crossing control system with a few number of basic scenarios represented by interaction diagrams, which are modelled by open nets, called scenario nets. The interoperability of system components is specified by suitable integration and composition techniques for open nets. These techniques should be a basis for interoperability in train control systems in general, especially for real problems in the area of ETCS.}
}

@inproceedings{Engels1997,
  author = {Gregor Engels and Reiko Heckel and Gabi Taentzer and Hartmut Ehrig},
  title = {A view-oriented approach to system modelling based on graph transformation},
  booktitle = {Proceedings of the 6th European conference held jointly with the 5th ACM SIGSOFT international symposium on Foundations of software engineering (ESEC 1997/FSE-5), New York, NY (USA)},
  year = {1997},
  editor = {M. Jazayeri, H. Schauer},
  pages = {327--343},
  publisher = {Springer},
  address = {New York, NY, USA},
  abstract = {The idea of a combined reference model- and view-based specification approach has been proposed recently in the software engineering community. In this paper we present a specification technique based on graph transformations which supports such a development approach. The use of graphs and graph transformations supports an intuitive understanding and an integration of static an dynamic aspects on a well-defined semantical base. On this background, formal notions of view and view relation are developed and the behaviour of views is described by a loose semantics. We define a construction for automatic view integration which assumes that the dependencies between different views are described by a reference model. The views and the reference model are kept consisten manually, which is the task of a model manager. All concepts and results are illustrated at the well-known example of a banking system.},
  volume = {1301}
}

@inproceedings{Engels97,
  author = {Gregor Engels AND Reiko Heckel AND Gabriele Taentzer AND Hartmut Ehrig},
  title = {A View-Oriented Approach to System Modelling Using Graph Transformations},
  booktitle = {Proceedings European Software Engineering Conference (ESEC 1997), Z{\"u}rich (Switzerland)},
  year = {1997},
  editor = {M. Jazayeri, H. Schauer},
  pages = {327--343},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {The idea of a combined reference model- and view-based specification approach has been proposed recently in the software engineering community. In this paper we present a specification technique based on graph transformations which supports such a development approach. The use of graphs and graph transformations supports an intuitive understanding and an integration of static and dynamic aspects on a well-defined semantical base. On this background, formal notions of view and view relation are developed and the behaviour of views is described by a loose semantics. We define a construction for automatic view integration which assumes that the dependencies between different views are described by a reference model. The views and the reference model are kept consistent manually, which is the task of a model manager. All concepts and results are illustrated at the well-known example of a banking system.},
  volume = {1301}
}

@inproceedings{Knoke97,
  author = {Stefan Knoke AND Ralph Depke AND Wolfram Sch{\"o}ne AND O.S. Brozek AND Andreas T{\"u}nnermann AND H. Welling},
  title = {Einfrequenzbetrieb von Nd:YAG-Stablasersystemen hoher Ausgangsleistung},
  booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Weinheim (Germany)},
  year = {1997},
  publisher = {Physik-Verlag},
  month = {October},
  abstract = {Festk{\"o}rperlasersysteme mit Ausgangsleistungen von mehr als 10W im Einfrequenzbetrieb sind attraktive Strahlquellen f{\"u}r Anwendungen in der Grundlagenforschung und in Bereichen der nichtlinearen Optik. Es werden mit fasergekoppelten Diodenlasern gepumpte Nd:YAG-Stablaser vorgestellt, die das Potential hoher Ausgangsleistungen in der transversalen Grundmode bieten. Durch die Ankopplung der Hochleistungslaser an einen monolithischen Miniatur-Ringlaser mit der Technik des Injection Lockings wird ein sehr stabiler und effizienter Einfrequenzbetrieb mit Laserausgangsleistungen von mehr als 40W erreicht. Ergebnisse der Untersuchungen zur {\"U}bertragung des Polarisationszustandes, der Amplituden- und Frequenzstabilit{\"a}t der Strahlung des monolitischen Ringlasers als Masteroszillator auf den angekoppelten Hochleistungs-Slavelaser werden dargestellt und diskutiert.},
  volume = {32}
}

@inproceedings{Heckel1997,
  author = {Reiko Heckel AND Hartmut Ehrig AND Uwe Wolter AND Andrea Corradini},
  title = {Integrating the Specification Techniques of Graph Transformation and Temporal Logic},
  booktitle = {Proceedings of the 22nd International Symposium on Mathematical Foundations of Computer Science (MFCS 1997), Bratislava (Slovakia)},
  year = {1997},
  pages = {219--228},
  publisher = {Springer},
  address = {London, UK},
  abstract = {The aim of this paper is an integration of graph grammarswith different kinds of behavioural constraints, in particular with temporallogic constraints. Since the usual algebraic semantics of graphtransformation systems is not able to express constrained behaviour weintroduce - in analogy to other approaches - a coalgebraic semanticswhich associates with each system a category of models (deterministictransition systems). Such category has a final object, which includesall finite and infinite transition sequences. The coalgebraic frameworkmakes it possible to introduce a general notion of 'logic of behaviouralconstraints'. Instances include, for example, graphical consistency constraintsand temporal logic constraints. We show that the consideredsemantics can be restricted to a final coalgebra semantics for systemswith behavioural constraints. This result can be instantiated in order toobtain a final coalgebra semantics for graph grammars with temporallogic constraints.},
  series = {LNCS}
}

@inproceedings{Depke97-1,
  author = {Ralph Depke AND Stefan Knoke AND Wolfram Sch{\"o}ne AND Andreas T{\"u}nnermann AND H. Welling},
  title = {Thermooptische Effekte in Nd:YAG-Slablasern},
  booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft},
  year = {1997},
  publisher = {Physik-Verlag},
  address = {Weinheim, Germany},
  abstract = {Vorteile von Laserkristallen in Slab-Geometrie gegen{\"u}ber St{\"a}ben liegen in einer Reduktion der thermisch induzierten Linsenwirkung und der spannungsinduzierten Depolarisation durch einen zick-zack-f{\"o}rmigen Strahlverlauf innerhalb des Kristalls. Durch die Analyse der durch die Anordnung der Pumpquellen und die Dotierungskonzentration bestimmten Temperatur- und Spannungsverteilungen mit Hilfe eines Finite-Element-Modells und die Berechnung der resultierenden optischen Eigenschaften lassen sich die genannten Zielgr{\"o}{\ss}en optimieren. Die Verfahren wurden auf am Laser Zentrum Hannover e.V. entwickelte Nd:YAG-Stab- und Slablaser angewandt und erm{\"o}glichten die Entwicklung diodengepumpter Festk{\"o}rperlaser-Systeme mit Ausgangsleistungen von mehr als 750W bei guter Strahlqualit{\"a}t. Modellerweiterungen unter Ber{\"u}cksichtigung der Wechselwirkung zwischen Lasermoden und aktivem Material werden diskutiert. Diese Arbeit wird gef{\"o}rdert durch das BMBF, FKZ: 13 N 6361 },
  volume = {32}
}

@inproceedings{EEH+96,
  author = {Gregor Engels AND Hartmut Ehrig AND Reiko Heckel AND Gabriele Taentzer AND Andrea Corradini},
  title = {A View-Based Approach to System Modelling},
  booktitle = {Report on Dagstuhl-Seminar 9637 on Graph Transformations in Computer Science},
  year = {1996},
  editor = {H. Ehrig, U. Montanari, G. Rozenberg, H.-J. Schneider},
  pages = {11},
  publisher = {Technical University of Berlin},
  month = {September},
  abstract = {In order to manage the complexity of large system specifications, they have to be decomposed into subspecifications. Each subspecification describes a certain part of the system. This might be a certain aspect, like the data, dynamic, or functional aspect, as it is known from object-oriented modelling techniques. Or it might be a certain view onto the system, as it is known from database modelling techniques. The talk motivates the usage of views in graph grammarbased specifications. First, the usage of typed graph grammars inherently ensures an integration of the data and the functional aspect within a view. Second, it is explained that it is not appropriate in case of views to have a fixed semantics.The standard fixed semantics, i.e. a graph transformation system, has to be relaxed to a loose semantics, i.e. a graph transition system. This reflects the idea that a view models only a part of the complete system. Other views may overlap a view with respect to data or functionality. A complete system specification is yielded by exploiting the approach of cooperative parallel composition of graph grammars (see talk by Leila Ribeiro).},
  series = {Dagstuhl-Seminar-Report},
  volume = {155}
}

@inproceedings{Hec96,
  author = {Reiko Heckel},
  title = {Behavioral Constraints for Loose Graph Transformation Systems},
  booktitle = {Report on the Dagstuhl-Seminar 9637 on Graph Transformations in Computer Science},
  year = {1996},
  editor = {H. Ehrig, U. Montanari, G. Rozenberg, H.J. Schneider},
  pages = {12--13},
  publisher = {Technical University of Berlin},
  month = {September},
  abstract = {In this lecture, the concept of synchronization of views presented at the same seminar in the framework of typed graph transformation systems with loose semantics is extended by behavioral constraints. Such constraints can be used to control the transformation process, to express properties of systems for their verification, or (what provided the initial motivation of this talk) to restrict the loose semantics of productions. Examples of behavioral constraints include starting and ending graphs, application conditions for productions, static and dynamic integrity constraints, programmed graph transformations, etc.In order to support a variety of behavioral constraints we develop a generic framework for behavioral constraints for typed graph transformation systems in the double-pushout approach. The framework, called logic of behavioral constraints, provides the main notions and results presented in the talk on synchronization of views and loose semantics of productions on an axiomatic basis. The techniques are motivated by the concepts of logic of constraints and institutions in the field of algebraic specification of abstract data types.Known instances of logics of behavioral constraints include (so far) delete/create permissions for graph transitions, negative application conditions for productions, as well as static and dynamic integrity constraints expressed by temporal logic.For any given logic of behavioral constraints, the synchronization by parallel composition of graph transformation systems as well as the transition sequence semantics extend to graph transformation systems with constraints. Moreover, the compositionality of the semantics w.r.t. the synchronization has been transfered to the extended setting.The framework can be made approach independent if we assume a category of graph transformation systems (of whatever approach) such that a morphism of that category corresponds to a translation of the transformation steps in the source system to transformation steps in the target system. Then, a flat (unstructured) graph transformation system becomes comparable to a flat GRACE transformation unit, which could provide a new way of structuring transformation units, featuring refinement and synchronization in addition to the currently available use relation.},
  series = {Dagstuhl-Seminar-Report}
}

@inproceedings{Bunje1996,
  author = {Tineke de Bunje AND Gregor Engels AND Luuk Groenewegen AND Aart Matsinger AND Martin Rijnbeek},
  title = {Industrial maintenance modelled in SOCCA: an experience report},
  booktitle = {Proceedings of the Fourth International Conference on the Software Process (ICSP 1996), Brighton (UK)},
  year = {1996},
  pages = {13--26},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {A large industrial process, software maintenance, has been modelled by using the process modelling language SOCCA. The paper reports about the experiences with this trial. In particular, feasibility, expressiveness, quality and the overall benefits of a formal SOCCA model are discussed and compared to the formerly existing informal process description. In order to illustrate the results, a well chosen process model fragment from the larger model is outlined in detail. It addresses in particular the human-intensive cooperation within the process and shows the seamless combination of technical components and human agent components in the SOCCA model. The main conclusions from this trial are that formal SOCCA models are suited to model realistic industrial processes and that due to an intrinsic modular structure of a SOCCA model, even huge models remain reasonably readable and understandable}
}

@inproceedings{EngelsGK1996a,
  author = {Gregor Engels AND Luuk Groenewegen AND Gerti Kappel},
  title = {Object-oriented specification of coordinated collaboration},
  booktitle = {Proceedings of IFIP World Conference on IT Tools (1996), Canberra (Australia)},
  year = {1996},
  editor = {N. Terashima, Ed. Altman},
  pages = {437--452},
  publisher = {Chapman \& Hall},
  month = {September },
  abstract = {Object-oriented specification mechanisms have become famous for modelling structure and behaviour together in terms of autonomous objects communicating via message passing. However, whereas most object-oriented specification methods are strong in modelling the local behaviour of single objects, they fall short on modelling the coordinated behaviour and collaboration of several objects together The aim of this paper is to contribute to fill this gap. The paper reports on concepts, language constructs, and experiences with three collaboration formalisms in the area of object-oriented specifications.}
}

@inproceedings{Ehrig1996a,
  author = {Hartmut Ehrig AND Reiko Heckel AND Julia Padberg AND Gabriele Taentzer AND Uwe Wolter AND Andrea Corradini AND Gregor Engels},
  title = {Synchronization of Views and Loose Semantics of Typed Graph Productions},
  booktitle = {Report on the Dagstuhl-Seminar 9637 on Graph Transformations in Computer Science},
  year = {1996},
  pages = {11--12},
  publisher = {Technical University of Berlin},
  month = {September},
  abstract = {The concept of views is used on two levels. First, so-called design views are developed for structuring specifications, that is, a system is modeled according to different views (e.g., representing the needs of different kinds of users) which have to be synchronized afterwards in order to build the whole system. Views can be specified by means of typed graph transformation systems, where the type graph determines the visible types and the productions describe the known operations of that view. The synchronization of views is done by the construction of cooperative parallel composition of graph transformation systems, developed by Leila Ribeiro and presented at the same seminar.If the specification is complete, a view may describe an observation of the system in operation. In this case we speak of a user view. It turns out that the semantics of such a view cannot be described by computations (i.e., graph transformations), but just by observations of computations of the global system. Such observations of computations cannot be represented by graph transformations in the usual sense because a local view may lack operations (productions) of the global system, so that state changes may be observed that do not have a cause in the local view.Therefore, the notion of graph transition is introduced as loose semantics for productions, where the production specifies only a lower bound to the activities that are to happen during application. Contrastingly, in the classical doublepushout approach to graph rewriting, productions are interpreted as complete descriptions of the transformations to be performed.For typed graph transformation systems a transition sequence semantics is developed, comprising all finite and infinite sequences of transitions in a system.Moreover, this semantics is shown to be compositional w.r.t. the synchronization of views.}
}

@inproceedings{HMTW95,
  author = {Reiko Heckel AND J{\"u}rgen M{\"u}ller AND Gabriele Taentzer AND Annika Wagner},
  title = {Attributed Graph Transformations with Controlled Application of Rules},
  booktitle = {Proceedings of the Colloquium on Graph Transformation and its Application in Computer Science},
  year = {1995},
  editor = {G. Valiente Feruglio, F. Rosello Llompart},
  publisher = {Universitat de les Illes Balears},
  abstract = {We present a combination of recent extensions to single-pushout graph transformations, as there are attribution, application conditions and amalgamated graph transformations and add a simple transaction concept on top of this formalism. Thereby, we provide the formal basis for several examples, where these concepts are used in combination.},
  series = {Technical Report}
}

@inproceedings{Hec95b,
  author = {Reiko Heckel},
  title = {Embedding of Conditional Graph Transformations},
  booktitle = {Proceedings of the Colloquium on Graph Transformation and its Application in Computer Science},
  year = {1995},
  editor = {G. Valiente Feruglio, F. Rosello Llompart},
  publisher = {Universitat de les Illes Balears},
  abstract = {Single pushout graph transformations at injective matches are extended by negative application conditions. It is shown, how right-sided application conditions can be transformed into equivalent left-sided ones. Based on this result, conditional derived rules are introduced and a theorem, similiar to the double pushout embedding theorem is shown. Finally, three variants of contextual application conditions are discussed with respect to their expressive power and expected results.},
  series = {Technical Report}
}

@inproceedings{Thoben1995,
  author = {Wilfried Thoben AND Hans-J{\"u}rgen Appelrath AND Stefan Sauer},
  title = {Record Linkage of Anonymous Data by Control Numbers},
  booktitle = {Proceedings of the 18th Annual Conference of the Gesellschaft f{\"u}r Klassifikation, Oldenburg (Germany)},
  year = {1995},
  editor = {W. Gaul, D. Pfeifer},
  pages = {412--419},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  note = {From Data to Knowledge: Theoretical and Practical Aspects of Classification, Data Analysis and Knowledge Organisation},
  series = {Studies in Classification, Data Analysis, and Knowledge Organization}
}

@inproceedings{Thoben1994,
  author = {Wilfried Thoben AND Hans-J{\"u}rgen Appelrath AND Jens Rettig AND Stefan Sauer},
  title = {Ber{\"u}cksichtigung von Datenschutzaspekten in einem bev{\"o}lkerungsbezogenen Krebsregister},
  booktitle = {Proceedings of the conference on Medizin und Information, Biometrie und Epidemiologie (GMDS 1994), Dresden (Germany)},
  year = {1994},
  editor = {H. Kunath, U. Lochmann, R. Straube, K. J{\"o}ckel, C. O. K{\"o}hler},
  pages = {88--90},
  publisher = {MMV Medizin Verlag},
  address = {M{\"u}nchen},
  month = {September },
  note = {Medizin und Information, Tagungsband Medizinische Informatik, Biometrie und Epidemiologie},
  abstract = {Die Pilotphase 1993/ 94 zum Aufbau eines Nieders{\"a}chsischen Krebsregister untersucht das im Entwurf des Bundeskrebsregistergesetzes vorgesehen Modell f{\"u}r ein bev{\"o}lkerungsbezogenes Krebsregister. Darin werden die Krebsmeldungen in einer Vertrauensstelle erfa{\ss}t und die personenidentifizierenden Daten vor der {\"U}bermittlung an die Registerstelle anonymisiert, wo sie dann zu einem bev{\"o}lkerungsbezogenen Krebsregister verdichtet und epidemiologischer Forschung zur Verf{\"u}gung gestellt werden ([1], [2], [3]). Dieses sogenannte \glqq{}Michaelis\grqq{}-Modell erlaubt eine bev{\"o}lkerungsbezogene Registrierung von Krebsf{\"a}llen unter Ber{\"u}cksichtigung datenschutzrechtlicher Aspekte (\glqq{}Informationelles Selbstbestimmungsrecht\grqq{}) der einzelnen Betroffenen.In vier Teilprojekten werden dabei in der Modellregion Weser-Ems die Integration krebsregistrierender Einrichtungen, die Chiffrierung/ Dechiffrierung von Krebsmeldungen, der Abgleich anonymisierter Meldungen in der Registerstelle und die Entwicklung eines epidemiologischen Informationssystem betrachtet ([4], [5]).}
}

@inproceedings{Engels1994b,
  author = {Gregor Engels AND Gerti Kappel},
  title = {Object-Oriented System Development: Will the New Approach Solve Old Problems?},
  booktitle = {Proceedings of the IFIP 13th World Computer Congress on Information Processing, Hamburg (Germany)},
  year = {1994},
  editor = {K. Duncan and K. Krueger},
  pages = {434--441},
  publisher = {Elsevier},
  month = {August },
  abstract = {Object-oriented system development is wideley recognized as improving productivity and reducing system maintenance costs. However, existing approaches have not sufficiently addressed the following three questions which are equally important to users and researchers. Firstly, what are the benefits of object-oriented system development compared to traditional approaches? Secondly, what are the essential features of an objectoriented life cycle model to fulfill the benefits of object-oriented development? And thirdly, what are the pitfalls of object-oriented development and how to cope with them? The paper investigates answers to all three questions in concert.},
  volume = {3}
}

@inproceedings{Ebert1994a,
  author = {J{\"u}rgen Ebert AND Gregor Engels},
  title = {Structural and Behavioural Views on OMT-Classes},
  booktitle = {Proceedings of the International Symposium on Object-Oriented Methodologies and Systems (ISOOMS 1994), Palermo (Italy)},
  year = {1994},
  editor = {E. Bertino, S. Urban},
  pages = {142-157},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {Object-oriented specification languages provide means to specify the static structure, as well as the allowed dynamic behaviour of objects. Here, the dynamic behaviour is usually described by giving the methods and a state transition diagram which defines the allowed sequences of methods on objects of a certain class.Specialized classes are defined using the inheritance relationship. In order to enable reusability while guaranteeing type substitutability, subclass specifications have to be compatible with respect to static and dynamic aspects with their corresponding superclass specifications.Classes have to provide a large shopping list of operations to satisfy the needs of all possible users. The interests of specific users are often restricted to a subset of operations and thus to a restricted behaviour.This paper describes a formalization of class descriptions given by attributes, operations, as well as state transition diagrams. It defines compatibility between sub- and superclasses and introduces the notion of views in the sense of hiding parts of a class description. It turns out that a view has the same properties as a (virtual) superclass.},
  volume = {858}
}

@inproceedings{Engels94,
  author = {Gregor Engels AND Hartmut Ehrig},
  title = {Towards a Module Concept for Graph Transformation Systems: The Software Engineering Perspective},
  booktitle = {Proceedings Colloquium on Graph Transformation and its Application in Computer Science},
  year = {1994},
  editor = {G. Valiente Feruglio and F. Rossello Llompart},
  publisher = {Universitat de les Illes Balears, Departament de Ci},
  month = {M{\"a}rz},
  series = {Technical Report },
  volume = {B-19}
}

@inproceedings{Engels1993,
  author = {Gregor Engels AND A.A. Verrijn-Stuart},
  title = {Integrationsaspekte bei verteilter Software-Entwicklung},
  booktitle = {Fortschritt-Berichte VDI},
  year = {1993},
  pages = {45--53},
  publisher = {VDI Verlag},
  month = {October},
  series = {Reihe 10: Informatik/Kommunikationstechnik}
}

@inproceedings{Koopman1992,
  author = {Pieter Koopman AND Luuk Groenewegen AND Gregor Engels},
  title = {Functional Description of Parallel Processes},
  booktitle = {Proceedings of the conference SION Computing Science in the Netherlands (CSN '92), The Netherlands},
  year = {1992},
  editor = {J.L.G. Dietz},
  pages = {156--167},
  note = {SION}
}

@inproceedings{Hohenstein1990,
  author = {Uwe Hohenstein AND Gregor Engels},
  title = {Formal Semantics of an Entity-Relationship Query Language},
  booktitle = {Proceedings of the 9th International Conference on Entity-Relationship Approach (ER 90), Lausanne, Switzerland},
  year = {1990},
  editor = {H. Kangassalo},
  pages = {177--188},
  publisher = {ER Institute},
  month = {October}
}

@inproceedings{Engels1989a,
  author = {Gregor Engels},
  title = {CADDY-O: Syntaxgest{\"u}tztes, graphisches Entwerfen konzeptioneller Datenbankschemata},
  booktitle = {Tagungsband GI-Fachtagung "Interaktive Schnittstellen f{\"u}r Informationssysteme", TU Clausthal, Notizen zu Interaktive Systeme},
  year = {1989},
  editor = {A. Heuer, I. Kupka},
  pages = {1-16},
  month = {November},
  volume = {18}
}

@inproceedings{Engels1989b,
  author = {Gregor Engels AND Uwe Hohenstein AND Klaus H{\"u}lsmann AND Perdita L{\"o}hr-Richter AND Hans-Dietrich Ehrich},
  title = {CADDY: Computer-Aided Design of Non-Standard Databases},
  booktitle = {Proceedings of the International Conference on System Development Environments \& Factories, Berlin, Germany},
  year = {1989},
  editor = {N. Madhavji, W. Sch{\"a}fer, H. Weber},
  publisher = {Pitman Publishing},
  address = {Berlin},
  month = {May}
}

@inproceedings{Ebert1989,
  author = {J{\"u}rgen Ebert AND Gregor Engels},
  title = {Konzepte einer Software-Architektur-Beschreibungssprache},
  booktitle = {Software-Entwicklung: Konzepte, Erfahrungen, Perspektiven, Fachtagung, 1989, Marburg (Germany)},
  year = {1989},
  editor = {W.-M. Lippe},
  pages = {238--250},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  month = {June},
  series = {Informatik-Fachberichte},
  volume = {212}
}

@inproceedings{Engels1988,
  author = {Gregor Engels AND Thorsten Janning AND Wilhelm Sch{\"a}fer},
  title = {A Highly Integrated Tool Set for Program Development Support},
  booktitle = {Proceedings of the conference on ACM SIGSMALL/PC symposium on ACTES (SIGSMALL 1988), Cannes (France)},
  year = {1988},
  pages = {1--10},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  note = {SIGSMALL '88: Proceedings of the 1988 ACM SIGSMALL/PC symposium on ACTES},
  abstract = {This paper describes the design of the integrated user interface of the software development environment IPSEN (Integrated Programming Support Environment). We explain the characteristic features of the IPSEN user interface, namely the structured layout of the screen, the command-driven tool activation, and especially the highly integrated use of the IPSEN tool set. We demonstrate those features by taking a sample set of tools of the IPSEN environment. That tool set supports all the programming-in-the-small activities within IPSEN. Finally, we sketch the realization of two prototypes running on an IBM-AT and a net of SUN workstations.}
}

@inproceedings{EngelsHNSE1988a,
  author = {Gregor Engels AND Uwe Hohenstein AND Leonore Neugebauer AND Gunter Saake AND Hans-Dietrich Ehrich},
  title = {Konzeption einer integrierten Datenbank-Entwurfsumgebung},
  booktitle = {Proceedings of DBTA/SI Data Dictionaries und Entwicklungswerkzeuge f{\"u}r Datenbank-Anwendungen, Z{\"u}rich, Switzerland},
  year = {1988},
  editor = {F. Oertly},
  pages = {151--157},
  publisher = {Verlag der Fachvereine an den Schweiz. Hochschulen und Techniken}
}

@inproceedings{Engels1987,
  author = {Gregor Engels AND Andy Sch{\"u}rr},
  title = {A Hybrid Interpreter in a Software Development Environment},
  booktitle = {Proceedings of the 1st European Software Engineering Conference (ESEC '87), Strasbourg (France)},
  year = {1987},
  editor = {H.K. Nichols, D. Simpson},
  pages = {80--88},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {This paper describes the realization of an execution tool for Modula-2 modules which ispart of an integrated tool set in a software development environment termed IPSEN (IncrementalProgramming Support Environment). In this environment, all software documents, e.g.Modula-2 modules, are manipulated by syntax-directed editors and are represented internallyby attributed graphs. The execution of Modula-2 modules is done by two cooperating interpreters.The first one is a graph interpreter which traverses the internal graph from statementto statement. These statements are translated into a low-level, more efficiently executable objectcode and interpreted by a second interpreter. This concept of a hybrid interpreter allowsthe realization of an execution tool which offers a lot of runtime support features to the user.},
  volume = {289}
}

@inproceedings{EngelsNS1987a,
  author = {Gregor Engels AND Manfred Nagl AND Wilhelm Sch{\"a}fer},
  title = {On the Structure of Structure-Oriented Editors for Different Applications},
  booktitle = {Proceedings of the ACM SIGSOFT/SIGPLAN Software Engineering Symposium on Practical Software Development Environments, Palo Alto, USA},
  year = {1987},
  editor = {P. Henderson},
  pages = {190--198},
  publisher = {ACM SIGPLAN Notices},
  month = {January},
  journal = {SIGPLAN Not.},
  volume = {22}
}

@inproceedings{EngelsLNS1986b,
  author = {Gregor Engels AND Claus Lewerentz AND Manfred Nagl AND Wilhelm Sch{\"a}fer},
  title = {On the Structure of an Incremental and Integrated Software Development Environment},
  booktitle = {Proceedings of the 19th Hawaii International Conference on System Sciences, Hawaii, USA},
  year = {1986},
  pages = {585--597},
  volume = {2a}
}

@inproceedings{Engels1985a,
  author = {Gregor Engels AND Wilhelm Sch{\"a}fer},
  title = {Graph Grammar Engineering: A Method Used for the Development of an Integrated Programming Support Environment},
  booktitle = {Proceedings of the International Joint Conference on Theory and Practiceof Software Development (TAPSOFT 1985), Berlin (Germany)},
  year = {1985},
  editor = {H. Ehrig, C. Floyd, M. Nivat, J. W. Thatcher},
  pages = {179--193},
  publisher = {Springer},
  address = {Berlin/Heidelberg},
  abstract = {We introduce a method to specify the functional behaviour of software tools in an incremental and integrated software development environment. This specification method is based on graph grammars. It is an adequate method to specify the behaviour of all software systems using graphs as internal data structures. We show that a specification can be developed systematically by which the adaptability of the environment is increased towards modification of tools or extension by new tools. Furthermore, guidelines for the implementation can directly be derived from this specification.},
  series = {LNCS},
  volume = {186}
}

@inproceedings{EngelsS1985m,
  author = {Gregor Engels AND Wilhelm Sch{\"a}fer},
  title = {The Design of an Adaptive and Portable Programming Support Environment},
  booktitle = {Proceedings of the International Computing Symposium, Amsterdam (The Netherlands)},
  year = {1985},
  editor = {G. Valle, G. Bucci},
  address = {Florenz}
}

@inproceedings{Pletat1982,
  author = {Udo Pletat AND Gregor Engels AND Hans-Dietrich Ehrich},
  title = {An Operational Approach to Conditional Algebraic Specifications},
  booktitle = {Proceedings of the 7eme Colloque sur les Arbres en Algebre et en Programmation, Lille (France)},
  year = {1982},
  editor = {H.J. Schneider, H. G{\"o}ttler},
  pages = {254--270},
  month = {March },
  abstract = {We suppose to give conditional specifications of abstract data types hierarchically. Considering algebraic specifications from an operational point of view this approach enables us to present simple syntactic criteria for the Church-Rosser property, which implies the welldefinedness of the operational semantics of a conditional specification. Furthermore, these criteria are sufficient for the termination of the full substitution reduction strategy. },
  volume = {82}
}

@inproceedings{Engels1982,
  author = {Gregor Engels AND Wilhelm Sch{\"a}fer},
  title = {Specification of a Programming Support Environment by Graph Grammars},
  booktitle = {Proceedings of the conference on Graphtheoretic Concepts in Computer Science (WG`82), M{\"u}nchen (Germany)},
  year = {1982},
  editor = {H.J. Schneider and H. G{\"o}ttler},
  pages = {47--62},
  publisher = {Hanser},
  address = {M{\"u}nchen/Leipzig}
}

@inproceedings{fle2013,
  author = {Masud Fazal-Baqaie AND Markus Luckey AND Gregor Engels},
  title = {Assembly-based Method Engineering with Method Patterns},
  booktitle = {Software Engineering 2013 Workshopband},
  year = {2013},
  editor = {M. Kuhrmann, D. M. Fern{'a}ndez, O. Linsen, A. Knapp},
  pages = {435-444},
  publisher = {GI, K{\"o}llen Druck+Verlag GmbH, Bonn},
  abstract = {Software development methods prescribe and coordinate the activities necessary to plan, build, and deliver software. To provide methods that account for the situational context of a development project, e.g., an acquirer-supplier-relationship or specific communication needs, the existing method creation approaches represent a trade-off between flexibility and ease of use. On the side, less flexible configurable methods offer a fixed set of configurations to quickly adapt a method to the situation at hand. On the other side, flexible assembly-based approaches allow creating methods from scratch by combining preexisting building blocks, thus are capable of creating methods not covered by configurations of configurable methods, e.g., a mixture of agile and plan-driven ideas. However, assembly-based approaches are not easy to use and require considerable expert knowledge. In this paper we suggest the use of method patterns during the assembly-based method creation. Method patterns represent desirable principles for the to-be-method and therefore support the right choice and combination of method building blocks, simplifying assembly-based method creation.},
  journal = {Software Engineering 2013 Workshopband}
}

@inproceedings{spij2013,
  author = {Michael Spijkerman},
  title = {Ein pragmatischer Ansatz zur Entwicklung situationsgerechter Entwicklungsmethoden},
  booktitle = {Proceedings of Modellierung von Vorgehensmodellen - Paradigmen, Sprachen, Tools (MVV2013) at SE 2013 (to appear)},
  year = {2013},
  editor = {M. Kuhrmann, D. M. Fern{'a}ndez, O. Linsen, A. Knapp},
  note = {to appear}
}

@inproceedings{CAiSE13_Nagel,
  author = {Benjamin Nagel AND Christian Gerth AND Jennifer Post AND Gregor Engels},
  title = {Kaos4SOA - Extending KAOS Models with Temporal and Logical Dependencies},
  booktitle = {Proceedings of the Forum at the CAiSE'13 Conference on Advanced Information Systems Engineering(accepted for publication)},
  year = {2013},
  publisher = {CEUR-WS.org},
  series = {CEUR Workshop Proceedings}
}

@inproceedings{GSSEDFF2013,
  author = {Marvin Grieger AND Stefan Sauer},
  title = {Wiederverwendbarkeit von Migrationswissen durch Techniken der modellgetriebenen Softwareentwicklung},
  booktitle = {Software Engineering 2013 Workshopband},
  year = {2013},
  editor = {Stefan Wagner und Horst Lichter},
  pages = {189-200},
  publisher = {GI, K{\"o}llen Druck+Verlag GmbH, Bonn},
  journal = {Software Engineering 2013 Workshopband}
}

@inproceedings{CAiSE12_Huma_Gerth,
  author = {Zille Huma AND Christian Gerth AND Gregor Engels AND Oliver Juwig},
  title = {A UML-based Rich Service Description for Automatic Service Discovery},
  booktitle = {Proceedings of the Forum at the CAiSE'12 Conference on Advanced Information Systems Engineering},
  year = {2012},
  pages = {90--97},
  publisher = {CEUR-WS.org},
  abstract = {Service-oriented computing (SOC) emerges as a promising trend solving many issues in distributed software development. Followingthe essence of SOC, service descriptions are dened by the service partners in their independent heterogeneous domains based on current standards, such as, WSDL. However, these standards are mostly syntacticand do not provide any semantic description which may lead to inaccurate service discovery results. Currently many research efforts aim at formulating rich service descriptions for service partners comprisingsyntactic as well as semantic information. However, due to the underlying heterogeneity of service partners in terms of different underlying ontologies, different description notations, etc., matching of rich servicedescriptions for accurate service discovery is a complex task. In this paper, we come up with a proposal for rich service descriptions based on the UML.},
  series = {CEUR Workshop Proceedings},
  volume = {855}
}

@inproceedings{cma12,
  author = {Gunter Mussbacher AND Omar Alam AND Mohammed Alhaj AND Shaukat Ali AND Nuno Am{'a}lio AND Balbir Barn AND Rolv Bræk AND Tony Clark AND Benoit Combemale AND Luiz Marcio Cysneiros AND Urooj Fatima AND Robert France AND Geri Georg AND Jennifer Horkoff AND J{\"o}rg Kienzle AND Julio Cesar Leite AND Timothy C. Lethbridge AND Markus Luckey AND Ana Moreira AND Felix Mutz AND A. Padua A. Oliveira AND Dorina C. Petriu AND Matthias Sch{\"o}ttle AND Lucy Troup AND Vera M. B. Werneck},
  title = {Assessing composition in modeling approaches},
  booktitle = {Proceedings of the Workshop about Comparing Modeling Approaches 2012 (@MODELS 2012)},
  year = {2012},
  publisher = {ACM},
  address = {New York, NY, USA},
  series = {CMA'12}
}

@inproceedings{Arifulina2012a,
  author = {Svetlana Arifulina AND Christian Soltenborn AND Gregor Engels},
  title = {Coverage Criteria for Testing DMM Specifications},
  booktitle = {Proceedings of the 11th International Workshop on Graph Transformation and Visual Modeling Techniques (GT-VMT 2012), Tallinn (Estonia)},
  year = {2012},
  editor = {A. Fish, L. Lambers},
  publisher = {European Association of Software Science and Technology (EASST)},
  abstract = {Behavioral modeling languages are most useful if their behavior is specified formally such that it can e.g. be analyzed and executed automatically. Obviously, the quality of such behavior specifications is crucial. The rule-based semantics specification technique Dynamic Meta Modeling (DMM) honors this by using the approach of Test-driven Semantics Specification (TDSS), which makes sure that the specification at hand at least describes the correct behavior for a suite of test models. However, in its current state TDSS does not provide any means to measure the quality of such a test suite.In this paper, we describe how we have applied the idea of test coverage to TDSS. Similar to common approaches of defining test coverage criteria, we describe a data structure called invocation graph containing possible orders of applications of DMM rules. Then we define different coverage criteria based on that data structure, taking the rule applications caused by the test suite's models into account. Our implementation of the described approach gives the language engineer using DMM a means to reason about the quality of the language's test suite, and also provides hints on how to improve that quality by adding dedicated test models to the test suite.},
  series = {Electronic Communications of the EASST},
  volume = {47}
}

@inproceedings{Geisen 022012,
  author = {Silke Geisen},
  title = {Ein Ansatz zur Anpassung von Software Engineering Methoden im laufenden Projekt},
  booktitle = {Proceedings of Software Engineering 2012 (SE 2012) - Doktorandensymposium},
  year = {2012},
  pages = {7-12},
  publisher = {Petra Hofstedt, Claus Lewerentz (BTU Cottbus)},
  abstract = {Um die erfolgreiche Entwicklung einer Software zu gew{\"a}hrleisten, wird die Software Engineering Methode (SEM) zu Beginn eines Projektes auf die Projektsituation abgestimmt. Doch gerade {\"A}nderungen an der Projektsituation oder mangelnde Qualit{\"a}t w{\"a}hrend der Durchf{\"u}hrung machen eine dynamische Anpassung der SEM n{\"o}tig. Mit bekannten Verbesserungs- bzw. Anpassungsverfahren wie Six Sigma oder dem Deming Cycle, ist dies nur schwer oder gar nicht m{\"o}glich. Ans{\"a}tze aus dem Autonomic Computing beobachten selbstst{\"a}ndig Systeme {\"u}ber Feedbackschleifen und passen das System gegebenenfalls an. Diese Arbeit besch{\"a}ftigt sich mit der Idee, wie sich eine solche Feedbackschleife f{\"u}r die dynamische Anpassung von Software Engineering Methoden nutzen l{\"a}sst.},
  volume = {Report 01/12}
}

@inproceedings{Geisen_Luckey092012,
  author = {Silke Geisen AND Markus Luckey AND Gregor Engels},
  title = {Ein Ansatz zur dynamischen Qualit{\"a}tsmessung,-bewertung und Anpassung von Software Engineering Methoden},
  booktitle = {Proceedings of 19. GI-WIVM Workshop: Qualit{\"a}tsmanagement und Vorgehensmodelle},
  year = {2012},
  pages = {111-120},
  publisher = {Shaker Verlag},
  month = {September},
  abstract = {Damit die erfolgreiche Entwicklung einer Software und damit der Erfolg eines Projektes gew{\"a}hrleistet ist, wird h{\"a}ufig eine Software Engineering Methode (SEM) zu Beginn auf die Projektsituation abgestimmt. Doch w{\"a}hrend der Durchf{\"u}hrung der Software Engineering Methode k{\"o}nnen {\"A}nderungen an der Projektsituation oder mangelnde Qualit{\"a}t den Projekterfolg gef{\"a}hrden. Diese Situationen machen eine dynamische Anpassung der SEM, insbesondere zur Erreichung der Qualit{\"a}tsziele, erforderlich. Bekannte Verbesserungs- bzw. Anpassungsverfahren wie Six Sigma oder dem Deming Cycle sind aufgrund ihrer langen Durchf{\"u}hrungsdauer kaum f{\"u}r eine solche Anpassung geeignet. Ferner finden diese Verfahren typischerweise nach einem Projekt statt und betrachten selten {\"A}nderungen an der aktuellen Projektsituation oder die Qualit{\"a}t der SEM w{\"a}hrend der Durchf{\"u}hrung. Agile Methoden wie Scrum nutzen erste M{\"o}glichkeiten zur Inspektion und Anpassung im laufenden Projekt. Diese Idee soll aufgegriffen und weiter verbessert werden. Im Gegensatz zu Six Sigma und dem Deming Cycle beobachten Ans{\"a}tze aus dem Autonomic Computing zur Laufzeit selbstst{\"a}ndig Systeme {\"u}ber Feedbackschleifen und passen das System gegebenenfalls an. Das bekannteste Modell ist die sogenannte MAPE-K Schleife. Diese Arbeit stellt einen Ansatz vor, wie sich die MAPE-K Schleife f{\"u}r die dynamische Anpassung von Software Engineering Methoden sowie zur kontinuierlichen Qualit{\"a}tsmessung und Bewertung nutzen l{\"a}sst.}
}

@inproceedings{GSL2012,
  author = {Baris G{\"u}ldali AND Stefan Sauer AND Perdita L{\"o}hr},
  title = {Entwicklung eines Softwarewerkzeugs f{\"u}r die modellgetriebene Migration betrieblicher Informationssysteme},
  booktitle = {Proceedings of the Workshop Modellbasierte und Modellgetriebene Softwaremodernisierung (MMSM 2012)},
  year = {2012},
  editor = {Udo Kelter},
  pages = {5-6},
  publisher = {Softwaretechnik-Trends},
  month = {Mai},
  journal = {Softwaretechnik-Trends},
  volume = {32}
}

@inproceedings{nagel_mdhpcl12,
  author = {Benjamin Nagel AND Christian Gerth AND Enes Yigitbas AND Fabian Christ AND Gregor Engels},
  title = {Model-driven Specification of Adaptive Cloud-based Systems},
  booktitle = {Proceedings of 1st International Workshop on Model-Driven Engineering for High Performance and Cloud Computing (MDHPCL) at MODELS'12},
  year = {2012}
}

@inproceedings{luckey_cma12,
  author = {Markus Luckey AND Felix Mutz},
  title = {Modeling with Adapt Cases},
  booktitle = {Repository for Model-Driven Development (ReMoDD)},
  year = {2012},
  organization = {University of Paderborn},
  note = {http://www.cs.colostate.edu/remodd/v1/content/modeling-adapt-cases}
}

@inproceedings{luckey_eval4saso12,
  author = {Markus Luckey AND Christian Thanos AND Christian Gerth AND Gregor Engels},
  title = {Multi-Staged Quality Assurance for Self-Adaptive Systems},
  booktitle = {Proceedings of 1st International Workshop on EVALUATION for SELF-ADAPTIVE and SELF-ORGANIZING SYSTEMS at SASO'12 (to appear)},
  year = {2012}
}

@inproceedings{GGSWSR142012,
  author = {Marvin Grieger AND Baris G{\"u}ldali AND Stefan Sauer},
  title = {Sichern der Zukunftsf{\"a}higkeit bei der Migration von Legacy-Systemen durch modellgetriebene Softwareentwicklung},
  booktitle = {Proceedings of the 14th Workshop Software-Reengineering (WSR 2012)},
  year = {2012},
  editor = {Udo Kelter},
  pages = {37-38},
  publisher = {Softwaretechnik-Trends},
  journal = {Softwaretechnik-Trends},
  volume = {32}
}

@inproceedings{Arifulina2012b,
  author = {Svetlana Arifulina},
  title = {Towards a Framework for the Integration of Modeling Languages},
  booktitle = {Proceedings of the Doctoral Symposium of the 5th International Conference on Software Language Engineering 2012 (SLEDS 2012), Dresden (Germany)},
  year = {2012},
  editor = {Ulrich W. Eisenecker; Christian Bucholdt},
  pages = {23-26},
  publisher = {CEUR Workshop Proceedings (CEUR-WS.org)},
  month = {Sep},
  abstract = {In software markets of the future, customer-specific software will be developed on demand from distributed software and hardware services available on world-wide markets. Having a request, services have to be automatically discovered and composed. For that purpose, services have to be matched based on their specifications. For the accurate matching, services have to be described comprehensively that requires the integration of different domain-specific languages (DSLs) used for functional, non-functional, and infrastructural properties. Since different service providers use plenty of language dialects to model the same service property, their integration is needed for the matching. In this paper, we propose a framework for integration of DSLs. It is based on a parameterized abstract core language that integrates key concepts needed to describe a service. Parts of the core language can be substituted with concrete DSLs. Thus, the framework serves as a basis for the comprehensive specification and automatic matching of services.}
}

@inproceedings{rich_change_mgmt_gerth_luckey_2012,
  author = {Christian Gerth AND Markus Luckey},
  title = {Towards Rich Change Management for Business Process Models},
  booktitle = {Proceedings of the Workshop on Comparison and Versioning of Software Models (CVSM'12)},
  year = {2012},
  editor = {Udo Kelter},
  pages = {32-34},
  publisher = {FG Softwaretechnik, Gesellschaft f{\"u}r Informatik e.v. (GI)},
  month = {November},
  abstract = {Business process models play an important role in the development of large IT systems, since they are easy to understand by all project stakeholders. High-level process models may be created by domain experts, which are stepwise refined in later development phases until they become executable. To establish such model-driven development (MDD) approaches in praxis, a comprehensive tool support of the complete model life cycle is necessary including model change management in particular. In this position paper, we give an overview of our framework for change management of business process models. This framework allows to merge process models in different modeling languages and considers the execution semantics of process models during comparison. Based on these results, we derive further research challenges with the aim to obtain a rich change management solution for business process models.},
  journal = {Softwaretechnik-Trends},
  series = {Softwaretechnik-Trends},
  volume = {32}
}

@inproceedings{brueseke2011a,
  author = {Frank Br{\"u}seke AND Steffen Becker AND Gregor Engels},
  title = {Palladio-based performance blame analysis},
  booktitle = {Proceedings of the 16th International Workshop on Component-Oriented Programming (WCOP; satellite event of the CompArch 2011), Boulder Colorado, CO (USA)},
  year = {2011},
  editor = {R. Reussner, C. Szyperski, W. Weck},
  pages = {25-32},
  publisher = {ACM},
  address = {New York, NY (USA)},
  abstract = {Performance is an important quality attribute for business information systems. When a tester has spotted a performance error, the error is passed to thesoftware developers to fix it. However, in component-based software development the tester has to do blame analysis first, i. e. the tester has to decide, which party is responsible to fix the error. If the error is a design or deployment issue, itcan be assigned to the software architect or the system deployer. If the erroris specific to a component, it needs to be assigned to the corresponding component developer. An accurate blame analysis is important, because wrong assignments of errors will cause a loss of time and money. Our approach aims at doing blame analysis for performance errors by comparing performance metrics obtained in performance testing and performance prediction. We use performance prediction values as expected values for individual components. For performance prediction we use the Palladio approach. By this means, our approach evaluates each component's performance in a certain test case. If thecomponent performs poorly, its component developer needs to fixthe component or the architect replaces the component with afaster one. If no omponent performs poorly, we can deduce that there is a design or deployment issue and the architecture needs to be changed. In this paper, we present an exemplary blame analysis based on a web shop system. The example shows the feasibility of our approach. }
}

@inproceedings{Nagel2011,
  author = {Benjamin Nagel},
  title = {Semi-automatische Ableitung externer Anpassungsmechanismen f{\"u}r selbst-adaptive Systeme},
  booktitle = {Proceedings of the Software Engineering 2011 (SE 2011), Karlsruhe (Germany)},
  year = {2011},
  publisher = {Gesellschaft f{\"u}r Informatik (GI)},
  address = {Bonn},
  series = {Lecture Notes in Informatics}
}

@inproceedings{GerthWS10,
  author = {Christian Gerth},
  title = {A Framework for Change Management of Business Process Models},
  booktitle = {Proceedings of the Joint Workshop of the German Research Training Groups in Computer Science},
  year = {2010},
  editor = {DFG Research Training Group 1298 "AlgoSyn" RWTH Aachen University},
  pages = {183-184},
  organization = {DFG},
  month = {May}
}

@inproceedings{EMDT2010,
  author = {Baris G{\"u}ldali AND Michael Mlynarski},
  title = {Agility vs. Model-based Testing: A fair Play?},
  booktitle = {Proceedings of the IWK2010 Workshops: The First International Workshop on Evolution Support for Model-Based Development and Testing (EMDT2010)},
  year = {2010},
  editor = {Bode,S. et al.},
  pages = {55-58 },
  note = {(invited paper)},
  abstract = {Agile manifesto defines principles for a light-weight software development process aiming at an improved customer satisfaction. Automated testing plays an important role in fulfilling these principles, because it enables efficient execution of test scripts for checking the quality of delivered software. However, the implementation and the maintenance of the test scripts can be very tedious and error-prone. In order to deal with that, model-based testing extends the automated test execution by test design and test implementation. Thus, model-based testing can speed up the test automation and improve the maintenance of test scripts. Nevertheless, introducing model-based testing requires some initial and some continual efforts, like creating test models, buying or developing tools, etc. In this talk, we will discuss how model-based testing can support agile development without conflicting with the principles of agile manifesto.},
  series = {CEUR Workshop Proceedings},
  volume = {646}
}