ICB Institut für Informatik und Wirtschaftsinformatik Research Group Core Research Topics Prof. Dr. H. H. Adelsberger E-Learning, Knowledge Management, Skill-Management, Information Systems for Production and Operations Simulation, Artificial Intelligence Management Prof. Dr. P. Chamoni Information Systems and Operations Research, Ulrich Frank MIS and Management Science / Operations Research Business Intelligence, Data Warehousing Prof. Dr. F.-D. Dorloff E-Business, E-Procurement, E-Government Procurement, Logistics and Information Management Prof. Dr. K. Echtle Dependability of Computing Systems Dependability of Computing Systems Prof. Dr. S. Eicker Process Models, Software-Architectures Information Systems and Software Engineering Prof. Dr. U. Frank Enterprise Modelling, Enterprise Application Integration, Information Systems and Enterprise Modelling IT Management, Knowledge Management Prof. Dr. M. Goedicke Distributed Systems, Software Components, CSCW The MEMO Meta Modelling Language Specification of Software Systems Prof. Dr. V. Gruhn Design of Software Processes, Software Architecture, Usabi- (MML) and Language Architecture Software Engineering lity, Mobile Applications, Component-based and Generative Software Development Prof. Dr. T. Kollmann E-Business and Information Management, ICB-RESEARCH REPORT E-Business and E-Entrepreneurship E-Entrepreneurship/E-Venture, Virtual Marketplaces and nd Mobile Commerce, Online-Marketing 2 Edition 43 Prof. Dr. B. Müller-Clostermann Performance Evaluation of Computer and Communication Systems Modelling Systems, Modelling and Simulation Prof. Dr. K. Pohl Requirements Engineering, Software Quality Assurance, Software Systems Engineering Software-Architectures, Evaluation of COTS/Open Source- Components Prof. Dr.-Ing. E. Rathgeb Computer Networking Technology Computer Networking Technology Prof. Dr. Enrico Rukzio Novel Interaction Technologies, Personal Projectors, Mobile Mensch Computer Interaktion mit Software Services Pervasive User Interfaces, Ubiquitous Computing Prof. Dr. A. Schmidt Pervasive Computing, Uniquitous Computing, Automotive User Pervasive Computing Interfaces, Novel Interaction Technologies, Context-Aware Computing Prof. Dr. R. Unland Data Management, Artificial Intelligence, Software Data Management Systems and Knowledge Representation Engineering, Internet Based Teaching Prof. Dr. S. Zelewski Industrial Business Processes, Innovation Management, Institute of Production and Industrial Information Management Information Management, Economic Analyses ISSN 1860-2770 (Print) ICB-Research Report No. 43 ISSN 1866-5101 (Online) February 2011 Die Forschungsberichte des Instituts The ICB Research Reports comprise für Informatik und Wirtschaftsinfor- preliminary results which will usually matik dienen der Darstellung vorlä u- be revised for subsequent publica- figer Ergebnisse, die i. d. R. noch für tions. Critical comments would be spätere Veröffentlichungen überarbei- appreciated by the authors. tet werden. Die Autoren sind deshalb für kritische Hinweise dankbar. Alle Rechte vorbehalten. Insbesondere All rights reserved. No part of this die der Übersetzung, des Nachdru- report may be reproduced by any ckes, des Vortrags, der Entnahme von means, or translated. Abbildungen und Tabellen – auch bei nur auszugsweiser Verwertung. ICB Research Reports Authors’ Address: Edited by: Ulrich Frank Prof. Dr. Heimo Adelsberger Prof. Dr. Peter Chamoni Institut für Informatik und Prof. Dr. Frank Dorloff Wirtschaftsinformatik (ICB) Prof. Dr. Klaus Echtle Universität Duisburg-Essen Prof. Dr. Stefan Eicker Universitätsstr. 9 Prof. Dr. Ulrich Frank D-45141 Essen Prof. Dr. Michael Goedicke [email protected] Prof. Dr. Volker Gruhn Prof. Dr. Tobias Kollmann Prof. Dr. Bruno Müller-Clostermann Prof. Dr. Klaus Pohl Prof. Dr. Erwin P. Rathgeb Prof. Dr. Enrico Rukzio Prof. Dr. Albrecht Schmidt Prof. Dr. Rainer Unland Prof. Dr. Stephan Zelewski Contact: Institut für Informatik und Wirtschaftsinformatik (ICB) Universität Duisburg-Essen Universitätsstr. 9 45141 Essen Tel.: 0201-183-4041 Fax: 0201-183-4011 Email: [email protected] ISSN 1860-2770 (Print) ISSN 1866-5101 (Online) Preface to Revised Edition A substantial amount of research and critical evaluation had gone into the MEMO meta modelling language when it was first published in 2007. This was for a good reason: A meta modelling language should be invariant for a longer time, since it is the foundation of an entire family of languages. Therefore, changing the meta modelling language jeopardizes the integrity of the respective modelling languages and the corresponding model editors. Never- theless, our work on specifying modelling languages produced some additional require- ments we were not aware of at first. It also revealed a few misconceptions. These discoveries led to a minor revision of the meta modelling language that was published in 2010. During the last months one further requirement evolved that is related to the very conception of modelling language. It also turned out that one concept in the meta meta model was speci- fied on an inappropriate level of abstraction. Fortunately, this misconception did not result in erroneous implementations of corresponding tools because it was filtered out by an ade- quate interpretation of those who developed the software. The resulting revision of the meta modelling language may seem minor, because it affects mainly concepts in the meta meta model only. Nevertheless, it represents a major change, because it reflects an extended con- ception of modelling language. In addition to that, the meta modelling language was sup- plemented by an extensible set of ‚auxiliary‛ types. While these do not affect the semantics of the meta meta model, they promote the productivity of developing modelling languages and contribute to a higher level of consistency and coherence within a family of modelling languages. I also used the opportunity of a new edition for applying a few marginal changes. Among other things, they comprise the renaming of ‚deferredExternal‛ attributes to ‚ob- tainable‛. The changes are mainly motivated by the demand to provide an effective support for speci- fying domain-specific modelling languages. Unfortunately, they are accompanied by the unpleasant side-effect that the complexity of the meta meta model was increased – which compromises the reasonable requirement to keep a meta language simple. Since the research on modelling languages and their specification is far from having reached a mature state, it would be presumptuous to assume that the meta meta model will not require further modi- fications. I hope, however, that it serves us as a suitable foundation for developing languages and tools for the next years. Essen, February 2011 Ulrich Frank i Abstract The family of languages that builds the foundation of the MEMO method is intended to fea- ture a high degree of inter-language integration. For this purpose, the languages need to share common concepts. In order to define concepts that are semantically equivalent, it is recommendable to use the same meta modelling language for specifying the MEMO model- ling languages. The previous version of the meta modelling language used for this purpose needed a revision. At the same time, there was need to account for alternative approaches to specifying modelling languages, especially those offered by the OMG or the Eclipse founda- tion. This report starts with an analysis of requirements that should be accounted for by a meta modelling language. Subsequently, the UML infrastructure library and meta object fa- cility (MOF) are evaluated against these requirements. In addition to that, the report presents an evaluation of the Ecore model, which serves to represent meta models within the Eclipse Graphical Modeling Framework (GMF). The evaluation of both approaches shows that none of them is satisfactory as a meta modelling language for enterprise modelling. Then, the new version of the MEMO meta modelling language (MML) is presented. The language specifica- tion consists of a meta meta model that specifies that semantics and abstract syntax and a corresponding graphical notation (concrete syntax). The new version features a concept called intrinsic features that allows for differentiating between features that apply to types and those that apply to instances. It also includes a modified graphical notation that supports a clear distinction of meta models from models on other levels of abstraction. Finally, the report presents the outline of a tool that supports the creation and editing of MEMO meta models as well as their transformation into representations which can be used in the Eclipse modelling framework. ii Table of Contents PREFACE TO REVISED EDITION .................................................................................................................. I 1 INTRODUCTION ..................................................................................................................................... 1 2 META MODELLING LANGUAGES: REQUIREMENTS ................................................................. 2 2.1 GENERAL REQUIREMENTS FOR META MODELLING LANGUAGES .......................................................... 4 2.1.1 Formal Requirements ...................................................................................................................... 4 2.1.2 User-Oriented Requirements .......................................................................................................... 5 2.1.3 Application-Oriented