UML vs. IDEF: AN ONTOLOGY-ORIENTED COMPARATIVE STUDY IN VIEW OF BUSINESS MODELLING Ovidiu Noran School of Computers and Information Technology, Griffith University Nathan (Brisbane) QLD 4111 Australia Keywords: Expressive power, modelling language, business modelling, UML, IDEF, ontologies, metamodels, modelling methodologies, Object-Oriented Analysis and Design. Abstract: The UML and IDEF sets of languages characterize typical modelling approaches of software engineering and computer integrated manufacturing, respectively. This paper presents a comparative analysis of these languages based on their ontologies and in view of their use in business modelling. A brief introduction to UML and IDEF is followed by a high-level comparison taking into account underlying paradigms and language structure. This is followed by a comparative assessment of the expressive power of the two groups of languages, based on the ontologies of their relevant components. The analysis is structured using a set of views deemed appropriate for the modelling domain (i.e. business). The key findings of this paper aim to provide an insight into the suitability of UML 'versus' that of IDEF in business modelling. 1 INTRODUCTION1 languages for developing business models. Also, the often-perceived failure of the software system to ac- The survival of businesses in today's demanding curately reflect the business that it supports has re- global market greatly depends on their agility, i.e. sulted in calls for the same set of languages to be their capability to respond adequately and timely to used in modelling both the business and its informa- changes in the environment. Agile businesses typi- tion system. cally thrive on such changes by implementing their This paper makes a contribution towards an own, continuous internal transformation processes. ontology-oriented comparison of the suitability and Business models help promote a deep understand- expressive powers of two candidate sets of languages 2 ing of the business and can support its operation .A for the purpose of business modelling, namely the business model is based on an ontology of changeand Unified Modelling Language (UML) and the Inte- as such it is an enabler of business agility. Busi- grated DEFinition (IDEF) family of languages. Both ness modelling aims to produce models that accu- sets of languages may be used to model aspects of a rately reflect aspects of the business required for the business, although they provide different degrees of intended use of the models, and which are understood support for the various views involved in the business by the target audience. Thus, the models must strike modelling effort. This comparative analysis intends to a balance between complexity and expressiveness, re- help the enterprise architect understand the available flected in the choice of modelling frameworks, lan- options, and thus make an informed choice of mod- guages and methodologies involved in the modelling elling languages for a specific business engineering effort. task. The complexity of the modelled targets often brings about the necessity to use a set of candidate 1the full version of this paper with additional compari- son aspects and a proposed assessment framework may be obtained from the author ( http://www.cit.gu.edu.au/˜noran) 2e.g. by means of model-based control 674 Noran O. (2004). UML vs. IDEF: AN ONTOLOGY-ORIENTED COMPARATIVE STUDY IN VIEW OF BUSINESS MODELLING. In Proceedings of the Sixth International Conference on Enterprise Information Systems, pages 674-682 DOI: 10.5220/0002629306740682 Copyright c SciTePress UML VS. IDEF: AN ONTOLOGY-ORIENTED COMPARATIVE STUDY IN VIEW OF BUSINESS MODELLING 2 INTRODUCTION TO IDEF AND 2.2 UML UML The Unified Modelling Language (UML) originates in three modelling method streams, represented by 2.1 IDEF Booch (Booch, 1991), Jacobson (Jacobson, 1994) and Rumbaugh (Rumbaugh et al., 1991). UML has The IDEF (originally an acronym for ICAM DEF- been subsequently complemented by the Unified Pro- inition) family of languages has its origins in the cess (Jacobson et al., 1999) - a software develop- 1970's US Air Force Integrated Computer Aided ment methodology based on an iterative development Manufacturing (ICAM) program, which aimed to cre- paradigm. ate computer-implementable modelling methods for The UML is a set of essentially graphical languages analysis and design (Menzel and Mayer, 1998). As expressed as diagrams. The component languages shown in Table 1, after the initial project which (refer Table 2) reflect the history of UML: created by yielded IDEF0 (NIST, 1993a; IEEE, 1998), IDEF1 unification, rather than competition 5. Despite their and IDEF2, there have been another two initia- syntax and semantics being defined in a set of meta- tives that have produced IDEF1X (IDEF1 eXtended) models (Rumbaugh et al., 1999) and associated se- (NIST, 1993b), and IDEF3 (Mayer et al., 1993), mantics (OMG, 1999b), the languages composing the IDEF4 and IDEF5, respectively. UML are not completely formalised, and hence sub- The current efforts within IDEF are focused on the ject to interpretation6. A comprehensive description refinement and integration3 of the existing languages, of UML is beyond the purpose of this paper 7. and the development of few others (see Table 1). The currently most used IDEF languages are IDEF0, IDEF1X and IDEF3. A complete introduc- Table 2: UML language components tion to the IDEF family of languages is beyond the UML Diagram Purpose Comments scope of this paper, but comprehensive IDEF infor- Class Structure modelling 4 mation is available . Structure (particular) Derived from Object modelling Class Use Case Function modelling High-level Table 1: The IDEF languages (based on (Cho, 2000)) Equiv to Sequence Behaviour modelling Collaboration Project Language Purpose Equiv. to st IDEF0 Function (activity) Modelling Collaboration Behaviour modelling 1 Generation Sequence (Original ICAM IDEF1 Information modelling State(chart) Behaviour modelling Project ) IDEF2 Simulation Modelling Use subset for Behaviour / Function nd Activity function 2 Generation. modelling (USAF Integrated modelling IDEF1x Data modelling Info Support Software- Component Implementation modelling System Project) specific 3rd Generation Behaviour modelling Environment (config.) Software- IDEF3 Deployment (USAF Integrated .(Process description capture) modelling specific Information for IDEF4 Object-oriented design Concurrent IDEF4++ C++ Object-oriented design Engineering Project) IDEF5 Ontology description capture IDEF6 Design Rationale Capture 3 A HIGH-LEVEL COMPARISON IDEF8 Human-System Interaction Design In Development IDEF9 Business Constraint Discovery IDEF14 Network Design 3.1 Evolution IDEF7 Information System Auditing Both sets of languages have appeared at a suitable IDEF10 Implem. Architecture .Modelling 8 Envisaged IDEF11 Information Artifact Modelling time and have had industry endorsement, either via IDEF12 Organizational Design Method 5e.g. it has been argued that some of the UML languages IDEF13 3-schema Archit Design Method are somewhat redundant or overlapping in their scope. 6precise UML (pUML, http://www.puml.org) is one ini- 3hence the IDEF acronym shift from ICAM DEFinition tiative that aims to address such issues. to Integration DEFinition 7for more information refer (Rumbaugh et al., 1999) 4white papers on IDEF languages and methods are cur- 8IDEF has answered a need for computer implementable rently available on www.idef.com and www.kbsi.com. Analysis and Design modelling methods/languages in man- 675 ICEIS 2004 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION government specification (IDEF) or merging of mod- (Rumbaugh et al., 1991). Thus, the IDEF family gives elling methods through developer, and end user par- the user flexibility in the choice of the analysis and de- ticipation in a consortium (in the case of UML). IDEF sign languages and modelling methods (although cur- has preceded UML by nearly a decade, and while rently, IDEF's OO extensions are not widely used or as such it has had more time to mature, it has also supported by modelling tools). needed to adapt to historic changes in modelling re- The IDEF family of languages offers components quirements. The ICAM project developing IDEF has (languages with associated methods) which allow tak- initially produced three languages aiming to model ing a holistic approach to business modelling (such as the static, informational and dynamic aspects. How- representing business artifacts in the context of life ever, various changes in the usage of analysis and de- cycle phases). On the UML side, the Unified Process sign paradigms (such as a shift from Data- and Func- may also provide a life cycle modelling methodology. tion Driven to Object-Oriented) has prompted a re- finement of existing languages and the addition of 3.3 Language Structure several new members to the IDEF family. Currently, the IDEF suite numbers 16 languages, A set of integrated languages must be based on a com- of which 6 are actively used. It appears that some mon metamodel that guarantees the consistency of its languages have subsumed the scope of others (e.g. components. The syntax and semantics of the IDEF 9 IDEF3 has obsoleted IDEF2 and contains IDEF5 el- languages are separately described in their associated ements; IDEF4 contains IDEF6 elements, and IDEF9 documentation; however, IDEF developers have not appears to have included most of IDEF6's scope). published a common metamodel underlying the com- UML has started with a total