Enterprise Modelling

Over the last decade, Enterprise Modelling (EM) has received considerable attention in terms of applications and developments of new languages, tools and methodologies. Various formalisms and methods are now available (IDEF suite of methods, GRAI method, CIMOSA, ARIS or IEM, to name a few) and many commercial tools are available on the market (e.g. ARIS Toolset, FirstSTEP, Enterprise Modeller, MEGA, IBM Flow Mark, NCR Metis, PrimeObjects, Bonapart, MOGO, Imagim and many others including most work ̄ ow systems which have modelling capabilities). The three major thrusts for the rapid growth of enterprise modelling techniques have been: Enterprise Engineering (i.e. systematic and shortened development cycle engineering of a business entity, including Business Process Reengineering or BPR techniques), Enterprise Integration (i.e. increasing synergy and interoperation among people, systems and applications throughout the enterprise, including integration in manufacturing or CIM), and work ̄ ow management (WfM) dealing with automation of paper and document ̄ ows as well as control of business processes (AMICE 1993, Petrie 1992, Vernadat 1996, Kosanke and Nell 1997). Enterprise Modelling is concerned with externalising and structuring knowledge about various aspects of an enterprise, such as functional, information, organisation, economic or resources aspects. The scope and content of an enterprise model is decided by the end-user. The entity to be modelled is also decided by the end-user. The ® nality or the usage of the model will constrain what needs to be modelled and to what level of details. The aim of EM is to represent elements of the structure, behaviour and organisation of a business entity (be it an application system, a manufacturing cell, a complete manufacturing facility, an enterprise or a network of enterprises). The goal of EM is to support understanding of what happens in an enterprise, support design and analysis of a business entity, support performance evaluation of some parts of an enterprise, learn about the things of the enterprise, support decision-making activities both in the engineering and operation phases of the enterprise, and ® nally support enterprise reengineering programmes for continuous management of change. Enterprise Modelling has its origins back in the 70’ s when the ® rst structured modelling and analysis methods were developed in systems engineering and software engineering. The earlier approaches have been SADT (Structured Analysis and Design Technique) (Ross, 1977, 1985) from the functional viewpoint and the entity-relationship approach (Chen, 1976) from the information viewpoint. They have been followed by a number of so-called data ̄ ow diagram (DFD) techniques (DeMarco, 1978; Gane and Sarson, 1979) and many information system analysis and design methodologies (NIAM, MERISE, HIPO, DATAID, REMORA, . . .). Then, came the IDEF methods for integrated manufacturing (ICAM, 1981) and the GRAI method for production system analysis (Doumeingts, 1984). These were very much activity-centred. More recently, the ® eld of Enterprise Modelling has been drastically impacted by two diå erent classes of approaches: one which is strongly emphasising the business process centred approach (Mayer et al., 1992; AMICE, 1993; Vernadat, 1996; Scheer, 1999), and one which is fundamentally objectoriented (Rumbaugh et al., 1991; Booch, 1994; Jacobson et al., 1995). They can be combined as shown in recent books taking advantage of the UML (Uni® ed Modelling Language) notation (Marshall, 1999; Penker and Eriksson, 2000). As far as the Enterprise Modelling and Integration community is concerned, research and standardisation activities are co-ordinated by the IFAC-IFIP Task Force on Architectures for Enterprise Integration (http://www.cit.gu.edu.au/ bernus/taskforce/) and ISO TC 184 SC5 WG 1 in connection with CEN TC 310, its European counterpart. Enterprise Modelling can be applied to any part of an enterprise and has the potential to provide a detailed picture of what happens or should happen in the enterprise, especially if it is tightly coupled with simulation. Production Planning and Control activities are no exceptions. Indeed, planning and control systems need to be more accurate, more reactive and need to cope with continuous change in the enterprise. The implementation of ERP (Enterprise Resource Planning) systems is usually preceded by a detailed characterisation or modelling phase of the company’ s business. Also, because of new regulations concerning oæ cial working time per week and the need to optimise the use of human competencies, human aspects need to be taken into account in production planning and control systems. EM can therefore