The DEMO Methodology

In this chapter, DEMO is presented (Design and Engineering Methodology for Organisations), in order to produce the essential model of an enterprise or in general of a Scope of Interest (which may cover a part of one enterprise or of a network of enterprises). Like every proper methodology, DEMO comprises a Way of Thinking (WoT), a Way of Modelling (WoM) and a Way of Working (WoW). The WoT consists of the theories that are discussed in Part II of this book. The WoM consists of an integrated whole of four partial or sub-models: the Cooperation model (CM), the Action Model (AM), the Process Model (PM) and the Fact Model (FM). The CM of a Scope of Interest (SoI) is the ontological model of its construction, thus of the identified transactor roles and the coordination structures among them. Three structures are distinguished: the interaction structure, the interimpediment structure and the interstriction structure. The AM of an SoI is the ontological model of its operation. For every internal actor role, it provides the rules that guide the role fillers in doing their work. The guidelines for responding to coordination events are called action rules (similar to business rules), and the ones for performing production acts are called work instructions. The PM of an SoI is the ontological model of the state space and the transition space of its coordination world. The PM connects the CM and the AM of an SoI as far as coordination is concerned. The FM of an SoI is the ontological model of the state space and the transition space of its production world. The FM connects the CM and the AM of an SoI as far as production is concerned. All four sub-models are expressed in the DEMO Specification Language (DEMO-SL), which comprises diagrams, tables and formal textual descriptions. To produce essential models of enterprises, the WoW of DEMO offers the OER method (Organisational Essence Revealing). It consists of a number of steps in which the four DEMO models are produced.