The DEMO Methodology

Abstract

In this chapter DEMO (Design and Engineering Methodology for Organisations) is presented, 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 B of this book. The WoM consists of an integrated whole of four aspect 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), 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. It contains the existence laws and occurrence laws for all internal and border transactor roles. 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. It contains the existence laws and occurrence laws for all identified entity types, value types, property types, attribute types, and event types. The PM 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 (DEMOSL), which comprises diagrams, tables, and formal textual descriptions. For producing 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 aspect models are produced, preferably in a spiral way.