Concepts for real-world modelling

Abstract

Simple, intuitive, and yet powerful languages are needed to model the real-world in the problem analysis phase of information system development. However, contemporary real-world modelling languages are either weak in expression or cluttered with rigorous detail. In the former case, models become to vague to be meaningful, while the latter case makes modelling even of rather simple dynamic systems a complex task and hardly facilitates communication with end users. Object-orientation is not considered appropriate for this purpose, due to its low emphasis on dynamics. Dataflow diagrams, on the other hand, emphasise dynamics, but unfortunately, some major conceptual deficiencies make DFDs, as well as their various formal extensions, rather useless for real-world modelling. This paper presents concepts for real-world modelling which rely on some seemingly small, but essential modifications of the DFD language. Hence the well-known, communication-oriented diagrammatic representations of DFDs can be retained. It is indicated how the approach can support a smooth transition into later stages of object-oriented design and implementation.