A TAXONOMY FOR REAL-WORLD MODELING CONCEPTS

A major component in problem analysis is to model the real world itsel f. However, the modelling languages suggested so far, suffer from seve ral weaknesses, especially with respect to dynamics. First, dynamic mo delling languages originally aimed at describing data-rather than real -world-processes. Moreover, they are either weak in expression, so tha t models become too vague to be meaningful, or they are cluttered with rigorous detail, which makes modelling unnecessarily complicated and inhibits the communication with end users. This paper establishes a si mple and intuitive conceptual basis for the modelling of the real worl d, with an emphasis on dynamics. Object-orientation is not considered appropriate for this purpose, due to its focus on static object struct ure. Dataflow diagrams, on the other hand, emphasize dynamics, but unf ortunately, some major conceptual deficiencies make DFDs, as well as t heir various formal extensions, unsuited for real-world modelling. Thi s paper presents a taxonomy of 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 re presentations of DFDs can be retained. It is indicated how the approac h can support a smooth transition into later stages of object-oriented design and implementation.