A pluralistic knowledge-based approach to software specification

We propose a pluralistic attitude to software specification, where multiple viewpoints/methods are integrated to enhance our understanding of the required system. In particular, we investigate how this process can be supported by heuristics acquired from well-known software specification methods such as Data Flow Diagrams, Petri Nets and Entity Relationship Models. We suggest the classification of heuristics by method and activity, and show how they can be formalised in Prolog. More general heuristics indicating complementarity consistency between methods are also formalised. A practical by-product has been the generation of "expert-assistance" to the integration of methods: PRISMA is a pluralistic knowledge-based system supporting the coherent construction of a software specification from multiple viewpoints. The approach is ilustrated via examples. Theoretical and practical issues related to specification processes and environments supporting a pluralistic paradigm are also discussed.