Development and application of design transformations in ForSyDe

The formal system design (ForSyDe) methodology has been developed for system level design. Starting with a formal specification model, which captures the functionality of the system at a high level of abstraction, it provides formal design transformation methods for a transparent refinement process of the specification model into an implementation model which is optimised for synthesis. The formal treatment of transformational design refinement is the central contribution of this article. Using the formal semantics of ForSyDe processes we introduce the term characteristic function to be able to define and classify transformations as either semantic preserving or design decision. We also illustrate how we can incorporate classical synthesis techniques that have traditionally been used with control/data-flow graphs as ForSyDe transformations. This approach avoids discontinuities as it moves design refinement into the domain of the specification model