Prototyping core functionality using JSD

In the JSD approach to systems development, an abstraction of requirements is developed first and then used as the basis for a detailed functional specification. The model consists of a set of sequential processes, mutually constrained by their common events in the manner of CSP. The model describes the problem domain in terms of the behaviour of the significant entities. Encapsulated in each process are attributes that describe the static properties of the entities. Thus the model contains a conventional data model of the kind usually expressed as an E-R or other similar diagram. Prototyping tools have been used to develop early executable versions of the model plus a few key functions. The approach is called prototyping of core functionality to distinguish it from the complementary form of prototyping that concentrates on the outward appearance of the system. Two different prototyping toolsets have been used: one generates a quick cut down version of the application and the other supports the animation of the design diagrams as the prototype application executes