Specification Based Prototyping of Control Systems

Abstract

The capability to dynamically analyze, or execute, the description of a software system early in a project has many advantages; it helps the analyst to evaluate and address poorly understood aspects of the system behavior, improves communication between the different parties involved in specification effort, allows empirical evaluation of alternative solutions, and is one of the more feasible ways of validating a system's behavior. In this paper, we focus on an approach to simulation and debugging of formal software specifications for control systems called specificationbased prototyping [1]. Within the context of specification execution and simulation, specification-based prototyping combines the advantages of traditional formal specifications (e.g., preciseness and analysis) with the advantages of rapid prototyping (e.g., risk management and early user involvement). The approach lets us refine a formal and executable model of the system requirements specification to a detailed model of the software requirements specification. Throughout this refinement process, the specification is used as an early prototype of the proposed software. By using the specification as the prototype, most of the problems that plague traditional code-based prototyping disappear. First, the formal specification will always be consistent with the behavior of the prototype (excluding real-time response) and the specification is, by definition, updated as the prototype evolves. Second, the common problems associated with evolving the prototype into a production system are largely eliminated. Finally, the dynamic evaluation of the prototype can be augmented with formal analysis.