Systems specification, analysis, and validation by means of timed predicate/transition nets and logic programming

Abstract

A method is presented for systems design, specification and analysis based on predicate/transition nets (PrT nets) and logic programming. In order to evaluate and optimize the behavior of systems, the PrT net models are extended with quantitative time. The firing times are assigned to transitions and are given by arithmetic expressions which might contain variables An approach to transforming requirements driven PrT net models into logic programs is given. The generated logic programs contain the static structure and the dynamic behavior of the PrT net models and can be used for simulation and analysis purposes. Moreover they can be viewed as a precise and lucid specification of the programs to be implemented. Three examples are given which illustrate how Prolog goals can be used to validate system model properties. Example 1 describes the transformation steps for simple PrT net models. In Example 2 the generated Prolog program corresponding to a PrT net model containing formulae inside the transitions is described. Example 3 illustrates how time constraints of PrT net models with variable time can be validated.