Integrating Trace Logic and Petri Nets Specifications

This paper presents an experience in formal methods integration for the speciication and validation of distributed, fault-tolerant systems. The speciication formalisms we deal with are a trace logic, based on the CSP theory, and stochastic Petri nets. Their integration allows to combine the power of event traces to specify the behaviour of a system in an intuitive and modular way and the power of Petri nets for the analysis of concurrent systems. The integrated speciication technique is discussed by applying it to a real industrial control system, which uses redundant modules to guarantee given operational conditions despite failures, and incorporates a voting algorithm for arbitration over the replicated units.