Analysis of Real-Time Concurrent System Models based on CSP Using Stochastic Petri Nets
Frederick T. Sheldon · European Simulation Multiconference on Simulation · 1998
This paper addresses the real-time and reliability analysis of models for concurrent systems. Such models define independent entities that cooperate by explicit communication. Communications represent visible actions which, if they do not occur or are delayed beyond their deadline, will cause a failure to occur. This approach converts a formal functional system description into the information needed to predict its behavior as a function of observable parameters (i.e., topology, fault-tolerance, deadlines, communications and failure categories). The models are translated into Stochastic Petri nets (SPNs) using our tool CSPN ( C SP-to- S tochastic P etri N ets). 1 CSPN uses algorithms which codify the canonical translations between essential CSP constructs and SPNs. The term CSP-based is used to distinguish between the exact notation of Hoare's original CSP and our textual representations which are similar to occam2. The grammar is sufficient to preserve the structural properties of the original model. Consideration of other CSP properties (e.g., traces, refusal sets, livelock, etc.) are not precluded, however they are not considered here. A basic example is provided to illustrate the link between failure behavior and model characteristics (i.e., derivation of timing failure probability and reliability predictions as they would affect the cost for implementing a candidate model specification).