Stochastic Refusal Graph for Testing Non-Deterministic Systems

The test is one of the approaches commonly used for validating systems to ensure qualitative and quantitative implementation requirements. In this paper we are interested in refusals test based for testing stochastic systems. We propose a new kind of refusals graph named stochastic refusals graphs (SRG) for specification in maximality-based stochastic labeled transition systems (MSLTS) model. In SRG, refusals could be temporary or permanent. Permanent refusals are induced by the non-determinism in the specifications. However, temporary refusals are provoked by the fact that actions elapse in time. In the MSLTS model the durations of actions are governed by probability distributed functions, which allow the quantification of the refusals by a certain probability. We propose a framework for generating stochastic refusals graph. This framework is implemented by Matlab programming language. Finally, we argue the use of SRG in the test of stochastic systems.