On the use of model checking techniques for dependability evaluation

Over the last two decades many techniques have been developed to specify and evaluate Markovian dependability models. Most often, these Markovian models are automatically derived from stochastic Petri nets, stochastic process algebras, or stochastic activity networks. However whereas the model specification has become very comfortable, the specification of the dependability measures of interest most often has remained fairly cumbersome. In this paper we show that our recently introduced logic CSL (continuous stochastic logic) provides ample means to specify state- as well as path-based dependability measures in a compact and flexible way. Moreover due to the formal syntax and semantics of CSL, we can exploit the structure of CSL-specified dependability measures in the dependability evaluation process. Typically, the underlying Markov chains that need to be evaluated can be reduced considerably in size by this structure exploitation.