Enhancement of the AltaRica 3.0 stepwise simulator by introducing an abstract notion of time

International audienceAltaRica 3.0 is an event-based, object-oriented modeling language dedicated to (probabilistic) safety analyses of complex systems. It makes it possible to design models at higher level than done with formalisms traditionally used for safety analyses (fault trees, Markov Chains, stochastic Petri nets, etc.), without increasing the complexity of calculations of risk indicators. Several assessment tools have been developed for AltaRica 3.0, including a stepwise simulator. This tool is of a great help for the design and the validation of AltaRica 3.0 models. It is the analog for modeling of debuggers for programming. In this article, we show how the AltaRica 3.0 stepwise simulator has been greatly enhanced by the introduction of an abstract notion of time. The key mathematical property is that abstract and concrete simulation are bisim-ilar: any concrete (timed, stochastic) execution can be simulated by an abstract execution and reciprocally any abstract execution corresponds to at least one concrete execution. This important result paves the way to the design of efficient model-checking algorithms, e.g. generators of sequences of events leading to a failure state