Toward an Intelligent Distributed Safety Instrumented Systems: Dependability Evaluation

In this paper, the modelling and thus the performance evaluation relating to the dependability are studied for structures which have intelligence in the instruments constituting the Safety Instrumented Systems (SIS) in order to determine the contribution of the intelligent instruments in the safety applications. Dynamic approach using Stochastic Petri Nets (SPN) is proposed and the metrics used for the evaluation of the dependability of the Intelligent Distributed Safety Instrumented Systems (IDSIS) refer to two modes of failures mentioned by the safety standards: mode of dangerous failure and mode of safe failure.