Dependability Analysis of Safety Critical Real-Time Systems by Using Petri Nets

The failure of such systems leads to the catastrophic effects, including injury or death to humans, and harm to the environment. Petri nets (PNs) have been widely used for verification and validation of real-time systems. However, the existing approaches do not consider the critical aspects of reliability and safety that include nonliveness, deadlock, stability, and throughput. In this paper, we introduce these as metrics of reliability and safety for safety critical real-time systems. This paper also proposes an innovative methodology for analysis of nonliveness, deadlock, stability, and throughput metrics by linear programming using PN modeling. The application of the proposed techniques has been validated by applying it on four different safety critical systems, running in six nuclear power plants and shown for reactor protection system.