Reliability Analysis of Safety-Critical Systems using Optimized Petri Nets

Unified modeling language (UML) has emerged as a powerful tool for designing and modeling safety-critical systems. However, UML is not useful in illustrating the dynamic behavior of a critical system. UML does not consider the important critical aspects of the reliability of a safety-critical system, such as non-liveliness, deadlock, stability, and throughput. Therefore, we propose a framework based on UML and Petri Net (PN). In this framework, UML is used to capture all the safety-critical system requirements, whereas PN is used to deliver an in-depth analysis of the reliability aspects of a safety-critical system. Since the PN model suffers from the state space explosion problem, the converted PN may have a large number of redundant states, resulting in a high amount of time required for reliability analysis. Therefore, six reduction algorithms have been derived in this framework to overcome this limitation. The proposed framework is validated with 32 safety-critical system instances of the Nuclear Power Plant on the Reactor Core Isolation Cooling System.