一种准确识别损失场景的 STPA

System-theoretic accident model and processes (STAMP), which considers system safety as an emergent property of systems, provides a more accurate accident/loss causality model for modern complex systems. System-theoretic process analysis (STPA), a new approach to risk analysis based on STAMP, is getting more and more attention and is now included in several international standards. However, STPA is mainly conducted manually, so it is difficult to identify the loss scenarios emerging in complex systems. In this paper, we clarify the concepts of unsafe control action (UCA), loss scenario, and process model, and use finite state machines to construct all the behaviors needed for the identification of either UCAs or loss scenarios. Meanwhile, Model checking technology is employed to identify loss scenarios for time-dependent and time-independent UCAs. The improved STPA is capable of accurate identification of loss scenarios, while reducing the probability of missed identification or false identification.