A safety analysis method of process control system based on statechart diagram

STPA is a safety analysis method of process control systems, which can find interactive hazards between components on system level, and analyze the reason of accidents from the perspective of failed control. However, poor usability has been a problem in application and the results of different users may vary widely. By modifying the understanding of hazards in STPA and discretizing the system, this paper proposed a novel safety analysis method of process control system. A case study of a typical control system is also provided to further describe the operating procedures of the method.