Risk analysis of phased-mission systems with multiple failure modes

General systems such as production plants and aircrafts can be regarded as a phased-mission system, which perform several different functions depending on their operation stage. This paper proposes a novel, simple and practical risk analysis method of phased mission systems with multiple failure modes. Firstly, based on the physical definition of a system accident, system accident occurrence conditions at each phase are obtained in terms of component state conditions at start/end of a phase. Evaluating component state conditions, the system accident occurrence probability can be easily evaluated. An illustrative example of a batch process in the chemical reactor shows the merits and details of the proposed method.