Synthetic safety analysis: A systematic approach in combination of fault tree analysis and fuzzy failure modes and effect analysis

Abstract

Two classical methods in safety analysis, FTA and FMEA, are generally used separately in operating analysis orientations. But this one-direction systematic technique becomes more difficult in facing today’s software architecture with increasingly higher complexity; moreover, the simple risk priority number (RPN) in original FMEA can no longer meet the urgent request of higher accuracy in the development of efficient safety analysis. Thus, a new synthetic approach is put forward with the combination of FTA and FMEA. In addition, a system-level fuzzy-RPN and top-fRPN are provided to show the effect of events on their systems to help people make decisions based on a three-dimensional risk ranking instead of failure probability. The case study has demonstrated the methodology thus developed. Our method tends to improve the range of technical adaptability of safety analysis.