Macro Fault Tree and its Application to Petro Chemical Plant-Accidents

Abstract FTA and ETA are popular method for analyzing the accidents of large scale process plants. While these are useful for the evaluation of rare but essential accidents of a specified plant, we can not use then effectively to such accidents that are caused by the combination of small and daily troubles. Most of them are based on human errors. In this paper, we introduce a new method which is effective for the analysis of this kind of troubles. We combine Fault Tree Analysis with Multi-variable Analysis by considering sets of events. The grade of occurrence and the transition of of macro-events are fuzzified in the calculation of MFT. We can obtain common characteristics of accidents through this analysis and the general counterplans are easily deduced. We apply this method to the analysis on real data of the plant-accidents happened in Kawasaki industrial area in 12 years and comfirm its effectiveness.