Solution method for accident tree structural importance

Aimed at addressing the inconsistency resulting from use of the three prevailing methods for calculating structural importance of accident tree,this paper features the use of the small accident tree case for developing three solutions,as is required,so as to identify the how and where they behave better.The proposed methods range from the smallest cut set designed for the larger number of basic events occurring accident tree,to the structure importance degree coefficient method suited for more accurate calculation and the structure importance degree coefficient method or probability importance degree coefficient method tailored for addressing the inconsistence in sequence due to the of the smallest cut set.The analysis of the accidents caused by falling or fallen objects as is the case with lifting equipment proves the validity of solution method for accident tree structural importance.The study provides reference for proper selection and application of structural importance solution.