Correlated FMEA method of complex system with linguistic vagueness

Considering some inherent shortcomings of the conventional failure mode and effects analysis(FMEA),a correlated FMEA method was proposed for reprioritization of interrelated failure modes with linguistic vagueness.The fuzzy linguistic knowledge in an evaluation of failure mode was quantified by fuzzy set theory,and an effective number of each failure mode was obtained with a fuzzy-modified technique for order preference by similarity to ideal solution(TOPSIS).A digraph of direct relations between failure modes was constructed,and then a matrix of failure influences was gained using decision making trial and evaluation laboratory(DEMATEL) method.The risk evaluation of failure modes in a complex system with linguistic vagueness was completed with obtained causal degree of each failure mode from the matrix of failure influences.The proposed method was applied to safety analysis of the complex centrifugal pump.The results indicated that,compared with the risk priority number(RPN) method and the fuzzy FMEA method,the proposed correlated FMEA method could greatly improve the analysis reliability.