Multilevel fault tree analysis using fuzzy numbers

• Published in: Computers & operations research Vol. 23; no. 7; pp. 695 - 703
• Main Authors: Kim, C.E., Ju, Y.J., Gens, M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.1996; Elsevier Science; Pergamon Press Inc
• Subjects: Applied sciences; Exact sciences and technology; Fault tolerance; Fuzzy logic; Operational research and scientific management; Operational research. Management science; Operations research; Reliability; Reliability theory. Replacement problems; Studies; Systems analysis; Dominance; Multivalued logic; Possibility theory; Fuzzy number; Reliability; Fault tree
• ISSN: 0305-0548; 1873-765X; 0305-0548
• DOI: 10.1016/0305-0548(95)00070-4

This paper applies fuzzy concepts to fault tree analysis (FTA), where the basic events are considered as fuzzy numbers, and shows that n-ary fuzzy AND and OR operators are used to evaluate the possibility of systems failure. L− R type fuzzy numbers can be defined completely by a triplet ( m, α, β) and the value m is also considered a triangular fuzzy number (TFN). The comparison method is based on the dominance property. By the dominance criteria, each value m is determined to obtain the optimistic and pessimistic possibilities of the system accident. We can extend major and minor TFNs to fuzzy FTA for better results. The goal of this paper is to replace probabilistic considerations in the FTA by the possibilistic ones and to reduce the difficulty arising from the inexact and insufficient information of the distribution functions of basic event.