Research on reliability evaluation method of complex multistate system based on fuzzy fault tree

The failure mode of complex multistate system is uncertain, and the normal work probability or the failure probability of the system can not reflect the actual use of a single system. Users concern about whether the system works to a certain point of time then will fail, and then targeted for maintenance. How to evaluate the reliability of complex multistate system becomes an important research direction. In view of the above problems, a method of reliability evaluation of complex multistate system based on fuzzy fault tree was proposed in this paper. The mapping relationship between system set and fault tree set was established, and the system reliability evaluation analysis was transformed into fault tree analysis method: defined the reliability evaluation rules, established the “time - reliability” truth table of the units, established the reliability truth table of subsystems and complex systems at different time, and carried out the maintenance to the system. The evaluation rules of the method were expressed by a simple complex multistate system, and the effectiveness of the proposed method was proved.