ABSTRACT
For many years, the fuzzy set theory has been used in system reliability analysis. Using an introduced approach, we formulate the membership function of fuzzy reliability where a time-dependent hexagonal fuzzy number is used to represent the parameter of the failure rate of every component of the systems. The main benefit of using hexagonal fuzzy numbers in reliability theory is that a hexagonal fuzzy number has six parameters, which gives better results than triangular and trapezoidal fuzzy numbers. Thus, in this chapter, a fuzzy reliability function is proposed to formulate its membership and the uses of α-cut time-dependent hexagonal fuzzy numbers are introduced. Two numerical examples are given to exemplify the methodology for fuzzy reliability evaluation of systems.
