Reliability estimation under the fuzzy environments

This paper proposes new methods for fuzzy reliability estimation where lifetime random variables have a distribution function with fuzzy parameter. First, a fuzzy estimation is constructed for the parameter. Then, using such a fuzzy estimation, a fuzzy reliability estimation is constructed. In first method, we used Buckley method with precise observation. In secound one we uesd fuzzy point estimation with fuzzy observation. In third method, using a fuzzy estimation of mean time to failure (MTTF), we constructed a fuzzy confidence bound and a fuzzy confidence band for reliability function for a given t0 and for a given ?0 respectively. This method has been used in lifetime distributions as fuzzy normal distribution, fuzzy exponential distribution and fuzzy Weibull distribution.