Determining the characteristics of parametric reliability according to the fuzzy set theory

New concept of the reliability theory based on the fuzzy set theory postulates, is described. This concept has some pronounced advantages over the formal reliability theory based on the probability theory. It is shown that application of the membership functions allows to evaluate with any validity the guaranteed probability of failure-free operation and lifetime of complicated multicomponent systems containing the elements with great difference in their failure distribution laws. The proposed approach allows to solve other problems of the reliability theory on the ground of fuzzy range concept.