A Variance Minimization Method of Reliability Design

This approach to reliability design seeks to minimize the variance on system lifetime within s-expected life and economic constraints. We consider the case where the parameters of the lifetime distribution are constant and discuss the more general case where the parameters of the lifetime distribution are random variables. The design procedure is illustrated by simple numerical examples which show that for a small increase in cost an appreciable decrease in the variance of the lifetime is obtained. We have restricted our attention to active redundancy but the extension to standby redundancy is straightforward.