Reliability control for mission‐critical items

Reliability control for mission‐critical items is studied. The purpose of the control is to ensure the attainment during mission time of a required performance level which is based on suitably defined measures. This is achieved by replacing the item during normal operation time as soon as the reliability requirement is violated. We first consider the case of a known life distribution, but the main focus of the work is on the case where the life distribution is not completely specified. A Bayesian approach is taken and a replacement procedure is constructed on the basis of the overall uncertainty we face, namely, the stochastic failure process and our (continuously revised) probabilistic assessment of the underlying life distribution. The resulting replacement policy is investigated and detailed results are obtained for some common life distributions.