Optimal Scheduling of Replacement and Inspection

This paper summarizes research on the optimal scheduling of replacement and inspection for stochastically failing equipment, it is assumed that for some parts of the equipment, the state of the equipment—whether good or failed—is not known with certainty. Periodic policies for inspection or replacement of equipment consisting of a single stochastically failing module are discussed, first under the assumption that the distribution of times to failure of the stochastically failing module is known and secondly under the assumption that the form of the distribution is known but that the failure rate is unknown. “Opportunistic” policies for inspection and/or replacement of equipment consisting of more than one stochastically failing module are discussed, for such policies, the action to be taken for a given part may depend on the state of other parts.