Control of production processes subjectto random shocks

Abstract

Quality of industrial production processes may suffer from wear‐out phenomena continuously growing in time, and from sudden disturbances occurring at random time. Either of them affects process quality and thus process yield. Consequently, there should be counter‐actions, which aim to remove signs of wear before they result in a decrease of process yield on the one hand, and which detect disturbances before their impact has become serious. In this paper, it is assumed that the wear‐out phenomena are sufficiently compensated by means of continuous maintenance. It remains to determine an appropriate monitoring policy in order to detect disturbances. A unified economic approach is proposed and investigated, including different modes of process monitoring together with a decision function reacting simultaneously on shifts in the process mean and process variability.