JOINT DETERMINATION OF PRODUCTION QUANTITY, INSPECTION SCHEDULE, AND CONTROL CHART DESIGN

This paper presents a model for jointly determining an economic produc tion quantity, inspection schedule and control chart design of an impe rfect production process. The process is subject to the occurrence of a non-Markovian shock having an increasing failure rate. The product q uality of the process is monitored under the surveillance of an xBAR-c ontrol chart. The objective is to determine the optimal control chart design parameters and production quantity so as to minimize the expect ed total cost (the quality control cost and the inventory control cost ) per unit time. Both uniform and non-uniform inspection schemes are c onsidered. For non-uniform inspection schemes, the length of the inspe ction intervals are regulated to regulated to maintain a constant inte grated hazard rate over each inspection interval. Examples of Weibull shock models having increasing failure rates are provided. It is shown that the non-uniform and decreasing process inspection intervals sche me resulted in a lower cost than the uniform inspection scheme.