Production and maintenance strategy for a high-reliability imperfect process with free-repair warranty

Abstract

ABSTRACTManufacturers have increasingly emphasised improving process performance and equipment effectiveness in their routine operations. Therefore, this paper integrates maintenance, production, reliability and free-repair warranty (FRW) programs into an economic production quantity model of an imperfect process with an increasing hazard rate. Such a production system should be periodically inspected and maintained to retain a reliability value higher than a prespecified value r. The system is replaced following an out-of-control production run period or when the reliability falls below r. If the production run period is in the out-of-control state, then the defective items are reworked. In this paper, an inferior item is defined as an item that satisfies specifications during inspection but is likely to incur postsale servicing costs when sold under FRW. Reworked items are assumed to incur a higher postsale servicing cost than do defect-free items. The optimal N and lot size that minimise the total cost are discussed herein. Finally, a numerical example is presented to illustrate the model.