Integrated maintenance-quality policy taking into account the economical impact of reworking activities

摘要

In this paper, we study integrated strategies joining maintenance and quality. We consider an imperfect manufacturing system composed of a single machine subject to an increasing random failure rate and producing conforming (first and second choice) and non conforming items. In order to decrease the failure rate and its impact on teh quality of output products, a preventive maintenance (PM) policy, block type, with minimal reapair is applied. Indeed, two different strategies are developed: The first strategy consists on selling top quality products at the best price, selling products with substandard quality at a lower price and rejecting non-conforming items. For the second strategy, we propose reworking activities for products with substandard quality and non-conforming items in order to be sold at the best price. We aim to establish the optimal number of batches produced N* before each PM action maximizing the total profit per time unit. These two strategies are studied for both an infinite and finite horizon. A comparative study between these two strategies for an infinite horizon is developed in order to identify the most economical strategy. Numerical and sensitivity studies are developed, inspired from an industrial case, in order to illustrate the proposed models.