ABSTRACT
For repairable products sold with two-dimensional warranty, although burn-in and Preventive Maintenance (PM) actions result in extra costs, they both can be effective approaches to reduce number of warranty claims and servicing cost by early detecting defects and reliability improvement. Longer burn-in or higher burn-in usage rate can remove more defects, but it accelerates the product degradation and incurs more wear-out failures, which in turn need to be alleviated by PMs in the warranty period. This article aims to propose a new warranty performance-based model to minimize the warranty claims and find out the optimal burn-in and PM decisions for two-dimensional warranted products. More specifically, the proposed model subsumes a special case under one-dimensional warranty, allows different failure modes—i.e. defects and wear-out failures, and takes usage heterogeneity into consideration. We find that, it is always reasonable to carry out a burn-in on products. If wear-out failures are more (less) sensitive to product usage rate than defects, the burn-in duration should be extended (increased with the upper limit of PM degree); The optimal burn-in usage rate should be increased with the upper limit of PM degree (conducted at conditions as harsh as possible) and decrease with the upper limit of detecting degree; the optimal PM should always be set at its upper limit.
