Burn-in and imperfect preventive maintenance strategies for warranted products

Abstract

Manufacturers are currently carrying out two effective strategies to reduce the warranty servicing cost of products with bathtub shaped failure rates. The first strategy is the burn-in procedure when products are operated for a reasonably short period of time prior to usage. This strategy can be effective when the initial failure rate is strictly decreasing (infant mortality). The second strategy is preventive maintenance actions at discrete time instances over the warranty period which can effectively reduce the age of the item when the failure rate is strictly increasing (wear-out). In this paper, the optimal burn-in time and imperfect preventive maintenance strategies for a warranted product with the bathtub-shaped failure rate are investigated. We provide a numerical study to illustrate our results.