Preventive maintenance modelling in lifetime warranty

Abstract

Lifetime warranty is a type of long-term assurance that is now ubiquitous. With a long period of coverage, however, the expected number of failures and the associated costs are likely to add up. Hence, maintenance policies over a lifetime warranty can have a substantial impact on warranty servicing costs. Maintenance policies impose additional costs and would be worthy only if the reduction amount in total costs due to maintenance is greater than maintenance costs. The focus of this paper is on modelling preventive maintenance during a lifetime warranty in order to derive optimal maintenance policy and optimal level of repair based on the structures of a cost function and a failure rate function. Our investigation demonstrates that the optimal strategy for preventive maintenance can be achieved by considering minor repairs during early ages and marginal repairs near the end of a product life. Numerical examples are provided to evaluate our developed models and support the corresponding results.