OPTIMAL AGE-DEPENDENT PREVENTIVE MAINTENANCE POLICIES WITH IMPERFECT MAINTENANCE

Abstract

This paper proposes three age-dependent preventive maintenance models with imperfect repair and/or imperfect preventive maintenance (pm). In these models imperfect repair is treated in a way that after repair the lifetime of a unit will decrease to a fraction of its immediately previous one and its repair time will increase to a multiple of immediately previous one. In this paper, the expected maintenance cost rate and asymptotic average availability are derived with a consideration that the maintenance and repair times are not negligible. The optimum maintenance policies are then determined for the three imperfect maintenance models respectively. A class of related optimization problems is also discussed. Finally, a numerical example is presented to illustrate the results.