Multi-objective optimization of flexible period preventive maintenance on a single machine

Preventive maintenance (PM) plays a very important role in production process. In this paper, the optimization PM planning in finite time horizon for a single machine with minimal repair at failures is discussed. Not only two conflicting objectives of maintenance cost and maintenance time but also two constraints of the reliability and availability of the machine are simultaneously considered in the optimization problem. Three types of PM actions including replacement, repair and mechanical service are considered. In order to make the suiTABLE PM planning, flexible period PM strategy was proposed. In this strategy, the intervals between two coterminous PM actions were with a flexible range of choice. The multi-objective genetic algorithm is used to solve the flexible period PM optimization problem. Numerical case study shows that comparing with periodic PM strategy, flexible period PM strategy can save more maintenance cost and maintenance time.