Optimizing preventive maintenance for mechanical components using genetic algorithms

This paper presents periodic preventive maintenance (PM) of a system with d eteriorated components. Two activities, simple preventive maintenance and p reventive replacement, are simultaneously considered to arrange the PM sche dule of a system. A simple PM is to recover the degraded component to some level of the original condition according to an improvement factor which is determined by a quantitative assessment process. A preventive replacement is to restore the aged component by a new one. The degraded behavior of com ponents is modeled by a dynamic reliability equation, and the effect of PM activities to reliability and failure rate of components is formulated base d on age reduction model. While scheduling the PM policy, the PM components within a system are first identified. The maintenance cost and the extende d life of the system under any activities-combination, which represents wha t kind of activities taken for these chosen components, are analyzed for ev aluating the unit-cost life of the system. The optimal activities-combinati on at each PM stage is decided by using genetic algorithm in maximizing the system unit-cost life. Repeatedly, the PM scheduling is progressed to the next stage until the system's unit-cost life is less than its discarded lif e. Appropriately a mechatronic system is used as an example to demonstrate the proposed algorithm. (C) 2001 Elsevier Science Ltd. All rights reserved.