The Preventive Maintenance Decision Model Based On Multiplicate Factors Of System

Maintenance decision is an important application of reliability model. All maintenance strategies are based on preventive maintenance concept. And tend to be considering many factors when determining preventive maintenance cycle. In this paper, use different preventive maintenance strategies and optimization methods to determine the optimal preventive maintenance cycle in view of the system under the condition of many factors.Firstly there are two hybrid hazard rate models which are based on the age reduction factor and hazard rate increase factor. By introducing the hybrid hazard rate , the equivalent periodic preventive maintenance model which the reliability or the cost can be taken as an object function respectively on the finite interval is built. This provides reliable decision making for the systematic maintenance activities so as to pursue different system goals. Then by introducing the hybrid hazard rate, the unequal periodic preventive maintenance model which the cost can be taken as an object function and the reliability can be taken as constraint condition on the infinite interval is built. We also contrasted the equivalent periodic model with the unequal periodic model.And then with the periodic maintenance policy on minimal repair, a multi-objective optimization model of preventive maintenance cycle was constructed relying on steady state availability, average spending rate and average reliability. By using the"min-max"to solve this multi-objective optimization model, preventive maintenance cycle was determined. We also contrasted this method with the linear weighted sum method.Finally with the common Age Maintenance Policy, a fuzzy decision model of determining the optimal cycle of preventive maintenance was established by the related theory of fuzzy mathematics . This method considering the different role of average spending rate and steady state availability in the system obtained their weight by Gathering Statistics Iterative Method. Then the optimal cycle of preventive maintenance was determined according to the classic comprehensive evaluation. Their respective objective functions of the two factors and their degree of membership was discussed mainly in this paper.