A Study On The Periodic Imperfect Preventive Maintenance Policy

Along with the growing scale of modern enterprise equipment, increasingly complex devices, precision and multi-functional development, and equipment maintenance costs increased year by year, the maintenance of production systems equipment has a significant impact on the cost of enterprise manufacturing and production operations, which is one of the key factors to determine the economic efficiency and market competitiveness. In order to solve a series of new problems of technology and economy and management arising from the use of modern equipment, get rid of the limitations of traditional equipment maintenance management, further research and development of new equipment maintenance strategy, maintenance and maintenance management, which plays an important role in modern manufacturing enterprises.In the practice of modern enterprise equipment maintenance, imperfect preventive maintenance is increasingly recognized and applied. Compared to traditional maintenance, imperfect preventive maintenance abandon the primarily maintenance model judged by experience and qualitative, using a variety of maintenance modeling methods and optimization technique, focusing on the maintenance of quantitative description and analysis. It can better guide maintenance practice of enterprise and improve operational performance. The paper adopts periodic imperfect preventive maintenance for the production system equipment in the infinite time domain, introducing improving factor methods of imperfect preventive maintenance. Based on the actual maintenance situation, this article formulates an effective dynamic improvement factor to measure the age restoration after imperfect preventive maintenance for equipment. Meanwhile, it analyzes and optimizes the cost model in two kinds of imperfect preventive maintenance strategy; it studies each factor of the cost model, so as to provide a basis to develop the optimal maintenance strategy.The dissertation focuses on a certain periodic maintenance strategy and its modeling under the imperfect maintenance conception in infinite time horizon. The paper firstly start with the relevant basic knowledge of the development of imperfect preventive maintenance, the formulation of improvement factor and the optimal solution model, give a review of them and also make a comment. Based on theory of reliability and failure model of different maintenance methods, it formulate a dynamic improvement factor which is assumed to be affected by equipment's age, the cost ratio of imperfect preventive maintenance, and the experience and the learning rate of the repairer. It can accurately measure the effect of imperfect preventive maintenance. The all cost of equipment in the whole life cycle is composed of the cost of minimal repair, penalty cost of minimal repair, the cost of periodic imperfect preventive maintenance, the production cost and preventive replacement cost. Each part of cost is analyzed to formulate the corresponding mathematical model. Then, with the principle of minimizing the total cost in unit time, the paper optimize and solve the cost model of two different kinds of periodic imperfect preventive maintenance policies using enumeration method, analysis the results to come to a conclusion of the best maintenance frequency and the optimal interval of imperfect preventive maintenance and the time of preventive replacement. At last, through collecting a series of real failure data of equipment in some enterprise, two proposed strategies of periodic imperfect preventive maintenance are applied, and the two maintenance strategy results are compared and analyzed the various parameters of model, the sensitivity analysis is made to explore the key factors of formulating the rational economic maintenance policy, it draws relevant conclusions.