Research On Preventive Maintenance Strategy Of S Company’s Machining Center

As an important component of an enterprise’s production system,equipment directly affects the efficiency of the production system and the economic benefits of the enterprise.Scientific and reasonable equipment maintenance strategies can effectively reduce unexpected failures of equipment and reduce equipment maintenance costs,ensuring the safety and reliability of production system operation.Currently,traditional equipment maintenance strategies mostly focus on periodic preventive maintenance,lacking state performance analysis of different equipment and subsystems,which can easily lead to two problems in maintenance management: "excessive maintenance" and "insufficient maintenance.".This article takes the machining center of S Company as the research object,and develops corresponding maintenance strategies based on its maintenance operation rules.The main research content of this article includes the following three aspects:(1)The importance of machining center subsystems is divided.The machining center is a complex equipment with multiple systems,and each subsystem has different importance to the entire machine.Therefore,based on the fuzzy comprehensive evaluation method,the importance of each subsystem of the machining center is divided into key systems,important systems,and secondary systems;Key systems and important systems have a significant impact on equipment,and they are the main subsystems of the machining center.Their reliability should be guaranteed as much as possible.Therefore,preventive maintenance models should be established around the main subsystems in subsequent chapters;The secondary system has a small impact on the equipment,and the strategy of timely maintenance after the event can be adopted.(2)A two-stage delay time model is used to describe the degradation state of the subsystems of the machining center,and the relevant reliability parameters of the main subsystems are estimated based on the historical maintenance records of the enterprise.Based on the reliability decision goal of minimizing maintenance costs in a finite time domain,a single system preventive maintenance model for a machining center is constructed,and the optimal preventive maintenance cycle for the main subsystems is solved by combining the relevant parameters of the machining center.Compared to the original maintenance plan,the maintenance downtime of the single system preventive maintenance strategy has been reduced by 9 hours,and the maintenance cost has been reduced from 238400 yuan to 204516 yuan,a decrease of 14.21%.(3)Considering the time and economic correlations of subsystems,the concept of opportunity maintenance is introduced to reduce maintenance downtime.A dual objective opportunity preventive maintenance model is established with the optimization objectives of minimizing maintenance costs and maximizing average availability of machining centers in the effective time domain.The model is solved using genetic algorithms,and finally,a preventive maintenance strategy for the entire machining center is obtained,compared to the single system preventive maintenance strategy,the downtime for maintenance was reduced by 21 hours,and the total maintenance cost was reduced from 204516 yuan to 159452 yuan,a decrease of 22.05%.The total maintenance cost and average availability were significantly improved,verifying the effectiveness of opportunistic preventive maintenance.