Integrated Optimization Of Production Scheduling And Preventive Maintenance Of Flexible Job Shop In L Company

Production scheduling and preventive maintenance plan are two important factors to the efficiency of a production system.Production scheduling is the foundation for the production plan,the efficient production scheduling can improve the utilization of production equipment,shorten the production cycle and reduce the production costs.Preventive maintenance of equipment is the key to ensure the reliable operation of equipment,improve the production efficiency of equipment and reduce manufacturing costs.However,there is a coupling contradiction between them.Production scheduling will affect the machine load,so it can affect the reliability and stability of the machine indirectly.The equipment degradation could result in equipment failure.Preventive maintenance ensures long-term reliable operation,but it will take up the operation time of the machine.Therefore,studying the integration of production scheduling and equipment maintenance to construct a practical joint optimization model based on optimization theory could be a great point to guide the production practice of enterprises and improve the production efficiency and economic efficiency of enterprises.The mechanical workshops of L company are flexible workshops under the model of multivariety and small batch production.At present,the manual scheduling scheme is still adopted,and the manual scheduling scheme is limited and not optimized necessarily.When making scheduling plan,it is assumed that the equipment is always available,without considering the maintenance problem of equipment.It not only leads to a long processing cycle in the workshop,but also leads to a large deviation between the actual completion time and the plan,which affects the promotion of the follow-up plan,and also leads to an increase in production costs.Punctual delivery and lower production costs are the key factors for manufacturing enterprises to gain advantages in the fierce market competition.Therefore,the goal of this thesis is to shorten the processing cycle and control the maintenance cost of the mechanical workshops of L company.The main content of this thesis is consist of the following three parts:Firstly,this thesis review the domestic and foreign research status of integration of production scheduling and equipment maintenance.The current situation of the scheduling and preventive maintenance in the machine shop of L company is analyzed and the existing problems in the workshop scheduling is summarized.Secondly,the integrated model of flexible job shop scheduling and preventive maintenance is built,which regards the mechanical workshops of L company as background.And the solution algorithm is designed based on non-dominated sorting genetic algorithm(NRGA)to optimize the integrated model.Finally,the actual production data and equipment failure and maintenance data of the machine workshop in L company are analyzed and arranged with the aid of MATLAB programming.The simulation results show that the study can effectively shorten the processing cycle of the workshop,and control the production cost of the workshop.