Research On Job Shop Scheduling Of Building Material Equipment Manufacturing Enterprise Considering Preventive Maintenance

Building materials equipment manufacturing industry occupies a very important position in China’s manufacturing industry.As China moves from a large manufacturing country to a powerful manufacturing country,improving enterprise production efficiency,enhancing energy conservation,emission reduction and green production capacity are the goals pursued by building materials equipment enterprises.In the actual production process of the enterprise,the preventive maintenance of the machine and the transportation process of the workpiece in the processing process will have an impact on the processing efficiency and energy consumption.Therefore,it is necessary to reasonably plan the scheduling arrangement of each link in order to achieve the goal of improving production efficiency and reducing energy consumption.Taking the job shop of building materials and equipment manufacturing enterprises as the research object,this paper studies the flexible job shop scheduling problem considering equipment preventive maintenance.The main research contents and work are as follows:(1)This paper studies the manufacturing characteristics of workshop in building materials equipment manufacturing enterprises,analyzes the production business process and production scheduling status of enterprises,and summarizes the problems existing in the production and scheduling process of building materials and equipment manufacturing enterprises.(2)Aiming at the preventive maintenance of equipment and the transportation of workpieces in the production process of flexible job shop in resource constrained building materials equipment manufacturing enterprises,a mathematical model of flexible job shop scheduling problem with the optimization objectives of minimizing completion time and minimizing total energy consumption is established,and an improved NSGA-Ⅱ algorithm with heuristic initialization adjustment strategy and variable neighborhood search is proposed to solve it.Combined with the characteristics of the problem,a three-layer chromosome coding scheme and crossover and mutation rules based on different coding layers are designed.At the same time,heuristic population initialization strategy and variable neighborhood search strategy with different neighborhood structure are added.Finally,test examples and enterprise examples show the effectiveness and applicability of the model and algorithm.(3)Aiming at the uncertainty of processing,transportation and maintenance in building materials and equipment manufacturing enterprises,a mathematical model of flexible job shop scheduling problem in building materials and equipment manufacturing enterprises considering multi factor fuzzy time is established with the optimization objectives of minimizing the maximum fuzzy completion time and minimizing the total fuzzy energy consumption.An adaptive improved NSGA-Ⅱalgorithm is proposed to solve it.Aiming at the complexity of the problem,a plug-in greedy decoding operation is designed;In crossover and mutation,a crossover strategy of adaptive learning factor and adaptive chromosome crossover rate and mutation rate are added.Finally,the effectiveness of the algorithm is verified by test examples and enterprise examples.