Research On Shop Scheduling Optimization With Deterioration

Manufacturing industry greatly promotes the development of our national economy,and the prosperity of the manufacturing industry plays a vital role in the promotion of the comprehensive national strength.The manufacturing industry involves many production process,which are mostly multi-type and small batch production,increasing the complexity of technological process.In the actual processing,job processing time varies according to the starting time,which is the deterioration.Therefore,reasonable production scheduling not only meets various constraints of production and processing,but also takes the influence of deterioration into account.Based on the principle of "starting from actual production—linking theory with practice—applying to the actual production",combined with the process of Steelmaking—continuous casting—hot rolling in iron and steel production,two kinds of scheduling problems in the environment of permutation flowshop and unrelated parallel machines scheduling with deterioration are abstracted in this paper.First,the basic theory of shop scheduling problem with deterioration is introduced.The current research situation at home and abroad is analyzed.The application status of flowshop scheduling and parallel machine scheduling is summarized,and then the problem is identified in this paper.Next,based on the general genetic algorithm,corresponding improvement strategies for different problems from the aspects of coding,population initialization,selection,operator design of crossover and mutation was proposed: two-segment coding,initial population embedding an improved heuristic,adaptive update crossover and mutation operator.Then,aiming at permutation flowshop scheduling with deterioration,considering constraints such as each machine processes all jobs in the same order,the model was built,and the hybrid genetic algorithm combined with heuristic method is proposed to solve the problem.Compared with heuristic algorithm and genetic algorithm,it shows the efficiency of the proposed algorithm.Last,as for the unrelated parallel machines scheduling with deterioration,jobs have constraints such as a selective function on multiple parallel machines with the same function was considered.Based on two-segment coding adaptive genetic algorithm for both job sorting and machine allocation was proposed to solve the problem.Compared with simulation experiments and genetic algorithm,the efficiency of the proposed method is fully verified.The experimental result shows that the proposed solution has advantages both in time and quality,which provide theoretical and practical guidance for the study of job shop scheduling problems with deterioration characteristics.