The Algorithm Research Of Job Shop Scheduling Problem In MES System

With the advent of the industry 4.0,the development and application of intelligent manufacturing has greatly promoted the progress and development of human society.Manufacturing Execution System(MES)is an intelligent control system used by manufacturing enterprises to manage and monitor work processes in the production workshop.It is a bridge between the upper-level plan management system and the lower-level industrial control system.MES focuses on the execution of production plans,so shop scheduling has become one of the most basic functions of MES.The accuracy and rationality of the scheduling process is particularly important,and a good production plan can greatly improve manufacturing efficiency.Flexible Job Shop Scheduling Problem(FJSP)is an extension of the traditional Job Shop Scheduling Problem(JSP).FJSP is closer to the actual production workshop than JSP.It is a kind of scheduling problem that needs to be solved urgently in the production workshop of the enterprise,and it is more challenging.In this paper,based on the current research status of job-shop scheduling problem,this paper first proposed an improved non-dominated genetic algorithm(NSGA-?),and then use the improved algorithm to solve multi-objective FJSP.This paper is based on the study of the NSGA-? algorithm,combined with the practical application of multi-objective flexible shop scheduling.Using Matlab software to carry out simulation experiments.The paper can be summarized as follows:(1)Proposed improved NSGA-?.To solve the problem of convergence and diversity of solution sets in traditional NSGA-?,we used non-uniform mutation operator instead of polynomial mutation operator.Subsequently,we proposed a new crowding evaluation mechanism.Meanwhile,Considering the shortcomings of Pareto solution set that are prone to similar crowding distance or even the same individuals,an improved elite individual retention strategy is proposed.Finally,through experiments to verify the effectiveness of the improved algorithm.It is concluded that the improved nsga-ii algorithm can effectively improve the convergence and diversity of solution sets.(2)Study the application of the improved NSGA-? algorithm in multi-objective FJSP.Established a multi-objective FJSP mathematical model and applying the improved algorithm proposed in this paper to the multi-objective FJSP.Finally,theresults show that the proposed algorithm can solve a good feasible scheduling scheme and verify the effectiveness and stability of the proposed algorithm.