Research On Multi-Objective Flexible Job Shop Scheduling Problem Based On Improved NSGA-?

The workshop scheduling method and scheduling optimization technology are the key to achieving high efficiency,high quality,high flexibility and low cost in enterprise production.With the development of modern manufacturing industry,the traditional workshop scheduling method and scheduling optimization technology are not suitable for solving the current scheduling problem.It is of great theoretical and practical significance to explore and design a scheduling problem model and solution method that is more suitable for the production of manufacturing enterprises to better guide the production of enterprises.Based on the current status of production shop scheduling,this paper expands and improves the traditional workshop scheduling method and scheduling optimization technology.A multi-objective flexible job shop scheduling problem(FJSP)model is constructed and an improved non-dominated sorting genetic algorithm(NSGA-II)is proposed,which is used to solve multi-objective FJSP.Finally,the research results are applied to actual production enterprises.The multi-objective FJSP is studied thoroughly and systematically from the following four aspects:1.Aiming at the limitations of traditional multi-objective FJSP research,the multiobjective FJSP mathematical model considering time T,quality Q and cost C is constructed by considering the different release time of workpieces and the connection time between processes.2.This paper improves the NSGA-II algorithm,which adopts adaptive crossover operator and adaptive mutation operator based on close relative index.An improved elite individual selection strategy is put forward.Finally,the effectiveness of the improved algorithm is proved by standard international examples.3.By investigating the production data of a workshop of CHT company and combining the company's job shop scheduling,the scheduling model is established,and the improved NSGA-II algorithm is used to solve it.Eventually,using the analytic hierarchy process and fuzzy comprehensive evaluation method(AHP-FE)to help decision makers choose a satisfactory scheduling scheme.4.Using the B/S software architecture to develop a job shop scheduling prototype system for the company.