Research On Mixed-model U-shaped Assembly Line Balancing Optimization In Company S

With the diversification of consumer demand and the fierce competition in the market,manufacturing enterprises have gradually changed from the traditional mass production to the multi-variety small-volume production or JIT production,to be able to respond quickly to market demand,shorten product delivery time and reduce production cost.Mixed-model U-shaped assembly lines emerged as the times required,and its high flexibility is widely favored by manufacturing enterprises.However,while bringing many benefits to enterprises,the mixed-model U-shaped assembly line balancing problem has also brought many challenges to enterprises.S company,an electrical enterprise,has steadily increased its product sales in the past two years,plans to increase output and expand market share.However,when improving the Si assembly line,the largest output assembly line of the company,it was found that the imbalance of the front assembly section hindered the increase of production.Under this background,this thesis takes the Si mixed-model U-shaped assembly line of the Si assembly line front section as the research object.Firstly,it starts from the current situation of the S1 assembly line of S company,finds out the existing problems,and concludes that the main reasons for the imbalance of the S1 mixed-model U-shaped assembly line are the unbalanced workstation load,the severe blockage of the assembly line and the insufficient utilization of the advantages of the U-shaped line.Secondly,it studies the production process of HVX-O?HVX-A and HVX-40.5KV which are producted in the S1 mixed-model U-shaped assembly line,including the process division,process operation completion time measurement and product combination priority relationship diagram drawing.Then according to the existing problems,the mathematical model of the mixed-model U-shaped assembly line balancing type-2 problem is constructed based on the maximization of assembly line efficiency and the minimization absolute deviation of workstation workload as the objective optimization goal,and the genetic algorithm is improved to make it suitable for the model,it proposes the priority-based coding and decoding method and position-based mapping crossover operator,the algorithm is implemented by Matlab programming.Finally,after verifying the validity of the algorithm by the well-known test problem,the mathematical model of the mixed-model U-shaped assembly line balancing is solved,and the results is analyzed.This thesis uses the mixed-model U-shaped assembly line balancing technology to solve the problems existing in the actual production of enterprise,which has specific practical significance.The results show that the optimized S1 mixed-model U-shaped assembly line has a balanced workload,no in-process inventory and running smoothly,its production efficiency increased by 26%and output increased by 58.89%.Besides,the optimized assembly line also has essential management significance in production balance,flexible production,cost reduction,and easy management.