Lean Inproving Research And Application Of F Enterprise’s Automobile Armrest Assembly Line

With the continuous progress of modern technology and the rapid development of market economy,people are more and more high demand for material culture,which makes the customer’s personalized demand for products increasingly diverse.This trend has brought many new challenges to China’s auto parts manufacturing enterprises,whether it is the existing mode of production,or business philosophy.In addition,under the double pressures of rising costs of labor and raw material,enterprises are forced to transform from traditional push production to pull production,implementing lean production.However,in the process of transformation,there is a big gap between the existing assembly line balancing technology and a flow concept of lean production in many aspects,and not fully achieve the lean,which result in adverse phenomenon seriously from lacking capacity,low resource utilization and high WIP caused by assembly line imbalance.Being unable to respond to customer needs timely makes the enterprises at a disadvantage and lack of market competition.Therefore,basing on the guidance of lean production,it is very important to make full use of the essence of lean thinking to optimize and improve the assembly line balance,thus to improve the production capacity to meet the market demand.In this paper,the automobile armrest assembly line of F enterprise is taken as the research object.Firstly,using lean IE technology and constraint theory on workshop assembly line analysis,it is found that the operation time of each armrest assembly line workstation is not balanced and with many bottlenecks.The assembly line imbalance is very serious,and it is pointed out that the main defects of the assembly line such as the confusing site based management,the lacking assembly line capacity,the unreasonable production process and the unsuitable worktable design etc.Secondly,being aimed at the above problems,this paper has given the corresponding improvement measures by utilizing the idea of lean production and lean IE technology :(1)Through the lean management of site workshop,and standardizing items,eliminating all external waste,improving the site management level will be achieved by the effective implementation of lean 5S,and also to establish a good working environment for assembly line balance improvement based on lean production.(2)By lean improvement of layout for the armrest assembly line of F enterprise,and using "U" type production layout,the existing 2 independent straight assembly lines are merged into 1 U type assembly line,which is beneficial to eliminate over handling waste and also reduce WIP and management cost,so that make the whole assembly process more continuous and orderly.(3)Utilizing the analysis of the program and double hand operation,referencing chasing rabbit of cell production idea,according to ECRS and the principles of economical motion,the bottleneck workstation is partially improved emphatically.Then from an overall perspective,the first balancing problem of the assembly line will be proposed.Focusing on the premise of improving local bottlenecks,to solve the minimum of workstations as objective function,applying with mathematical modeling methods establishes 0-1 linear programming model for the first kind of balance problem of armrest assembly line,and utilizes the Lingo programming solution.After optimization,the rate of assembly line balancing reaches 89.9%,which is significantly improved than before.(4)Basing on the lean production’s idea of people-oriented,with the foundation of fully considering the physiological and psychological characteristics of the workers,the work table design of the assembly line is improved,and make a reasonable timetable for the operators to product more comfortably and efficiently and to provide guarantee for assembly line balancing.Finally,utilizing ED simulation software to have a modeling Simulation of the improved assembly line,by analyzing and evaluating the improvement effect with capacity as index,the simulation results show that the capacity is improved significantly,and the assembly line balancing improvement is effective and feasible based on lean production.