Study Of The Mixed-model Assembly Line Within Variable Launching Interval

changed ---from a small species, large quantities of a single species model of assembly line to more variety, small batch production model of mixed-model assembly line, which can meet customers'needs without increasing inventory levels. The mixed-model assembly line can continuously produce different products within a line, improves production efficiency and reduces the number of products to enhance the production flexibility and adaptability. Compared with single-model assembly line, the mixed-model assembly line has a greater flexibility, high adaptability to help improve product quality, making the company's rapid response to the market, being independent on goods inventory, and improving the market environment of rapid response capability, to achieve the goal of JIT. It is widely used in the European, American and other developed countries, the mainly application is in the automotive industry. Toyota is one of the best examples. Early studies for the mixed-model assembly line are running at a fixed launching interval or omitting the interval. However, the variable launching interval can effectively reduce the bottleneck station and improve work efficiency.Firstly, this paper describes the concept of mixed-model assembly lines. The development of the mixed-model assembly line, characteristics and research are introduced.Secondly, from the perspective of balance problem within variable launching interval. Researching a new model, the improved genetic algorithm is introduced. The following aspects are been improved: the initial population of a problem; design a unique chromosome coding rules &de-coding rules.Thirdly, from the perspective of sequence problem within variable launching interval. Researching a new sequence model, an improved simulated annealing algorithm are introduced based on the problem analysis.At last, for an enterprise instance, using of simulation software---Witness to simulate assembly process, providing effective decision-making.The results show that variable launching interval of mixed assembly line is more efficient and flexible, for enterprises ,which can achieve higher productivity and greater returns.