The Design Of Mixed Model Assembly Line Scheduling Optimization

In just-in-time production mode, a mixed model assembly line can achieve custom, small-batch and diversiform production plan. As a kind of flexible mode of production, it has a feature that can response rapidly to market needs. Therefore, mixed model assembly line becomes the main production mode of many manufacturing enterprise. The assemble time of different types of products are basically unable to reach consensus in mixed model assembly production. Only reasonable configuration of the type of product, launching, equipment load, staffing, and assemble time can reach the maximize the capacity of the assemble line. Launching sequencing needs to be managed rationally to make production continually. Study on sequencing problem of mixed assembly line can help enterprise manage the production process better, reduce operating costs, response rapidly to competitive external environment.In just-in-time production mode, the core problem of mixed model assembly line is sequencing problem of variable launching. In this study, we apply the method of Work Study to analysis the mixed model assembly line of enterprise A. After summarizing up the mixed flow assembly line balance theory and methods of variable launching sequencing and considering product weighting,we set up a novel sequencing model to minimize makespan. In this case we transfer the sequencing problem into a kind of integer programming problem. Then we adopt the method of lagrangian relaxation and subgradient to solve this problem. A case study is given to verify the feasibility and practicability of the model. At last, this model is applied to enterprise A production scheduling project. At the same time, we provide an optimal solution for decision-makers within the scope of the selection decisions as small as possible.