Research And Application On Production Control Of Mixed-model Assembly Lines In Car Plant

With the increasingly development of the living standard, people change their idea from ‘one car to purchase’ to ‘which car to purchase’. It would be a strong initiative to the market for those who meet the need of the customer at this moment. Since the updating speed of the products grows up as the requirement of which changes so fast, the enterprises have to organize their production according to the needs of market and customer. The key points of production control level of mixed-model assembly line is that how to make the production stable when facing emergency such as changing market need, equipment problem or shortage of material supply, etc.The mixed model assembly line production problem during emergency is detail described in this paper, whose main research object is how to return to the original optimum status when facing emergency during production. The united algorithm is applied by the production control solution based on the genetic algorithm and the total period of no bypass car(TTPONBC) to change the working time and get the optimum production sequence. It is made the conclusion through the comparison with none-change action, normal manual action and the algorithm above that manual action is only suitable for emergency of front shops while united algorithm performs well for emergency of both front and rear shops, especially the latter situation. By the test of the example of the buffer line between body shop and paint shop, the united algorithm can reduce TTPONBC to zero and raise JPH from 28.6 average value to 30 of the full capacity with the Umlauf improved from the situation too low or too high to the ideal level with 50% and the mixed-model percentage changed from ‘20/80’ to ‘40/60’, which proves the availability of this method.