MIXED-MODEL ASSEMBLY LINE PROBLEM WITH CONSIDERATION OF CONVEYER SPEED

In this paper, we treat a mixed-model assembly line problem to maximize the work efficiency. There are some objectives for the point such as minimizing works congestion or line stop time. In case of minimizing line stop time, long cycle time compresses the stop time and makes evaluation value better. However, it increases idle time and makes work efficiency low. In other words, short cycle time increases line stop time but there is possibility to make work efficiency high. Many studies decided job sequence with fixed cycle time. If an assembly line system changes cycle time, it will make work efficiency high. This paper treats the assembly line system which can adjust conveyer speed to change cycle time and requires restart time from a line stop. In order to consider the work efficiency including idle time, line stop time and restart time, the objective function is set to minimize makespan as the time interval between the launch of the first product and the completion of the last product. The solution of this problem consists of job sequence and conveyer speed. We propose some methods using by Simulated Annealing(SA) and show the effect of the methods by numerical experiments.