A Sequencing Method for Mixed-Model Assembly Line with the Aid of Relief Man

Abstract

This paper concerns with a sequencing problem to raise the efficiency of line handling in a mixed-model assembly line where products are assembled in the same cycle time. The goal of the sequencing is to attain two objectives simultaneously, i.e., smoothing of work-load and smoothing of part usage. On real mixed-assembly lines, there exist large variations in the assembly times among different product-models. This causes inefficiency such as line stop or increase in idle time. In this paper, we propose a sequencing method to achieve the above two objectives with the help of Relief Man in such situation. For this purpose, the sequencing problem of minimizing both line stop times and idle times is formulated. Since this problem refers to combinational optimization problems, we develop a hierarchical method that applies meta-heuristics like SA (Simulated Annealing) together with NNM (Nearest Neighbor Method). Finally, we examine effectivness of the proposed method through computer simulations.