A Study on Time Extension of Process Operation in Manual Assembly Line

― A Case of Major Home Appliance Assembly Line at Oversea Base ―

Abstract

In recent years, short-line production, which are allocated many work elements in a process, has become the mainstream in manual assembly bases in order to cope with multi-product production. In these production lines, many examples are seen in which the target productivity which is set at the process planning cannot be achieved because these lines cannot perform with the tact time and line balance which is assumed at process planning. It is indicated that the reason is because allocating many work elements in a process causes process time extension.

Therefore, this study analyzed real manual assembly lines of major home appliance based on overseas, and observed that there is 1.8 times process time extension between net process time and process time which is set at the process planning. Moreover, it was observed that the process time extension was affected by the number of work element in a process. Then, this study proposed a method to estimate process work time considering the number of work element in a process.