2015 Volume 65 Issue 4E Pages 321-327
The focus of this paper is the scheduling problems in the lot production lines of the Toyota production system (TPS). As the problems are serious in not only the TPS, but also other production systems, the author introduces some results gained by studying the problems in hope that the problems will be researched more widely. It is well known that lot production lines of the TPS are operated utilizing an order point system. However, a problem exists in that the setup schedule for each lot production line when utilizing this method is not made in advance; thus, setup cannot be implemented based on the schedule. As such, another method is adopted for the TPS. This other method is not well known, so it must be analyzed and scheduling algorithms developed for it. Moreover, the author demonstrates the properties of operating lot production lines controlled by the method. As a result, it is shown that this method can be utilized for not only the TPS, but also other production systems. There is another problem as well. Generally speaking, it is very difficult to reduce the number of employees working on a lot production line in proportion to the decreasing production quantity of the line. For this, the author researches how to improve worker productivity on lot production lines when the production quantities of the lines drop. Though this problem is basically a scheduling issue, it is shown that this problem should be investigated from a wider perspective.
