Optimal resource assignment for manufacturing systems based on cost flow analysis

Theory of constraints(TOC) attracts attention as a method to improve a production system, and it is expected as a key to one of a solution for supply chain management. The objective of TOC is to maximize system through-put and to minimize inventory based on identification of the system constraint. To achieve this, TOC requires to set buffers for work-in-process inventory on front and rear of the bottleneck process to avoid interrupting the operation. However, TOC does not explain how to determine each size of the buffers exactly. In this paper, we propose a method to determine the optimum size of the buffers from a view point of the cost maximization problem with probable breakdowns of machines.