In a competitive manufacturing industry, understanding the cost structure is very important because price is typically influenced by cost. Moreover, sales and profits are affected by changes in costs, depending on the setting, structure, and establishment. Various methods exist to clarify the cost structure, such as the cost accounting method, cost–volume–
profit (CVP) analysis, activity-based cost (ABC), activity-based management (ABM). The ABC method, for example, traces costs. Further, an indirect cost is divided into each activity depending on the time taken for the activity. Consequently, the method comprehends real activity cost. However, it is not enough that the ABC method uses only an activity’s time
because various activity indicators exist, such as number of laborers, equipment, and operating time. To obtain detailed information, realizing a “process” in a manufacturing situation and discussing the cost and profit structure of a detailed process are useful.