Inventory check is usually performed only at the end of the accounting period or once or twice a six months, and it is done for all items at a once, which makes it called Simultaneous Stocktaking as well. In Cycle Counting, a fixed quantity of items are checked sequentially in a fixed cycle such as once a three days.

In this case, one method is that shelves and sections to be checked are defined in advance and a stocktaking is performed in series, but ABC Analysis method is commonly employed, where items are categorized in terms of importance. For example, as shown in the figure, inventory goods are classified into three types(A, B, C), where more emphasis is placed on higher value items of A so that the inventory investment can be minimized. Thus, for example, the inventory of A items is performed monthly, while less time and attention are given for C items and thus that of C items is done such frequently as only at the end of the accounting period so that finished goods do not run out. It is crucial to improve the inventory accuracy of important items in order to improve the planning accuracy of MRP.