3.4.3 Inventory holding cost
The non-activity cost also includes the opportunity cost of the investment tied up in
inventory costs, the costs associated with inventory items such as taxes and insurance on
inventory, and the costs associated with the loss of inventory values due to obsolescence
and shrinkage. Inventory holding cost is not caused by activity required by products;
rather it is caused by the effect of the activity already performed. This inventory holding
cost should not be assigned to products, but should be treated as a period expense.