Inventory management includes planning, coordinating, and controlling activities related to the flow of inventory into, through, and out of an organization. Consider this breakdown of operations for three major retailers for which cost of goods sold constitutes their largest cost item.

The table depicts revenues; costs, including cost of goods sold, selling and administration costs, other costs, interest, and taxes, as well as total costs; and net income for Costco, Kroger, and Walmart. The details of the table are as follows:
1. Revenues
Costco: 100.0 percent
Kroger: 100.0 percent
Walmart: 100.0 percent
2. Deduct costs, cost of goods sold
Costco: 87.0 percent
Kroger: 78.3 percent
Walmart: 74.9 percent
3. Deduct costs, selling and administration costs
Costco: 9.8 percent
Kroger: 17.5 percent
Walmart: 20.8 percent
4. Deduct costs, other costs, interest, and taxes
Costco: 1.0 percent
Kroger: 1.6 percent
Walmart: 3.0 percent
5. Total costs to deduct
Costco: 97.8 percent
Kroger: 97.4 percent
Walmart: 98.7 percent
6. Net income
Costco: 2.2 percent
Kroger: 2.6 percent
Walmart: 1.3 percent
The low percentages of net income to revenues mean that improving the purchase and management of goods for sale can cause dramatic percentage increases in net income.
In addition to the costs of the actual goods purchased, there are a number of different types of costs associated with inventory. These costs fall into the following six categories:
Note that not all inventory costs are captured in financial accounting systems. For example, opportunity costs are not recorded in financial accounting systems but are a significant component in several of the inventory cost categories.
Information-gathering technology increases the reliability and timeliness of inventory information and reduces the costs related to inventory. For example, barcoding technology allows a scanner to record individual units purchased and sold. As soon as a unit is scanned, a record of its movement is created, which helps a firm better manage its purchasing, carrying, and stockout costs. In the next several sections, we consider how relevant costs are computed for different inventory-related decisions in merchandising companies.