What criterion primarily guides the classification of items in ABC Analysis?

The primary criterion that guides the classification of items in ABC Analysis is the cost and profitability contribution of each item. This method categorizes inventory items into different classes based on their financial impact on the organization. Typically, items are divided into three categories: 'A' items represent a small percentage of the total items but account for a large portion of the inventory value; 'B' items are of moderate value; and 'C' items are numerous but contribute minimally to overall value. By focusing on the cost and profitability contribution, businesses can prioritize their management efforts on those items that have the most significant impact on their financial performance, ensuring efficient inventory control and resource allocation.

In contrast, other factors like weight, frequency of usage, and shelf life can be important for operational efficiency and logistics but are not the primary focus of ABC Analysis, which is fundamentally concerned with the economic value of the inventory items.