BSB Composition Sustainment Practice Test 2026 - Free Practice Questions and Study Guide

An SKU is the specific, unique identifier you use to track a particular item configuration in inventory—think of it as the exact product variation you stock, pick, and replenish (for example, a red medium T-shirt with a particular SKU). It serves transactional and operational needs: on-hand quantities, location, reorder point, and picking routes.

The item master, on the other hand, is the central record that stores all descriptive attributes about the item itself—name, category, unit of measure, dimensions, weight, supplier, lead time, pricing, and other data needed across systems. It’s the authoritative source of item information.

Usually, one item master record can support multiple SKUs when variants exist (such as different colors or sizes), while an individual SKU represents a specific configured instance used in inventory operations.