Stockout

A stockout, or out-of-stock (OOS) event is an event that causes inventory to be exhausted. While out-of-stocks can occur along the entire supply chain, the most visible kind are retail out-of-stocks in the fast-moving consumer goods industry (e.g., sweets, diapers, fruits). Stockouts are the opposite of overstocks, where too much inventory is retained. A backorder is an order placed for an item which is out-of-stock and awaiting fulfillment.