Stockout

thumb|Stockout of dog food 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.

==Extent== According to a study by researchers Thomas Gruen and Daniel Corsten, the global average level of out-of-stocks within retail fast-moving consumer goods sector across developed economies was 8.3% in 2008. This means that shoppers would have a 42% chance of fulfilling a ten-item shopping list without encountering a stockout. Despite the initiatives designed to improve the collaboration of retailers and their suppliers, such as Efficient Consumer Response (ECR), and despite the increasing use of new technologies such as radio-frequency identification (RFID) and point-of-sales data analytics, this situation has improved little over the past decades.