Stockout Rate

Stockout rate measures how often inventory is unavailable under a stated observation rule. Organizations may count demand events, affected orders, item-location observations, or unfulfilled units. The name alone does not specify the denominator.

If three of 50 eligible orders have at least one unavailable item, the affected-order rate is 3 / 50 = 6%. If those orders request 100 units in total and only three units are unavailable, the unfilled-unit share is 3%. Both describe the same hypothetical records, but answer different questions.

Fix the fulfillment window and treatment of partial supply, reservations, cancellations, and missing observations. A unit fill rate and an unfilled-unit share sum to 100% only when they partition the same demand with the same rules. A stockout-event rate generally does not complement a unit fill rate.

Related reference: Oracle inventory planning and reporting documentation. Examples and calculations here are illustrative.