Backorder
A backorder is a customer order accepted but unable to ship because the item is out of stock; the order is held open and filled when inventory arrives. It differs from a lost sale, where the customer cancels or buys elsewhere, and from a stockout, which is the inventory condition that causes both. Backorder volume and aging show how badly supply is trailing demand.
Examples
Aging tells the story: A distributor shows 1,840 units on backorder across 22 lines. About 1,150 units are under a week old with replenishment in transit: normal flow. But 312 units aged past 30 days all trace to one supplier whose lead time doubled without anyone updating the planning system.
Backorder or lost sale: A connector goes out of stock for three weeks. OEM customers with the part designed in wait it out, so that demand backorders at 100%. Web aftermarket buyers cancel within 48 hours, and roughly $18,000 of demand disappears without ever appearing in a backorder report.
Definition
Three terms get blurred. A stockout is the inventory condition: zero available when demand arrives. A backorder is the commercial outcome when the customer agrees to wait. A lost sale is the outcome when they will not. Which one a stockout becomes depends on switching costs: a qualified custom component gets backordered because requalifying a substitute costs more than waiting, while a catalog fastener becomes a lost sale in an afternoon.
Backorders cost more than the delay. There are expediting fees to compress recovery, customer line-down penalties, extra order administration, and the slow erosion of the service reputation that won the business. Track volume and aging together: 500 units backordered for three days is normal flow; 500 units aged six weeks is a broken supply line.
Chronic backorders on the same items are a parameter problem wearing an execution costume. It is usually one of three things: safety stock sized on old demand, a reorder point built on a lead time the supplier no longer honors, or a forecast bias nobody measured. Fix the parameter and the firefighting stops; fix only the order and it returns next cycle.
Frequently asked questions
What is a backorder in simple terms?
A backorder is a customer order that has been accepted but cannot ship because the item is out of stock; the order is held open and filled when inventory arrives. Backorder volume and aging, tracked together, show how badly supply is trailing demand.
What is the difference between a backorder, a stockout, and a lost sale?
A stockout is the inventory condition: zero available when demand arrives. A backorder is the commercial outcome when the customer agrees to wait, and a lost sale is the outcome when they will not. Which one a stockout becomes depends on switching costs: a qualified custom component gets backordered because requalifying a substitute costs more than waiting, while a catalog fastener becomes a lost sale in an afternoon.
Why do backorders cost more than just the delay?
Backorders carry expediting fees to compress recovery, customer line-down penalties, extra order administration, and slow erosion of the service reputation that won the business. Lost demand can also hide alongside them: aftermarket buyers who cancel within 48 hours never appear in a backorder report, so the visible number understates the damage.
How should you track backorders?
Track backorder volume and aging together. Five hundred units backordered for three days is normal flow, while 500 units aged six weeks is a broken supply line. Aging concentrated on one supplier often traces to a lead time that changed without anyone updating the planning system.
What causes chronic backorders on the same items?
Chronic backorders on the same items are usually a planning parameter problem rather than an execution problem. The typical causes are safety stock sized on old demand, a reorder point built on a lead time the supplier no longer honors, or a forecast bias nobody measured. Fixing the parameter stops the firefighting, while fixing only the individual order lets the problem return next cycle.