What is Available-to-Promise?

Available-to-Promise (ATP) checks current inventory, existing orders and reservations, incoming production or replenishment, and typical delivery times to produce a realistic delivery promise at the moment of order.

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Why ATP matters

Without ATP, retailers either overpromise delivery dates they can't keep, or underpromise and lose sales to competitors who commit faster. ATP sits at the exact point where inventory accuracy meets customer expectation. Get it wrong and the cost shows up either in canceled orders or in customer complaints after the fact.

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What an ATP calculation takes into account

• Current inventory across all fulfillment locations (not just one warehouse)
• Open orders and reservations already committed against that stock
• Planned production or incoming replenishment
• Typical carrier and delivery lead times per location

The accuracy of an ATP promise is only as good as the weakest input here. If inventory data is delayed or siloed by location, the promise itself becomes unreliable, regardless of how sophisticated the calculation logic is.

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ATP vs. static inventory checks

‍A basic inventory check only confirms whether a product is in stock somewhere. ATP goes further: it confirms whether that stock is actually available for this specific order, accounting for what's already reserved elsewhere and how long it will realistically take to reach the customer. This distinction matters most during high-demand periods, when stock is visible in the system but already spoken for.

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Where ATP fits in the order lifecycle

ATP doesn't run as a one-time check. It needs to hold up throughout the order lifecycle, not just at the moment of purchase. This is where order management comes in: as orders move from checkout through fulfillment, the system has to re-confirm that the original promise still holds as inventory shifts across channels, or trigger a re-routing if it doesn't. Retailers running ATP as an isolated calculation, disconnected from live order orchestration, are the ones most likely to see promises made at checkout fail to hold by the time the order ships.

‍Related Terms: Availability and Promising, Global Inventory Hub

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