What is order promise timing?
Order promise timing is how a business decides when it can deliver an order, based on the stock it can safely commit. Available to Promise (ATP) is the demand-planning capability behind it. ATP shows how much product a company can commit to new customer orders without overselling.
You can use an inventory management system to track inventory for ATP. Integrating it with a warehouse management system (WMS) tracks inventory across multiple channels and supply chains.
How does ATP differ from safety stock?
ATP and safety stock serve different purposes in inventory management.
Safety stock is buffer inventory held to protect against demand variability and supply uncertainty. It is never promised to customers.
ATP is the quantity available for customer commitment after accounting for safety stock, current inventory and committed orders. Safety stock prevents stockouts, while ATP enables accurate customer promises and satisfaction.
How is Available to Promise calculated?
The basic ATP formula combines three inputs:
Quantity on hand: The amount of items available for sale
Supply inventory: The amount of inventory ordered or produced
Demand: The projected amount of items that will be sold in the future
ATP equals quantity on hand plus supply inventory, minus demand.
What are the benefits of order promise timing?
Accurate order promise timing helps determine realistic delivery dates and quantities.
Rather than promising inventory that does not exist or missing revenue by being too conservative, ATP balances customer satisfaction with operational reality through accurate, real-time availability calculations.
It can also help identify sales opportunities by capturing demand that would otherwise be lost, and improve cash flow through accurate order fulfillment timelines.
Promise only what you can ship
How technology supports order promise timing
Order promise timing is only as reliable as the inventory data behind it. An Order Management System (OMS) keeps that data current and applies it at the moment a customer orders, so the date you promise matches what you can deliver.
An OMS supports order promise timing by:
Showing real-time visibility into physical, in-transit and future stock at the time of order
Unifying inventory across warehouses, stores, suppliers and third-party locations in a single view
Applying safety stock rules and allocation buffers so committed stock stays protected
Segmenting inventory by channel, customer tier or location so priority orders get priority stock
Choosing the best fulfillment node for each order, based on cost, speed and service level
Using predictive analytics to refine delivery estimates as conditions change