Available to Promise in brief
When you receive an order from the customer you will be capturing the Order with basic details such as:
1. Item (s) ordered
2. Date when the items are required
3. Quantity of each item ordered
4. Price at which the item is being ordered
5. Where to Ship the goods
6. Where to bill the payment
One critical response that you will struggle to do as a sales rep will be on the date when the items of ordered quantities can be delivered (shipped).
Sales rep with minimum visibility to the Inventory status and orders in and out for the items, will not be able to respond quickly.