A quantity contract is essentially an agreement that your customer will order a certain quantity of a product from the company during a specified period. The contract contains basic quantity and price information but no schedule of specific delivery dates and quantities.
The customer fulfills a contract by placing sales orders against it. These sales orders are known as release orders . When such a release order is created, it has to be created with reference to the contract, so that the system automatically releases/reduces the quantity from the contract.