Or to put it yet another way:
- During the life of the contract
- The vendor promises to deliver a product meeting defined specifications;
- In quantities specified in purchase orders received, up to a maximum aggregate quantity;
- Within a defined time after receiving each purchase order;
- At a specified price payable on specified terms.
How the vendor satisfies those obligations will be up to the vendor.
"It is long been a principle of ours that one is no more armed because he has possession of a firearm than he is a musician because he owns a piano. There is no point in having a gun if you are not capable of using it skillfully." -- Jeff Cooper