Contracts 
A contract is a type of outline purchase agreement against which release orders (releases) can be issued for agreed materials or services as and when required during a certain overall time-frame. You can create quality based contracts (MK) or value based contracts (WK).
The system allows you to create and process contracts for different stock segments of a material.
Structure
The contract consists of items defining the individual materials, material groups with prices and target quantities for different stock segments of a material. For example, you can create contract with vendor-specific quantities or order value of the same material for different stock segment.
If you maintain values for different stock segments in the material master under Additional Data, the system displays the valid weights and volumes in the detail view for the different stock segments of the material.