Multiple Units of Measure in Trading Contracts 
Multiple Units of Measure in Trading Contracts
Use
A material is sold and purchased in various units of measure. You use this function to maintain multiple units of measure in the trading contract. You can define different units of measure for sales and purchasing sides for a given line item. For example, customer orders material in 500 pallets and you issue a purchase order in 2,500 cartons. The system automatically converts those units to basic unit of measure in material master. You must maintain unit conversion for each unit in material master before you enter those units in the trading contract.
A trading contract contains two units of measure:
This is the unit in which the material is sold.
This is the unit in which the material is procured. If no conversion factor is specified in the system, you must enter a conversion factor on the item detail screen
In the SAP R/3 System, you can therefore define various units of measure by maintaining in the trading contract item. You need to maintain the fields of the units of measure only if they deviate from that from the material master record. Otherwise, the system automatically takes the unit of measure from the material master record as a basis for its calculations