Segmentation: Purchasing Documents 
Segmentation allows you to logically segment materials based on certain attributes, for example, Quality or Customer segment. When you use materials with segmentation, you can also process quantities and conditions in purchasing documents for individual stock segments.
For more information about processing of purchasing documents in the standard ERP system, see Purchasing (MM-PUR).
Prerequisites
You have activated the business function Material Segmentation Across Logistics (LOG_SEGMENTATION)
You have created the characteristics for segmentation using transaction CT04
You have defined segmentation structures in Customizing for
Logistics – General 
Segmentation Define Segmentation Structures 
You have defined segmentation strategies in Customizing for
Logistics – General Segmentation Define Segmentation Strategies You have created materials and assigned a segmentation strategy in the material master (transaction MM01)
Process
To procure materials with segmentation, the system allows you to maintain data in purchasing documents for the corresponding stock segment. You can manually enter the stock segment or the system copies the value from various sources such as other purchasing documents, or determine during requirement planning (MRP).
The system does not allow you to enter or maintain stock segment for a material if one of the following condition is true:
Material is not relevant for segmentation
Plant to which the material belongs is not relevant for segmentation
Material is relevant for segmentation but you did not assign or fix the segmentation strategy and the segmentation structure
Scope is Only Requirement Segments Maintained in the segmentation strategy
For more information about how segmentation is handled in individual purchasing documents, see the following: