Withdrawal Posting of Alternative Items 
Use
Withdrawal posting is used for components that have been reserved for the production order. The alternative items are taken into account during this process.
Prerequisites
For each alternative item, you have maintained a sequence and a strategy for the withdrawal in the Alternative item data dialog box in the BOM.
The system does not take the strategy into account during MRP.
Features
You can define a withdrawal sequence and several withdrawal strategies for the withdrawal posting of alternative items for the reservation of a production order:
- Manual specification of the withdrawal
You define manually which material is withdrawn.
- Withdrawal according to usage probability
The system uses the usage probabilities and the sequence to decide which material to withdraw.
- Withdrawal only with 100% availability of an alternative
The system looks for the material that is first in the sequence to cover the complete requirement and reserves this material for the withdrawal. The system will only withdraw an alternative if it can completely cover the requirement. The requirement cannot be split among several alternative items.
You can find further information on this in the SAP document PP – Bills of Material.