Entering Used Material in Inventory Management 
You can withdraw both reserved and unreserved material with reference to an order. For this, you use the functions in inventory management (application component MM-IM).
Call up the transaction for entering goods movements. Depending on the application component in which you are working, choose one of the following menu paths:
The initial screen appears for entering goods movements.
Then choose Goods movement ® Enter with reference ® To order.
For more information about how to withdraw material, see
Entering a Goods Issue with Reference to an Order.
For more information about inventory management, see
Inventory Management.