After Usage Decision: Sample Destroyed 
The stock placement in WM should only take place after the usage decision in QM has been made. The sample quantity is destroyed during the inspection.
SAP Recommendation:
In WM, the stock is posted to an interim storage bin using dynamic coordinates (purchase order number) with a corresponding stock placement transfer requirement. These goods have the stock category "Q" and an inspection lot number.
Release 90 pieces to available stock. When you execute the IM posting, the system creates interim storage quants and a posting change in WM.
Designate 10 pieces as a goods issue to sample. The system reduces the stock placement transfer requirement and the stock in the interim storage bin (dynamic coordinate purchase order number) by 10 pieces.
Here the stock category is changed form "Q" to "__" (blank) in the stock (90 pieces) in the dynamic coordinate interim storage bin and in transfer requirement for the stock placement.

If you activate automatic transfer order creation for movement type 321, this process will be started directly in the background from the usage decision.