Hi,
Create two blocking keys ZP and ZS in t.code: OMS4 for Material X and Finished goods A.
For blocking key ZP.
Use t.code: OMS4 & create a Blocking Key ZP by setting B in Purchasing segment in field of. Purchasing msg. & save.
For blocking key ZS
Use t.code: OMS4 & create a Blocking Key ZS by setting B in Purchasing segment in field of. Purchasing msg. , B in Inventory management segment in field of Inventory mgmt msg., B in for Sales segment and and save.
Now assign Blocking Key ZP in Purchasing view of Material X and save,as no Purchasing required.
Once Finished goods A sold, then assign blocking key ZS in basic data-1 view of Finished goods A and save.
Regards,
Biju K