Tina
Can you used PM Module in your company.
When a Purchase Requisition (PR) is created from PM order using control key PM03 after approval of PR, Purchase Order (PO) is issued. After completion of maintenance job and acquiring services or material procured against PR which has been created from PM order, PM order is Technically completed. When order status is set as TECO, PR got deleted. This behavior of deletion of PR when order is TECO
This is standard behaviors in the PM/CS order As Of My Knowledge can you used PM Module in your company