Functionally a "Purchase Order" is the "Confirmation" that goods are Ordered at the supplier and scheduled to be receipt (see 23.13). If goods are NOT allowed to be ordered yet, this is a REQUEST to order goods. (Requisition, see difference 23.13). So functionally, the "Approval Procedure" should authorize the CHANGE of a REQUISITION in a PURCHASE ORDER. Looking at your question, I believe you need to evaluate the "Approval Procedure". If the procedure of the company is not "in line" with the concept of QAD/APICS you will allways have to build a customization to comply. My advice would be to redesign the Approval Procedure.