Requisition and PO approval

Good day,

I need to get some advise from expert who implemented Requisition and PO approval.  How purchasing will get information for the approved requisition.  Do they need to get approved requisition print  from the requisition departments?  (Or) in the requisition approval route purchase manager to make it as final approver, so that each requisition approval, purchasing will get the requisition in purchase managers work center/ email.  Please advise which is best option in the best industry practice.