Approval Process for PO with Contract Terms

Hi,

We want to use Contract Terms within a purchase order. We have created and approved a Contract Template and now able to assign it to the purchase order along with contract administrator. I would like to know if the purcahse order with contract terms also goes through the same approval process. We use Position Hierarchy for PO approval and we could see that the workflow is finally completing in ERROR after the po has been approved.

We don't need any special approval process rather want the PO to be in approved status once the approver approves the PO which are with contract terms.