I am not sure the exact flow you are trying to achieve. Can you describe the flow more completely? For example, where are you interacting with the PRs? In Ariba? In SAP MM? In another ERP?
In the 14s release, we delivered a flow from SAP MM RFQ object, to Ariba Sourcing. It creates a Sourcing Request that is used to create a soucing project, either full or quick, RFP or auction. The bidders provide responses, the buyer awards the event, and then sends the results back to MM to create either a PO or an Outline Agreement.
David Morel