Make Purchase Order (PO) Drive Project Billing

Organization Name (Required - If you are an Oracle Partner, please provide the organization you are logging the idea on behalf of):

Oracle's Client

Description (Required):

Our customer wants the billing in Project contract to be driven by customer PO. We found a workaround, where, customer PO will be recreated as a contract and linked to Customer Contract. But this solution is still insufficient; since they are scared of entering wrong PO.

Use Case and Business Need (Required):

Our question is: is there a way in Saas or Paas to manage this type of situation?

Enhancement Request / Service Request: