We have a business requirement that needs to work like following. This is on r12.1.3
Step 1: On iprocurement pagem there will be a check box called "Add to Existing PO" on PR entry and submission page
Step 2: When user checks the box, he/she must select a PO# in a nearby field. This will tell the process that new PR line is required to be added into the PO specified by the user in that field.
Step 3: When a PR is submitted for approval and PR is approved, it needs to add a new line into an existing PO that was specified in Step 2 above.
Step 4: A revision will be created and the PO will be resubmitted for Approval.
I am new to OAF and Workflow. How can I accomodate following by workflow customization?