Hi Mudasir,
As mentioned by you above, the system is correct. The two scenarios (simple explanation) are as follows:
1. Once a PO has been created with reference to the PR, it means that the quantity has been completely utilized (if all quantity has been included in the PO). In this case the system will not allow to create any RFQ.
(Note: the system will allow to create RFQ after creating the PO, but it will ask to enter quantity manually).
(e.g. PR for Pencil, 10 box required and PO has been created for 10 box pencil, PR is closed)
2. If a RFQ has been created with reference to the PR, it means that the PR is still open (as the PR quantity has not been utilized). Therefore this PR is still open and a PO can be created for this PR.
(e.g. PR for Pen, 5 box required, RFQ has been created, in this case the PR is still open).
If you want to issue RFQ after PO creation, then select the line item(s) of the PO, and delete this. Then you can issue RFQ.
Best Regards,
Zakir