There has been a bug in Oracle Purchasing System that once if a Contract PO is created and approved, the field 'Enable All Sites' becomes non-editable. Hence, if any Standard PO is created with the same Supplier with different Site as of the Contract PO, the PO does not refer the Contract PO. For this, the 'Enable All Sites' field should be made editable.
Have taken advise from Oracle Notes that a Pll file needs to be modified. Now, the pll changes are done and now it's working fine.
After the Enable All Sites field checked for 2 PO's, the User asks for the following
There are 2 Contract PO's with same Supplier but with different Site. (Enable All Sites Field Checked)
CPA1 - Supplier A - Site A
CPA2 - Supplier A - Site B
If a Standard PO is made against the Supplier A though the Site B is selected, the PO has the reference as CPA1(Supplier A and Site A). User requires if a Standard PO is created with Supplier A and Site A,
the PO should have the reference as the Contract PO with Supplier A and Site A. Any Standard Po is created with Supplier A and any Sites, it has the Contract PO with Supplier A and Site A as it's reference.