PO Cancellation if Invoice Status is Not Paid and Work Confirmation is not Processed.

Hello,

If invoices status is Not Paid and ERS is generated; how to prevent buyers from Cancellation or Closing of Purchase Orders? And if Work Confirmations exist but not processed.

Currently system does allow to cancel a PO or a line if status is Not Paid and ERS is generated;

Second, if Work Confirmations process has started but not completed the approval cycle and status is not Processed.

Appreciate any insight.

Regards