You can revoke the permission to end the user to reopen the PO line and only to be grated to the super user.

Hi Rasika

Thanks for your respond, Can you explain the process? 

Hi,

You can Enable the PO authorization rule valid for change order authorization.

But for this to work you should enable the check box Enforce Use of PO change orders at Site master data.

By making this type of configuration the user can only create PO change orders even for Reopening thereby, new authorization will be triggered.

Regards,

Karthik