Budget control at PM Order level

Hi Experts,

Payments for external maintenance tasks are made through PRs created via PM order. These PRs will convert to POs later. In our scenario, value entered at the PR level would not allowed to be changed at PO level. Further budget controls are applied at PO level through FM.

Other option available for PM budget control is via a WBS element which linked to IM.

Query is to knowwhether there is another way to control budget at PM Order level.. ?

Thanks in Advance..