when the old PO’s are closed out, is there a way to provide a ledger summary of the pre/post amounts

Once Step 1 is completed :

          Step 1 -> open PO’s show as committed costs and as a result when a PO is cancelled it will reduce the value of the PO, those additional funds would then be released and returned to the applicable BU’s budget.

                          where the val budget = BA  - AA - PA.

          Step 2 ->  so now to validate this - when the old PO’s are closed out, how can we review a ledger summary of the pre/post amounts showing how much was released from committed costs.

Please help...thank you very much.