SAP BPC 10.1NW: Change ACCTYPE after Go Live

Hi,

After implement BPC 10.1 NW and use it during one year, our customer require to change the way of entering data: reveneu in positive and expensive in negative.

This involves to change ACCTYPE property to EXP in all members of account type Dimensions. It affects all calculations (input template with cell formulas, scriptlogic, BADIs,...). In addition, traceability with historical data will be lost.

Should I considerer something else?