Hi,
As mentioned above, changing the rules in FMDERIVE will take care of all the postings made after the change. But, you have to think about your budget, which was already partially consumed. Especially, of the documents which are not yet at the end of their life cycle. For example, open PR/POs, commitments, etc.
If mapping of budgetary changes in the middle of fiscal year, in most cases, reassignment is to be foreseen. Mass reassignment could be executed via FMCG/FMCT transactions. You can maintain reassignment strategy, deriving fund centres in the same way you'd do it in FMDERIVE. Reassignment strategy is defined in IMG - Public Sector Management - Funds Management Government - Master Data - Derivation Strategy for Reassignment.
Regards,
Eli
