Hello,
Please read SAP KBA 2087660 - Fiscal Year Variant change in production environment
The change of the fiscal year or the change of the fiscal periods in a live SAP system has an effect in many modules, for example, in FI, FI-AA, FI-SL, FI-LC, EC-CS, IM, CO, EC-PCA, MM, PP, SD, PS, PM. Corresponding risks (for example, data inconsistency, system standstill) can arise from incorrect changes to the fiscal year or from incorrect changes to the fiscal periods in a live SAP system.
SAP does not recommend to change a Fiscal Year Variant that has already been assigned to a company code and has already some postings.
Also read carefully SAP note 672255 - Shortened fiscal year/changing fiscal periods
and 210861 -Changing fiscal year variant in production system.
Best Regards,
R.Brahmankar