Hello Marisa,
I would recommend you to use a depreciation key like 0000 to calculate
no depreciation and to change this key as soon as you want to calculate
depreciation.
Regarding the issue, whenever you change a depreciation calculation
paramenter (i.e. depreciation key), you should execute the asset
recalculation, TRANSACTION AFAR. However, you can only recalculate planned depreciation
for fiscal years that are still open.
Values in closed fiscal years in AA cannot be modified.
I hope this helps
thanks and regards
Ray