Fa tax book depreciation method definition

Hello all,

We need to define the depreciation method to meet the Fa tax book depreciation requirement,

 If a fix  asset is in use at the first fiscal  year, so the total allowance for the first year is initial allowance + annual allowance 

 

And  the annual allowance of the first fiscal year is calculated based on the balance of the cost * initial allowance of this year.

for the following years, the depreciation rate is the fix rate.

So how can we define the depreciation method for the first fiscal year?

Thanks for your help and hoping your reply