Define Cut-off value key for residual value of 5%

Dear Expert,

My client has not implemented the depreciation calculation as per the company act 2014. Now they want to incorporate these changes in the system.

According to client requirement they need to Define Cut-off value key for residual value of 5%.

If Acquisition  value is  1000 and useful life is 5 year then calculation should be like this

Calculation

Acquisition value -5%scrapvalue/Remaining useful life

1000(Acquisition value )-50(5%scrapvalue )=950/5(Remaining useful life)=190 dep per

I have taken the below mention steps

1. Define the value of cut off key(ANHAL)
2. Created a new depreciation key & assigned the  cut off value key

3. Assignment of calculation method

4. Assignment of new Dep key in the asset

For New asset, The calculation is ok but when I am making changes in the existing asset then dep calculation is not coming correctly .

Exp

Asset no -200607

Useful life=10

Remaining life-8

Net book value on 01.04.2016=23,600.00

The correct calculation should be like this

23600(Acquisition value )-1180(5%scrapvalue )=22420/8(Remaining useful life)=2802.5 dep per year

But it is not coming

Please suggest.