Need Help: Yearly step-down calculation based on a fixed percentage

[realdaniel1989]

Hi, 

I'm new to DAX and I need help with coming up with a DAX computation

The scenario here is that at the start of each new year from [Period No.] = 8 onwards, I need to compute a degredation.  

The first year (ie. [Period No. = 8]), there will be no degredation therefore 100% but in subsequent years, there will be a degredation of 0.7% p.a.  and this degradation will only happen at the start of the year.  

Please help on what DAX expression should be written to achieve the results above. 

Thanks

Year	Year. No	Period No.	Start date	End date	Degredation
2018	1	1	1-Apr-18	30-Jun-18
2018	1	2	1-Jul-18	30-Sep-18
2018	1	3	1-Oct-18	31-Dec-18
2019	2	4	1-Jan-19	31-Mar-19
2019	2	5	1-Apr-19	30-Jun-19
2019	2	6	1-Jul-19	30-Sep-19
2019	2	7	1-Oct-19	31-Dec-19
2020	3	8	1-Jan-20	31-Mar-20	100.0%
2020	3	9	1-Apr-20	30-Jun-20	100.0%
2020	3	10	1-Jul-20	30-Sep-20	100.0%
2020	3	11	1-Oct-20	31-Dec-20	100.0%
2021	4	12	1-Jan-21	31-Mar-21	99.3%
2021	4	13	1-Apr-21	30-Jun-21	99.3%
2021	4	14	1-Jul-21	30-Sep-21	99.3%
2021	4	15	1-Oct-21	31-Dec-21	99.3%
2022	5	16	1-Jan-22	31-Mar-22	98.6%
2022	5	17	1-Apr-22	30-Jun-22	98.6%
2022	5	18	1-Jul-22	30-Sep-22	98.6%
2022	5	19	1-Oct-22	31-Dec-22	98.6%
2023	6	20	1-Jan-23	31-Mar-23	97.9%
2023	6	21	1-Apr-23	30-Jun-23	97.9%
2023	6	22	1-Jul-23	30-Sep-23	97.9%
2023	6	23	1-Oct-23	31-Dec-23	97.9%
2024	7	24	1-Jan-24	31-Mar-24	97.2%

[v-chuncz-msft · Accepted solution]

@realdaniel1989 

You may use DAX below to add a calculated column.

Column =
VAR p = 'Table'[Period No.] - 8
RETURN
    IF ( p >= 0, 1 - QUOTIENT ( p, 4 ) * 0.7 / 100 )

[Greg_Deckler]

Probably something like:

Degradation = 
VAR __period = [Period]
VAR __degradation = 
    IF([Period] < 8,
        BLANK(),
        INT( (__period - 😎 / 4) * .7
    )
RETURN 100 - __degradation

[realdaniel1989]

Hi @Greg_Deckler 

This error shows up