Help with circular reference calculation

[Anonymous]

Hello,

 I need to perform a difficult calculation on my model and I can not seem to find the answer to this.

The context is:

Every month I have a total cost, but I have a limit on how much I can pay, if the cost exceeds this limit I have to carry the difference to next month.

The problem is that this calculation is giving me the circular reference problem.

Illustration of the problem:

The problem is that the current red row references the previous orange row, which references the previous red row, I have no idea of how to solve this issue on power bi.

Can anyone help me?

[Vera_33 · Accepted solution]

Hi @Anonymous 

What are your original columns? I got Month, Cost, Limit only, then 3 Calculated columns

Difference = 
VAR CurMonth = 'Table'[Month]
VAR T1=FILTER('Table','Table'[Month]<=CurMonth)
RETURN
SUMX(T1,[Cost]-[Limit])

Previous Month = 
MAXX(FILTER('Table','Table'[Month]=EDATE( EARLIER('Table'[Month]),-1)),[Difference])

Total = [Cost]+[Previous Month]

[Anonymous]

Works perfectly! I just included an if statement on the difference to yield '0' if negative, this way we won't accumulate negative values at the difference.

If you have the time, could you explain to me why this works ??

I was trying using Calculate(sum(difference, Filter (previous month)) and it was not working, giving the circular error

[Vera_33]

Hi @Anonymous 

I don't have enough context to understand how you calculated all the values, are they all DAX Calculated columns or measures? Have you checked if there is certain value like referencing each other?