Forecast based on what-if parameter commencing after actuals

Hello Paulo84

please see see this possibility:

Project open accounts = 
var _periode = SELECTEDVALUE('Table'[Year_Month_ID])+1 - (YEAR(TODAY())*100+MONTH(TODAY()))

var _last_month = 
    CALCULATE(
        MAX('Table'[Year_Month_ID]),
        FILTER(ALL('Table'),'Table'[Open Accounts]<>BLANK())
    )

var _value = 
    CALCULATE(
        sum('Table'[Open Accounts]),
        FILTER(ALL('Table'),'Table'[Year_Month_ID]=_last_month)
    )

return 
if( 
    [Total Open Accounts] = BLANK(), 
    _periode*[Project Monthly Member Gain] + _value,
   BLANK()
)

also i share an example so can compare with yours in the following LINK:

max by category.pbix

Best regards

Bruno Costa | Solution Supplier

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Thanks for reply onurbmiguel_ ! 

Unfortunately, your solution didn't quite work with my existing measures - However, I tweaked it slightly to produce the outcome I was looking for:

Forecast open accounts = 

VAR _date = SELECTEDVALUE('DATE'[End of month])

VAR LatestDate =
    CALCULATE(
        MAX('DATE'[end of month]),
        FILTER(ALL('DATE'), NOT(ISBLANK([Total Open Accounts])))
    )

VAR MonthNumDifference = 

    CALCULATE(
        DATEDIFF(LatestDate, _date, MONTH)
    )

VAR LatestCount =
    CALCULATE(
        [Total Open Accounts],
        FILTER(ALL('DATE'), 'DATE'[end of month] = LatestDate)
    )

VAR NetMbrGain = [Projected Monthly Mbr Gain]

VAR MonthlyDefections = 'Parameter - Monthly Defections'[Parameter Value]

RETURN

IF(
    _date <= LatestDate, 
    BLANK (), 
    (NetMbrGain * MonthNumDifference) + LatestCount 
)

 
Many thanks for your assistance!