Accumulate sum

Hi jps_HHH ,
here's an example of how to calculate a forecast assuming a percentage growth:

ForecastActualCosts =
VAR _maxActualDate = CALCULATE(
    MAX('Cost Production Lines'[Month]),
    'Cost Production Lines'[Type] = "ACT"
)
VAR _futureMonths = SELECTCOLUMNS(
    FILTER(
        ALL('Cost Production Lines'[Month]),
        'Cost Production Lines'[Month] > _maxActualDate
    ),
    "Month", [Month]
)
VAR _forecastValue = 1.05 -- Example: 5% monthly growth
RETURN
SUMX(
    _futureMonths,
    CALCULATE(
        SUM('Cost Production Lines'[Val.in rep.cur.]) * _forecastValue,
        'Cost Production Lines'[Month] <= _maxActualDate
    )
)

Modify _forecastValue or replace the growth logic with your specific forecast method.

Now you can combine Actual and Forecast Lines:

CombinedActualAndForecast =
VAR _maxdate = MAX('Cost Production Lines'[Month])
VAR _actualMaxDate = CALCULATE(
    MAX('Cost Production Lines'[Month]),
    'Cost Production Lines'[Type] = "ACT"
)
RETURN
IF(
    _maxdate <= _actualMaxDate,
    CALCULATE(
        SUM('Cost Production Lines'[Val.in rep.cur.]),
        ALLSELECTED('Cost Production Lines'),
        'Cost Production Lines'[Month] <= _maxdate,
        'Cost Production Lines'[Type] = "ACT"
    ),
    ForecastActualCosts
)