DAX optimization & variables with SWITCH statement

Hello Anonymous 

I believe each Variable will calc before it makes it to the switch but what you can do is turn each variable into a measure then just read your filterTimeCalculations[time_calculation] and do the switch.  This also makes it easier to add additional measures to your list and the measures you do write can be used in other parts of the report.

prior_year = 
    CALCULATE (
        [Total_Labor_Dollars],
        FILTER (
            ALLEXCEPT (
                dimSalesDates,
                dimSalesDates[Sales_Week_Number],
                dimSalesDates[Period_Number]
            ),
            dimSalesDates[Year]
                = MAX ( dimSalesDates[Year] ) - 1
        )
    )

prior_year_growth = [Total_Labor_Dollars] - [prior_year]

prior_year_growth_percent = 
    FORMAT ( DIVIDE ( [prior_year_growth], [prior_year] ), "Percent" )

prior_year_to_date = 
VAR filter_week =
    MAX ( dimSalesDates[Week_End_Date] )
RETURN
    CALCULATE (
        [Total_Labor_Dollars],
        ALL ( dimSalesDates ),
        dimSalesDates[Week_End_Date] <= filter_week - 364)

year_to_date = 
VAR filter_week =
    MAX ( dimSalesDates[Week_End_Date] )
RETURN
    CALCULATE (
        [Total_Labor_Dollars],
        ALLEXCEPT ( dimSalesDates, dimSalesDates[Year] ),
        dimSalesDates[Week_End_Date] <= filter_week
    )

ytd_growth = [year_to_date] - [prior_year_to_date]

ytd_growth_percent = 
    FORMAT ( DIVIDE ( [ytd_growth], [prior_year_to_date] ), "Percent" )

Time_Calculation_Total_Labor_Dollars_2 = 
VAR TimeCalcSelection = 
    SELECTEDVALUE( filterTimeCalculations[time_calculation], "Current Year")

RETURN
    SWITCH (
        TRUE(),
        TimeCalcSelection = "Current Year", [Total_Labor_Dollars],
        TimeCalcSelection = "Prior Year", [prior_year],
        TimeCalcSelection = "Prior Year Growth", [prior_year_growth],
        TimeCalcSelection = "Prior Year Growth Percent", [prior_year_growth_percent],
        TimeCalcSelection = "Prior Year YTD", [prior_year_to_date],
        TimeCalcSelection = "Current YTD", [year_to_date],
        TimeCalcSelection = "YTD Growth", [ytd_growth],
        TimeCalcSelection = "YTD Growth %", [ytd_growth_percent],
        [Total_Labor_Dollars]
    )