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Posts: 47
Registered: ‎02-09-2016

Cumulative (Running) Totals in DAX

A common Measure that you’ll probably find useful in PowerPivot or SSAS Tabular Models is finding running totals.  For example, you may want to see total sales of a product as it accumulates over time, or for inventory models the total on hand at a given time.  You can find more tips and tricks at my blog, www.bipatterns.com.

Let’s start with a base measure in a very simple pivot table.
Total Sales :=
CALCULATE ( SUM ( FactSales[SalesAmount] ) )

Total Sales

Now lets take our first attempt at computing a running total.  This is the most intuitive formula, but it has one common pitfall that isn’t necessarily easy to see right away.
Cumulative Total Sales :=
CALCULATE (
    [Total Sales],
    FILTER (
        ALL ( DimDate[Datekey] ),
        DimDate[Datekey] <= MAX ( ( DimDate[Datekey] ) )
    )
)
Key parts of the Formula: The use of ALL(DimDate[DateKey]) results in the current context being ignored, so dates outside of the current pivot row context will be analyzed.  The second key step is the comparison of DimDate[Datekey] <= MAX ( ( DimDate[Datekey] ).  This means that all dates in the DateKey column that are before the current pivot table row context will be calculated.

If we put this measure on a table, we’ll get the correct numbers but we will have one issue remaining.

Cumalative Total Sales

The formula returns a number for dates that have no sales.  We need to add some error handling, which is outlined below.
Cumulative Sales (Correct) :=
IF (
    COUNTROWS ( FactSales ) > 0,
    CALCULATE (
        [Total Sales],
        FILTER (
            ALL ( DimDate[Datekey] ),
            DimDate[Datekey] <= MAX ( ( DimDate[Datekey] ) )
        )
    ),
    BLANK ()
)

The IF Function checks to make sure that there are sales in the current selected context, otherwise returning blank.  You can see the difference between the two measures below:

Cumalative Total Sales (Correct)

If you have any questions for me, you can reach me via LinkedIn or in the PowerBI Community.