Semi-Additive Measures in DAX

Values such as inventory and balance account, usually calculated from a snapshot table, require the use of semi-additive measures. In Multidimensional you have specific aggregation types, like LastChild and LastNonEmpty. In PowerPivot and Tabular you use DAX, which is flexible enough to implement any calculation, as described in this article.

A semi-additive measure does not aggregate data over all attributes like a regular additive measure. For example, measures like balance account and product inventory units can be aggregated over any attribute but time. Instead of considering the period selected (one year, one month .) you consider only a particular moment in time related to the period selected. It could be the first day, the last day, the last day that had transactions, and so on.