Being able to specify the preferred format for measures and calculated measures in SSAS is a great feature since you just do the definition once and clients can leverage this central definition.
But for a KPI expression (value, goal, status, trend) it’s not directly possible to specify the format. But there is still a simple trick to do so: You just have to define the calculation itself as a calculated member within your cube script like this:
member currentcube.Measures._BacktestingTotal as 100, visible=0
member currentcube.Measures._BacktestingValue as 5, visible=0 , format_string = "0.00%"
member currentcube.Measures._BacktestingTarget as 5, visible=0 , format_string = "0.00%"
I removed the real computation formulas for the three values and replaced them by constants because they would simply be confusing. But you can see how the format string is applied here. These members shouldn’t be visible, so I set visible=0.
In our KPI definition you can simply point the expression to the calculated member like this:
By doing so, the format of the calculated member defines the format for the KPI value, target etc.