For one of our BI projects, our client keeps asking for an interactive control to do What-if scenarios. This used to be limitation for PowerBI but guess what? In this latest release, PowerBI supports What-if parameters! Problem solved! 

In the latest Designer, there is a Modeling tab called What If, which lets us add a New Interactive Parameter. We’ll need to specify its Name, Data Type, Min & Max values, Default and internally PowerBI will create a table with 2 columns. The first is a column with all the possible values for the parameter. It’s very useful for putting in a slider for viewers to use when using the report. The second column is a measure which will be equal to the currently selected value and we use this as a reference in our calculations.

PowerBI will add a slider to your page: