Hi everyone. A Power BI newbie here!
I'm trying to use Power BI to provide me with a forecast for some 12 month rolling totals. So for example, the figure for January 2008 would be the sum of figures from February 2007 up to and including January 2008. It's my understanding that having the data arranged in 12 month rolling totals will smooth out any seasonality impact.
Here is the same 12 month rolling data on two charts with different forecasting seasonality values. As you can see, the forecast is very different depending on the setting used.
I'm not sure what setting I should use on the SEASONALITY field on the forecast options? Does anyone have any idea what value I should use in here please?