Trailing Twelve Months Calculation with Drill Down to Customer and Product

[jclancyjr]

Hi, I have a question. Does anyone have any articles or videos on calculating Trailing Twelve Months (TTM) sales and comparing it to the previous TTM sales? I was successful in formulating a TTM Sales (see below) if there are sales in the current period. In my example my last reported period is June 2018. The DAX formula below roles back twelve months and calculates correctly. However, when I use this same formula to calculate the TTM for each customer and product it does not work. I have determined that the reason it is not working is, if a customer or product is not sold in June 2018 it starts at the date of it's most recent months sales. So if the customer did not buy anything since March 2018 the formula goes from March 2018 to April 2018. How do I lock the dates for June 2018 to July 2017?


CALCULATE(sum(tblActSales[<wbr>Sales]),DATESBETWEEN(tblDates[<wbr>DateValue],[Last Date - 12 MO],[Last Sales Date]))



LASTDATE(tblActSales[Date])

 

[gazpage]

Best to create a separate calendar table with contiguous dates.