How to associate columns with a certain quarter

[eriwet]

Hi, this seems to me like a trivial task, but I fail to figure out how to do it in a simple and straight forward way.

I'd like to evaluate the accuracy of a forecast against the actual outcome.  I have the forecasted volumes for some part numbers in one table (Table 1 below), with each part number having the forecasted total volume per quarter in four different columns.

The actual output have the same part numbers and the actual call-offs of those part numbers - one row for the total volume per day. (Table 2)

Now, I'd like to visualize the accuracy of the forecast by subtracting the sum of the actual call-offs per part number for each quarter.

I have made an auto date/time table in which I can get the Quarter and connect to the the call-off table, but how do I associate the columns in the first table to each quarter?

I'd lika also to maintin the possibility to see the difference on a more aggregated level (i.e. for all quarters at the same time).

[eriwet]

Thanks, quite simple to unpivot - thanks for the advice. 

[ray_aramburo · Accepted solution]

You will necessarily need to have a date column in table 1 in order to match the periods with table 2. I know sometimes forecast are flat values but you can use either the first or last day of the quarter/month as reference. 

[eriwet]

Ok, sounds reasonable, but since each row in Table 1 has four different columns with forecasted volumes (one per quarter) would I then have to transform Table 1 to have four rows for each part number?

[ray_aramburo]

That's right, you can unpivot it on Power Query.