Moving average forecast does not work correctly

[Former Member]

Hello,

I have a forecast model with the strategy moving average 6 months. When I checked the forecast values in the planning book, I recognized that there is a mismatch with the calculation of the forecast:

There is a drift of 2 months when showing the values in the appendant buckets. The first bucket which is filled with forecast values (bucket: current month + 1) contains the moving average value from month - 8 until month - 2.

Example: forecast value for Feb 12 is calculated as follows:

(Nov 11 + Oct 11 + Sep 11 + Aug 11 + Jul 11 + Jun 11) / 6

It is the same procedure for all other following months.

The right calculation should be as follows:

(Jan 12 + Dez 11 + Nov 11 + Oct 11 + Sep 11 + Aug 11) / 6

I checked several settings in the activity and job creation and in the setting of the forecast profiles. I expected that an offset of 2 months is set, but there is nothing.

So, I do not know how to explain this system behaviour....

Hope anybody can help!

Thanks and kind regards

Heinz

[former_member209769]

Hello Heinz,

The only place to check is the forecast profile. Let me assume that you are not talking with reference to SPP. Also, that the period indicator in your master profile is Months. So, this would mean that you have maintained forecast profile as follows:

You need to cross-check that the offset in the section history horizon of the master profile should have value +1, since you are running the forecasting during January, and you want January history to be considered in average calculation. Periods in history horizon should be 6.

Similarly, in the forecast horizon in the master profile, you should have an offset of +1, since you are running the forecast in Jan, but you want the forecast to happen from the month of Feb onwards.

Also, check in the univariate profile tab that you are checking for the right KF for history values, when you look in the planning view.

There is nothing more to standard forecasting apart from few things like 'like profile' or 'phase-in, phase-out' profile. Other option for changes is some custom logic, but it doesn't seem that there is a need for it if calculation is for simple moving average.

So, if the above points don't explain your situation, then better to raise OSS for SAP, to see if there could be some bug.

Thanks - Pawan

[Former Member]

Hello Heinz,

This strategy calculates the average of the time series values in the historical time horizon. You define the historical time horizon in the master forecast profile. I think your history horizon is from June 2011 to November 2011.

For more info:

http://help.sap.com/saphelp_scm70/helpdata/en/19/98ad1765354d7ba54b1eb164c377e0/frameset.htm

Definition/Re-definition of forecast models-> Creating a master forecast profile-> Univariate forecast-> Forecast strategies-> Moving average.

Hope this helps.

Thanks and Regards,

Nithin.

[former_member187488]

Hello, if you don't set 'offset' field in your master forecast profile (first tab of /sapapo/mc96b), please check your customizing code if there is any.