Ex-Post Error Evaluation: Auto strategies

[Former Member]

Dear Experts,

Sometime somewhere I recall having read on help.com that Auto strategy evaluates ONLY MAD when testing for models, irrespective of the error measures selected in the forecast profile. I can't trace it right now.

Question:

Is this true ?

If I develop my own measure (using the BADI provided), does the system propose the forecast based on this measure? All strategies ?

Thanks

BS

[Former Member · Accepted solution]

ok. Alles klar

Automatic Model Selection Procedure 2 - Creating a Master Forecast Profile - SAP Library

SAP's intimidating English

It uses these parameters to execute a forecast. It then chooses the parameters that lead to the lowest error of measure that defined in the forecast profile –

default is MAD.  
The system can use all measures of error and allows you to use a measure of error

that you have defined yourself using the Define Measure of Forecast Error Business Add-In (BAdI) (see Customizing for Demand Planning)

Plain English (should be)

Default Error Measure used for evaluation is MAD. The system can only use any one measure of error from amongst the error measures available, incl. customer defined one.

Only strategy 12 and strategy 56 (Auto2), allows for a selection of error measure for evaluation of models and that includes your own one

Wish they wrote it in context help. What a waste of time digging into such basics

[satish_waghmare3 · Accepted solution]

Hello BS,

Thanks for sharing the details.

Just want to add a few comments on the BADI -  This BADI /SAPAPO/SDP_FCSTERR can be used for Measure of Forecast Error.  It helps in creating your own measure of error for univaraite forecasts.

However it has only one method ERROR_CALCULATE using formula option Forecast error can be calculated Forecast and History. The table IT_FCSTVIEW shows the History and Forecast key figures.

In transaction SE18 -   BAdI Name = /SAPAPO/SDP_FCSTERR. Click on Documentation for the details

Some of the SAP Notes which helps in resolving the issue with this BADI:
1629126 - BAdI /SAPAPO/SDP_FCSTERR: input parameter should be optional
1527369 - BAdi /SAPAPO/SDP_FCSTERR add input parameter
1649458 - BAdI /SAPAPO/SDP_FCSTERR doesn't return the error short text

Thank you

Satish Waghmare

[Former Member · Accepted solution]

Thank you Satish,

I appreciate your enthusiasm to educate with full effort. Full marks. I was evaluating this method yday with our developer based in one of the pacific islands to use our own error measure that was proposed by a data scientist :-)...to be more useful for comparisons across models, data, time and space.

Thanks a ton

BS

[Former Member · Accepted solution]

Hi Satish,

May I ask, how do I show my own forecast error in the selection of forecast errors in forecast profile and the results tab of forecast errors in interactive forecast screen. How complex will this development be ?

I expect that this error measure is included in the diagnosis group and also in Alert monitor for forecast errors. My developer on contract says this will take a month to develop. I don't quite understand ABAP mambo jambo. My school going son says this is a waste of money and makes fun of my job.

Please advise

Thanks

BS