Demand Management provides the possibility in the post processing steps to calculate and store a forecast error in a key figure, which is used as decision criteria for best fit models.
You may have seen, that only key figures without time dimension are allowed to be used to store the error value.
This error value is used in the messages only and cannot be used in planning view display, not so easy to find e.g. the last MAPE if you optimized by MASE:
Here is how you can make it visible in the Excel planning views or Analytics with some extra configuration in a calculated key figure:
The default errors in the Unified Plannin g area (UPA) are FORECASTMAPE “Model Fit error: MAPE” (FCSTMAPE in SAP6) and FORECASTMASE “Model Fit error: MASE” (FCSTMASE in SAP6) are stored on level PRODCUSTLOC.
So assuming we run the forecast weekly and want to store the e.g. MAPE every week into the current week.
Than I create stored keyfigure WKFCSTMAPE and calculated key figure WKFCSTMAPEC on level ZWKPRODLOCCUST.
Via copy operator I copy from the calculated to the stored key figure after a successful statistical forecast run from which I want to keep the MAP.
Via the calculated key figure I can already directly and on the fly see the MAPE value from current forecast run.
I work in UPA, so lowest granularity is days, and my weeks are PERIODID4.
As neither averaging nor summing up an error measure makes any sense, I put a MAX on Request level for the two new key figures. However, this KF is only useful on BPL (base planning level)
Calculation on BPL can than be:
WKFCSTMAPEC@WKPRODLOCCUST = IF( “PERIODID4” = “$$PERIODID4CU$$” , “WKFCSTMAPEC1@WKPRODLOCCUST” , “WKFCSTMAPE@WKPRODLOCCUST” ) :
KFCSTMAPEC1@WKPRODLOCCUST = “FORECASTMAPE@PRODCUSTLOC” * “ZCOUNTERWKPRODLOCCUSTC2@WKPRODLOCCUST”
WKFCSTMAPE is simple stored KF, no formula, filled by copy operator from WKFCSTMAPEC for the one current week
The counter ZCOUNTERWKPRODLOCCUSTC2 always has value 1 on level WKPRODLOCCUST and is only used to break down to weeks
P.S.: As this requires that the error measure is stored on the data base, it will NOT work if you run statistical Forecast in simulation mode.