Hello Guys,
I'm trying to figure out the calculations in SAP APO forecasting models precisely Seasonal Model (Strategy 30 ). For this model the initialization values is 1 season ( in my case it's 12 months). Total history horizon is of 3 years (01.2013 - 12.2015 ) and forecast horizon is 3 months (01.2016 - 02.2016). No Ex-Post method is chosen.Alpha = 0.1 Gamma = 0.7
As per SAP, for seasonal model :
Basic value = Mean of the historical values of the first historical season
Trend value = 0
Seasonal index for a period = Historical value for that period divided by the basic value
Mean absolute deviation (MAD) = 0
In my case Basic value is generated from 01.2014 and for that particular bucket value calculated by system is 788.33 ( which is not the average of sales of past season i.e. from 01.2013 till 12.2013, as per the logic mentioned by SAP (the average is 716.67) and SI = 0.14 (which is again irrationally calculated).
There are few formulas mentioned in help.sap under this link http://help.sap.com/saphelp_scm70/helpdata/en/66/a2ca53f1a1214be10000000a174cb4/content.htm?frameset=/en/63/a2ca53f1a1214be10000000a174cb4/frameset.htm¤t_toc=/en/5c/3ec95360267614e10000000a174cb4/plain.htm&node_id=16
but that is again not helping.
I have attached a text file, just Copy and paste it into excel (it should get aligned )
Questions:
1. How does system calculates the Basic Values ? For first bucket just after season 1,as well as subsequent buckets.
2. Which values are calculated first by the system Basic or SI ? It seems to me has to be Basic, but still would like to clarify my doubt
!