# Basic Value Calculation in seasonal model

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

data-in-tabular-form.txt

!