Forecast Initialization SCM

Question

Dear Sirs,
In order to understood the best forecast parameters to be use on my data type, i'm studying analytic formula behind the SAP forecast process.
i have found in this forum this link:
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/7a4025f8-0a01-0010-0fb2-b7ab22597675
It is very useful to understand haw SAP work.
The only think that i have not understood is initialization process.
In particular:
I'm using a Trend model whit first order exponential smoothing:
We start with two parameters that are initialized:
Basic Value and Trend Value
Basic Value is initialized as the average of value in initialization period + Trend
Trend value is initialized as follow in case of 3 value:
Hist (3) - Hist (1)
          2
The question is how is initialize the Trend value if Historical period is > 3?
What happen at the initialization basic value and initialization trend value with 12 value as initialization?
Thank you very much for your help!
BR
Andrea

Answer 1

Hallo Shibu UP,
Thank you very much for your answer.
You are right, this is the Equation with 3 value as Initialization period.
I need to understood the equation of Initialization with 4,5,6....12 values as Initialization period.(i think that Modeling of Ex-post forecast is the same)
Initialization:
B(4)=?
T(4)=?
Modelling:
B(t) = (1 - α) * (B(t-1) + T(t-1)) + α * H(t)
T(t) = (1 - β) * T(t-1) + β * (B(t) - B(t-1)) for t = 5,…,N
Thank you very Much!!
BR
Andrea