Diagnosis
There are two automatic model selection procedures:

Procedure 1
The system carries out statistical tests and checks whether a trend ora seasonal requirements pattern applies.
In the trend test, the system subjects the historical values to aregression analysis and checks to see whether there is a significanttrend pattern.
In the seasonal test, the system clears the historical values of anypossible trends and carries out an autocorrelation test.

Procedure 2
The system calculates the models to be tested using variouscombinations for alpha, beta, and gamma. The smoothing factors are alsovaried between 0.2 to 0.8 in intervals of 0.2.
The system then chooses the model which displays the lowest meanabsolute deviation (MAD).
Procedure 2 is more precise than procedure 1 but takes much longer.

System response
Procedure 1 is always used in Flexible Planning. Both procedure 1 andprocedure 2 are possible when you run the forecast in materialrequirements planning.

What to do
If you use the forecast in material requirements planning, you set theselection procedure in the material master record.