The purpose of using a trend quantity with the mathematical forecast is to use history information to make out a trend to use.
The trend quantity indicates the difference between average demand in two consecutive forecast periods. It is calculated automatically using exponential smoothing. The beta factor is used as a smoothing constant for this calculation.
In 'Forecast Method. Open' (FCS300/F), set the parameter Extrapolate with trend to 2 (trend quantity) for the forecast method to use.
In this example, the Beta factor is set to 0.5.
If the demand for 0211 is 100 and for 0212 is 120, the forecast for 0301 equals 1200/12+((120-100)*0,5) = 110.