SAP Note 22713 - Problem: Material Forecast

Symptom:

Different forecast values for current and following period

Cause and prerequisites

It really should be like that, everything else IS WRONG

Solution
The forecast for the current period and the following period use
different consumption data.

The forecast of the current period uses the consumption data UP TO THE END of the LAST period.

The forecast for the next period uses IN ADDITION the consumption data
of the CURRENT PERIOD. This makes sense if the current
period is almost over and you expect little change in the consumption
of the current period.

If you think about it, if the values were the same, why would you want
to do a forecast for the following period? You could simply take
the forecast for the current period and read the forecasted values
for the following periods. There may be more than just one forecasted
periods for forecast dates in both current and next period.