The Sales and Operations Plans are in general made on a monthly basis, which means that the data entered into the forecasting module are monthly historical data.
The historical data are sequentially entered, year by year. It is possible to create new lines for the different years by using the buttons Previous Year and Next Year.
Historical data for a given yearly period can also be cancelled via the button Delete.
When all the historical data have been entered, the procedure has to be validated with the OK button. The window is closed and the numerical forecasts are computed and/or updated.