The forecast simulation program simulates the forecast calculation spanning over all periods. It allows you to change the methods and parameters used in calculating forecast for a given item/warehouse combination, choose any historical period to recalculate forecast from, and analyse the results on the screen.
Using this simulation you can change forecast data for certain forecast period(s) and simulate the forecast calculation to see what effect the changes you make have on the Forecast file, and specifically on the forecast error.
- Select the Simulate forecast menu item.
- On the Forecast simulation panel, enter an item/warehouse combination to use in this simulation and click OK.
- You access Forecast simulation on which you select the method, and establish the parameters that you want to use to calculate the simulated forecast for the item/warehouse combination displayed in the header.
- You access Forecast simulation showing a work file that is a copy of the Forecast file for the selected item/warehouse combination. It contains the future forecast periods for one year, and historical forecast periods for one or two years, depending on the value in History, no of years in the IC control file.
- Select a forecast period to maintain forecast information and demand statistics for the selected item/warehouse combination.
- Select a forecast period and click Rec frm mark line to recalculate the forecast from a historical period or the present period. The system recalculates the values in the period you choose and continues through all future periods.
When you access this panel, data from Work with forecast control codes for the method and parameters that are active for this item/warehouse combination already exists on the panel. The class and keys used for this record are shown in the header. You can change the values if you want to simulate the forecast using another method and/or parameters.
Note: If you want to use other values in this simulation, you can change the information manually, or click Select forecast codes to retrieve another record from Work with forecast control codes.
Click Perform simulation when you have defined the methods and parameters. The forecast will be recalculated, starting with the present period and continuing up through all future periods.
The periods are listed in descending period order. Both past, current and future periods are displayed, and a cursor is positioned at the current period. The future periods contain forecast information for each period. The historical forecast periods and the present forecast period contain the actual demand value for each item/warehouse and the forecast information for each period.
In the subfile you can see the MAD value, representing the size of the forecast error up until the present period. The MAD value indicates how changing different forecast values influences the forecast error.
You have the following options on this panel:
Note: You cannot recalculate starting with a future forecast period. Furthermore, you are not permitted to recalculate the forecast starting with the very oldest period, since this period has no history on which to base the forecast.
Exit the routine.