Step Two
Changing Forecast Values


The forecast values of a Determinant Variable can be changed in one of two ways:

change variable.jpg

Changing the value in the Main Grid (Boxes with a red border only)

This is a quick test option. Change the value in the cell with the red boarder for the selected variable(s) and then press the button at the top marked ‘run scenario.

Its is quick but

It does a linear fit from the variable’s value for the base year through to this value in the selected future year and then on to 2043.

Selecting the ‘Change’ Button and changing the variable cross the entire year range.

change button.jpg

This is more sensitive and recommended approach. Most variables do not follow a linear trend and this enables you to vary the rate of change over time.

For each of the variables that can be changed there is a button in the box labelled ‘change’.

Click on that and you are taken to a new window (see below) showing the value of that variable under the base case through to 2043.

If you have made no changes yet, then the first two rows will be the same. (current scenario is also the base case) and the chart will show just one line. (the values in the blue line are explained below)

Note that the table shown here extends out to the right to 2043. It is not shown here for layout reasons.

forecast values.jpg

Entering Forecast Values

You then enter values in the blue row for future years. You can:

enter a value for every year


enter a value for selected years (which can, if you want, just be the last year (2043)).

If you do not enter values for every future year then click on the button ‘fill between points if blank’ and the model will put values in the intervening blank cells assuming a linear trend between those two points.

The resulting data set will then be shown in the chart.

If you are not happy with the forecast simply click the second button ‘Clear NEW forecast values’ and enter a new set.

Once Completed you can either

Press the ‘insert new Data into Model’ button in which case the data is captured into the data set and used for the forecast - but NOTE - the data for that variable has been updated but the new scenario still needs to be run by clicking the ‘run scenario’ button. The program is done like this as you may want to alter more than one of the determinant variables before running the solution.


Simply return to the main grid with no change.