STEM help / Model structure

9.1.3 Adding new global input parameters

In addition to the User Data fields provided for service, transformation, function and resource elements, STEM lets you define extra inputs which can be referenced from any element. These are located in a global User Data dialog, accessed from the Data menu on the Editor main window, or by right-clicking on the background of a view.

These global fields can be referenced as Globals.User1, etc., in any formulae within a model. One particularly useful application for such a parameter is a ‘lever’ to control a range of values defining a particular scenario. For example, you could define resource costs as <base value> * Globals.User1, where <base value> was the original numeric input, and then see how varying User 1 around 1.0 would affect the subsequent results. (The Globals tag is only necessary to distinguish Globals.User1 from User1 for an individual element.)

Just like User Data for an individual element, these fields can also be renamed to clarify their usage, using the Rename Field… command on the dialog Edit menu. You will notice that the Rename Field dialog does not include an All Elements text box. In this case you can skip the Globals part of the reference, so that the formula would simply be shown as, e.g., <base value> * "Cost Sensitivity Factor".

Note: The double quotes in the formula above are only necessary if you include spaces in the label for User1.

The Rename Field dialog for global User Data


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