In order to effect a technology migration from one Resource to another, the Resources must be grouped into a Function so that STEM will recognise that one Resource can be a replacement for another – see 10.3.17 Functions.
When a Function grouping is created, STEM will draw a blue link to the Function from any Service or Transformation which has a Requirement for any Resource in the Function. You can then double-click this blue link to review and edit the respective Mapping inputs for each Resource in the Function as a time-series.
Figure 1: The Mapping dialog for a Function
Note: The Mapping dialog is shown automatically when you link a Service or Transformation to the second Resource in a Function, so that you can define an appropriate share of incremental demand between these Resources.
Mappings for a Function
You can review the full set of Services and Transformations which require a Function:
- Select Mappings from the Function icon menu. The Mappings dialog for the Function is displayed, with a cell for each Service and Transformation in the model.
Clicking on the small button to the right of the cell (when selected) takes you to the individual Mapping dialog for the corresponding Service or Transformation.
Note: A tabular equivalent of this dialog can be accessed from the icon menu for a selection or Collection of Functions.
Requirements for the Resources in a Function
The Function icon menu provides direct access to tabular versions of each of the standard Resource data dialogs. Thus, if you select Requirements from the Function icon menu, you will see a tabular dialog with rows of cells for each Service and Transformation in the model and a separate column for each Resource in the Function. Clicking on the small button to the right of each cell (when selected) takes you to the individual Requirement dialog for the corresponding Service/Transformation and Resource.
Figure 2: The Requirements dialog for a Function
Alternatively, you can click a new 
Expand button on the Requirements dialog menu in order to expand each cell in place, thus providing an interface to compare the complete Requirement assumptions for each Resource in the Function.
Figure 3: The expanded Requirements dialog
An expanded Requirements dialog can be unexpanded simply by clicking on the Expand button again.