The Two-Way Sensitivity Analyses (2WSA) Inputs page allows you to select the parameters included in 2WSAs, as well as the method used to vary the value of each parameter included in these analyses. To access the 2WSA Inputs page, click in the Navigation Sidebar on the left side of your screen, and then select ‘Inputs’.
To create a new 2WSA, click the ‘Add’ button located at the top left of the 2WSA Inputs page, and select the two variables that you would like to use in your first 2WSA, using the dropdown menus (please note that you cannot vary group-dependent or strategy-dependent variables in 2WSAs). Once you select a parameter, its description will be automatically populated along with its base case value. There is no limit to the number of parameter pairs that you can select for inclusion in your 2WSAs. You can navigate between parameter pairs by clicking the names of the two variables (eg, variable_X vs variable_Y) located on the left side panel of the 2WSA Inputs page.
Once you have selected a pair of parameters to include in your 2WSA, you then have to specify the method that will be used to define the domain of values across which each selected parameter will be varied, as well as the specific values to be used with the specified method. There are three possible methods that can be used to specify the domain of values for each parameter, as follows:
- Range: This method allows you to specify the values for a variable based on a minimum value, a maximum value, and the number of steps between these values. The minimum number of steps required to run a 2WSA using the range method is 1, and the maximum number of steps you can specify is 5. Minimum and maximum values may be entered as constants or as formulas that reference the base case value (eg, 0.8 * bc).
- Radius: This method allows you to specify the values for a variable based on a radius around the base case value and the number of steps to use in either direction. The minimum number of steps required to run a 2WSA using the radius method is 1, and the maximum number of steps you can specify is 10. The radius method always includes the base case value (the range method, described above, may or may not include the base case value). Minimum and maximum values may be entered as constants or as formulas that reference the base case value (eg, 0.8 * bc).
- Custom: This method allows you to specify custom values for a particular parameter, which you can enter as a comma-separated list. Minimum and maximum values may be entered as constants or as formulas that reference the base case value (eg, 0.8 * bc).
The screen shot that follows shows a fully specified parameter pair for a 2WSA.
As noted above, you can define an unlimited number of parameter pairs on the 2WSA Inputs page. Once you are done specifying parameter pairs, you can select the ones you would like to include in a particular 2WSA by using the checkbox to the left of each parameter pair; you can also use this checkbox to deselect a parameter pair, and therefore not include it in your 2WSA. You can use the search bar to find parameter pairs of particular interest among those that you have already specified. You can search across both X axis and Y axis parameters, or you may limit your search to a single axis alone.
Please note, you may not include time-dependent variables in 2WSA (instead, we recommend that you create a separate input that can be referenced by the time-dependent variable, and that that you instead include the variable that is not time-dependent in the 2WSA)