Scenarios' Sheet Wizard - Step 3 of 3 - Possible Values Names
In the following dialog, you must enter all possible scenarios (enter only the name of scenarios, not their values -you can do it later)
Also, enter table headings for each input variable.

For example, in this heading, you can enter, periods of analysis, etc.
Now click on the Finish button to get the following result:
WARNING
It is very important to bear in mind the following recommendations for this tool to work appropriately:
In this worksheet, column C is hidden to prevent users from unintentionally delete references of the model.
Moreover, this worksheet contains other formulas which should not be deleted or modified; otherwise, the structure
and logic underlying the add-in will be altered and its functionalities may no longer work correctly.

See Manage Scenarios for further details on how to work in this spreadsheet.