Each time you create a Scenario you will need to add the attributes you would like to model. This post will cover how to add or remove a Property from a Scenario.
Under Properties you can see which Properties are included in your Scenario as well as which ones can be added.
To add a Property to your Scenario, click the Add icon.
To remove a Property from a Scenario, click the Remove icon.
If you want to read more about Properties, consider reading these additional blog posts.