Navigate to this page via Settings > Create Scenario.
On this page you can save the current Active Scenario (containing the results from the most recent model solution) for later comparisons. Enter a name a description and click Save Scenario to add the Scenario to the database. This page also contains a table with all the existing scenarios for reference. This can help you to select a unique name (which is required), but also to help you in following a naming convention.
If you want to share this Scenario with other users in your organization, turn on the switch Scenario Visible to Everyone option before saving.