There are three options on the Scenario 360 toolbar to open an existing analysis A Scenario 360 analysis is a means of evaluating an issue or opportunity, including alternative approaches ("scenarios"), community input, outcome analysis, and decisions. In Scenario 360, an analysis provides the overall framework for a project. It includes all of the map data, scenarios, calculations, and indicators for the various alternatives you may consider when evaluating an issue or opportunity.:
OPTION
1: Click the Scenario 360
toolbar menu, click Analysis,
then click Open. Select
an analysis from the Open Recent Analysis
List or click the Open Existing
Analysis button 
.
OPTION
2: Click the Scenario 360
toolbar menu and click Start.
Select
an analysis from the Open Recent Analysis
List or click the Open Existing
Analysis button .
OPTION
3: Click the Start a Scenario
360 analysis toolbar button 
. Select
an analysis from the Open Recent Analysis
List or click the Open Existing
Analysis button .
You can also open an analysis from ArcCatalog by browsing to your analysis folder and launching the .mxd file.
If you have an existing analysis open, you will be prompted to save or discard any changes to that analysis before opening a different analysis.