A Scenario 360 analysis is a means of evaluating an issue or opportunity, including alternative approaches ("scenarios"), community input, analysis, outcomes, and decisions. When an analysis has more than one scenario An analysis contains one or more scenarios. Each scenario represents a different decision-making alternative. The first scenario in your analysis is called the base scenario. It can represent existing conditions, the primary proposal under evaluation, business as usual, or the first of several alternatives you wish to compare in an analysis., one of them will be designated the active scenario. The active scenario is the one you're currently working with. You can always tell which scenario is active because its name is shown in bold text in the table of contents (see the example in the graphic below).
Make a scenario the active scenario by clicking the 360 Analysis tab, clicking the Active Scenario drop-down list, and selecting the active scenario. You can also by right-click on the scenario name in the ArcMap table of contents and click Activate on the pop-up menu.