Determine the phases of work that you want to track for the project, and create a phase for each.
The Phasing dialog opens, displaying the Project Phases tab. By default, each project has phases called Existing and New Construction.
Revit LT selects the entire phase row. The following image shows the New Construction phase selected.
To insert a phase before or after the selected phase, under Insert, click Before or After.
Revit LT names the phases sequentially as you add them. For example: Phase 1, Phase 2, Phase 3, and so on.