Project phase: A series of project tasks grouped together by time frame.
Project phases help you complete a portion of your project before moving on to other activities. If your project is so big that it needs phases, good for you! It probably means you have many resources assigned to it, and you need to break things up to manage them effectively. This is not always so, but often the case.
Both Microsoft Project® and Standard Time® let you create phases or breakdowns. They are called by many names: summaries, subprojects, subsystems, or just plain phases. Anyway you look at it, they are project breakdowns that represent groups of tasks lumped into a time frame. In other words, all the tasks are expected to be completed within a close proximity of time.
To create a summary task in Microsoft Project, simply click the task under it, and then click the Indent toolbar button. That will cause the task above it to become bold, signifying that it summarizes the tasks below it. As you add more tasks to the summary, certain fields (like start and finish dates) will roll up to the summary level. You can collapse the summary to hide detail. In Standard Time, these tasks are displayed on the timesheet.