You could construct a tower by building the pinnacle first and then adding the middle and bottom sections. But you probably won’t get many visitors to an upside-down tower.
You’d do better if you performed your tasks in a logical order and grouped them so that you did all of the tasks for each stage of construction at about the same time. That’s just what Microsoft Project enables you to do with your project tasks. By organizing your tasks logically, you can:
Organizing your tasks is a three-step process. First, put your tasks in a logical order; next, group related tasks; and then outline your task list.
Enter or move tasks such that your task list shows the required or most efficient order for performing the tasks. For example, put "Digging the hole for a building’s foundation" before "Pouring the concrete." In another part of the project, you might find it more efficient to put up the roof before constructing the internal walls (with a roof, fewer work days are lost to adverse weather).
You can cluster tasks to be done together in the same section of the task list. For example, you might group all the tasks for laying a foundation at the beginning of a task list for constructing a tower. Microsoft Project makes it easy to move tasks where you want them.
Once you’ve logically ordered and grouped your tasks, you can show hierarchical dependencies among them by outlining them. When you outline tasks, they look like the chapters and topics outlined in a book’s table of contents. For instance, you might show "Laying a foundation" as a main step and "Digging a hole" and "Pouring concrete" as substeps beneath it. Outlining visually distinguishes one group of related tasks from another, allowing you to focus on the details of one group of tasks at a time.
After grouping your tasks, you create a task outline by indenting tasks and outdenting tasks. When you indent a task to a level lower than the task above it, the task above becomes a summary task. Typically, a summary task represents a phase or a subphase of your project.
It is by creating summary tasks that you harness the real power of outlining.