Task as Milestone is a task that is linked to some date or event signifying successful completion of preceding tasks. It is a successor to a number of other tasks that all have to be accomplished prior to date and time specified by the respective milestone.
Using tasks as milestones provides a mechanism of effective task planning through summarizing tasks and establishing deadlines for their completion. Such a mechanism lets create timelines and schedules consisting of a number of tasks regarded as milestones. Then by using these tasks it is easier to plan various projects and processes by phases, activities, tasks, and sub-tasks.
The mechanism is also helpful for goal setting. Every goal or objective can be assigned to a milestone having the features (duration, assignment, dependency, etc.) of a task. Tasks as milestones represent goals and objectives to be accomplished by completing designated tasks.
Tasks as milestones are used to break work down into pieces. A work breakdown structure can be built by setting tasks as milestones and determining preceding activities. In project management this capability makes it possible to put all tasks into a WBS and then determine project goals.