What is Level 3 schedule in planning?

A level 3 schedule in planning is one of the 5 levels is common use. Level 1 is the "highest" and shows the main milestones to complete the project. Level 2 shows the scope of work to achieve the milestones, Level 3 shows the deliverables to achieve the scope of work, these three levels are the summary levels. Level 4 shows the tasks or work packs needed to complete the deliverables, and at level 5 the tasks will be fully resourced. A Level 1 is typically 1 or 2 pages, Level 2 around 50 activities, Level 3 about 250. Level 5 on a large project will be many thousands of activities.