Project participants frequently misunderstand the definition of schedule levels, which limits the quality and value of the information provided to the stakeholders and project participants.
Project participants and stakeholders require different types of data and levels of detail relative to their schedule usage.
The project owner is most likely to be interested in milestones and start and completion dates at a higher or summary level.
Contractors would monitor and control their subcontractors at an intermediate level and control their direct hire project efforts at a much greater level of detail.
Subcontractors and vendors would typically monitor and control their own work at a task list level.
Ultimately, the project contract documents, terms and conditions will determine the format and content of the project or program schedule levels.
Generally schedule levels are identified by a numeric designator.
Level 0: This is basically a single bar spanning the project time from start to finish. Functionally there is very little practical application for a schedule that is only a single bar other than to represent an element of a project or program time line. Level zero schedules normally will include the project or program major milestones and bars indicating key scope.
Level 1: Represents the schedule’s major components. A Level 1 schedule is normally displayed as a bar chart and may include key milestones.
Level 2: Each major component is further subdivided. In most cases Level 2 schedules can only be shown as a bar chart although key constraints and Milestones are also included.
Level 3: This is the first level where a meaningful critical path is obtained and the schedule can be used to monitor and control the project.
Levels 4‐higher: In higher levels, usually segments of the total schedule are worked upon. A portion of the lower level (say Level-3) schedule is broken down into greater detail to the maximum/desired extent possible. Generally used for short term planning in order to effectively work towards the larger overall goal.
There is no universal agreement as to the number of schedule levels and their format. Schedule levels are determined by the detail required of the key project stakeholders. Since schedules are developed for the purposes of performing that specific phase of the work, all schedules therefore should roll‐ up from more detailed scope of the activities and tasks.