Levels of Scheduling

Level 1 Schedule is the highest level, called overall project summary level.
It includes major milestones or achievements, highlights major activities and key deliverables. Especially, it is also used in progress reporting.
Level 2 Schedule

Examples of level 2 element are 

(a) Utility Plant Modification Project, Hydro Cracker Revamp Work ( For Oil refinery plant expansion project)

(b) Furnace Area, Compressor Area Shutdown Work (For Chemical Plant Shutdown Work.

 Level 3 Schedule

is a project coordinating and project reporting schedule. Roll up summary of level 4 schedule.For instance, piping engineering, mechanical engineering, civil/structure engineering, process engineering and electrical and instrumentation engineering are level 3 elements which are the disciplines of design engineering. Normally developed and established by EPC (engineering, procurement and construction) contractor. Used as a proposal schedule during the process of tendering. Also is used as a guide line for subcontractors and vendors for their bid submissions.

Level 4 Schedule

is a low level schedule. It consists of the task or work categories to be carried out. Level 3 schedule is further broken down into level 4 as an execution schedule (working schedule).

Level 5 schedule

is the lowest level of schedule. The task list and work sequence is usually developed by the task supervisor or engineer and incorporated into level 4 schedule to monitor day to day work.