EPC Schedule Levels
Imagine you are the Vice-President of a company and you request for the schedule of one of the EPC projects under your portfolio and you are issued with a 35 paged detailed schedule. Do you really need that amount of data?
The level of details in an issued schedule should be aligned to the project hierarchy or the level of involvement of the recipient in the project, hence the need to have different schedule levels on a project.
Schedule levels refer to the details of activities in an issued schedule and should not be confused with the physical level of a schedule i.e. the depth of the schedule (e.g. WBS levels in Primavera P6 or Outline Levels in Microsoft Project). While most Subject Matter Experts (SME), textbooks and Project Management guidelines define 5 schedule levels, personally I have only ever used 4 different schedule levels during the Execution stage of projects, so this post will discuss them.
Level 1 Schedule or High-Level Schedule
The Level 1 schedule is usually a one-paged Gantt schedule which is issued to senior management and external stakeholders as it summarises the key project milestones and key activities. The Level 1 schedule is popular with senior management because it contains key high-level project information they can easily refer to and it also looks good in presentation slides.
Level 1 is usually a high-level summary of the Level 3 schedule and though it can be produced in scheduling software such as OnePager or Milestones Pro, my personal preference is to use Microsoft Excel as previously explained in the blog post, My Settings #05: Schedule Roll-up in Microsoft Excel. An ideal frequency of update is monthly or on an ad-hoc basis.
Level 3 Schedule or Control Schedule
The Level 3 schedule is the heartbeat of an EPC Project hence the tag of a Control Schedule. It is a precedence network where Project activities for all phases (Engineering, Procurement, Fabrication, Construction and Commissioning) are logically linked and have details of required resources to complete these activities.
The Level 3 schedule has clearly identified critical and sub-critical paths, and is usually underpinned by a Schedule Basis document. This is the schedule that is used for schedule monitoring and control as well as schedule performance management and also forms the basis of the schedule risk model used to determine schedule contingencies.
The typical duration of activities in a Level 3 schedule is usually over 2 weeks and the unit of duration is usually in weeks or months though it is still OK to use days. Level 3 usually summaries Level 4 schedule activities and/or incorporates contractors/subcontractors schedule activities.
The Level 3 schedule needs to comply with the WBS 100% rule and should cover the whole Project Execution stage timeline. The frequency of update of a Level 3 schedule is usually monthly.
Level 4 Schedule or Detailed Schedule
The Level 4 Schedule is the detailed schedule that is used to support the execution of planned activities of a discrete work package or in a worksite, so this might be; a FEED schedule, a detailed design schedule, a procurement schedule, a construction site schedule, a fabrication yard schedule, or a facility's commissioning schedule.
The typical duration of activities in this schedule is in days and spans the entire duration of work package or site activities. Resources in this schedule are usually assigned shift patterns. The Level 4 is a CPM schedule and just like Level 3, has clearly identified critical and sub-critical paths.
The frequency of update is usually daily or weekly and is usually issued to Construction Manager, Package Managers or Leads and Site Supervisors.
Level 5 Schedule or Mini-Schedule
The Level 5 Schedule is an optional schedule level and only required when it becomes necessary to further decompose a work unit in the Level 4 schedule. This is the lowest level of a schedule and is usually in the form of a standalone mini schedule developed for the execution of a work unit at a worksite.
The typical duration of activities in a Level 5 schedule is less than 24 hours and the overall duration of this schedule is usually less than 2 to 4 weeks. This schedule is normally developed by the site planner or scheduler and is issued to the Site Supervisor and the men doing the physical work. The frequency of update for a Level 5 schedule is daily.
Final Word
A schedule is a key project document that should be accessible to every member of the project team so instead of issuing same Schedule Level to the whole project team, I would recommend issuing different Schedule Levels according to the intended use of the schedule.
