Level 1 (Management/Milestone level)

This corresponds to an executive summary of the programme, also called the Project Master Schedule, or PMS. It is normally a list of the most relevant project milestones. It is a good way to share the project's key dates with company management.

Used for: contractual milestone list, executive summary and assigning priorities between projects.

Level 2 (Master)

A level 2 programme is formed by summary bars with the duration of the main deliverables or phases, such as engineering, procurement, fabrication, assembly and commissioning.

It is a way to consolidate one or several plans into a simple plan in order to create a global summary, the Summary Master Schedule or SMS. It must include all level 1 information, but with a higher level of detail.

Used for: project management and executive reporting.

Level 3 (Project level)

A level 3 schedule is a summary of the detailed planning, level 4, and also feeds level 2. Each deliverable or phase is divided into summary activities with logical relationships between them. To create a level 3 schedule, the use of specialised software, mainly MS Project, is recommended so that the critical path can be calculated.

This is the most common level during the tender phase of a project. The main contractor develops this planning to show the work to be performed, dates and basic work sequence.

In some cases, a baseline can be established after some time has passed following signature of the EPC contract, with the aim of advancing engineering and therefore preparing a more accurate level 3 programme.

Used for: contractual documentation, monthly progress reporting, establishing the project critical path and summarising level 4 schedules.

Level 4 (Control/Execution level)

The execution schedule is a detailed work plan that establishes the specific tasks to be performed in order to deliver the project on time. At this level, the daily and weekly activities of the different teams involved can be managed, as well as component deliveries, interferences between contractors and resource management.

Level 4 schedules are developed and maintained by the project execution team, usually the main contractor, together with subcontractors before work starts on project execution. They allow daily work activities to be monitored and controlled and serve as the basis for measuring project progress and performance.

The schedule developed may cover the whole project or only part of it, depending on project size and work complexity. It is important to keep each schedule at a reasonable size so that it can be easily managed, updated and validated.

Used for: daily activity management, progress detail, three-week lookahead reporting, critical and subcritical path analysis and delay analysis.

Level 5 (Detail Level)

A level 5 schedule is a detailed breakdown of each level 4 activity. This level of planning may be necessary when there are particular or highly specialised tasks that require planning by the hour or by the day. For example, software transition plans are often created hour by hour so that the team knows exactly which actions to take for migration, or for shutdowns and maintenance activities in large industrial facilities such as blast furnaces or refineries.

It is therefore a level that is not usually necessary for most projects. Primavera P6 offers the possibility of creating a more detailed breakdown of existing activities through the use of Steps, which can sometimes be very useful.

Used for: managing critical or extremely complicated activities and organising coordination between contractors in very high detail.

Bullet points

  • The levels are normally developed from the upper level to the lower level and updated from the lower level to the upper level.
  • Levels 1 and 2 are normally developed as part of the pre-feasibility study to determine project viability.
  • The level 3 schedule is initially developed as a general description of the activities to be carried out. If the project is relatively small, the level 3 schedule is expanded into a level 4 schedule to coordinate execution of the works. In larger projects with multiple level 4 schedules, the level 3 schedule is maintained as the overall integrated project schedule.
  • Every project requires a level 4 schedule for daily work coordination. However, the total size of this schedule must be manageable and aligned with the complexity of the works.
  • Only in very specific cases is level 5 planning required.