A work breakdown structure (WBS) is a multi-tiered framework that organizes activities
of work into progressively more detail, thus allowing a breakdown of the project
into manageable chunks. Each level of the WBS typically corresponds to a level of
management. The WBS should reflect the entire scope of work. Levels of schedule
detail correspond to the levels of the WBS.
The WBS provides a common structure for the coordination of all controls functions.
It should be developed as a collaboration of each control function, project management,
and construction or discipline supervision. Typically, various amounts of controls
rework stems from a lack of early construction input to the development of the WBS.
Because of the increasing electronic interface of controls data during project startup,
a well-conceived WBS becomes crucial. Modifications to the WBS during a project are
to be avoided because of the impact on established controls systems.
The most prevalent method of WBS subdivision is the physical areas of the project.
Two other methods include systems and time. In all of these forms of subdivision,
there is always some point of interface between one area/system/phase to another.
It is important to identify what physical point, or process step, makes the transition
to the next WBS area or system and insure that all parties are aware.
A work breakdown structure should be:
- Organized so that each work element can be estimated, scheduled, and progress-measured.
- Developed to the level of detail for which a single discipline, craft or subcontractor
- Construction-driven, based primarily on construction work plan and sequence.
- Developed immediately upon project initiation.
- Ideally it must follow client’s price schedule (if there’s one). This facilitates
- Cost Breakdown Structure: Budget (based on tender submitted amounts), Actual and
Forecasted costs follow WBS structure.
- Schedule must follow WBS too (at higher level, though it will have more detail/
activities at lower level).