What is a project WBS?
A project Work Breakdown Structure (WBS) is a key component of project management deliverables. A project WBS is used for breaking down a project into easily manageable components, or bites. Here we’ll break down the process for you, making it easy to use these structures in your project planning.
The Project Management Body of Knowledge (PMBOK 5) defines the work breakdown structure as an “A hierarchical decomposition of the total scope of work to be carried out by the project team to accomplish the project objectives and create the required deliverables.”
It is common for work breakdown structure elements to be numbered sequentially to reveal the hierarchical structure. The purpose for the numbering is to provide a consistent approach to identifying and managing the WBS across like areas regardless of supplier or trade (in construction).
For example, 1.4.1 Separable Part 1 (in the example below) identifies this item as a Level 3 WBS element, since there are three numbers separated by a decimal point.
A coding scheme also helps WBS elements to be recognized in any written context and allows for mapping to the WBS Dictionary.
A practical example of the WBS numbering in a construction program/schedule
|Level 1||Level 2||Level 3||Level 4||Level 5|
|1. Project||High Level Scope Breakdown||Scope Breakdown||Work Stream||Trade|
|1.1 Milestones and Prelims|
|1.4.1 Separable Part 1|
|22.214.171.124 Earthworks||126.96.36.199.1 Scrub & Clear|
|188.8.131.52.2 Trim and Grade|
|184.108.40.206 First Fix Services||220.127.116.11.1 Electrical|
|18.104.22.168 Fit Out||22.214.171.124.1 Framing|
|126.96.36.199.5 Services Fit Off|
|1.4.2 Separable Part 1|
|188.8.131.52 Earthworks||184.108.40.206.1 Scrub & Clear|
|220.127.116.11.2 Trim and Grade|
|18.104.22.168 First Fix Services||22.214.171.124.1 Electrical|
|126.96.36.199 Fit Out||188.8.131.52.1 Framing|
|184.108.40.206.5 Services Fit Off|
Why Use a Work Breakdown Structure?
The work breakdown structure has a number of benefits in addition to defining and organizing the project work. Project work breakdown structures can also be used to identify potential risks in a given project. A project budget can be allocated to the top levels of the work breakdown structure, and department budgets can be quickly calculated based on each project’s work breakdown structure. By allocating time and cost estimates to specific sections of the work breakdown structure, a project schedule and budget can be quickly developed.
Guidelines when developing a project Work Breakdown Structures
A WBS is not difficult to develop after you have reviewed and understood the project documentation, drawings and requirements.
The quick and best approach for planners is to develop a WBS using the preferred planning software.
- The top level represents the final deliverable or project (WBS level 1)
- Breaks down projects into manageable work packages
- Sub-deliverables contain work packages that are assigned to other sections of project
- All elements of the work breakdown structure don’t need to be defined to the same level
- The work package defines the work, duration, and costs for the tasks required to produce the sub-deliverable
- Work packages should be independent of other work packages in the work breakdown structure
- Work packages are unique and should not be duplicated across the work breakdown structure (most planning software will not let you duplicate WBS IDs)
- Provides a proven, systematic and repeatable approach to planning projects.
This is a practical example of a project WBS – structural section
The project WBS is the first step in developing good project programs/schedules and setting you and your project team on the road to success.