What Is a Work Breakdown Structure (WBS)?
A work breakdown structure (WBS) is a visual, hierarchical and deliverable-oriented deconstruction of a project. It is a helpful diagram for project managers because it allows them to break down their project scope and visualize all the tasks required to complete their projects.
All the steps of project work are outlined in the work breakdown structure chart, which makes it an essential project planning tool. The final project deliverable, as well as the tasks and work packages associated with it rest on top of the WBS diagram, and the WBS levels below subdivide the project scope to indicate the tasks, deliverables and work packages that are needed to complete the project from start to finish.
Project managers make use of project management software to lay out and execute a work breakdown structure. When used in combination with a Gantt chart that incorporates WBS levels and task hierarchies, project management software can be especially effective for planning, scheduling and executing projects.
ProjectManager is an online work management software with industry-leading project management tools like Gantt charts, kanban boards, sheets and more. Plan using WBS levels in our tool, then execute with your team via easy-to-use kanban boards and task lists. Try it for free today.
ProjectManager’s online Gantt charts feature a column for the WBS code—learn more
Why Use a WBS In Project Management?
Making a WBS is the first step in developing a project schedule. It defines all the work that needs to be completed (and in what order) to achieve the project goals and objectives. By visualizing your project in this manner, you can understand your project scope, and allocate resources for all your project tasks.
A well-constructed work breakdown structure helps with important project management process groups and knowledge areas such as:
- Project Planning, Project Scheduling and Project Budgeting
- Risk Management, Resource Management, Task Management and Team Management
In addition, a WBS helps avoid common project management issues such as missed deadlines, scope creep and cost overrun, among others.
In other words, a work breakdown structure serves as your map through complicated projects. Your project scope may include several phases, or smaller sub-projects—and even those sub-projects can be broken down into tasks, deliverables, and work packages! Your WBS can help you manage those items, and gain clarity into the details needed to accomplish every aspect of your project scope.
Related: Free WBS Template for Excel
Work Breakdown Structure Example
Now that we’ve gone through the definition of a WBS and learned why they are a great project management tool, let’s take a look at a work breakdown structure example.
For our WBS example, we’ll be creating a work breakdown structure to lay down the work plan for a commercial building construction project. This is potentially a complex project, but a WBS chart will take that complexity and boil the project scope down to simpler tasks to make the project manageable.
Study the phase-based work breakdown structure example of a construction project below:
At the top of the work breakdown structure is your final deliverable (in this instance, the construction project). Immediately beneath that is the next WBS level, which are the main project phases required to complete the project. The third and lowest level shows work packages. Most WBS charts have 3 levels, but you can add more depending on the complexity of your projects.
Each of those five project phases—initiation, planning, execution, control and closeout, also act as control accounts and branch off the main deliverable at the top. Once decided, they are then broken down into a series of deliverables. For example, the initiation phase includes site evaluation work and creating the project charter.
You’ll also need a work package to go with each of those project deliverables. In the execution phase in our construction example, we can look at the interior work deliverable. That deliverable is divided into two work packages, which are installing the plumbing and setting up the electricity.
The WBS, when created as thoroughly as possible, is the roadmap to guide you to completion of what would seem to be a very complicated project scope. However, when broken down with a WBS, project planning, scheduling and resource planning suddenly become much more manageable.
Types of WBS
There are two main types of WBS: deliverable-based, and phase-based. They depend on whether you want to divide your project in terms of time or scope.
Deliverable-Based Work Breakdown Structure
A deliverable-based WBS first breaks down the project into all the major areas of the project scope as control accounts, and then divides those into project deliverables and work packages.
Here’s an example of a deliverable-based WBS that’s taken from our free work breakdown structure template. Download the template today to practice building your own work breakdown structure in Excel.
An deliverable-based WBS example showing control accounts, work packages and tasks.
Phase-Based Work Breakdown Structure
The phase-based WBS displays the final deliverable on top, with the WBS levels below showing the five phases of a project (initiation, planning, execution, control and closeout). Just as in the deliverable-based WBS, the project phases are divided into project deliverables and work packages. Our previous graphic in the “Work Breakdown Structure Example” section contained a phase-based WBS example.
Types of WBS Charts
Once you’ve chosen a deliverable-based or phase-based WBS, you can also choose between different types of WBS diagrams. Let’s take a look at the main types of work breakdown structure charts.
Work Breakdown Structure List: Also known as an outline view, this is a list of work packages, tasks and deliverables. It’s probably the simplest method to make a WBS, which is sometimes all you need.
Work Breakdown Structure Tree Diagram: The most commonly seen version, the tree structure depiction of a WBS is an organizational chart that has all the same WBS elements of the list (phases, deliverables, tasks and work packages) but represents the workflow or progress as defined by a diagrammatic representation.
Work Breakdown Structure Gantt Chart: A Gantt chart is both a spreadsheet and a timeline. The Gantt chart is a WBS that can do more than a static task list or tree diagram. With a dynamic Gantt chart, you can link dependencies, set milestones, even set a baseline. This is the most common version in project management software.
Build a work breakdown structure Gantt chart diagram in ProjectManager in just a matter of minutes. Get started for free today.
A Gantt chart with WBS codes in ProjectManager. Learn more
WBS Elements
A typical project work breakdown structure is made up of several key components. We’ll use our WBS example above to identify each of the main WBS elements.
- WBS Dictionary: A WBS dictionary is a document that defines the various WBS elements. It’s an important component of a WBS because it allows the project participants and stakeholders to understand the work breakdown structure terminology with more clarity.
- WBS Levels: The WBS levels are what determines the hierarchy of a WBS element. Most work breakdown structures have 3 levels that represent the project’s main deliverable, control accounts, project deliverables and work packages.
- Control Accounts: Control accounts are used to group work packages and measure their status. They’re used to control areas of your project scope. In our example the execution project phase could be a control account because it has several deliverables and work packages associated to it.
- Project Deliverables: Project deliverables are the desired outcome of project tasks and work packages. In our WBS example, we can observe some examples of project deliverables such as the project budget or interior work. Both of them are the result of smaller tasks and work packages.
- Work Packages: As defined by the project management institute (PMI) in its project management body of knowledge book (PMBOK) a work package is the “lowest level of the WBS”. That’s because a work package is a group of related tasks that are small enough to be assigned to a team member or department. As a project manager you can estimate costs and duration of these work packages, which makes them an essential WBS element.
- Tasks: Your tasks make up your work packages and therefore, your project scope. A WBS will help you define each task requirements, status, description, task owner, dependencies, and duration.
If you prefer a visual and verbal explanation of this information on work breakdown structures, watch this video.
How to Create a Work Breakdown Structure In Six Steps
To create a WBS for your project, you’ll need information from other project management documents. Here are six simple steps to create a work breakdown structure.
1. Define the Project Scope, Goals and Objectives
Your project goals and objectives set the rules for defining your project scope. Your project scope, team members, goals and objectives should be documented on your project charter.
2. Identify Project Phases & Control Accounts
The next level down is the project phases: break the larger project scope statement into a series of phases that will take it from conception to completion. You can also create control accounts, which are task categories for different work areas you want to keep track of.
3. List Your Project Deliverables
What are your project deliverables? List them all and note the work needed for those project deliverables to be deemed successfully delivered (sub-deliverables, work packages, resources, participants, etc.)
4. Set WBS Levels
The WBS levels are what make a work breakdown structure a “hierarchical deconstruction of your project scope”, as defined by the project management institute in its project management body of knowledge book (PMBOK). You’ll need to start at the final project deliverable and think about all the deliverables and work packages needed to get there from the start.
5. Create Work Packages
Take your deliverables from above and break them down into every single task and subtask that is necessary to deliver them. Group those into work packages.
6. Choose Task Owners
With the tasks now laid out, assign them to your project team. Give each team member the work management tools, resources and authority they need to get the job done.
WBS Software
Work breakdown structure software is used to outline a project’s final deliverable and define the phases that are necessary to achieve it.
Software facilitates the process in several different ways. Some use a network diagram and others use a Gantt chart. All of them, however, are a visual representation of the project, literally breaking down the various stages and substages needed to assemble the final project deliverable.
