In terms of project management, the work breakdown structure (WBS) is a hierarchical breakdown of a project’s deliverables or phases. On a basic level, a WBS allows project managers to organize the project’s activities into different categories to create an overall project plan.
Generally, each layer of the WBS represents an increasingly more detailed definition of the stages of the project. Often displayed as a diagram, the work breakdown structure allows project managers to break down the project’s work in order to better visualize the project’s timeline. Creating a work breakdown structure tends to make it easier to identify tasks required for the project, as it provides a quick visualization of the project’s requirements.
Creating a work breakdown structure is often a required step during the project planning phase for most organizations. Luckily, most project management software programs, such as Primavera P6, make it easy to create a WBS and apply it to a given project.
Why is a WBS important for project management?
Even if a WBS is not required for a project, it can be an extremely useful project management tool for several reasons, including:
Breaks down complex projects
When working with a large, complex project with thousands of tasks, project management can seem overwhelming. With a work breakdown structure added, projects can be broken down into smaller, more manageable tasks.
Provides clarity for project teams
Most projects involve a wide variety of individuals and project teams working together on meeting deliverables. With a work breakdown structure, responsibilities can be visualized clearly, ensuring that every team member knows what they need to do within the project.
Helps avoids project management issues
With a large project, it can be easy to run into common project issues such as missed deadlines, increased scope, and overrunning the budget. Tracking these deliverables at the WBS level can help ensure that no deadline or budget constraint falls through the cracks and the project stays on track.
Assists with measuring project performance
Project performance can generally be measured by analyzing whether or not activities have finished on time and within budget. With only individual tasks, you would need to run through each activity’s dates and costs individually to get a better understanding of the project’s
Before we dive too much deeper into work breakdown structures, we should first go over the definitions of some key components that make up a WBS.
A work breakdown structure breaks down a project’s work into hierarchical levels, or layers. WBS levels make up the overall breakdown structure. The WBS can have as many levels as needed, but most structures have at least 3 levels.
Project Scope is the overall work that needs to be done in order to complete the project. This is generally a detailed description of the work, and includes pertinent details such as time and budget constraints.
Project deliverables are the end result of work performed within a project. This is the product, service, or overall goal that is achieved through work performance. Generally, projects have several deliverables for different stages of the project. A deliverable-based WBS focuses on each of the project’s deliverables to create an overall project plan.
Project phases are the different stages needed to be completed to finish the overall project. For example, a construction project could have the basic phases of Mobilization, Procurement, and Grading. A process-based WBS will focus on the specific project phases required to complete the project.
Tasks, also known as activities, are the items that are needed to be performed to complete the overall project. Tasks are generally given a duration, start and finish date, and dependencies with other activities. Whereas the WBS will breakdown the project into different chunks of work, the WBS layer will be further broken down into the tasks required for its completion. Creating a WBS before defining tasks is often useful, as it provides an overall roadmap to project completion.
Types of Work Breakdown Structures
Work Breakdown Structures can be created in several different ways. In project management, two types of work breakdown structures are generally used: a process-based WBS and a deliverable-based WBS. Project managers can choose to utilize either one or the other, or use both together to fully define the project’s scope.
Process-Based Work Breakdown Structure
A process-based WBS will divide the project into different phases. A process-based WBS will have the overall project or deliverable at the top, with the different layers breaking the project up into different phases of work – such as Pre-Construction, Construction, and Project Completion. Phases can be broken down into subphases as needed to create an overall hierarchical outline of the work needed to be performed.
Deliverable-Based Work Breakdown Structure
A deliverable-based WBS will break the project down into different areas of the project scope, such as deliverables and work packages. This type of WBS will define the project by its individual deliverables needed to complete the overall project, rather than phases of work. A deliverable-based WBS can be useful to help project team members understand how each individual deliverable contributes to the overall project scope.
Ultimately, it is up to the organization to determine which WBS type to utilize for their project, and different projects may need to use different types of work breakdowns. It is also possible to create a WBS that combines both process and scope to track both the project’s phases of work and the specific deliverables needed, as well.
Work Breakdown Structure Displays
Along with the different types of WBS that can be utilized, they can also be displayed in different ways. The way that your WBS displays will generally be determined by whether or not you’re utilizing a project management software, and the type of software you’re using. Most project management software programs also allow you to switch between these different work breakdown structure displays as needed.
A work breakdown structure list is an outline of each WBS layer. In most project management software applications, such as Primavera P6 and Microsoft Project, this is the default view when creating and displaying the WBS.
WBS Gantt Chart
In project management, a Gantt Chart allows you to visualize each of the project’s tasks on a timeline. This can assist in quickly providing principal project details, such as when each activity starts and finishes, their durations, and their dependencies with one another. A WBS gantt chart will provide the same for each WBS layer, allowing you to view WBS layers on a dynamic timeline. In both Primavera P6 and Microsoft Project, a WBS Gantt Chart will automatically display along with the WBS list.
WBS Tree Diagram
A work breakdown structure tree diagram, other times called a WBS chart, will display each WBS layer visually as through a connected network diagram. The project itself will be at the top of the diagram, with each sublayer below it to display the overall WBS hierarchy. In both Primavera P6 and Microsoft Project, a tree diagram won’t automatically display while creating and viewing WBS – however, both programs allow you to switch the WBS display to it as needed.
Now that we’ve gone over the basics of what a work breakdown structure is, let’s take a look at a basic WBS example. This project involves the construction of an addition to a commercial office building. Because this project features a variety of phases and tasks, creating a WBS will help break down the project into more manageable chunks of work.
The top layer of the WBS is the overall deliverable – that being, the construction of the office building addition. There are 6 sublayers to this project, representing the main phases of work involved: Design & Engineering, Foundation, Structure, Mechanicals, Exterior Finishes, and Interior Finishes. Some of these phases are broken up further to better describe the work performed – for example, Exterior Finishes is broken down into sublayers of Brick, Roof, and Doors & Windows. Overall, this gives us a WBS with 3 hierarchical levels.
We could continue to come through and break these layers down further as needed. With this work breakdown structure, we now have a guide to better understand the steps involved to complete this project.
How to Create a Work Breakdown Structure
Let’s go over the steps to create a work breakdown structure. It’s important to note that most program management applications ease the process of creating a WBS, so all of the following steps may not be necessary.
On a basic level, there are 7 steps required to create a successful work breakdown structure:
1. Define the Project Scope
The first step in creating a work breakdown structure is to have a clearly defined project scope. You will want to know what the end goal is for the project and what needs to be accomplished to get there. It may be useful to define further project details here as well, such as the estimated start and finish dates, duration, budget, and project team.
2. Identify Project Deliverables
Next, you will want to identify and list all of the project deliverables. Again, deliverables are the end-product of performed work within a project. A project will have several deliverables – for example, construction projects often require deliverables such as submittals, proposals, and reports. If you plan on creating a deliverable-based WBS, you will want this list to be fully defined – but it’s often useful for process-based work breakdown structures to also have deliverables identified beforehand.
3. Identify Project Phases
Along with deliverables, you will also want to identify the phases of the project. You will want to think about what types of work are required for project completion. For example, a construction project will generally have phases of Procurement, Earthwork, and Structure. Often, these phases can also be broken down into sub-phases – such as Earthwork being broken down into Grading and Utilities. If you plan on creating a process-based WBS, this step will be necessary to create the WBS levels.
4. Create WBS levels
Finally, you can begin to construct your WBS by creating WBS levels. The top level of the WBS should be the final project deliverable, and additional sub-levels should be added to define the structure. These levels can be created differently depending on the type of WBS you’re aiming to create – for a deliverable-based WBS, you can base your levels off of the project’s deliverable, whereas a process-based WBS’ levels should be based off of the project’s phases. You’ll want to add as many WBS levels as needed to reach project completion.
5. Assign tasks to WBS levels
With the work breakdown structure created, you can now utilize the WBS by creating and assigning activities to it. This can be done by taking the defined deliverables and breaking them down into every activity necessary to complete them. With these tasks created, you will add them to the different WBS levels. This will give you a project plan, so you know what needs to be completed within the project and the order in which these tasks will be performed.
6. Assign Responsibility
Working with your project team, you will now want to assign different WBS levels and/or tasks to different project team members. This will allow each team member to know exactly what their role is within the project, and they can work to ensure that each required task is completed in time and within budget.
7. Create a visual display*
Finally, you will want to create a visual presentation of the WBS to easily refer back to as needed. This could either be a simple hierarchical list, a tree diagram, or a Gantt Chart display, as covered earlier. A Gantt Chart display can be especially useful, as it will quickly show when each WBS layer is set to begin and end and how long they will take to complete
*It’s important to note here that most project management software applications, like Primavera P6 and Microsoft Project, will automatically create a visual display for you after the WBS has been created. Both programs will automatically create all three types of WBS displays: a hierarchical list, a tree diagram chart, and a Gantt chart.
Although it is possible to create a work breakdown structure and manage a project by hand, it is highly recommended to utilize project management software. Without the software, creating a work breakdown structure will be a daunting, time-consuming task, and it is much more likely to make critical errors that will affect the overall project. Additionally, most project management applications will automatically create visual WBS displays, easing the time needed to complete creating and maintaining a WBS.
There are a variety of different project management softwares available that can assist with WBS creation. Here at Taradigm, we offer the premier CPM scheduling application, Primavera P6. Along with easing the process of creating a work breakdown structure, P6 is also a powerful scheduling tool, allowing users to create and manage their projects from start to finish. Most scheduling related jobs from larger firms require CPM scheduling using Primavera P6 in their contracts.
If you plan on utilizing Primavera P6 for your WBS and project management needs, it may be a good idea to become proficient in the program through training. At Taradigm, we offer Primavera P6 training with a live, experienced instructor, and self-paced online video training.
Additionally, for those who would like to outsource their scheduling to experts, we specialize in WBS creation, CPM training, and scheduling with decades of experience.
For those who are moving their business to the cloud, we are pleased to offer Oracle Primavera Cloud (OPC). OPC is the next evolution of Primavera P6 and is more affordable, easier to set up and maintain, and offers more features than Primavera P6. We also offer comprehensive training for OPC for Primavera P6 veterans and those new to scheduling.
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Lauren Hecker is an Oracle Primavera Cloud and Primavera P6 Instructor and teaches onsite and virtual scheduling courses. To see her next open enrollment course, please visit our calendar. To schedule an onsite or custom course, please contact us!