What are the levels of a WBS called?

Each layer of the WBS represents an increasingly detailed definition of the stages of the project. The WBS is often displayed as a diagram. This helps project managers break down the project’s work and better visualize the project’s timeline. Creating a work breakdown structure makes it easier to identify tasks that are required for the project. The WBS provides a quick visualization of the project’s requirements.

For most organizations, the work breakdown structure is a required step during the planning phase of the project. Luckily, most project management software programs, like Primavera P6, make it easy to create a WBS.

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. Work breakdown structures allow you to break projects down into smaller, more manageable tasks.

Provides clarity for project teams

Most projects involve many people and teams working together to meet deliverables. With a work breakdown structure, you can clearly visualize responsibilities. This ensures that every team member knows what work they need to do to keep the project running.

Helps avoids project management issues

With a large project, it is common to run into issues like missed deadlines, increased scope, or an overrun budget. Tracking these deliverables at the WBS level can help you make sure that no deadline or budget constraint falls through the cracks and that your project stays on track.

Assists with measuring project performance

You can measure project performance by analyzing whether activities have finished on time and within budget. For individual tasks, you would need to run through each activity’s dates and costs individually. This will help you get a better understanding of your project’s status.

WBS Components

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.

WBS Levels

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.

Scope

Project scope is all work that needs to be done in order to complete the project. This is generally a detailed description of the work which includes important details like time and budget constraints.

Deliverables

Project deliverables are the end result of work performed in a project. This is the product, service, or goal that you can achieve through work performance. Projects often have deliverables for different stages. A deliverable-based WBS focuses on each of the project’s deliverables to create a project plan.

Phases

Project phases are the stages that you need to complete in order to complete your project. For example, a construction project could have the basic phases: Mobilization, Procurement, and Grading. A process-based WBS focuses on the specific project phases required to complete your project.

Tasks

Tasks, also known as activities, are the items you need to complete your project. Tasks are generally given a duration, start and finish date, and dependencies with other activities. While the WBS breaks the project down into smaller pieces, the WBS layer breaks those pieces down further into tasks. Creating a WBS before defining tasks is useful because 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, there are two types of WBSs’ that are generally used. A process-based WBS and a deliverable-based WBS. Project managers can choose to use either one or the other, or both together, to define the project’s scope.

Process-Based Work Breakdown Structure  

A process-based WBS divides the project into different phases. A process-based WBS has the project or deliverables at the top, with different layers that break the project into phases of work. Some phases may include Pre-construction, Construction, and Project Completion. Phases can be broken down into sub-phases to create a hierarchical outline of the work that needs to be completed.

Deliverable-Based Work Breakdown Structure

Deliverable-based Work Breakdown Structures break the project into different areas of project scope. For example, deliverables and work packages. This type of WBS defines the project by the individual deliverables, rather than phases, needed to complete the project. A deliverable-based WBS can be useful to help project team members understand how each deliverable contributes to the project’s scope.

It is ultimately up to the organization to determine which WBS type to use for their project. Different projects may require different types of work breakdowns. It is also possible to create a WBS that combines both process and scope. This can track both the project’s phases of work and the specific deliverables needed.

Work Breakdown Structure Displays

The Work Breakdown Structure types can be displayed in various ways. This depends on the type of project management software that you are using. Most project management software programs also allow you to switch between different WBS displays as needed.

WBS List

A work breakdown structure list is an outline of each WBS layer. In most project management applications, like Primavera P6 and Microsoft Project, this is the WBSs’ default view.

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 you in quickly providing principal project details. For example, it can show when each activity starts and finishes, their durations, and their dependencies on one another. A WBS Gantt chart provides the same for each WBS layer. This allows 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, also called a WBS chart, displays each WBS layer through a connected network diagram. The project itself is at the top of the diagram. Each sub layer below it displays the WBS hierarchy. In both Primavera P6 and Microsoft Project, a tree diagram will not automatically display while you create and view the WBS. However, both programs allow you to switch the WBS display as needed.

WBS Examples

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. The overall deliverable  is the construction of the office building addition. There are 6 sub layers to this project. Each layer represents the main phases of work involved: Design & Engineering, Foundation, Structure, Mechanicals, Exterior Finishes, and Interior Finishes. Some of the phases are broken up to better describe the work performed. For example, Exterior Finsides is broken down into sub layers of Brick, Roof,  and Doors & Windows. This gives us a WBS with 3 hierarchical 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. You should add additional sub-levels to define structure. You can create these levels differently depending on the type of WBS you’re aiming to create. For deliverable-based WBS, you can base your levels off of the project’s deliverable. A process-based WBS’s levels should be based off of the project’s phases. You can add as many WBS levels as needed to reach the project’s completion.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. This can include the estimated start and finish dates, duration, budget, and project team. 

2. Identify Project Deliverables

Next you will want to identify and list all the project deliverables. Deliverables are the End-product of the work performed during the 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. However, it’s often useful for process-based work breakdown structures to have the 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. You should add additional sub-levels to define structure. You can create these levels differently depending on the type of WBS you’re aiming to create. For deliverable-based WBS, you can base your levels off of the project’s deliverable. A process-based WBS’s levels should be based off of the project’s phases. You can add as many WBS levels as needed to reach the project’s completion.

5. Assign tasks to WBS levels

With the work breakdown structure created, you can now use the WBS by creating and assigning activities to it. You can do this by taking the defined deliverable and breaking them down into every activity necessary to complete them. After you have created these tasks you can add them to the different WBS levels. This will give you a project plan. The project plan will show you work that needs to be completed and the order in which tasks should be performed.

6. Assign Responsibility

When working with your project team, you will want to assign different WBS levels and/or tasks to different team members. This will allow each team member to know exactly what their role is within the project. With clear understanding of their role, team members 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.

WBS Software

Although it is possible to create a work breakdown structure and manage a project by hand, it is highly recommended that you use project management software. Without the software, creating a work breakdown structure will be a daunting, time consuming task. Without the software, it is also much more likely you will make critical arrows that will affect the overall project. Additionally, most project management applications will automatically create visual WBS displays. This lessens the amount of time needed to complete and maintain a WBS. 

There are a variety of different project management software programs available to assist with WBS creation. Here at Taradigm, we offer the premier CPM scheduling application, , Primavera P6. P6 not only makes creating a WBS easier, it is also a powerful scheduling tool. Primavera P6 allows 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. It is more affordable, easier to set up and maintain, and offers more features than Primavera P6. We also offer comprehensive training for OPC for both Primavera P6 veterans and those new to scheduling.

If you have any comments, questions or suggestions, please use the comment section on the bottom of this page, and don’t forget to subscribe to our blog to get more scheduling tips & tricks directly in your inbox!

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!

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