Work breakdown structure vs Product breakdown structure (2024)

The Work Breakdown Structure and the Product Breakdown Structure are often confused because they are very similar yet quite different.

These two breakdown structures play a critical role in the project planning process and how successful – or not – the outcome will be.

In this article, we will try to clarify the difference between the Work Breakdown Structure (WBS) and the Product Breakdown Structure (PBS).

What is a Work Breakdown Structure (WBS)?

The WBS provides a hierarchical structure for the project effort. Essentially, this is a map that details every piece of work needed, breaking it down into smaller, more manageable parts.

Simply put, it stands for the project’s “to-do list,” and its main focus is on “work,” not “things.”

The WBS provides the foundation for a project plan, allowing it to be broken down into work packages and activities.

The level of detail depends on the complexity of your project and the level of control you want to have.

A WBS is especially beneficial for teams managing large projects because, as previously mentioned, it breaks the project down into smaller, more manageable components.

Generally speaking, the WBS clearly states what needs to be done and makes it easier to assign work to the project team.

Therefore, this will help the project manager to estimate resources, time, and risks better.

What is a Product Breakdown Structure (PBS)?

In the WBS, the project is broken down into work packages and activities to be accomplished, while the product breakdown structure presents products (or results) to be delivered by the project.

The focus of the “to-do list,” in this case, is on the “things” and not the “work.”

By focusing on the “whats” rather than the “hows,” PBS guides team members in understanding the expected results and ensuring that each deliverable has appropriate quality and meets specifications.

The PBS breaks down the project’s main product into its forming blocks as a hierarchical structure.

The main benefits offered by the PBS are:

• It defines the project scope;
• It raises awareness among your team about what will be delivered;
• It forces your team to think about the content of the product, say if it is a database: what type, how many records, format, etc;
• It provides a better way to determine what quality criteria will be applied to the product, how it will be reviewed, and what skills are required to undertake the review;
• It serves as the foundation for creating the Work Breakdown Structure.

Work breakdown structure vs Product breakdown structure in project planning

The WBS and the PBS play complementary roles in the project planning process scenario.

Ideally, project managers would begin by creating a PBS to clarify the outputs and products needed and then use the WBS to organize and detail the work required to achieve them.

This integrated approach ensures that project plans are thorough, covering both output (project or product) and work-related aspects and making it easier to spot discrepancies or oversights.

Both techniques are valuable during the planning process and ideally should be used jointly to ensure success.

Together, they help project managers determine:

• What is the result?
• What is necessary to achieve it?
• When will it be achievable?
• How will people know they have achieved it?
• Who is required to accomplish it?

First and foremost, you should outline a PBS that clarifies what needs to be built or imported from elsewhere.

The product registry is a handy way to find suppliers for third-party products, and a product flow chart helps pinpoint the order in which products are required.

This helps in understanding the plan’s logic at a high level before detailed planning begins.

Then, you design a WBS to organize and build a feasible plan for the associated work packages and activities. Thus, having an overview of the plan that includes both “things” and “work” will cover all variants of your project.

Are there products without work packages? In this case, you will not be able to deliver the desired result, or the PBS will include products that are not needed for the scope of your project.

Are there work packages without products? If so, you may be undertaking unnecessary work or missing something in your PBS.

When used jointly, the PBS and WBS techniques provide powerful tools for ensuring the accuracy and completeness of project plans, whether simple or complex. Both must be used for their intended purpose correctly without blurring the boundaries between “what” and “activity.”

If this part is achieved and the relationship between deliverables is critically reviewed early in the planning process, the risk of completing work without the required deliverables being completed can be significantly reduced.

In this context, project management tools like Twproject can offer significant support, facilitating the integration between Work breakdown structure and Product breakdown structure, improving collaboration and efficiency of project teams.

Twproject allows easy management of project hierarchical structures, ensuring that all aspects are considered and that communication among stakeholders is effective.

Moreover, it enables the project manager to have a comprehensive view of the project, improving planning, execution, and monitoring, thus contributing significantly to the project’s success.