What Is a Work Breakdown Structure? An Intro Guide to WBS in 2019

Jasmine Lee
Jasmine Lee  |  December 17, 2018

When I was a youngster, embarking upon the intricacies of essay writing for the first time, I received advice on how best to break down any sort of essay structure.

“Think of it like an umbrella,” my English teacher told me. “Start big and general, and then narrow the focus in each subsequent paragraph.”

Now, while the rule isn’t a hard and fast one, it’s supremely helpful for students when setting up essay structure and avoiding irrelevant tangents.

But why are we talking about sixth-grade essay writing advice? Because that umbrella idea can be applied to a whole slew of scenarios, including where ones project management (and project management software) is involved. Specifically, the umbrella idea aligns neatly with a strategy called “work breakdown structure.”

Imagine a work breakdown structure, also known as WBS, like a family tree. The family tree starts with the overall project, and then it breaks down into distinct branches, which are identified tasks and deliverables. Those branches splinter off into more specific leaflets, appropriately assigning out those deliverables to the appropriate team member.

What Is Work Breakdown Structure

Let’s get even more specific.

A work breakdown structure is a deliberate method of breaking down project requirements into tangible, manageable nuggets. A well-oiled WBS is integral to the success of a project. With WBS, the project manager or team lead can drive efficiency, accountability and productivity. Instead of getting lost in the weeds or undertaking a project without proper oversight, a work breakdown structure divides and conquers.

Unfortunately, there is no discernable origin story for a work breakdown structure. The formalized concept has existed since the late 1970s, heralded by recognizable project management thought leaders like Dr. Harold Kerzner. Kerzer leveraged his background as an engineer to systemize the overall approach for strategic project management. An effective work breakdown structure is, after all, rational and requires thorough analysis.

The most significant aspect for project managers and team members to realize regarding WBS is that it doesn’t break down work, it breaks down deliverables. Along those same lines, a WBS doesn’t need or require a timeline.

A WBS is not easy to create, yet is essential in getting a project off the ground and ensuring that the project makes it to completion. Work breakdown structures are difficult to create because they are not quite project scopes; nor are they project proposals. They also require quite a bit of planning from everyone who will be roped into the project. The format of a WBS is strangely unfamiliar as well; most “to-do lists” or task management solutions feature action items such as “remember to buy milk” or “X task is dependent on Y task.” We will discuss this in full later on, but a WBS cannot, cannot, be made up of verbs or action items.

WBS WorkProject management jargon for “Work” differs from the common perception of the word.

Work Breakdown Structure Key Terms

Like most other things, the managed elements of a WBS reference specific jargon that is recognized within the industry, but perhaps not with first-time project managers or project managers who haven’t written a WBS before.

Work = The end result of any activity. Work does not necessarily equal effort.

Deliverable = Any unique, distinct product or result that counts towards project completion.

Work package = The work required to complete a specific element or aspect of the project.

How Do Project Managers Create Work Breakdown Structures?

The general method of creating work breakdown structures is:

  1. Identify and list out every required deliverable.

  2. Identify all the work necessary to ensure that each deliverable gets complete.

  3. Draft up work packages for the required work mentioned in the second step. The work packages will be made up of individual tasks and/or products that will eventually be assigned to specific team members.

Work-Breakdown-StructureThe rules for drafting up an effective WBS can vary, but so long as you follow these four, you’re on the right track.

Rules for Making a Work Breakdown Structure

There are a few “rules” when creating effective work breakdown structures. Depending on what resource a project manager turns to when researching how to best draw up a WBS, the individual details of those rules may vary.

But, essentially, there are four core rules: Make sure all outcomes account for 100 percent of the work, ensure that all elements are mutually exclusive, focus on outcomes not actions, and adhere to the 8/80 mindset.

The 100% Rule

The WBS should add up to 100 percent. That means that all necessary work represented within the WBS cannot exceed 100 percent, or, whatever amounts to 100 percent of the hours and resources required to complete a project. Again, to be clear, these tasks can only be absolutely required deliverables and products. Any work or deliverables that are extraneous or unrelated don’t count towards the 100 percent. Additionally, any “parent” task also has to follow the 100% rule: Each “child” task bundled underneath the parent task must equal 100 percent.

Mutually Exclusive

All elements in a work breakdown structure are mutually exclusive. The mutually exclusive rule spins off from the 100% rule. As the project manager drafts out their WBS, they should be on top of all subtasks, deliverables or tasks so as not to repeat any of them. If a deliverable is listed twice on a WBS, then the WBS would violate the 100% rule, and those deliverables may unfortunately overlap, unnecessarily be duplicated or suffer from miscommunication. This mutually exclusive rule results in accountability from within the team.

Focus on Outcomes

Outcomes and deliverables are the elements that make up a WBS. The WBS doesn’t and shouldn’t include any action words. Checking off the products and deliverables that were created is more important than keeping an eye on the moving parts that made it possible for those tasks to be completed. In a nutshell: The work breakdown structure should have zero verbs, only nouns.

The 8/80 Rule

Work packages within a WBS commonly take a minimum of eight hours of effort and should not exceed 80 hours of effort. That is the 8/80 rule. (To put it even more simply: One work package should take between one and 10 days of full-time work to complete.) The 8/80 rule is crucial in determining the appropriate levels of detail that will make up both your project scope and WBS. Most work breakdown structures include three levels of detail. More complex projects will require a more granular WBS, but they are the exception. Rule of thumb: If a proposed work package will require, for example, two weeks of effort, then that work package needs to be divvied up.

Significant Benefits of Work Breakdown Structures

  • Optimized Project Scheduling and Management — While work breakdown structures don’t lay out timelines and milestones within their documentation, they do facilitate their creation and management. Once the WBS is set, then project managers can go forward with their proposed project schedule and budget. The plus side to such oversight is that managers can get a more realistic overview about managing expectations and deadlines for work that exists outside the project.
  • Effective Project Execution — Work breakdown structures aren’t necessarily set in stone, but they do impress upon both project managers and team members the “meticulous accounting” of all details. After all, project managers should only submit a WBS once they’ve considered every single detail, need and probability that can crop up during the execution of a project. A work breakdown structure lends itself to effective project risk management, giving project managers the chance to anticipate potential hurdles and account for them before the project has lifted off.
  • Management of Project Vision — Both project scopes and work breakdown structures present parameters and framework for projects. Every person involved in a project can refer back to the statement of work, or other project documentation, to make sure they are staying on track and on goal.
  • Improved Communication and Collaboration — With a WBS, team members can maintain communication and reduce ambiguities with each other throughout each step of the process. When creating a WBS, project managers do not and should not plan in a vacuum; dialoguing is a key component of planning and implementing work breakdown structures.
  • Accountability — Assigning tasks and expectations within a WBS happens after deliverables are identified and determined. Both project managers and team members get a high-level look at what various team members’ responsibilities look like. This fosters accountability and ownership over completing and presenting those deliverables.

WBS-BenefitsWhile a completed WBS doesn’t look like a milestone-studded project overview, it still delivers quite a few benefits to the entire team.

Potential Obstacles to Effective Project Management

Not to put a damper on your project management goals, but simply creating a WBS will not grant all of your wishes. Like any strategy or other piece of software, a WBS is only as good as the person who has created it and who continues to maintain it. If a project manager gets bogged down planning out the intricacies of a WBS, then the actual project will not benefit.

Here are two potential WBS-created hurdles to avoid that can actually stymie a successful project:

  • Too Much Granularity — As mentioned previously, most work breakdown structures are only three levels deep. Only particularly complicated projects that require the careful management of a lot of resources yield work breakdown structures that go on for pages. Project managers must find the sweet spot between too much and not enough granularity when it comes to identifying and documenting deliverables.

  • Literal Project Scheduling — Work breakdown structures do not and should not include action items. We’ve mentioned this before, but it’s worth repeating: A WBS is a tabular or graphical representation of the overall project. The WBS helps project managers, team members and stakeholders keep track of all products and results that are necessary to reach the final, completed project. Literal project scheduling happens after a WBS is submitted.

How have you tackled creating work breakdown structures?

Specific WBS software does exist (look at WBS Schedule Pro, for example), but you need not narrow your focus to such focused tools if you want that software to cover more project management functionality.

Solutions like Planhammer and OpenProject offer users the ability to create their own work breakdown structures. Users can leverage mind mapping tools like XMind and MindGenius to drag-and-drop their own. (In fact, mind mapping software MindMeister is built to synchronizes with comprehensive project management solution MeisterTask for WBS building purposes.)

For those on a budget, check out free project management software to see if those specific platforms can help your team create a work breakdown structure.

Next Steps For Implementing a WBS

Do you use specific project management software that offers built-in WBS functionality? Or do you use notecards and manually deliberate over a physical whiteboard? If the former, leave a review on your project management solution of choice; if the latter, take a look at the 450-plus project management softwares that are featured on G2 Crowd to help you make the switch from paper-based to digital.

To learn more about project management terms and concepts, be sure to read how a project scope statement can help your projects succeed.

Jasmine Lee

Jasmine Lee

Jasmine is a Senior Research Specialist at G2 Crowd. She used to own the e-commerce and team collaboration spaces, but now she avidly researches as much as she can about the rapidly evolving and head-spinningly varied vertical industry spaces. She's passionate and hyperbolic about most things, but especially regarding the things that have anything to do with pop culture, fandom, gifs, and the wining and dining scene of Chicago.