Work breakdown structure (WBS) guide: Steps & rules

Alicia Raeburn contributor headshotAlicia Raeburn
June 9th, 2025
7 min read
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Summary

A work breakdown structure (WBS) is a project management tool that helps you break down complex projects into smaller, manageable parts arranged in a clear order. In this guide, you’ll learn about the main parts of a WBS, the two main types (deliverable-based and phase-based), important principles like the 100% and 8/80 rules, and how to create your own WBS using timelines, Kanban boards, or calendars.

A work breakdown structure (WBS) is a way to visually break down a project. It starts with the overall scope and shows each deliverable, making it clear how everything fits into the main project.

Since a work breakdown structure is displayed visually, it can be created using a combination of workflow management software and project management frameworks. Some of these methods include timelines, Kanban boards, and calendars.

In this guide, we’ll explain how to create a work breakdown structure, what to include, and give examples you can use in your own projects.

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What is the work breakdown structure in project management?

A work breakdown structure (WBS) is a hierarchical decomposition of a project's total scope into smaller, manageable deliverables. It visually organizes work from the top-level objective down to individual tasks, making it easier to plan, assign, and track progress.

Every WBS is made up of a few core components:

Project managers use work breakdown structures to help teams break down complex project scopesvisualize projects and dependency-related deliverables, and give team members a visual project overview.

From there, you'll organize your structure based on the hierarchical levels of sub-deliverables. Your project might also include phases based on the work needed and the overall project timeline.

The 2 types of WBS

  1. Deliverable-based WBS: This method breaks work into deliverables that support the main project goal. It works best for shorter projects with clear outcomes, like creating an annual revenue report.

  2. Phase-based WBS: This method organizes work into phases, with each phase containing groups of tasks done in stages. It’s helpful for longer projects with less defined outcomes, like increasing retention by 20% over three years.

Why use a WBS in project management

A WBS gives your team a clear way to plan and execute complex projects. Breaking large initiatives into smaller pieces helps you control scope, timelines, and resources more effectively.

Key benefits of using a WBS include:

  • Improved scope control: Defining every deliverable upfront reduces the risk of scope creep and missed requirements.

  • More accurate estimates: Breaking work into smaller components makes it easier to estimate time and costs.

  • Better team alignment: Everyone can see how their work contributes to the overall project objective.

  • Clearer accountability: Assigning owners to each work package ensures nothing falls through the cracks.

  • Easier progress tracking: You can monitor completion at each level to identify potential delays early.

No matter if you’re running a product launch, construction job, or marketing campaign, a WBS helps turn your ideas into clear, actionable steps.

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What are the 3 levels of work breakdown structure?

The levels in a WBS help separate tasks based on their dependencies. Because every project is different, your WBS levels may vary as well.

Levels of a work breakdown structure

Most WBS structures have three main levels of dependencies, but you might need more or fewer. Each level links to a parent task, and work is organized by these connections.

Level 1: The parent task

The first level of a WBS is the simplest version of the project. It includes the parent task, which is usually the main project goal.

For example, if your project team is revamping your website design, the first level might look like this:

  • Launch new website design

Level one is the basic objective and the first step of your many project management phases. The work needed to complete this objective comes in levels two and three.

Read: How to write an effective project objective, with examples

Level 2: Dependencies and tasks

Level two of your WBS lists the subtasks, or dependencies, of the main task. This level can become more detailed depending on your project’s scope.

For example, here are tasks needed to launch a new website design:

  • Host a creative brainstorming session

  • Revamp brand guidelines

  • Create a messaging approach

  • Redesign your logo

  • Add new photography

Level two gives a more detailed view than level one, but it still provides a high-level overview of the main dependencies needed to finish the project.

Level 3: Subtasks

At the third level of the WBS, you break down dependencies into smaller, actionable tasks. This is usually the most detailed level, where you define the specific tasks that make up your deliverables.

Continuing the above example, here are the level three tasks for a new site design:

  • Choose brand colors

  • Build a brand mood board

  • Assign UX designers

  • Build a mockup design

  • Review and approve mockups

  • Schedule a brand photoshoot

  • Resize and edit pictures

You can add more levels to your WBS to include more detail in your visual breakdown.

Key WBS principles

To build a strong WBS, it helps to know two key principles that guide how you break down and organize your project work.

The 100% rule

The 100% rule is the most important part of building a WBS. It means your WBS should include all the work in the project scope, nothing extra and nothing missing.

This rule applies at every level of the hierarchy. Each parent element must account for all the work in its child elements. If a task isn't in the WBS, it's not part of the scope. This prevents gaps and scope creep.

The 8/80 rule for work packages

The 8/80 rule helps you decide how big each work package should be. Ideally, a work package should take between 8 and 80 hours to finish.

  • Less than 8 hours: You've likely broken the work down too finely, creating unnecessary complexity.

  • More than 80 hours: You need to decompose the work further for better visibility and control.

This rule isn’t strict, but it’s a helpful guideline for finding the right amount of detail.

What's included in a work breakdown structure?

A work breakdown structure organizes your project deliverables in a visual hierarchy. Key elements include objectives, deliverables, timelines, and stakeholder assignments, similar to what you'd find in a project charter, but focused on the scope breakdown.

What's included in a work breakdown structure

Before you make your own WBS, it’s important to know what to include. Here are the main parts you should add.

WBS dictionary

A WBS dictionary is a document that explains each part of your WBS in detail. Since the visual chart can’t show everything, the dictionary gives your team the details they need. Consider involving team members from various departments when creating it to ensure accuracy and usefulness.

Some fields you should include in your dictionary are:

  • Task names: Keep this clear and simple, a few words at most.

  • Descriptions: Go into a little more detail, but no more than a sentence or two.

  • Deliverables: Be clear about what you're expecting the team to complete.

  • Budget: Your projected expenses, including how much you'll spend, for what, and by when.

  • Milestones: Significant moments on the project timeline where a batch of tasks is completed.

  • Approvals: Which tasks, if any, require approval?

Task description

Task descriptions should have a task name and a short summary of the goal. If you need to add more details, you can put them in your WBS dictionary. The aim is to make it easy for team members to quickly understand each task.

Task owner

Assigning a task owner is important for accountability and communication. This way, everyone knows who to contact with questions.

While project managers often serve as task owners, department heads and managers may own specific tasks depending on the work. Clear ownership improves team productivity by eliminating time wasted searching for answers.

Task budget

If your project has a large budget, track it closely. Setting budget limits for each task makes it easier to see how you’re doing compared to your total budget. Not tracking your budget can lead to spending more than you anticipated. Be sure to track both your total budget and the costs of individual tasks.

Completion date

It’s important to track when tasks are finished, but be ready to adjust as your project changes.

Break down each task in a timeline or project management tool to track progress effectively. This helps you catch delays early and prevent deadline issues from compounding when you manage multiple projects.

Task status

Documenting task status is important for quick progress checks. Many teams use terms such as open, in progress, and complete.

This helps track progress and gives a high-level overview of team productivity. If there's a pattern of teams unable to complete tasks, you can address team workload or communication issues early.

Read: How to write an effective project status report

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How to create a work breakdown structure

Since a WBS is presented as a visual hierarchy, you have several options for creating yours. To save setup time, start with a work breakdown structure template already formatted for timelines, boards, or calendars.

How to create a work breakdown structure

Popular visual methods are timelines, Kanban boards, and calendars. Let’s look at how each one works.

Timelines (or Gantt charts)

Timelines provide excellent visual clarity for WBS planning. Here are the key functions you get using a timeline view, also known as a Gantt chart:

  • Import traditional spreadsheets

  • Track progress

  • Adjust tasks

  • Connect tasks by dependencies

  • Adjust deadline shifts

  • Assign task owners

  • Store unscheduled tasks

  • Adjust color tracking

  • Section by levels

  • Filter and sort tasks

You can start your WBS by importing an existing spreadsheet or building it directly in timeline software. It's up to you to decide which visual is right for your team.

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Kanban boards

Kanban boards are similar to timelines but are organized vertically like boards instead of horizontally. Kanban software can help with the following:

A Kanban board is one of the most frequently used tools for day-to-day resource management. You can see task details up front, making it a great option if you can't create a WBS dictionary.

Calendars

The third option is using team calendar software. While not as commonly used for breakdown structures, calendars are helpful for switching between day, week, and month views for large projects.

To build your WBS with a calendar, you can import a spreadsheet or start a new project directly in your calendar tool.

Read: 3 visual project management layouts (and how to use them)

Common WBS mistakes to avoid

Even experienced project managers can make mistakes when building a WBS. Here are some common pitfalls to avoid:

  • Turning the WBS into a task list: Focus on deliverables and outcomes, not step-by-step activities. List what you're producing, not actions like "schedule meeting."

  • Over-decomposition: Breaking work down too finely creates unnecessary complexity. Use the 8/80 rule as your guide.

  • Ignoring the WBS after planning: Your WBS is a living document. Update it as the project scope evolves.

  • Violating the 100% rule: Gaps in your WBS mean work will fall through the cracks. Account for every deliverable.

Work breakdown structure example

Now that you know what goes into a WBS and how to build one, let's look at a tangible example. While your template will look different depending on the method you use, your WBS should include similar task hierarchies and levels.

Here is an example work breakdown structure to get you started:

Work breakdown structure example

WBS name: Website design

Description: Revamp our old website design to align with the new branding.

Completion date: 9/15/21

Budget: $50,000

Level 1:

  1. Revamp website design

Level 2:

  1. Revamp brand guidelines (Complete)

  2. Create messaging approach (Complete)

  3. Redesign logo (In progress)

  4. Add new photography (Open)

Level 3:

  1. Revamp brand guidelines

  • Brand colors, Kat Mooney

  • Brand mood board, Kat Mooney

  • Design UX, Ray Brooks

  1. Create a messaging approach

  • Headline, Daniela Vargas

  • Mission statement, Daniela Vargas

  • Language guidelines, Daniela Vargas

  1. Redesign logo

  • Sketch, Kabir Madan

  • Mockups, Kat Mooney

  • Final designs, Kat Mooney

  1. Add new photography

  • Photoshoot, Kabir Madan

  • Photo edits, Kat Mooney

  • Final selections, Kabir Madan

Remember that your WBS will look different depending on the project's size, complexity, timeline, and your chosen software.

Build your work breakdown structure with confidence

A work breakdown structure isn't hard to create once you get the hang of it. By adding a visual hierarchy to your project, you and your team gain clarity and focus on work that matters.

With Asana, you can easily switch between lists, timelines, boards, and calendars without missing a beat. Spending less time on busywork means more time for impactful work. Get started and see how Asana can help you build better projects.

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Frequently asked questions about work breakdown structures

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