What Is a Work Breakdown Structure?

A Work Breakdown Structure (WBS) is a hierarchical decomposition of the total scope of work to be carried out by the project team to accomplish the project objectives and create the required deliverables. In PMBOK 8, the WBS is a foundational planning artifact: it establishes the scope baseline, provides the framework for all subsequent planning (schedule, cost, resource), and defines the work packages that are assigned, executed, and controlled throughout the project. The 100% rule is the defining principle: the WBS must capture 100% of the project scope — every deliverable, every component, every piece of authorized work — with no gaps and no overlap.

What's Inside This Work Breakdown Structure Example

This Work Breakdown Structure example covers Project Phoenix — MCG's $72,250 website launch, March 17 to June 13, 2025. The spreadsheet presents the WBS in two formats:

• Hierarchical Outline tab: The full WBS in outline form with WBS codes, from Level 1 (Project Phoenix) through Level 4 (individual work packages)
• Tree Diagram tab: Visual WBS chart showing the full decomposition structure from project to deliverable to work package

The WBS has five Level 2 elements (phases): 1. Initiation, 2. Planning, 3. Execution, 4. Monitoring & Control, 5. Closure. Level 3 elements within Execution: 3.1 UX Design, 3.2 Content Planning, 3.3 Development, 3.4 Content Migration, 3.5 Testing & QA, 3.6 Training. Total work packages at Level 4: 32, spanning all five phases.

The WBS excludes: post-launch content updates, ongoing SEO management, social media campaign execution, and the live chat widget integration (deferred to Phase 2 per CR-004 rejection).

How Alex Morgan Used This WBS

Alex Morgan built the WBS in a 3-hour decomposition workshop during Week 1 with the full six-person team. Starting from the project objective (launch a functional, performant MCG website), the team decomposed deliverables until each element was small enough to be estimated, assigned, and completed within two weeks — PMBOK's recommended work package sizing guideline.

Three WBS decisions shaped the entire project structure:

• Separation of Content Planning and Content Migration: Many web project WBSs combine content activities into a single work stream. Alex separated them — Content Planning (what content to create/keep) and Content Migration (moving content from legacy CMS to new CMS) — because the two activities had different owners, dependencies, and risk profiles. This separation made the content migration scope issue (CR-002) traceable to a specific work package rather than hidden in a generic "content" bucket.
• Monitoring & Control as a Level 2 element: Project management activities (status reporting, change control, issue management, stakeholder communication) were explicitly included in the WBS as Level 2 element 4. This meant project management effort was estimated, budgeted, and scheduled — not invisibly absorbed. Alex Morgan's 240 hours of PM time were in the WBS and the Cost Estimates, making the cost of project management visible to Riley Park rather than buried in overhead.
• CR-001 WBS amendment: When the blog module was approved (CR-001), Alex added WP 3.3.7 (Blog Module Development) and WP 3.2.4 (Blog Content Structure) to the WBS as a formal amendment. The WBS remained the single source of scope truth throughout the project because every change went through the WBS.

Download and Customize

This Work Breakdown Structure example is available as a free download. Use it as a reference to build your own WBS, or start with the blank template and run a decomposition workshop with your project team.

• Download the Work Breakdown Structure Template — PMBOK 8 (blank, ready to use)
• Read the article: Work Breakdown Structure in PMBOK 8 — Guide and Best Practices

Work Breakdown Structure Example: Key Takeaways

The Project Phoenix WBS demonstrates two principles that distinguish professional scope management from amateur task listing. First, the 100% rule: every element of authorized scope was in the WBS, including project management activities — making the cost of oversight visible and accountable. Second, decomposition depth: work packages were sized at "estimatable and ownable in two weeks," which meant every package had a clear owner, a clear deliverable, and a duration short enough to detect performance problems while there was still time to recover. The WBS is not a project plan — it is the foundation that every other planning document is built on. Get it right, and every downstream document benefits.

Want to go deeper? The PMBOK Guide 8th Edition is the definitive reference for modern project management. Get your copy and use it alongside these examples to build a solid, practical understanding of every performance domain.