WBS Dictionary

According to the PMBOK Guide, the WBS Dictionary is a document that provides detailed information about deliverables, activities and scheduling for each component of the work breakdown structure.

The WBS dictionary provides detailed information about each WBS element, including deliverables, milestones, scope, duration, start and finish dates, required resources, costs, quality requirements, assigned team members and more.

What is the purpose of the WBS dictionary?

The WBS dictionary is a useful communication tool that helps key participants clarify and understand the WBS.

The second purpose of the WBS dictionary is to help prevent scope creep and gold plating by defining the scope of work. A clear work definition and transparent allocation of responsibilities help prevent miscommunication, so team members know what they are expected to do. No additional work will be performed.

The WBS dictionary complements the WBS, which is a graphical representation of the scope of work. A graphical WBS does not explain the work in detail, so the dictionary supplies additional information to make it complete and more useful.

WBS Dictionary Template

The WBS must contain 100% of the scope of work, but a graphical or tabular representation cannot show every detail. The WBS dictionary therefore explains the scope of each element to ensure that all work is covered.

Many experts describe the WBS dictionary as a work package description tool. Like the WBS, it is organized hierarchically to explain each element systematically.

How to Create a WBS Dictionary

Develop the WBS dictionary after creating the work breakdown structure. Start with the highest-level element and work downward to the work package level. This approach ensures that 100% of the scope of work is covered at every level.

When creating a WBS dictionary, use the template in the table above to keep it concise and meaningful without repeating the scope unnecessarily. Provide brief information that makes each work package easy to understand.

Use the following steps to develop a WBS dictionary:

#1. Review the WBS

Review the WBS to ensure that team members understand it, that it covers 100% of the scope of work and that there are no duplications. Make any necessary changes.

#2. Create the Higher-Level Elements

Determine the identification system you will use for WBS elements. Then name the highest-level element, add an identifier and describe it. You can include the main deliverable, budget, duration, milestone, assumptions, constraints and risks.

#3. Create the Lower-Level Elements

Next, create the lower-level elements using the same template. Check that they cover 100% of the work within their parent element. If changes to the higher level are required, make them.

#4. Create the Work Package

The work package is the lowest level of the WBS. Here, you can assign the responsible person and identify the associated control account. Finally, validate that 100% of the scope of work is covered.

Best Practices for Creating a WBS Dictionary

• Higher-level elements should contain less detail than lower-level elements.
• Use a standard template to develop the dictionary entry for each WBS element and maintain consistency.
• If you use a project management tool or flowchart software to develop the WBS, keep the WBS dictionary in the same location or document for easy reference.
• If you change the scope of work, update the WBS dictionary.

Contents of the WBS Dictionary

A WBS dictionary may include the following information:

• WBS Identifier: Each WBS element has a unique identifier and title.
• Description: All elements should have clearly defined boundaries, assumptions, constraints and scope.
• Responsible Team Member: Assign a team or team member to each element so that responsibility for completing it is clear.
• Deliverable: Include the product, service or result to be delivered, as well as any intermediate deliverables.
• Acceptance Criteria: Add the client’s acceptance criteria for the deliverable.
• Duration: Add the duration of the WBS element.
• Milestones: List all milestones, intermediate milestones and project dependencies.
• Budget: Add the budget for the WBS element.
• Risks: List all risks that affect the WBS element.

WBS Dictionary Example

The following is an example of a WBS dictionary:

Frequently Asked Questions About the WBS Dictionary

Why do we need a WBS dictionary?

Because the WBS is graphical, it does not provide enough detail, and project stakeholders may find it difficult to understand what is being communicated. In these cases, the WBS dictionary is useful because it explains and provides comprehensive information about each WBS element.

What tools are needed to create a WBS dictionary?

Most organizations use Excel or Word to create the WBS dictionary. For larger projects and organizations, project management tools such as MS Project, Smartsheet and Monday.com can help you develop the WBS and its dictionary quickly.

Who creates the WBS dictionary?

Creating a WBS dictionary is not a one-person task: it requires teamwork. Team members with project management skills need to contribute to its development.

A combined effort builds a sense of responsibility and encourages team members to commit to the work.

The project leader may also need help from subject matter experts to create the WBS dictionary.

Summary

The WBS dictionary is the backbone of the WBS. The WBS provides the framework, while its dictionary supplies detailed information about each element. It is the basis for preparing work authorizations, estimating costs, developing schedules and monitoring project tasks.

The WBS contains limited information, while the WBS dictionary provides concise, comprehensive information for developing project management plans.