WBS Dictionary

March 25, 2025
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What is a WBS Dictionary?

A WBS Dictionary is a detailed document that supports the Work Breakdown Structure (WBS) by providing comprehensive descriptions of each element or work package within the WBS. It defines each component’s scope, deliverables, responsibilities, resources, schedule, and sometimes cost estimates. This reference tool ensures team members understand each project part, preventing confusion and miscommunication. It acts as a critical companion to the WBS by adding depth and context to the hierarchical breakdown of work.

Key Points

  • It elaborates on each WBS element by including scope, milestones, assigned resources, and acceptance criteria.
  • The dictionary is created during the planning phase and is updated throughout the project lifecycle as needed.
  • It helps maintain alignment between project stakeholders by clarifying expectations for each work package.
  • The document is typically structured using a consistent format for every WBS component, promoting standardization and ease of use.
  • It plays a key role in supporting effective scope management and performance tracking.

Related Terms

  • The Work Breakdown Structure (WBS) is the hierarchical framework the dictionary explains in greater detail.
  • A work package is the smallest unit in the WBS and the main focus of each dictionary entry.
  • The project scope statement often provides input to the WBS Dictionary by outlining overall deliverables and constraints.
  • The scope baseline includes the WBS, WBS Dictionary, and project scope statement, which form a key reference for project control.
  • Project planning involves developing the WBS Dictionary to support detailed execution strategies.

WBS Dictionary: Example

A work package in the WBS might be labelled “Foundation Work ” in a construction project. The WBS Dictionary entry for this package would describe the specific tasks involved, such as excavation, pouring concrete, and curing. It would also list required materials, estimated labour hours, responsible teams, quality requirements, and deadlines. This level of detail helps ensure all stakeholders understand what “Foundation Work” includes.

WBS Dictionary: Best Practices

  • Use a standard format to record information for each WBS element to ensure consistency.
  • Involve subject matter experts when writing entries to improve accuracy and completeness.
  • Keep the document updated as project changes occur to reflect current information.
  • Link each entry clearly to its corresponding WBS code to maintain traceability.
  • Review the document with stakeholders to confirm shared understanding and approval.

Additional Resources

WBS Dictionary - Practice Standard for Work Breakdown Structures     WBS Dictionary - Work Breakdown Structures: The Foundation for Project Management Excellence

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