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WBS Dictionary – Everything Project Managers Should Know

what is a wbs dictionary, wbs dictionary example
WBS Dictionary

A WBS Dictionary is an element of the Work Breakdown Structure that provides detailed information about each project task. It is integral to project scope management, the scope statement, and the work breakdown structure. The three components combine to give the scope baseline, without which there is a chance of deviating from the desired project objectives.

Thus, having a clear idea about the WBS Dictionary is vital for aspiring project management professionals (PMPs). With the help of the work breakdown structure dictionary and the project scope statement, project managers can measure the project’s performance against the original project scope. This will help them keep the project within the schedule and estimated budget.


The PMBOK (Project Management Body of Knowledge) defines a WBS Dictionary as – a document that provides detailed deliverable, activity, and scheduling information about each component in the work breakdown structure.

A WBS Dictionary is a document that supports the work breakdown structure and defines each step to provide the final project deliverables. It also provides detailed information about the execution of each project task, including the resources required, estimated costs, quantity and quality requirements, schedule of completion, etc.

This is a brief statement of the work breakdown structure and can be described in textual form or as numerical data. WBS Dictionary provides additional information about some tasks that need more elaboration or explanation. So, for each WBS element or project task, the WBS Dictionary will include the task description, the project scope, milestones, and activities associated with the tasks.

The dictionary should further have all the necessary information that seems essential to the project’s stakeholders and the project team members to have some amount of project control. Project control goes beyond the cost and time of project completion. It allows project teams to complete each element of work breakdown structure with the information provided to achieve the desired project delivery.


The primary purpose of a WBS Dictionary is to provide information about the work breakdown structure. It is a visual tool explaining the tasks in detail becomes difficult. The titles and numbers often used in work breakdown structure correspond to the WBS Dictionary, where all the information regarding the tasks is described. This, in turn, helps project team members to understand each task mentioned in the dictionary and the specific requirements needed to complete the project successfully.

WBS Dictionary helps in keeping the stakeholders of the project updated with the progression of the project. It provides an actual estimation of the project scope and quality that would be delivered. This helps avoid costly revision that increases the timely delivery of the project. Project managers use a Work Breakdown Structure Dictionary to ensure that the project meets the stakeholders’ expectations and successfully fulfills the organizational objectives.

Components of a WBS Dictionary

Project managers usually create the WBS Dictionary by consulting the project team members. They consider all the variables and elements of the project to create a work breakdown structure dictionary that ultimately makes the tasks visible and easy to comprehend to all project stakeholders. There is no defined format or template for a WBS Dictionary. However, 12 components are a part of every WBS Dictionary. These are mentioned below:

No. ItemDescription
1IdentificationEach project task mentioned in the WBS should have a code or account identifier that allows the correct reference in the WBS Dictionary.
2DescriptionIt provides a brief description of the tasks. This can then be measured with the project expectations.
3Assumptions and ConstraintsMentioning the assumptions and constraints of the tasks in the WBS makes it easy to plan the potential delays.
4Assigning ResponsibilityEvery task should be assigned to the proper professional or teams who will be responsible for the performance of that task.
5Define MilestoneProjects have a start as well as an end date. A WBS Dictionary should mention all critical milestones in the project life cycle.
6Related DeliverablesIn the WBS Dictionary, all activities or deliverables associated with the project tasks must be indicated.
7Required ResourcesA WBS Dictionary also mentions the tools, materials, and equipment needed to perform a particular activity.
8Estimated CostsThis includes the estimation of costs associated with each task in the WBS.
9Quality RequirementsThe quality standards and the expectations of the stakeholders for each element in the WBS are mentioned in this section.
10Acceptance CriteriaThis section defines the acceptance criteria for each component and the person who has the authority to decide that.
11Technical ReferenceGuidelines, manuals, and standards used for the execution of the tasks can be indicated here.
12Agreement InformationLists of agreements, like contracts, corporate agreements, etc., are included in this section.

WBS Dictionary Example

Here is a simple example of a WBS Dictionary for a project that involves building a fence around a flower garden.

Let us have a look at the tasks of the project Build Fence can be listed as follows:

  1. Buy Materials (wooden posts, mesh wires, etc.)
  2. Dig hole
  3. 1. Plant posts
    3. 2. Attach wires
WBS Dictionary
WBS Dictionary Example
  • 1. Buy Materials
    After plotting the garden area to be fenced, materials like wooden posts, mesh wires, etc., need to be purchased. The materials would cost around $100, with additional charges of $50 to hire an installation person to finish the work in a day.
  • 2. Dig a hole
    This will be performed by the installation person who will bring the equipment.
  • 3.1. Plant posts
    The person might require a helper to assist in planting the wooden posts. Charges need to be discussed.
  • 3. 2. Attach wires
    The mesh wires must be fixed carefully, ensuring the flower beds are not disturbed. Damaged flowers need to be replaced in case of an accident.


From the above example, we can understand how a WBS Dictionary details the materials, costs involved, time required, equipment, and damages resulting in additional costs to complete the project Build Fence. Understanding this concept will help aspiring project managers ready to take professional training to visualize their tasks and completion. This will help them work towards achieving successful project delivery with confidence and attain the organizational objectives.

Posted in Project Management

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