WBS Dictionary – Everything Project Managers Should Know

what is a wbs dictionary, wbs dictionary example
WBS Dictionary

WBS Dictionary

A WBS Dictionary is an element of the Work Breakdown Structure (WBS) that gives detailed information about each project task. It forms an important part of project scope management along with the project scope statement and work breakdown structure. The three components combine to give the project scope baseline for the projects, 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 WBS Dictionary along with the project scope statement, project managers can measure the performance of the project against the original project scope. This will help them keep the project within the schedule and estimated budget.

Definition of WBS Dictionary

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

Purpose of a WBS Dictionary

The main purpose of a WBS Dictionary is to provide information about the work breakdown structure. Since WBS is a visual tool, it becomes difficult to explain the tasks in detail. The titles and numbers often used in WBS 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 WBS and the specific requirements needed to successfully complete the project.

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 the quality of the project that would be delivered. This helps in avoiding costly revision that increases the timely delivery of the project as well. Project managers use a WBS Dictionary to ensure that the project delivered meets the expectations of the stakeholders and fulfills the organizational objectives, successfully.

Components of a WBS Dictionary

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

No. ItemDescription
1IdentificationEach task of the project mentioned in the WBS should have a code or account identifier that allows the right 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 right professional or teams who will be responsible for the performance of that task.
5Define MilestoneProjects have a start as well as an end date. All important milestones in the project life cycle should be mentioned in a WBS Dictionary.
6Related DeliverablesIn the WBS Dictionary all activities or deliverables associated with the project tasks must be indicated.
7Required ResourcesThe tools, materials, and equipment that are needed to perform a particular activity are also mentioned in a WBS Dictionary.
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 is used to define 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 agreement, etc. is included in this section.
WBS Dictionary Components

A WBS Dictionary should have all necessary information that seems important to the stakeholders of the project and the project team members to have some amount of project control. Project control goes beyond the cost and time of the project completion. It allows project teams to complete each element of WBS with the information provided to achieve the desired project delivery.

WBS Dictionary Example

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

The WBS 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

The WBS Dictionary of the above WBS can be described as follows:

WBS Dictionary
WBS Dictionary Example
  • 1. Buy Materials
    After plotting the area of the garden to be fenced, materials like wooden posts, mesh wires, etc. need to be purchased. The costs of the materials would be around $100 with additional charges of $50 to hire an installation person to finish the work in a day.
  • 2. Dig hole
    This will be performed by the installation person who would 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 need to be fixed carefully, ensuring that the flower beds are not disturbed. Damaged flowers need to be replaced in case of an accident.


Therefore, from the above example we can understand how a WBS Dictionary provides the details of the materials, costs involved, time required, equipment, and damages that will result in additional costs to complete the project Build Fence. Understanding the concept of the WBS Dictionary will help aspiring project managers who are ready to take professional trainings to visualize their tasks and their completion. This will help them to work towards the goal of achieving successful project delivery with confidence and attain the organizational objectives.