Project Management Guide

The purpose of the WBS, as a project management tool, is to organize the scope of a project. WBS definition for programs and portfolios can use similar techniques to organize scope. There are many project management tools that use the WBS or its components as input:

Project Charter: The WBS takes the project charter as its starting point. The highest level element in the WBS should represent the project’s overall end-point product(s), service(s), or outcomes as described in the project charter. If the project’s major products cannot be described during the creation of the WBS, then the project management team should examine the charter to determine if it has been sufficiently defined.

Project Scope Statement: The scope statement for a project is intended to clearly and succinctly describe what the project is and is not intended to accomplish. The high-level elements in the WBS should match, word-for-word, the nouns used to describe the outcomes of the project in the scope statement. If the project management team has difficulty identifying the objects in the scope statement and applying them to the high-level WBS elements, the team should carefully examine the scope statement to determine if it sufficiently captures all project outcomes and deliverables. The WBS Dictionary can also be used to further document and clarify each deliverable.

Program and Portfolio WBS: The WBS can be used to define scope for projects, programs, and portfolios. For example, program offices are typically established to share tools, techniques, methodologies, and resources in managing one or more collections of related projects as program(s). The project WBS must illustrate a clear understanding of the relationship among highly decomposed work packages within individual projects and program (or higher order) scope definitions. If strategic changes are made, the impact on projects, resources, and budgets can be easily calculated, assuming the project WBS has been constructed correctly in consideration of these higher order factors.

RBS: The Resource Breakdown Structure (RBS) describes the project’s resource organization and can be used in conjunction with the WBS to define work package assignments. The link between work packages and the RBS can be used to verify that all members of the project team have been appropriately assigned work packages, and that all work packages have owners.

OBS: The Organizational Breakdown Structure (OBS) is loosely related to the WBS. The OBS depicts the organization hierarchy, allowing the project’s work packages to be related to the performing organizational units. This tool reinforces the guideline that each work package should have a single point of responsibility. The OBS can be a useful tool for project managers in that it clearly demonstrates the hierarchy of people or groups, whereas the WBS is strictly organized by deliverables.

WBS Dictionary: The WBS dictionary is a key document that accompanies the WBS and carries critical project information. The WBS dictionary defines, details, and clarifies the various elements of the WBS to ensure that each component of the WBS is accurately articulated and can be communicated to anyone referencing the WBS. The development of the WBS dictionary often uncovers ambiguity or other errors in the WBS itself, and results in revisions to the WBS. The WBS dictionary contains information about each element of the WBS, including a detailed description of the work, deliverables, activities, and milestones associated with each element. The WBS dictionary might also include an indication of the type and number of resources required and contract control information, such as a charge number or other similar data. Often, a WBS dictionary will include traceability matrices linking the WBS to other scope control documents such as statements of work or requirements documents.

Project Schedule Network Diagram: The network diagram is a sequential arrangement of the work defined by the WBS, and is essential to uncovering project dependencies and risks. The activities within the WBS work packages are arranged to show recedence and order. Developing the network diagram often uncovers problems in the WBS, such as incomplete decomposition, the assignment of too much work in an element, or the assignment of more than one person for an individual WBS element, thus resulting in needed revisions.

Project Schedule: The various elements of the WBS are used as starting points for defining the activities included in the project schedule. Implied dependencies can be recorded in the WBS Dictionary, and the activities as described in the WBS Dictionary are then included as detail in the schedule.