Week 3 Discussion

Breakdown Structure

The work breakdown structure (WBS) is one of the most important and useful documents produced during the planning process. It is so often misunderstood that it is

important to �rst review its basic de�nition.

The WBS is deliverable-oriented hierarchical decomposition of the work to be executed by the project team to accomplish the project objectives and create the required

deliverables. It organizes and de�nes the total scope of the project. Each descending level represents an increasingly detailed de�nition of the project work. The WBS is decomposed into work packages.

The WBS says nothing about the structure of the organization, whether it be the project organization or the organizational context in general.

The PMBOK® Guide de�nes organizational breakdown structure (OBS) as, "A hierarchically organized depiction of the project organization arranged so as to relate the

work packages to the performing organizational units."

As you will recall, project planning begins with the project vision, and then planning �ows logically and carefully through the project charter, the scope statement, and the

project plan. The WBS is the next step in the planning logic and it only uses the earlier planning documents in its construction. It does not consider the existing organizational structure. The organizational structure is derived from the WBS, if the project manager is lucky enough to have that much discretion and authority. This

would be true in some very pure project-based organizations.

When the organization is not project based and especially when the organization has a matrix structure, the project manager may �nd himself or herself at an impasse.

Diligently performing the planning sequence in the order described, the project manager may �nd the WBS looks nothing like the existing organizational matrix.

What happens when the project manager has a WBS that looks nothing like the existing organizational structure? The project manager produces a linear responsibility

chart.

What Meredith and Mantel (2009) describe as the linear responsibility chart in Project Management: A Managerial Approach is de�ned by the PMBOK® Guide as responsibility assignment matrix (RAM). The PMBOK® Guide de�nes RAM as, "A structure that relates the project OBS to the WBS to help ensure that each component

of the project's scope of work is assigned to a responsible person."

Often, the linear responsibility chart or RAM is also referred to as the responsibility, accountability, consult, and inform (RACI) chart. You can compare the RACI chart in

the PMBOK® Guide with the linear responsibility chart presented in Project Management: A Managerial Approach.

Note the linear responsibility chart is part of project planning but it is still developed during the planning stage of the project's life cycle. This means the tool has more

than one use. The RACI chart is a key tool and very important for you to understand. Seen from the perspective of a project's human resource manager, the RACI chart links the OBS and job descriptions, which are necessary for building teams. From the standpoint of planning the technicalities of the project, the RACI or RAM chart links

the WBS to the OBS.

While previously discussing WBS, you ended with an inference of some of the complexities created in project management by choosing the matrix type of project

management in an overall organization's scheme. Because a WBS is done to graphically depict the project's scope, with no necessary relationship to the existing

organizational structures, many disconnections may exist between the WBS and the OBS.

You can see a RAM, by any name, is far from overkill or micromanagement when it comes to project planning. In any project-based organization—especially a matrix organization—it would be a mistake for separate project and functional managers to design for their people different plans in great disagreement with each other without

a method of coordinating human resources. The simple-looking RAM is a tool that can be used effectively to make sure such problems do not surface. Of course, it may

take some keen con�ict resolution skills to resolve the differences.

Additional Materials

View a Pdf Transcript of Understanding the WBS (media/week3/SU_MGT3035_W3_L3_G1.pdf?_&d2lSessionVal=aVaTmfHd5UkmjmVnoP1XalSFd&ou=85477)

View a Pdf Transcript of Relationship between WBS and OBS (media/week3/SU_MGT3035_W3_L5_G1.pdf?

_&d2lSessionVal=aVaTmfHd5UkmjmVnoP1XalSFd&ou=85477)

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