OTHER CATEGORIZATIONS
There is no one best categorization or subdivision of the project. It is sometimes desirable to use a different structure because of the situation or culture of the stakeholders. Various commonly used categorization schemes at the top levels are:
Components of the product or service to be delivered: Automobile—Fenders, engine, hood, seats, frame, gas tank, and so on
Subsystems: Airplane—Hydraulic, electronics, structure, pneumatics, power plant, and so on
Projects: Program—Project A, Project B, Project C, and so on
Process Phases: Software—Requirements, Design, Coding, Test, and so on
Time Phases: Life Cycle—Conceptual, Planning, Implementation, and so on
Geographic Areas: New York City—Brooklyn, Queens, Manhattan, and so on
Organizational Units (Phases): Engineering, Construction, and so on
On the surface, it appears that some of these categorizations are inputs, such as organizational units. That is really not the case when used properly. The items represent phases of the project, as discussed later. The WBS under each of the categories is still output- or deliverable-oriented. It is important that there be a logical framework for planning that is internally consistent and represents all the work to be performed on the project. The WBS is output-oriented.
Other ineffective categorizations are sometimes proposed:
Organization: Engineering—Mechanical Design, Structural Design, System Analysis, and so on
People: Small Project—John, Mary, Ozzie, David, Courtney, and so on
Cost Accounts: Labor, Travel, Office Supplies, and so on
The preceding categorizations are all input-oriented and are not appropriate for a WBS. Organization names and codes, cost accounts, people, and other inputs are appropriate for coding work packages and activities so as to be able to provide reports or information sorted by these types of categories.
On occasion, people attempt to link WBS elements or to use the WBS to assist in the sequencing of work. Whether or not the WBS has a process, systems, or product structure focus, the sequence of work is not the objective. The important aspect of the WBS is whether the work required to deliver the project end items and meet the project objectives has been identified in enough detail to identify activities and resources, and assign responsibility. The sequencing is accommodated through the planning and scheduling processes.
On the surface, the WBS decomposition appears to be simple and straightforward. However, several different approaches can be taken, depending on the type of project and the category of work.
One rule that applies to all the methods is that the next level of decomposition of a WBS element must represent 100 percent of the work applicable to the next higher element. This is referred to as the “100 percent rule.” When followed, it ensures that the WBS encompasses all the work on the project.
There are three types of projects, based on the type of output: product, service, or result. The WBS for each type has its own characteristics and rules for decomposition. The “product” breakdown is a decomposition based on the natural physical structure of the output product being produced. The “service” breakdown is based on a logical grouping of similar and related work elements, functions, or skills. The “results” project has a series of planned and well-defined steps and is process-based.
In addition, there is another category for the WBS elements, referred to as “cross-cutting.” Cross-cutting elements are usually technical and supportive in nature. The four basic types are integrative, analytical, process, and project management. The latter exists in all projects as a Level 2 element. Conceptually, the project management element represents the “overhead” of the project.