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5 - PROJECT SCOPE MANAGEMENT

5.4.2 create WBS: tools and techniques

5.4.2.1 decomposition

Decomposition is a technique used for dividing and subdividing the project scope and project deliverables into
smaller, more manageable parts. The work package is the work defined at the lowest level of the WBS for which
cost and duration can be estimated and managed. The level of decomposition is often guided by the degree of
control needed to effectively manage the project. The level of detail for work packages will vary with the size
and complexity of the project. Decomposition of the total project work into work packages generally involves the
following activities:

• Identifying and analyzing the deliverables and related work;
• Structuring and organizing the WBS;

• Decomposing the upper WBS levels into lower-level detailed components;
• Developing and assigning identification codes to the WBS components; and
• Verifying that the degree of decomposition of the deliverables is appropriate.

A portion of a WBS with some branches of the WBS decomposed down through the work package level is shown
in Figure 5-11.

5.4.2.2 Expert Judgment

Expert judgment is often used to analyze the information needed to decompose the project deliverables down
into smaller component parts in order to create an effective WBS. Such judgment and expertise is applied to
technical details of the project’s scope and used to reconcile differences in opinion on how to best break down
the overall scope of the project. This level of expertise is provided by any group or individual with relevant training,
knowledge, or experience with similar projects or business areas. Expert judgment can also come in the form
of predefined templates that provide guidance on how to effectively break down common deliverables. Such
templates may be industry or discipline specific or may come from experience gained in similar projects. The
project manager, in collaboration with the project team, then determines the final decomposition of the project
scope into the discrete work packages that will be used to effectively manage the work of the project.

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