Page 157 -

5 - PROJECT SCOPE MANAGEMENT

Decomposition of the upper-level WBS components requires subdividing the work for each of the deliverables
or subcomponents into its most fundamental elements, where the WBS components represent verifiable products,
services, or results. The WBS may be structured as an outline, an organizational chart, or other method that identifies
a hierarchical breakdown. Verifying the correctness of the decomposition requires determining that the lower-level
WBS components are those that are necessary and sufficient for completion of the corresponding higher-level
deliverables. Different deliverables can have different levels of decomposition. To arrive at a work package, the
work for some deliverables needs to be decomposed only to the next level, while others need additional levels of
decomposition. As the work is decomposed to greater levels of detail, the ability to plan, manage, and control the 5
work is enhanced. However, excessive decomposition can lead to nonproductive management effort, inefficient
use of resources, decreased efficiency in performing the work, and difficulty aggregating data over different levels
of the WBS.

Decomposition may not be possible for a deliverable or subcomponent that will be accomplished far into the
future. The project management team usually waits until the deliverable or subcomponent is agreed on, so the
details of the WBS can be developed. This technique is sometimes referred to as rolling wave planning.

The WBS represents all product and project work, including the project management work. The total of the work
at the lowest levels should roll up to the higher levels so that nothing is left out and no extra work is performed.
This is sometimes called the 100 percent rule.

For specific information regarding the WBS, refer to the Practice Standard for Work Breakdown Structures –
Second Edition [7]. This standard contains industry-specific examples of WBS templates that can be tailored to
specific projects in a particular application area.

5.4.3 create WBS: outputs

5.4.3.1 Scope Baseline

The scope baseline is the approved version of a scope statement, work breakdown structure (WBS), and its
associated WBS dictionary, that can be changed only through formal change control procedures and is used as a
basis for comparison. It is a component of the project management plan. Components of the scope baseline include:

• Project scope statement. The project scope statement includes the description of the project scope,
major deliverables, assumptions, and constraints.

©2013 Project Management Institute. A Guide to the Project Management Body of Knowledge (PMBOK Guide) – Fifth Edition 131
®

Licensed To: Jorge Diego Fuentes Sanchez PMI MemberID: 2399412
This copy is a PMI Member benefit, not for distribution, sale, or reproduction.