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5 - PROJECT SCOPE MANAGEMENT

The PMBOK Guide distinguishes between project scope and product scope. The two scopes can be integrated
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in an activity-oriented WBS for software projects because of the nature of software and the way in which software is
developed or modified. As illustrated in Figure 5-3 product structure is embedded in the activity-oriented software
WBS.

Work packages can be used to document the tasks in a software project WBS. Factors documented in a work
package for constructing software components include:

• Estimated duration,
• Number of personnel by skill level,
• Additional resources needed,

• Software component or components to be developed or modified,
• Acceptance criteria for the software component or components developed or modified, and

• Risk factors.
Risk factors are potential problems that may inhibit successful completion of the software component or
components using the allocated effort and additional resources. Other factors that can be included in an activity-
oriented work package include predecessor and successor task for the task being documented and work products
to be placed under version control.

5.4.2.4 Rolling Wave Elaboration of WBS

According to Section 6.2.2.2 of the PMBOK Guide: rolling wave planning is an iterative planning technique in
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which the work to be accomplished in the near term is planned in detail, while the work in the future is planned
at a more general level. It is a form of progressive elaboration. Therefore, work can exist at various levels of detail
depending on where it is in the project life cycle.

Rolling wave planning is a valuable technique for progressively elaborating the work to be accomplished when
using an activity-oriented WBS for a predictive life cycle software project, based on the following considerations
(the equivalent of rolling wave planning for adaptive life cycle software projects is presented in Section 5.4.2.5 of
this Software Extension).

Every software project results in a unique product, either new or modified, because replication of existing
software is a simple process as compared to the replication of physical artifacts. Most software projects thus
require innovation and creative problem solving to satisfy new and evolving needs. For predictive life cycle software
projects, an activity-oriented WBS is elaborated in a rolling wave manner as the details of constructing the software
product are elaborated with increased understanding of the problem to be solved. Some rolling wave modifications
of work to be accomplished using an activity-oriented WBS may be accomplished within the overall scope
constraints of schedule, budget, resources, and technology, while other elaborations may require renegotiation of
the project scope constraints.

76 ©2013 Project Management Institute. Software Extension to the PMBOK Guide Fifth Edition
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