Crear wbs para proyectos de software

1. 5 - PROJECT SCOPE MANAGEMENT
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5.4 Create WBS
The inputs, tools and techniques, and outputs for Create WBS in Section 5.4 of the PMBOK® Guide are equally
applicable for creating work breakdown structures for predictive life cycle software projects. Comparable techniques
for adaptive software projects are described in Section 5.4.2.5 of this Software Extension.
Section 5.4 of the PMBOK® Guide includes the following statement: “In the context of the WBS, work refers
to work products or deliverables that are the result of activity and not to the activity itself.” The PMBOK® Guide
distinguishes between organizing a WBS by phase or by major deliverables at the second level.
For software projects, the top level of the WBS subdivides the project by life-cycle process or activity. The work
products and deliverables are shown as outputs of activities and tasks at lower levels in the WBS. This form of WBS
is referred to as an activity-oriented WBS (Section 5.4.2.3 of this Software Extension provides an example).
Activity-oriented work breakdown structures are desirable for most software development projects because
software is the product of the cognitive processes of software developers and does not involve fabrication of
physical work products or deliverables in media such as wood, metal, plastic, or silicon. Work packages for the
tasks in a software WBS include specification of the work activities and the work products or deliverables to be
created or modified by those work activities, as well as the acceptance criteria for the work products or deliverables.
Activity-oriented work breakdown structures are also applicable for other kinds of knowledge-based work.
Considerations for developing an activity-oriented WBS for a predictive life cycle software project can proceed
top-down as follows: (a) by first specifying the project activities at the top level and decomposing each top-level
element into subordinate activities and tasks; (b) by first identifying the lowest-level tasks to be performed
and grouping them into successively larger groupings (activities); or (c) by working “middle out” by identifying
intermediate-level activities and decomposing them downward and grouping them upward. In practice, all three
approaches are typically used to produce an activity-oriented WBS. Predefined templates for work breakdown
structures and work packages, plus examples designed to fit the local situation, make the task of constructing a
software WBS much easier than starting without guidance.
©2013 Project Management Institute. Software Extension to the PMBOK® Guide Fifth Edition 73

2. 5 - PROJECT SCOPE MANAGEMENT
The PMBOK® Guide distinguishes between organizing a WBS by phase or by major deliverables. Using the
technique of embedding the work to produce deliverables in an activity-oriented WBS and specifying the deliverables
and acceptance criteria in the work packages, as described in Section 5.4.2.3 of this Software Extension, merges
this distinction for software projects and other kinds of activity-oriented projects.
5.4.1 Create WBS: Inputs
The inputs in Section 5.4.1 of the PMBOK® Guide are equally applicable for creating an activity-oriented
software WBS.
5.4.1.1 Scope Management Plan
See Section 5.4.1.1 of the PMBOK® Guide.
5.4.1.2 Project Scope Statement
See Section 5.4.1.2 of the PMBOK® Guide.
5.4.1.3 Requirements Documentation
See Section 5.4.1.3 of the PMBOK® Guide.
5.4.1.4 Enterprise Environmental Factors
See Section 5.4.1.4 of the PMBOK® Guide.
5.4.1.5 Organizational Process Assets
See Section 5.4.1.5 of the PMBOK® Guide.
5.4.2 Create WBS: Tools and Techniques
The decomposition technique for creating a WBS described in Section 5.4.2 of the PMBOK® Guide is equally
applicable for creating an activity-oriented WBS for a software project. Additional considerations are presented in
Sections 5.4.2.2, 5.4.2.3, and 5.4.2.4 of this extension.
5.4.2.1 Decomposition
See Section 5.4.2.1 of the PMBOK® Guide.
74 ©2013 Project Management Institute. Software Extension to the PMBOK® Guide Fifth Edition

3. 5 - PROJECT SCOPE MANAGEMENT
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5.4.2.2 Expert Judgment
See Section 5.4.2.2 of the PMBOK® Guide.
5.4.2.3 Activity-Oriented WBS
An example of an activity-oriented WBS is illustrated in this section of the Software Extension; it is descriptive
of an approach to creating a WBS for a software project; it is not intended to be prescriptive. The top level of an
activity-oriented WBS for a software project includes the full scope, at a high level, of all the work required to
complete the project successfully, as illustrated in Figure 5-3. The top level of an activity-oriented WBS is reflected
in, and can provide an input for refining the project scope statement. The subordinate levels can provide an input
for refining the product scope statement because the elements of work to produce the product components are
embedded in an activity-oriented WBS. The lowest level elements of work for the software construction activity of
the WBS produce specific deliverables. The tasks for Activity 3.2 in Figure 5-3 include work to reuse, construct, and
buy some software components. For brevity of presentation, the example includes only the subordinate elements
of Construct Software.
Embedding product scope in an activity-oriented software WBS is depicted in Figure 5-3, which illustrates a
partial WBS for developing the software for an automated teller machine; the product components are indicated in
bold font. The figure in Section 5.4.2.4 of this Software Extension illustrates further decomposition of the “Construct
FINAT” element of the WBS in Figure 5-3.
ATM Project
3.
Construct
Software
4.
Verify
Software
3.2.
Construct
FINAT
3.3.
Construct
MAIND
3.4.
Buy
COMM
ATMSD: Software Drivers
FINAT: Financial Transactions
MAIND: Maintenance & Diagnostics
COMM: Communication Package
Analyze and
Design
LEGEND
2.
5.
Validate
Software
3.1.
Reuse
ATMSD
3.5.
Integrate
and Test
ATMSD, FINAT,
MAIND, COMM
Figure 5-3. Partially Decomposed Activity-Oriented WBS
1.
Manage
Project
6.
Deploy
Software
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4. 5 - PROJECT SCOPE MANAGEMENT
The PMBOK® Guide distinguishes between project scope and product scope. The two scopes can be integrated
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
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.
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5. 5 - PROJECT SCOPE MANAGEMENT
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An example of rolling wave elaboration of the WBS for the ATM project (see Figure 5-3) is illustrated in Figure
5-4, where the details of constructing the financial transaction component have been added, perhaps after some
prototyping and feasibility analysis once the project was underway. The work package for the financial transaction
component in Figure 5-3 (FINAT) is decomposed into work packages shown in Figure 5-4 for the four subordinate
software components plus the FINAT integration and test task. Note that the product components are denoted in
boldface font. Also, note the decision to reuse existing recorder software from another software product. A work
package for a software construction task includes the work needed to accomplish detailed design, coding, unit
testing, and integration and testing of the composite software module (e.g., the validator module in Figure 5-4).
Rolling wave elaboration of an activity-oriented software WBS is typically accomplished periodically, perhaps
monthly, to accommodate increased understanding of the problem to be solved. Rolling-wave elaboration also
may be accomplished as circumstances dictate, such as changes to requirements, schedule, budget, resources,
or technology.
ATM Project
3.
Construct
Software
4.
Verify
Software
3.2.
Construct
FINAT
3.3.
Construct
MAIND
3.4.
Buy
COMM
3.2.2.
Construct
Processor
3.2.3.
Reuse
Recorder
3.2.4.
Construct
Terminator
ATMSD: Software Drivers
FINAT: Financial Transactions
MAIND: Maintenance & Diagnostics
COMM: Communication Package
Analyze and
Design
LEGEND
1.
Manage
Project
2.
5.
Validate
Software
6.
Deploy
Software
3.1.
Reuse
ATMSD
3.5.
Integrate
and Test
ATMSD, FINAT,
MAIND, COMM
3.2.1.
Construct
Validator
3.2.5.
Integrate & Test
Validator,
Processor,
Recorder,
and Terminator
Modules
Figure 5-4. Rolling Wave Elaboration of Activity-Oriented WBS
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6. 5 - PROJECT SCOPE MANAGEMENT
5.4.2.5 Rolling Wave Planning for Adaptive Life Cycle Projects
The scope of an adaptive life cycle software project can be progressively elaborated in a rolling wave manner,
as illustrated in Figure 5-5, which is the equivalent of a rolling wave WBS. The small “boxes” in each quarter
(Q1 – Q4) are feature sets at the top level with increments of functionality for the features sets in the subordinate
levels. As indicated, the feature sets and increments of functionality are progressively elaborated during planning
for subsequent quarters of calendar time.
As stated in conjunction with Figure 5-2 of this Software Extension, it may be possible to specify an initial
release plan during the planning process for an adaptive software project. In other cases, the release plan may
evolve in a rolling wave manner. The elaboration in Figure 5-4 may have been developed initially or as a rolling
wave elaboration across the quarters. This form of elaboration and presentation could also be used for a predictive
life cycle software project that develops the product in deliverable increments of functionality (called feature sets
in Figure 5.5).
Feature
Set 1
Time
Q4
Plan
Feature
Set 2
Feature
Set 3
Feature
Set 1
Q4
Plan
Q3
Plan
Feature
Set 2
Feature
Set 3
Feature
Set 4
Q4
Plan
Feature
Set 2
Feature
Set 3
Figure 5-5. Rolling Wave Elaboration of an Adaptive Life Cycle Software Project
Feature
Set 1
78 ©2013 Project Management Institute. Software Extension to the PMBOK® Guide Fifth Edition
Feature
Set 4
Feature
Set 1
Feature
Set 2
Feature
Set 3
Feature
Set 4
Incr. 1 Incr. 1 Incr. 1 Incr. 1
Incr. 2 Incr. 2 Incr. 2 Incr. 2
Incr. 3 Incr. 3 Incr. 3
Incr. 4 Incr. 4
Incr. 1 Incr. 1 Incr. 1 Incr. 1
Incr. 2 Incr. 2 Incr. 2
Incr. 3 Incr. 3 Incr. 3
Incr. 4 Incr. 4
Incr. 1 Incr. 1 Incr. 1
Incr. 2 Incr. 2 Incr. 2
Incr. 3 Incr. 3
Incr. 4
Incr. 1 Incr. 1
Incr. 2 Incr. 2
Incr. 3
Incr. 4
DETAILED PLANNING FOR THE NEXT QUARTER
Q1
Q2
Plan
Q2 Q3 Q4
Q3
Plan
Q2
Plan
Q3
Plan
Q4
Plan

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5.4.3 Create WBS: Outputs
The outputs for creating a WBS in Section 5.4.3 of the PMBOK® Guide are equally applicable outputs from
creating an activity-oriented software WBS.
5.4.3.1 Scope Baseline
See Section 5.4.3.1 of the PMBOK® Guide.
5.4.3.2 Project Documents Updates
See Section 5.4.3.2 of the PMBOK® Guide.