Unknown macro: {div3}

1. Purpose

Topic 7.17 provides guidance on the development of a work breakdown structure (WBS) for software on projects. The WBS provides a common planning framework to use in estimating the scope of a project.

Unknown macro: {div3}

2. Definition

Per the NASA Systems Engineering Handbook ²⁷³(Section 6.1.2.1), a work breakdown structure is a hierarchical breakdown of the work necessary to complete a project. The WBS can be product- or process-oriented. A product-oriented WBS has work activities grouped by the product or service they support. A process-oriented WBS includes in the appropriate WBS element the work activities associated with the processes being used. ³⁸⁹The WBS provides the framework to plan, organize, and control a
project. ³⁸⁸

Excellent information on the development and usage of the WBS can be found in NASA/SP-2010-3404, NASA Work Breakdown Structure (WBS) Handbook. ³⁹⁰Additionally, both the NASA Systems Engineering Handbook ²⁷³and the "CMMI for Development, Guidelines for Process Integration and Product Improvement" ³⁸⁸provide further guidance on the development of WBS structures containing software. The NASA Software Engineering curriculum, especially

<ac:macro ac:name="unmigrated-wiki-markup">
<ac:plain-text-body><![CDATA[

SWE 301

]]></ac:plain-text-body>
</ac:macro>

³⁸⁹, addresses the use of the WBS for software on projects. These resources are cited in the Resources tab of this guidance topic.

Unknown macro: {div3}

3. The Basic WBS

A project's software may be a stand-alone system or exist as part of a larger system or project. For example, for a space flight project, software may be shown under the Avionics subsystem. For both types, the WBS developer needs to be aware of the responsibilities required of his or her project.

The WBS is updated iteratively over the project life cycle . The initial WBS is used for early estimating of cost and schedule. The detailed WBS helps organize and control the work done by populating the project's cost plans and schedule.

A companion WBS dictionary, which is also developed, fully describes the work being done including the title and objective of the element, expected products/services from each element, and the dependencies between elements.

The Software Development Plan ([SWE-102]) is a place to record the WBS of the life cycle processes and activities.

Unknown macro: {div3}

4. Common Issues

There are several work activities that are often forgotten in developing the WBS:

• Process planning and monitoring activities
• Requirement engineering activities
• Formal review activities
• Development activities
• Stakeholder activities
• Training activities
• Planning, documenting, and tracking of commitments from other organizations

Unknown macro: {div3}

5. Resources

5.1 Tools

Tools to aid in compliance with this Topic, if any, may be found in the Tools Library in the NASA Engineering Network (NEN).

NASA users find this in the Tools Library in the Software Processes Across NASA (SPAN) site of the Software Engineering Community in NEN.

The list is informational only and does not represent an “approved tool list”, nor does it represent an endorsement of any particular tool. The purpose is to provide examples of tools being used across the Agency and to help projects and centers decide what tools to consider.