WBS - Work Breakdown Structure

Revision as of 12:20, 17 February 2023

Author: Manuela Vazquez, s222648

Abstract

The International Organization for Standardization (ISO) defines the Work Breakdown Structure (WBS) as a “decomposition of the defined scope of a project or programme into progressively lower levels consisting of elements of work” ^[1]. It represents all the deliverables to be produced by the project or program for which work activities will be defined, planned, and executed ^[2]. No matter whether the project solution will result in a physical product, service, or process, all can be defined from the deliverables’ perspective. Therefore, the WBS is a key component in the project planning process, regardless of industry or discipline. Failing to do an appropriate WBS can result in rework, schedule changes, poorly distributed resources, and budget increases ^[3].

The present article first summarizes the different definitions of the WBS and references the current standards which directly address it. The history of its origin and development are also presented. In addition, the key attributes of the WBS are described, as well as the aspects that need to be considered when creating and evaluating the tool. The different possible visualizations for the WBS are presented, along with an extensive example of its application. Furthermore, the limitations of the WBS will be explored, as well as other complementary and related tools, such as the Organizational Breakdown Structures (OBS). Finally, additional bibliography is recommended for readers who want to learn more about the topic.

Definition and use

The WBS is a hierarchical decomposition in which the project or programme scope is divided into successively smaller work breakdown structure elements to be carried out by the project team ^[4]. ISO 21511 standard provides guidance on the use of this tool for those involved in developing and using it, and complements ISO 21500 and ISO 21504.

• ISO 21511:2018 Work breakdown structures for project and programme management
• ISO 21500:2021 Project, programme and portfolio management — Context and concepts
• ISO 21504:2022 Project, programme and portfolio management — Guidance on portfolio management

In addition, the Project Management Institute (PMI) released the third edition of the "Practice Standard for Work Breakdown Structures" in 2019. As explained by the PMI, "this practice standard aligns with other recent PMI standards, including A Guide to the Project Management Body of Knowledge (PMBOK® Guide) – Sixth Edition, providing practitioners with an indispensible tool to consistently track schedule, budget, risk and performance, regardless of discipline" ^[5].

History

Origin and development of the tool, retrieved from “Getting Started with Work Breakdown Structures (WBS)”. ^[6]

Key attributes

• It is “deliverable orientated”.
• It is hierarchical
• The 100% Rule (Haugan, 2002, p 17)
• Develop them down to a level of detail using the 8 to 80 rule
• Can be represented in a variety of ways

How to create a WBS

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How to evaluate a WBS

Different visualizations of WBS

Outline

Hierarchical Structure

Tabular Structure

Tree Structure

Example

Limitations

Related Tools

• Functional breakdown
• Organizational breakdown structures (OBS)
• Risk breakdown structure (RBS)
• Product breakdown structure (PBS)

Annotated bibliography

Good resources on WBS include:

• “The ABC Basics of the WBS” by Paul Burek, 2013
• “The Intelligent Structure of Work Breakdowns Is a Precursor to Effective Project Management”, Homer & Gunn, 1995
• “Practice Standard for Work Breakdown Structures”, Third Edition, 2019
• ISO 21511:2018, "Work breakdown structures for project and programme management"
• ISO 21502:2020, "Project, programme and portfolio management — Guidance on project management"

References

1. ↑ ISO/TR 21506:2018, Project, programme and portfolio management – Vocabulary(Committee: ISO/TC 258)
2. ↑ Burek, P. (2013), The ABC basics of the WBS. Paper presented at PMI® Global Congress 2013—North America, New Orleans, LA. Newtown Square, PA: Project Management Institute.
3. ↑ Jones, C. (2007). Creating an effective WBS with facilitated team involvement. Paper presented at PMI® Global Congress 2007—North America, Atlanta, GA. Newtown Square, PA: Project Management Institute.
4. ↑ ISO 21511:2018, Work breakdown structures for project and programme management (Committee: ISO/TC 258)
5. ↑ Practice Standard for Work Breakdown Structures – Third Edition (2019)(retrieved from: https://www.pmi.org/pmbok-guide-standards/framework/practice-standard-work-breakdown-structures-3rd-edition#)
6. ↑ Kate Eby, Getting Started with Work Breakdown Structures (WBS), (Retrieved on 11. February 2023 from https://www.smartsheet.com/getting-started-work-breakdown-structures-wbs).
7. ↑ ref name="NASA">, NASA, NASA Work Breakdown Structure (WBS) Handbook, January 2010, NASA/SP-2010-3404
8. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named NASA