---
ref_id: REF-18
ref_type: Companion
ref_index: 18
shortcode: WBS-3E
name: Practice Standard for Work Breakdown Structures (3rd ed.)
status: Active
version: "1.0.0"
file_path: "reference/companion-references/REF-18.md"
pmbok8_source: "PMBOK8 Guide §2.2.2.4 (Develop Scope Structure) · §2.2.2.3 (Define Scope)"
last_updated: "2026-06-03"
---

# REF-18 — Practice Standard for Work Breakdown Structures (3rd ed.)
**Shortcode:** WBS-3E  
**Publisher:** Project Management Institute (PMI), 2019  
**Authority:** PMBOK8 Companion — WBS Design and Decomposition  
**Version:** 1.0.0 · **Status:** Active

## Full Bibliographic Citation
Project Management Institute. (2019). *Practice Standard for Work Breakdown Structures* (3rd ed.). Project Management Institute. Official release: https://www.pmi.org/standards/work-breakdown-structures-third-edition

## What This Reference Adds Beyond PMBOK 8
The WBS Standard provides the complete technical and practical guidance for developing, validating, and using Work Breakdown Structures. It defines WBS construction rules (the 100% rule, mutually exclusive work packages, decomposition depth guidance), WBS dictionary requirements, and industry-specific WBS examples. It is the definitive reference for scope decomposition — the foundation of all scope, schedule, and cost baseline integration.

## PMBOK 8 Domain and Principle Coverage

| PMBOK 8 Element | WBS-3E Contribution |
|---|---|
| Scope Performance Domain — Develop Scope Structure (§2.2.2.4) | WBS construction rules, decomposition techniques, and quality criteria |
| Schedule Performance Domain (§2.3) | WBS work packages as the foundation for activity definition and scheduling |
| Finance Performance Domain (§2.4) | WBS as the basis for cost account structure and bottom-up estimating |

## PMOSkills Artifact and Skill Connections

| Item | Connection |
|---|---|
| A08 — Scope and Requirements Decision Record | WBS-3E decomposition model informs scope structure in A08 |
| SKL-03-05 — Define Scope | WBS construction rules from this standard are applied in this skill |

---
*Authority: PMI Practice Standard for WBS 3rd ed. (2019) · PMBOK8 §2.2.2.3, §2.2.2.4*  
*Repository: https://github.com/fakhruldeen/PMOSkills*
