HKSM
Risk Breakdown Structure (RBS)
A layered structure that organizes possible sources of project risk into categories and subcategories.
Key Points
- Shows risk sources in a tree from broad categories to detailed subcategories.
- Used during risk identification and planning to improve coverage and reduce blind spots.
- Enables aggregation of risk exposure and assignment of ownership by category.
- Can be customized and aligned with the WBS/OBS to support reporting and lessons learned.
Example
On a construction project, the team builds an RBS with top-level categories: Technical, External, Organizational, and Project Management. Under Technical they list items like design errors, material quality, and equipment failure; under External they include weather and regulatory changes. They brainstorm risks and tag each one to the RBS branch, ensuring complete coverage and allowing roll-up of exposure by category for reporting.
PMP Example Question
During qualitative risk analysis, the project manager wants to group identified risks and roll up exposure by source to focus response planning. Which artifact should the team use?
- Work Breakdown Structure
- Risk Breakdown Structure
- Risk Register
- Stakeholder Breakdown Structure
Correct Answer: B — Risk Breakdown Structure
Explanation: The RBS organizes risks by source, enabling grouping and roll-up. The WBS decomposes scope, the risk register lists risks, and the stakeholder breakdown structure categorizes stakeholders.
