Organizational Breakdown Structure (OBS)
A tree-structured view of the project organization that shows how specific work items are assigned to the organizational units responsible for doing them.
Key Points
- Displays the project's organizational units in a hierarchy and how they relate to the work.
- Maps WBS elements or activities to departments, teams, or roles that will perform the work.
- Supports creation of a responsibility assignment matrix (RAM/RACI) and resource planning.
- Clarifies accountability, reporting lines, and coordination across functional groups.
Example
On an ERP implementation, the OBS lists the PMO at the top, with Functional Finance, Supply Chain, Data Migration, QA, and Training teams beneath. WBS work packages such as "Configure GL," "Convert legacy data," and "User training" are linked to the Finance, Data Migration, and Training teams, respectively, showing who is responsible for each package.
PMP Example Question
Which artifact provides a hierarchical view that links project activities to the organizational units responsible for executing them?
- Work Breakdown Structure (WBS)
- Organizational Breakdown Structure (OBS)
- Resource Breakdown Structure (RBS)
- Responsibility Assignment Matrix (RAM)
Correct Answer: B - Organizational Breakdown Structure
Explanation: The OBS shows the project organization and maps work to performing units. The WBS decomposes deliverables, the RBS categorizes resources, and the RAM cross-references WBS and OBS to assign responsibilities.
