Organizational Breakdown Structure (OBS)
EVM Terms
Reviewed by forProject Technology - updated Sep 2026
Quick definition: The Organizational Breakdown Structure (OBS) is the organizational structure — including major subcontractors — responsible for accomplishing a project's authorized work.
The OBS can be viewed two ways: by Responsible Organization, the unit assigned responsibility for specific tasks, or by Performing Organization, the unit that actually applies resources to do the work. Together with the Work Breakdown Structure, it forms one axis of the Responsibility Assignment Matrix.
Why it matters
The OBS is what ties cost and schedule accountability to real people and departments. Without it, a Control Account has no clear owner answerable for its budget and its performance, and the Responsibility Assignment Matrix has nothing to map the work against.
Also known as
N/A
Used in
Responsibility Assignment Matrix
See also
FAQ
What's the difference between Responsible Organization and Performing Organization?
Responsible Organization is the unit assigned accountability for a task; Performing Organization is the unit that actually applies resources to do the work — they're often, but not always, the same group.
How does the OBS relate to the Work Breakdown Structure?
The OBS and WBS are combined in the Responsibility Assignment Matrix, which maps each WBS element to the organization accountable for it.
Definition maintained by forProject Technology.
© 2026 forProject Technology, Inc.
© 2026 forProject Technology, Inc.
