Common Mode Failure
A common mode failure occurs when multiple similar components fail in the same manner because they share a design, operating, manufacturing, or maintenance vulnerability.
What this term means in maintenance
A common mode failure occurs when multiple similar components fail in the same manner because they share a design, operating, manufacturing, or maintenance vulnerability.
Examples
Common mode failure may arise from:
- Same component design
- Same material weakness
- Same incorrect setting
- Same software version
- Same installation method
- Same environmental exposure
- Same maintenance procedure
Practical example
Several identical transmitters drift because one model has the same temperature-related design weakness.
Common mode versus common cause
Common mode emphasizes similar failure behavior.
Common cause emphasizes the shared event or condition producing multiple failures.
Controls
Diversity, redesign, qualification, monitoring, and independent review can reduce the risk.
Common mistake
Adding an identical standby component may preserve the same failure vulnerability.
How this term differs
Common Mode Failure is multiple similar components failing in the same manner because of a shared vulnerability. It is related to Common Cause Failure, Single Point of Failure, and Redundancy, but these terms describe different records, measures, roles, strategies, or decisions and should not be used interchangeably.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Common Cause Failure
A common cause failure occurs when one shared cause leads to the failure of two or more components, channels, or redundant systems.
Redundancy
Redundancy is the provision of additional equipment, components, or paths so a required function can continue when one element fails.
Failure Mode
A failure mode describes the specific way an asset, component, or function fails to meet its required performance.
Glossary FAQs
- What is common mode failure?
Multiple similar components failing in the same manner because they share a vulnerability.
- How is it different from common cause failure?
Common mode emphasizes the same failure behavior; common cause emphasizes the shared initiating condition.
- Can identical redundancy be vulnerable?
Yes. Identical components may share design, software, material, and maintenance weaknesses.