Definition
A failure cause is the specific circumstance, defect, or condition that initiated a failure: contamination, an installation error, an overload, a design weakness. It answers "why" a failure occurred, distinct from the failure mechanism, which explains the physical or chemical process by which that cause led to degradation.
Key facts
- Answers "why" a failure happened: the initiating circumstance or defect, not the physical process that followed.
- Often layered: an immediate cause (e.g., contamination) can itself have a root cause (e.g., a seal design flaw), which root cause analysis is built to separate.
- Distinct from failure mechanism, which describes how the cause physically degraded the component (fatigue, corrosion, wear).
- Confirmed causes should be evidence-based (measured, observed, or tested) not assumed from a similar past event.
What does Failure cause reveal about failures?
A failure cause identifies the specific circumstance that set a failure in motion (a contaminant entering a system, an incorrect installation torque, an unexpected overload, a material defect) established through evidence rather than assumption.
How do teams use Failure cause in failure analysis?
Failure cause explains why the failure started; failure mechanism explains the physical or chemical process that carried it forward (such as fatigue or corrosion); failure mode describes the way the function actually stopped working. The three describe different links in the same chain: cause triggers mechanism, mechanism produces mode.
FAQ
Frequently asked questions
Why did a specific failure occur?
The failure cause identifies the specific circumstance or defect (such as contamination, an installation error, or an overload) that initiated the failure, established through evidence rather than assumption.
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