Glossary · Maintenance and diagnostics
Failure cause
Also known as: Cause of failure
German: Ausfallursache
In dependability engineering, a failure cause is the set of circumstances that leads to a failure. It can originate in specification, design, manufacture, installation, operation or maintenance.
- Maintenance
In one sentence
A failure cause is the set of circumstances that leads to a failure, arising in design, manufacture, installation, operation or maintenance.
Example
A proximity switch failed because its cable was routed over a sharp edge; the failure cause lies in the installation, not in the switch itself.
How it applies
- Engineering: In an Failure Modes and Effects Analysis (FMEA), each Failure mode is linked to its possible failure causes, which then drive design or process measures.
- Maintenance: Recording the actual cause, not just the replaced part, makes maintenance data useful for improving reliability.
- Analysis: A Root-cause analysis traces a failure back through contributing causes to the ones that can be removed.
- Documentation: Troubleshooting tables in manuals list causes for each symptom. The documentation team should phrase causes as conditions the reader can check, and keep cause, symptom and remedy in separate fields.
Failure cause vs. failure mode
The Failure mode describes how an item fails (for example "contact does not open"). The failure cause explains why it failed (for example "contact welded by overcurrent"). Mixing the two in one column is a common weakness in FMEA worksheets and troubleshooting tables.