Distinguish a failure study from a safety-function claim
- FMEA / FMEDA
FMEA examines failure modes and their effects. FMEDA adds the relevant failure-rate and diagnostic information for the defined analysis.
- SIL / PFDavg / PFHThis term
The measures apply to different stated operating modes of a safety function. SIL is not a standalone material or cable-gland grade.
- Weibull analysis
Fit a statistical model to relevant data with stated assumptions and censoring. An example curve is not a measured life prediction.
Failure-mode analysis follows effects and diagnostics. Safety integrity concerns a defined safety function and operating mode, while Weibull analysis models stated failure-time or strength data.
Conceptual analysis relationships and an illustrative distribution. No SIL level, failure rate, probability estimate or cable-gland functional-safety approval is claimed.