Failure rate reference
Order-of-magnitude failure rates (λ, per hour) for common components, drawn from established generic-data sources. Use these as starting estimates when you don't have field data — then refine with vendor reliability reports or your own warranty returns. All values cited; sources listed at the bottom.
Use as estimates, not authority
Real component λ depends heavily on application stress (temperature, vibration, duty cycle), quality grade and operating environment. Generic-data sources can disagree by an order of magnitude on the same component class. For safety-case work, cite the source you used and document the application factors.
Electronic components
| Component | λ typical (per hour) | λ range | Source |
|---|---|---|---|
| Resistor (metal-film, fixed) | 5×10⁻⁹ | 1×10⁻⁹ to 2×10⁻⁸ | SN 29500-2 |
| Capacitor (ceramic, MLCC) | 2×10⁻⁹ | 5×10⁻¹⁰ to 1×10⁻⁸ | SN 29500-3 |
| Capacitor (electrolytic, aluminium) | 3×10⁻⁸ | 1×10⁻⁸ to 3×10⁻⁷ | SN 29500-3 |
| Diode (signal / rectifier) | 3×10⁻⁹ | 1×10⁻⁹ to 1×10⁻⁸ | IEC 62380 |
| Transistor (small-signal) | 5×10⁻⁹ | 2×10⁻⁹ to 2×10⁻⁸ | IEC 62380 |
| Microcontroller (ARM Cortex-M class) | 5×10⁻⁷ | 1×10⁻⁷ to 2×10⁻⁶ | SN 29500-2 |
| Power MOSFET | 2×10⁻⁸ | 5×10⁻⁹ to 1×10⁻⁷ | SN 29500-2 / IEC 62380 |
| Optocoupler | 1×10⁻⁸ | 5×10⁻⁹ to 5×10⁻⁸ | IEC 62380 |
| Quartz crystal oscillator | 5×10⁻⁸ | 1×10⁻⁸ to 2×10⁻⁷ | IEC 62380 |
| PCB (per joint, double-sided) | 1×10⁻⁹ | 3×10⁻¹⁰ to 5×10⁻⁹ | IEC 62380 |
Electromechanical & sensors
| Component | λ typical (per hour) | λ range | Source |
|---|---|---|---|
| Relay (general-purpose) | 5×10⁻⁷ | 1×10⁻⁷ to 2×10⁻⁶ | NPRD-2016 |
| Solenoid valve (process) | 3×10⁻⁶ | 1×10⁻⁶ to 1×10⁻⁵ | OREDA |
| Pressure transmitter (smart) | 1×10⁻⁶ | 3×10⁻⁷ to 5×10⁻⁶ | OREDA / Exida |
| Temperature sensor (PT100) | 3×10⁻⁷ | 1×10⁻⁷ to 1×10⁻⁶ | OREDA |
| Limit switch | 1×10⁻⁶ | 3×10⁻⁷ to 3×10⁻⁶ | NPRD-2016 |
| Connector (per pin) | 5×10⁻⁹ | 1×10⁻⁹ to 2×10⁻⁸ | IEC 62380 |
| Cable (per metre) | 5×10⁻¹⁰ | 1×10⁻¹⁰ to 5×10⁻⁹ | IEC 62380 |
| DC motor (brushed, small) | 5×10⁻⁶ | 1×10⁻⁶ to 2×10⁻⁵ | NPRD-2016 |
Process & rotating equipment
| Component | λ typical (per hour) | λ range | Source |
|---|---|---|---|
| Centrifugal pump (general service) | 3×10⁻⁵ | 1×10⁻⁵ to 1×10⁻⁴ | OREDA |
| Heat exchanger (shell & tube) | 5×10⁻⁶ | 1×10⁻⁶ to 2×10⁻⁵ | EIReDA |
| Pressure relief valve | 5×10⁻⁶ | 1×10⁻⁶ to 2×10⁻⁵ | OREDA / Exida |
| Motor-operated valve (gate) | 8×10⁻⁶ | 2×10⁻⁶ to 3×10⁻⁵ | OREDA |
| Compressor (rotating, lubricated) | 5×10⁻⁵ | 1×10⁻⁵ to 2×10⁻⁴ | OREDA |
| Pipe (per metre, in-service degradation) | 1×10⁻⁹ | 3×10⁻¹⁰ to 1×10⁻⁸ | PARLOC / EIReDA |
| Flange & gasket joint | 5×10⁻⁷ | 1×10⁻⁷ to 2×10⁻⁶ | PARLOC |
Sources cited
- SN 29500 — Siemens Norm, generic component reliability database widely adopted in automotive ISO 26262 work. Subdivided by component class (SN 29500-2 semiconductors, -3 capacitors, etc.).
- IEC 62380 — international standard derived from the French RDF 2000 / UTE C 80-810. Component-class λ with stress/temperature factors. Often used in aerospace.
- OREDA — Offshore and Onshore Reliability Data, oil & gas industry collaborative database. The reference for process equipment.
- NPRD-2016 — Nonelectronic Parts Reliability Data, Quanterion / RIAC publication; broad coverage of mechanical and electromechanical parts.
- EIReDA — European Industry Reliability Data; nuclear and chemical-industry equipment focus.
- PARLOC — Pipeline And Riser Loss of Containment study; UK HSE-funded source for pipeline failure rates.
- Exida — proprietary SIS-focused database; often cited alongside OREDA in IEC 61511 studies.
Most sources publish more than just λ — they also give stress/environment correction factors, demand-mode probabilities, and dangerous-undetected (λ_DU) breakdowns for SIS work. Consult the original source rather than relying solely on this summary.