KEVOS® MAKEOS · Maintenance
Weibull Reliability and B10 Life
What is the probability this component survives to a given time, and what are its B10 life and MTTF?
Reliability, probability of failure, hazard rate, B10 life and mean time to failure from Weibull shape and scale parameters, for a mission or maintenance interval.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Shape parameter β | Shape from a Weibull analysis of failure data (below 1: early failures; 1: random; above 1: wear-out). | |
| Scale parameter η (characteristic life) | h | Characteristic life: the time by which 63.2% have failed. |
| Mission time or interval | h | Operating time or maintenance interval to evaluate. |
Method and formulas
- R(t) = exp(−(t ÷ η)^β); F = 1 − R.
- Hazard h(t) = (β ÷ η)(t ÷ η)^(β − 1).
- B10 = η (−ln 0.9)^(1/β); MTTF = η Γ(1 + 1/β).
- Example: β 2, η 10000 h: reliability at 2000 h is 96.079%, B10 life 3,245.9 h.
Limitations
- Two-parameter Weibull (no failure-free period); parameters must come from relevant failure data.
- Preventive replacement only helps when β > 1 (wear-out).
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Set preventive maintenance intervals from failure data
- Estimate spares demand
- Explain wear-out versus random failures
Who it is for
- Maintenance engineers
- Reliability engineers
- Maintenance technicians
What you get
- Reliability at time t
- Probability of failure
- Hazard rate
- B10 life and MTTF
Interpreting the result
- With β ≤ 1, scheduled replacement does not reduce failures; use condition monitoring instead.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 128–133. Topic reference; no source tables or recommended settings are reproduced.
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