Worked Example: Worked Mathematical Example: Weibull Reliability & B10 Life
Model infant mortality (β<1), random failure (β=1), and wear-out (β>1) Weibull reliability.
- Specify the function parameters, matrix entries, or confusion matrix counts.
- Apply the closed-form or iterative formula: R(t) = exp( −(t / η)^β ); h(t) = (β / η) × (t / η)^(β − 1); B10_Life = η × (−ln(0.90))^(1/β).
- Examine the primary result, error bounds, and 3 interactive SVG plots.
Result: Computes Weibull Reliability & B10 Life via R(t) = exp( −(t / η)^β ); h(t) = (β / η) × (t / η)^(β − 1); B10_Life = η × (−ln(0.90))^(1/β).
Mathematics & Statistics · Probability Distributions & Survival Analysis
Weibull Reliability R(t) = exp(−(t/η)^β), Hazard Rate h(t) & B10 Life Calculator: inputs, method, and how to read the result
Model infant mortality (β<1), random failure (β=1), and wear-out (β>1) Weibull reliability.
Choose inputs for the case you are checking
The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.
- Shape Parameter Beta: Weibull shape slope β (<1 infant mortality, 1.0 constant hazard, >1 wear-out).
- Scale Characteristic Life Eta: Characteristic life scale parameter η (time at which 63.2% have failed).
- Mission Operating Time T: Target operating mission time t.
What the calculation includes
With the default values shown, Weibull Survival Reliability R(2500) is 80.442 %. The calculation follows Weibull Reliability & B10 Life Formula; the formula and variable definitions above show how the inputs combine.
One-input check: With the other defaults held constant, changing Shape Parameter Beta from 2.2 β to 2.42 β changes Weibull Survival Reliability R(2500) from 80.442 % to 82.956 %. This is a comparison inside the calculator's stated model, not a prediction.
Where to use caution
- Uses exact analytical or standard numerical analysis formulations from NIST DLMF.
- Double-precision floating-point arithmetic has ~15–17 significant decimal digits of precision.
Scope: Global Mathematical & Statistical Standard Check the assumptions and limitations against your situation before relying on the estimate.
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