Common Engineering Probability Distributions
A concise reference for the normal, lognormal, Weibull, extreme-value, uniform and triangular distributions — parameters, range and typical engineering applications.
Distribution summary
| Distribution | Parameters | Range | Typical use |
|---|---|---|---|
| Normal | mu, sigma | (-inf, +inf) | Tolerances, measurement error, symmetric variables |
| Lognormal | mu_ln, sigma_ln | (0, +inf) | Fatigue life, positive skewed variables |
| Weibull | k, lambda | (0, +inf) | Strength, life, failure statistics |
| Extreme value | loc, scale | Depends on type | Max/min loads, return levels |
| Uniform | a, b | [a, b] | Limited data, bounded uncertainty |
| Triangular | a, b, c | [a, b] | Expert judgement with most-likely value |