Life-data analysis · probability plot · B-life & mission reliability
F(t) = 1 − e−(t/η)β· R(t) = e−(t/η)β
x = ln(t), y = ln(ln(1/(1−F)))· Default fit: MLE when censored data exists, otherwise regression.
Fit failure data to a Weibull distribution — supports censored (suspended) data, multiple datasets, and confidence bounds.
Use Load sample or + Add dataset above to get started.
Weibull analysis fits failure data to a distribution defined by a shape parameter β and a characteristic life η. The reliability at time t is:
The shape parameter tells you the failure mode: β < 1 is infant mortality (early failures), β ≈ 1 is random failure, and β > 1 is wear-out.
Example: For η = 10,000 h and β = 2, the B10 life (time at which 10% have failed) is about 3,250 h, the mean life (MTTF) is about 8,860 h, and reliability at 5,000 h is about 0.78. The calculator reports β, η, B-life, MTTF, and reliability at any time, and supports censored (suspended) data.
Use this to turn field or test failure data into quantitative life predictions and to distinguish infant mortality from wear-out. Pair it with the Sample Size calculator when planning the test that generates the data.