Weibull++'s Accelerated Life Testing module allows users to perform a degradation analysis using the linear, exponential, power, logarithmic, Gompertz and Lloyd-Lipow models. The equations for these models are listed below:

- Linear:
*y *=* a*·*x*+*b*
- Exponential:
*y *=* b*·*e*^{a·x}
- Power:
*y* = *b*·*x*^{a}
- Logarithmic:
*y* = *a*·ln(*x*)+*b*
- Gompertz:
*y* = *a*+*b*^{c·x}
- Lloyd-Lipow:
*y* = *a*-*b*/*x*

where *y* is the degradation measurement, *x* is the inspection time and *a*, *b* and *c* are model parameters.

These models can be used to predict when the degradation of a given unit will reach the predefined failure level. The predicted time can then be treated as the failure time. Once the model parameters are estimated for each test sample, *x*_{i} can be extrapolated using the defined critical value of *y*. The computed *x*_{i}s from all the units can then be used as failure times for subsequent accelerated life data analysis.