# Comparing and Weighting Two Weibull Models

Comparing and Weighting Two Weibull Models

The Weibull model is widely used for estimating the reliability of engineering materials. More reliable parts tend to last longer (i.e. have a large time before failure). Estimates of Weibull model parameters can be achieved by using a least squares method to fit a straight line on a logarithmic plot. This Demonstration describes a method for comparing two Weibull models for reliability via weight measures. The PDFs or CDFs are plotted.

The weight functions measure a combination of failure time and failure probability. For a chosen weight function, larger weight values indicate higher reliability of the material whose failure time follows that Weibull distribution.