The hazard function provides a measure of the likelihood of failure as a function of how long a unit has survived. The empirical hazard function always results in an increasing function and therefore it assumes that the likelihood of failure increases as a function of age.

When you do not select a distribution (when you choose to perform a nonparametric analysis), the hazard plot is a step function with steps at the exact failure times.

When you hold your pointer over each step, Minitab displays the hazard rate and failure time.

## Interpretation

For the engine windings data, a hazard function for each temperature variable is shown on the hazard plot. The hazard function for 100° C shows a greater likelihood of failure for engine windings at all times. At a time of 45 hours, the rate of failure at 100° C is 0.0625 (6.25%), and the rate of failure at 80° C is 0.0250 (2.50)%.