The Weibull hazard rate is equivalent to the failure rate at a point along the hazard rate curve. This computation assumes that the failure rate (or hazard rate) is constant when evaluated at time t. This allows this failure rate to be added to other failure rates. The failure rate equation for the Weibull hazard rate method is:

Where:

β = The shape parameter.

η = The characteristic life parameter, which is also known as the scale parameter.

t = The minimum life parameter, which is also known as the failure-free time or location parameter.

t0 = The time at which to evaluate the hazard rate.