Hazard Plotting for Incomplete Failure Data

Summary: Incomplete failure data consisting of times to failure on failed units and differing running times or unfailed units are called multiply censored. Data on units operating in the field, for example, are usually multiply censored. Presented in this paper is a method of plotting multiply censored data on hazard paper to obtain engineering information on the distribution of time to failure. Step-by-step instructions on how to plot and interpret data on hazard paper are given with the aid of examples based on real and simulated data. Hazard paper is presented here for the exponential, Weibull, normal, log normal, and extreme value distributions. The theory underlying hazard paper and plotting is presented in an appendix.