The RELIABILITY Procedure

construct probability plots and fitted life distributions with left-censored, right-censored, and interval-censored lifetime data

fit regression models, including accelerated life test models, to combinations of left-censored, right-censored, and interval-censored data

analyze recurrence data from repairable systems

probability plotting and parameter estimation for the common life distributions: Weibull, three-parameter Weibull, exponential, extreme value, normal, lognormal, logistic, and log-logistic. The data can be complete, right censored, or interval censored.

maximum likelihood estimates of distribution parameters, percentiles, and reliability functions

both asymptotic normal and likelihood ratio confidence intervals for distribution parameters and percentiles. Asymptotic normal confidence intervals for the reliability function are also available.

estimation of distribution parameters by least squares fitting to the probability plot

Weibayes analysis, where there are no failures and where the data analyst specifies a value for the Weibull shape parameter

estimates of the resulting distribution when specified failure modes are eliminated

plots of the data and the fitted relation for life versus stress in the analysis of accelerated life test data

fitting of regression models to life data, where the life distribution location parameter is a linear function of covariates. The fitting yields maximum likelihood estimates of parameters of a regression model with a Weibull, exponential, extreme value, normal, lognormal, logistic and log-logistic, or generalized gamma distribution. The data can be complete, right censored, left censored, or interval censored. For example, accelerated life test data can be modeled with such a regression model.

nonparametric estimates and plots of the mean cumulative function for cost or number of recurrences and associated confidence intervals from data with exact or interval recurrence ages

maximum likelihood estimation of the parameters of parametric models for recurrent events data

horizontal plots of failure times for recurrent events data

You can construct probability plots of life data with the CAPABILITY procedure; however, the CAPABILITY procedure is intended for process capability analysis rather than reliability analysis, and the data must be complete (that is, uncensored).

The LIFEREG procedure fits regression models with life distributions such as the Weibull, lognormal, and log-logistic to left-, right-, and interval-censored data. The RELIABILITY procedure fits the same distributions and regression models as the LIFEREG procedure and, in addition, provides a graphical display of life data in probability plots.