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Quality and Reliability Methods - SAS

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Chapter 19<br />

<strong>Reliability</strong> <strong>and</strong> Survival Analysis<br />

Univariate Survival<br />

Survival data contain duration times until the occurrence of a specific event <strong>and</strong> are sometimes referred to as<br />

event-time response data. The event is usually failure, such as the failure of an engine or death of a patient. If<br />

the event does not occur before the end of a study for an observation, the observation is said to be censored.<br />

The <strong>Reliability</strong> <strong>and</strong> Survival menu includes several types of survival analysis.<br />

This chapter focuses on univariate survival, the Survival item on the <strong>Reliability</strong> <strong>and</strong> Survival menu.<br />

Survival calculates estimates of survival functions using the product-limit (Kaplan-Meier) method for one<br />

or more groups of either right-censored or complete data. (Complete data have no censored values.) This<br />

platform gives an overlay plot of the estimated survival function for each group <strong>and</strong> for the whole sample.<br />

JMP also computes the log rank <strong>and</strong> Wilcoxon statistics to test homogeneity between groups. Diagnostic<br />

plots <strong>and</strong> fitting options are available for exponential, Weibull, <strong>and</strong> lognormal survival distributions. An<br />

analysis of competing causes for the Weibull model is also available. Interval censoring is supported by<br />

Turnbull estimates.<br />

Life Distribution, Fit Life by X, <strong>and</strong> Recurrence Analysis are discussed in the following chapters: “Lifetime<br />

Distribution” on page 207, the “Lifetime Distribution II” on page 237, <strong>and</strong> “Recurrence Analysis” on<br />

page 261. The “<strong>Reliability</strong> <strong>and</strong> Survival Analysis II” chapter on page 371 gives details of both Fit Parametric<br />

Survival <strong>and</strong> Fit Proportional Hazards.

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