johnson_method: Estimation of Failure Probabilities using Johnson's Method

In weibulltools: Statistical Methods for Life Data Analysis

Description

This non-parametric approach is used to estimate the failure probabilities in terms of uncensored or (multiple) right censored data. Compared to complete data the correction is done by calculating adjusted ranks which takes non-defective units into account.

Usage

johnson_method(x, event, id = rep("XXXXXX", length(x)))

Arguments

x	a numeric vector which consists of lifetime data. Lifetime data could be every characteristic influencing the reliability of a product, e.g. operating time (days/months in service), mileage (km, miles), load cycles.
event	a vector of binary data (0 or 1) indicating whether unit i is a right censored observation (= 0) or a failure (= 1).
id	a character vector for the identification of every unit.

Value

A data frame containing id, lifetime characteristic, status of the unit, the adjusted rank and the estimated failure probability. For right censored observations the cells of the rank and probabilty columns are filled with NA values.

Examples

obs   <- seq(10000, 100000, 10000)
state <- c(0, 1, 1, 0, 0, 0, 1, 0, 1, 0)
uic   <- c("3435", "1203", "958X", "XX71", "abcd", "tz46",
           "fl29", "AX23", "Uy12", "kl1a")

df_john <- johnson_method(x = obs, event = state, id = uic)

Example output

weibulltools documentation built on May 2, 2019, 11:01 a.m.