Sometimes there are multiple causes of failure in a system. For example, suppose that a manufacturing process has several stages and the failure of any stage causes a failure of the whole system. If the different causes are independent, the failure times can be modeled by an estimation of the survival distribution for each cause. A censored estimation is undertaken for a given cause by treating all the event times that are not from that cause as censored observations.
The Competing Causes red triangle menu contains the following options:
Omit Causes
Removes the specified cause value and recalculates the survival estimates.
Save Cause Coordinates
Adds a new column to the current table called log(–log(Surv)). This information is often used to plot against the time variable with a grouping variable, such as the code for type of failure.
Weibull Lines
Adds Weibull lines to the plot.
Hazard Plot
Adds a Hazard Plot.
Simulate
Creates a new data table containing time and cause information from the Weibull distribution, as estimated by the data.