Quality and Reliability Methods - SAS

214 Lifetime Distribution Chapter 13
The Life Distribution Report Window
Figure 13.5 Event Plot for Mixed-Censored Data
failure (top line)
interval censored
(next two lines)
right censored (middle
two lines)
left censored (bottom
two lines)
In the Event Plot, the dots represent time measurements. The
was removed from observation.
Other line styles indicate the type of censored data.
line indicates that the unit failed and
Right-Censored Values
indicates that the unit did not fail during the study. The unit will fail in the future, but you do
not know when.
In the data table, right-censored values have one time value and a censor value or two time values.
Left-Censored Values
indicates that the unit failed during the study, but you do not know when (for example, a unit
stopped working before inspection).
In a data table, left-censored values have two time values; the left value is missing, the right value is the end
time.
Interval-Censored Values
indicates that observations were recorded at regular intervals until the unit failed. The
failure could have occurred any time after the last observation was recorded. Interval censoring narrows
down the failure time, but left censoring only tells you that the unit failed.
Figure 13.6 shows the data table for mixed-censored data.