Use the NENTER statement in conjunction with the FREQ statement to specify interval-censored lifetime data having a special structure; these data are called readout data. The NENTER statement specifies a variable in the input data set that determines the number of unfailed units entering each interval. See the section Weibull Analysis of Interval Data with Common Inspection Schedule for an example that uses the NENTER statement with readout data.

You can also use the NENTER statement in conjunction with the FREQ statement to specify recurrent events data when the event times are grouped into intervals, rather than being observed exactly. The NENTER statement specifies a variable in the input data set that determines the number of units observed in each interval.