Overview
The UCHART statement creates u charts
for the numbers of nonconformities (defects) per inspection unit
in subgroup samples containing arbitrary numbers of units.
You can use options in the UCHART statement to
- specify the number of inspection units per subgroup
- compute control limits from the data based on a multiple of
the standard error of the plotted values or
as probability limits
- tabulate subgroup summary statistics and
control limits
- save control limits in an output data set
- save subgroup summary statistics
in an output data set
- read preestablished control limits from a data set
- apply tests for special causes (also known as runs tests and
Western Electric rules)
- specify a known (standard) value for the average
number of nonconformities per inspection unit
- display distinct sets of control limits for data from
successive time phases
- add block legends and symbol markers to reveal
stratification in process data
- superimpose stars at points to
represent related multivariate factors
- clip extreme points to make the chart more readable
- display vertical and horizontal reference lines
- control axis values and labels
- control layout and appearance of the chart
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
