SPC Procedure

UCHART Statement

  • UCHART < / options>;

The UCHART statement produces control charts for the numbers of nonconformities per inspection unit in subgroup samples. Table 12 lists the options that you can specify in a UCHART statement. For detailed descriptions of these options, see the section Dictionary of Options.

Table 12: UCHART Statement Options

Option Description
ALLN Includes all subgroups in the analysis, regardless of sample size
EXCHART Produces results only for charts in which exceptions occur
LIMITN= Specifies the nominal sample size for fixed control limits
NO3SIGMACHECK Enables tests for special causes to be applied when control limits other than limits are in effect
NOPRINT Suppresses ODS output
OUTLIMITS= Creates an output data table that contains control limits
OUTTABLE= Creates an output data table that contains subgroup summary statistics and control limits
SIGMAS= Specifies the width of the control limits in terms of a multiple of the standard error of the subgroup summary statistic
SUBGROUPN= Specifies a variable in the input data table that contains subgroup sample sizes
TEST2RUN= Specifies the length of the pattern for Test 2
TEST3RUN= Specifies the length of the pattern for Test 3
TESTNSTD Applies tests for special causes to standardized chart statistics
TESTOVERLAP Performs tests for special causes on overlapping patterns of points
TESTS= Requests tests for special causes for the u chart


Last updated: May 14, 2026