See SHWTSC1 in the SAS/QC Sample LibraryIf a test is signaled at a particular point, the point is labeled by default with the index of the test, as illustrated in Figure 17.179.[98] You can use the TESTLABEL= option to specify a variable in the input data set whose values provide the labels, as illustrated by the following statements:
ods graphics on; title 'Analysis of Assembly Data'; proc shewhart history=Assembly; xrchart Offset * Sample / mu0 = 20 sigma0 = 2.24 limitn = 5 alln tests = 1 to 4 testlabel = ( comment ) vaxis = 16 to 24 by 2 split = '/' markers; label OffsetX = 'Avg Offset in cm/Range'; run;
The labels are shown in Figure 17.182. It is often helpful to specify a variable with the TESTLABEL= option that provides operator comments or other information that can aid in the identification of special causes.
Figure 17.182: Labeling Points with a TESTLABEL= Variable
[98] If two or more tests are positive at a particular point, the default label identifies the index of the test that was specified first with the TESTS= option.