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XSCHART Statement |
Variable | Description |
_ALPHA_ | probability () of exceeding limits |
_CP_ | capability index C_{p} |
_CPK_ | capability index C_{pk} |
_CPL_ | capability index CPL |
_CPM_ | capability index C_{pm} |
_CPU_ | capability index CPU |
_INDEX_ | optional identifier for the control limits specified with the OUTINDEX= option |
_LCLS_ | lower control limit for subgroup standard deviation |
_LCLX_ | lower control limit for subgroup mean |
_LIMITN_ | nominal sample size associated with the control limits |
_LSL_ | lower specification limit |
_MEAN_ | process mean ( or ) |
_S_ | value of central line on s chart |
_SIGMAS_ | multiple (k) of standard error of or s_{i} |
_STDDEV_ | process standard deviation ( or ) |
_SUBGRP_ | subgroup-variable specified in the XSCHART statement |
_TARGET_ | target value |
_TYPE_ | type (estimate or standard value) of _MEAN_ and _STDDEV_ |
_UCLS_ | upper control limit for subgroup standard deviation |
_UCLX_ | upper control limit for subgroup mean |
_USL_ | upper specification limit |
_VAR_ | process specified in the XSCHART statement |
Notes:
The OUTLIMITS= data set contains one observation for each process specified in the XSCHART statement. For an example, see "Saving Control Limits" .
Given a process name that contains eight characters, the procedure first shortens the name to its first four characters and its last three characters, and then it adds the suffix. For example, the procedure shortens the process DIAMETER to DIAMTER before adding the suffix.
Subgroup summary variables
are created for each process specified in the
XSCHART statement. For example, consider the following statements:
proc shewhart data=steel; xschart (width diameter)*lot / outhistory=summary; run;
The data set SUMMARY contains variables
named LOT, WIDTHX, WIDTHS, WIDTHN, DIAMTERX, DIAMTERS,
and DIAMTERN.
Additionally, the following variables, if specified, are included:
For an example of an OUTHISTORY= data set, see "Saving Summary Statistics" .
Variable | Description |
_ALPHA_ | probability () of exceeding control limits |
_EXLIM_ | control limit exceeded on chart |
_EXLIMS_ | control limit exceeded on s chart |
_LCLS_ | lower control limit for standard deviation |
_LCLX_ | lower control limit for mean |
_LIMITN_ | nominal sample size associated with the control limits |
_MEAN_ | process mean |
_S_ | average standard deviation |
_SIGMAS_ | multiple (k) of the standard error associated with control limits |
subgroup | values of the subgroup variable |
_SUBN_ | subgroup sample size |
_SUBS_ | subgroup standard deviation |
_SUBX_ | subgroup mean |
_TESTS_ | tests for special causes signaled on chart |
_TESTS2_ | tests for special causes signaled on s chart |
_UCLS_ | upper control limit for standard deviation |
_UCLX_ | upper control limit for mean |
_VAR_ | process specified in the XSCHART statement |
In addition, the following variables, if specified, are included:
Notes:
For an example, see "Saving Control Limits" .
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