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MCHART 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 |
_LCLM_ | lower control limit for subgroup median |
_LCLR_ | lower control limit for subgroup range |
_LCLS_ | lower control limit for subgroup standard deviation |
_LIMITN_ | sample size associated with the control limits |
_LSL_ | lower specification limit |
_MEAN_ | value of central line on median chart (,, , or ) |
_R_ | value of central line on R chart |
_S_ | value of central line on s chart |
_SIGMAS_ | multiple (k) of standard error of M_{i} |
_STDDEV_ | process standard deviation ( or ) |
_SUBGRP_ | subgroup-variable specified in the MCHART statement |
_TARGET_ | target value |
_TYPE_ | type (estimate or standard value) of _MEAN_ and _STDDEV_ |
_UCLM_ | upper control limit for subgroup median |
_UCLR_ | upper control limit for subgroup range |
_UCLS_ | upper control limit for subgroup standard deviation |
_USL_ | upper specification limit |
_VAR_ | process specified in the MCHART statement |
The OUTLIMITS= data set contains one observation for each process specified in the MCHART statement. For an example, see "Saving Control Limits" .
A subgroup standard deviation variable is included if you specify the STDDEVIATIONS option; otherwise, a subgroup range variable is included.
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.
Variables containing subgroup summary statistics are created for each process specified in the MCHART statement. For example, consider the following statements:
proc shewhart data=steel; mchart (width diameter)*lot / outhistory=summary; run;
The data set SUMMARY contains variables named LOT, WIDTHM, WIDTHR, WIDTHN, DIAMTERM, DIAMTERR, and DIAMTERN. The variables WIDTHR and DIAMTERR are included, since the STDDEVIATIONS option is not specified. If you specified the STDDEVIATIONS option, the data set SUMMARY would contain WIDTHS and DIAMTERS rather than WIDTHR and DIAMTERR.
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 median chart |
_LCLM_ | lower control limit for median |
_LIMITN_ | nominal sample size associated with the control limits |
_MEAN_ | estimate of process mean (, ,, or ) |
_SIGMAS_ | multiple (k) of the standard error associated with control limits |
subgroup | values of the subgroup variable |
_SUBMED_ | subgroup median |
_SUBN_ | subgroup sample size |
_TESTS_ | tests for special causes signaled on median chart |
_UCLM_ | upper control limit for median |
_VAR_ | process specified in the MCHART statement |
In addition, the following variables, if specified, are included:
Notes:
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