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PCHART Statement |
Variable | Description |
_ALPHA_ | probability () of exceeding limits |
_INDEX_ | optional identifier for the control limits specified with the OUTINDEX= option |
_LCLP_ | lower control limit for proportion of nonconforming items |
_LIMITN_ | nominal sample size associated with the control limits |
_P_ | average proportion of nonconforming items ( or p_{0}) |
_SIGMAS_ | multiple (k) of standard error of p_{i} |
_SUBGRP_ | subgroup-variable specified in the PCHART statement |
_TYPE_ | type (standard or estimate) of _P_ |
_UCLP_ | upper control limit for proportion of nonconforming items |
_VAR_ | process specified in the PCHART statement |
Notes:
The OUTLIMITS= data set contains one observation for each process specified in the PCHART 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 REJECTED to REJETED before adding the suffix.
Subgroup summary variables are created for each process specified in the PCHART statement. For example, consider the following statements:
proc shewhart data=input; pchart (rework rejected)*batch / outhistory=summary subgroupn =30; run;
The data set SUMMARY contains variables named BATCH, REWORKP, REWORKN, REJETEDP, and REJETEDN.
Additionally, the following variables, if specified, are included:
For an example of an OUTHISTORY= data set, see "Saving Proportions of Nonconforming Items".
Note that an OUTHISTORY= data set created with the PCHART statement can be reused as a HISTORY= data set by either the PCHART statement or the NPCHART statement.
Variable | Description |
_ALPHA_ | probability () of exceeding control limits |
_EXLIM_ | control limit exceeded on p chart |
_LCLP_ | lower control limit for proportion of nonconforming items |
_LIMITN_ | nominal sample size associated with the control limits |
_SIGMAS_ | multiple (k) of the standard error of p_{i} associated with the control limits |
subgroup | values of the subgroup variable |
_SUBP_ | subgroup proportion of nonconforming items |
_SUBN_ | subgroup sample size |
_TESTS_ | tests for special causes signaled on p chart |
_UCLP_ | upper control limit for proportion of nonconforming items |
_VAR_ | process specified in the PCHART statement |
In addition, the following variables, if specified, are included:
Notes:
For an example, see "Saving Control Limits".
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