Chapter Contents |
Previous |
Next |
UCHART Statement |
Variable | Description |
_ALPHA_ | probability () of exceeding limits |
_INDEX_ | optional identifier for the control limits specified with the OUTINDEX= option |
_LCLU_ | lower control limit for number of nonconformities per unit |
_LIMITN_ | sample size associated with the control limits |
_SIGMAS_ | multiple (k) of standard error of u_{i} |
_SUBGRP_ | subgroup-variable specified in the UCHART statement |
_TYPE_ | type (estimate or standard value) of _U_ |
_U_ | value of central line of u chart ( or u_{0}) |
_UCLU_ | upper control limit for number of nonconformities per unit |
_VAR_ | process specified in the UCHART statement |
Notes:
The OUTLIMITS= data set contains one observation for each process specified in the UCHART 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 NDEFECTS to NDEFCTS before adding the suffix.
Subgroup summary variables are created for each process
specified in the UCHART statement.
For example, consider the following statements:
proc shewhart data=fabric; uchart (flaws ndefects)*lot / outhistory=summary subgroupn = 10; run;
Additionally, the following variables, if specified, are included:
For an example of an OUTHISTORY= data set, see "Saving Nonconformities per Unit" . Note that an OUTHISTORY= data set created with the UCHART statement can be used as a HISTORY= data set by either the CCHART statement or the UCHART statement.
Variable | Description |
_ALPHA_ | probability () of exceeding control limits |
_EXLIM_ | control limit exceeded on u chart |
_LCLU_ | lower control limit for number of nonconformities per unit |
_LIMITN_ | nominal sample size associated with the control limits |
_SIGMAS_ | multiple (k) of the standard error associated with the control limits |
subgroup | values of the subgroup variable |
_SUBU_ | subgroup number of nonconformities per unit |
_SUBN_ | subgroup sample size |
_TESTS_ | tests for special causes signaled on u chart |
_UCLU_ | upper control limit for number of nonconformities per unit |
_VAR_ | process specified in the UCHART statement |
In addition, the following variables, if specified, are included:
Notes:
For an example, see "Saving Control Limits" .
Chapter Contents |
Previous |
Next |
Top |
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.