| PROC CAPABILITY and General Statements |
Overview
This chapter describes several statements that are generally
used with the CAPABILITY procedure:
-
The PROC CAPABILITY statement is required to invoke
the CAPABILITY procedure.
You can use this statement by itself to
compute summary statistics.
-
The VAR statement, which is optional,
specifies the variables in the input data
set that are to be analyzed.
By default, all of the numeric variables are analyzed.
-
The SPEC statement, which is optional, provides specification limits
for the variables that are to be analyzed.
When you use a SPEC statement, the procedure computes
process capability indices in addition to summary statistics.
Furthermore, the specification limits are displayed in
plots created with plot statements (such as HISTOGRAM)
that are described in subsequent chapters.
You can use the
PROC CAPABILITY statement to
request a variety of statistics
for summarizing the data
distribution of each analysis variable:
- sample moments
- basic measures of location and variability
- confidence intervals for the mean, standard deviation,
and variance
- tests for location
- tests for normality
- trimmed and Winsorized means
- robust estimates of scale
- quantiles and related confidence intervals
- extreme observations and extreme values
- frequency counts for observations
- missing values
You can use the
PROC CAPABILITY and SPEC statements together to
request a variety of statistics
for process capability analysis:
- percents of measurements within and outside
specification limits
- confidence intervals for the probabilities of
exceeding the specification limits
- standard capability indices and related confidence intervals
- tests of normality in conjunction with
capability indices
- specialized capability indices
In addition, you can use options in the
PROC CAPABILITY statement to
- specify the input data set to be analyzed
- specify an input data set containing specification limits
- specify a graphics catalog for saving graphical output
- specify rounding units for variable values
- specify the definition used to calculate percentiles
- specify the divisor used to calculate variances and standard
deviations
- request that plots be produced on line printers and
define special printing characters used for features
- suppress tables
You can use options in the
SPEC statement to
- provide lower and upper specification limits and
target values
- control the appearance of specification
lines on plots
- control the appearance of the areas under a
histogram outside the specification limits
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
