CC
Name:
Type:
Purpose:
Compute the process capability index (CC) for a variable.
Description:
The process capability index measure the performance (i.e., the
capability) of an industrial process. The CC is a variant of
the CP and CPK capability indices.
\(
\mbox{CC} = \max(\frac{\mbox{TARGET}  \bar{x}}
{\mbox{TARGET}  \mbox{LSL}},\frac{\bar{x}  \mbox{TARGET}} {\mbox{USL}})
\)
where USL and LSL are user specified upper and lower
specification limits, TARGET is the target engineering limit,
\( \bar{x} \) is the sample mean of the data. For this statistic,
smaller is better.
The specification limits define the range within which a
product is considered acceptable (values outside this range
indicate that a product is defective).
Syntax:
LET <par> = CC <y>
<SUBSET/EXCEPT/FOR qualification>
where <y> is the response variable;
<par> is a parameter where the computed CC is stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
LET A = CC Y1
LET A = CC Y1 SUBSET TAG > 2
Note:
The upper and lower specification limits and target value
must be specified by the user as follows:
LET LSL = <value>
LET USL = <value>
LET TARGET = <value>
Note:
Dataplot statistics can be used in a number of commands. For
details, enter
Default:
Synonyms:
Related Commands:
CONTROL
CHART

= Generate a control chart.

STATISTIC
PLOT

= Generate a statistic versus subset plot.

DEX ... PLOT

= Generate a dex <statistic> plot.

CP

= Compute the process capability index.

CPK

= Compute the process capability index.

CNPK

= Compute the process capability index.

CPM

= Compute the process capability index.

PERCENT DEFECTIVE

= Compute the percentage of defectives in a sample.

EXPECTED LOSS

= Compute the expected loss of a sample.

Reference:
Kaoru Ishikawa (1982), "Guide to Quality Control,"
Asian Productivity Organization, (chapter 13).
Applications:
Implementation Date:
Program:
SKIP 25
READ GEAR.DAT Y X
LET USL = 0.995
LET USL = 1.005
LET TARGET = 1.0
CHARACTER X BLANK
LINE BLANK SOLID
TITLE AUTOMATIC
XTIC OFFSET 0.5 0.5
TIC OFFSET UNITS DATA
CC PLOT Y X
