Compute Cpk Based on Fitted Lognormal Curve

 /****************************************************************/
 /*          S A S   S A M P L E   L I B R A R Y                 */
 /*                                                              */
 /*    NAME: CAPLCPK                                             */
 /*   TITLE: Compute Cpk Based on Fitted Lognormal Curve         */
 /* PRODUCT: QC                                                  */
 /*  SYSTEM: ALL                                                 */
 /*    KEYS: Capability Analysis, Capability Indices,            */
 /*   PROCS: CAPABILITY                                          */
 /*    DATA:                                                     */
 /*                                                              */
 /*   NOTES:                                                     */
 /*    MISC:                                                     */
 /*                                                              */
 /*     REF: Rodriguez, R. N. (1992), "Recent Developments in    */
 /*          Process Capability Analysis", Journal of Quality    */
 /*          Technology, Vol. 24, No. 4, pg. 176-187.            */
 /*                                                              */
 /****************************************************************/

options  ps=60 ls=80;

title1 'Compute Cpk Based on the Fitted Lognormal Curve';

 /*-------------------*/
 /*                   */
 /*  Lognormal Data   */
 /*                   */
 /*-------------------*/

data lognorm;
   input x @@;
cards;
3.62 3.41 3.16 3.20 3.36 3.56
3.69 3.12 3.15 3.25 3.13 3.25
3.40 3.22 3.31 3.27 3.98 3.38
3.71 3.37 3.34 3.29 3.20 3.68
3.52 3.72 3.37 3.27 3.26 3.95
3.36 3.76 3.30 3.40 3.44 3.52
3.28 3.75 3.50 3.26 3.26 3.31
3.57 3.15 3.83 3.54 3.60 3.80
3.62 3.56 3.27 3.22 3.63 3.17
3.31 3.21 3.54 3.43 3.46 3.36
;

 /*----------------------------------------------------*/
 /*                                                    */
 /* Display Histogram with Cpk and Parameter Estimates */
 /*                                                    */
 /*----------------------------------------------------*/

pattern1 c=blue  v=s;
pattern2 c=red   v=s;
pattern3 c=green v=s;

symbol1  c=white;

proc capability data=lognorm noprint;
   spec  lsl = 3.1    usl = 3.9
        clsl = white cusl = white
        llsl = 1     lusl = 2
        wlsl = 2     wusl = 2;
   hist x / lognormal(indices color=yellow w=2 theta=3.)
            cframe = gray
            nocurvelegend;
   inset lognormal(sigma scale theta (2.) cpk) /
                      pos    = ne
                      cfill  = blue
                      ctext  = white
                      cframe = white
                      format = 6.3;
   run;

goptions reset=all;