OPTIONS NODATE NONUMBER LS=80 PS=60;

*******************************************************;
***       np-chart (with unequal sample sizes)      ***;
*** The response is the number of failing batteries ***;
***          from 25 lots of varying size           ***;
*******************************************************;

 data battery;
    input lot $ nfailed sampsize @@;;
    label nfailed ='Number Failed'
          lot     ='Lot Identifier'
          sampsize='Number Sampled';
    cards;
 AE3  6  151     AE4  5  142     AE9  6  145
 BR3  9  149     BR7  3  150     BR8  0  156
 BR9  4  150     DB1  9  158     DB2  4  152
 DB3  0  162     DB5  9  140     DB6  7  161
 DS4  6  154     DS6  1  144     DS8  5  154
 JG1  3  151     MC3  8  148     MC4  2  143
 MK6  4  150     MM1  4  147     MM2  0  150
 RT5  2  154     RT9  8  149     SP1  3  160
 SP3  9  153
 ;

 symbol v=dot w=3;

 title 'Control Limits for Battery Failures';

 proc shewhart data=battery graphics;
    npchart nfailed*lot / subgroupn = sampsize
                        tests     = 1 to 8
                        ltests    = 20
                        zonelabels
                        tabletests
                        tablelegend;
    label nfailed='Proportion Failed'
          lot = 'Lot ID';
 run;