Using Block Variables to Stratify Data
/****************************************************************/
/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: SHWBLK */
/* TITLE: Using Block Variables to Stratify Data */
/* PRODUCT: QC */
/* SYSTEM: ALL */
/* KEYS: Shewhart Charts, Block Variables, */
/* PROCS: SHEWHART */
/* DATA: */
/* */
/* REF: SAS/QC Software: Usage and Reference, Version 6, */
/* First Edition, Volume 1 and Volume 2 */
/* */
/****************************************************************/
data Parts;
length Machine $ 4;
input Sample Machine $ Day Shift DiamX DiamS;
DiamN=6;
datalines;
1 A386 01 1 4.32 0.39
2 A386 01 2 4.49 0.35
3 A386 01 3 4.44 0.44
4 A386 02 1 4.45 0.17
5 A386 02 2 4.21 0.53
6 A386 02 3 4.56 0.26
7 A386 03 1 4.63 0.39
8 A386 03 2 4.38 0.47
9 A386 03 3 4.47 0.40
10 A455 04 1 4.42 0.37
11 A455 04 2 4.45 0.32
12 A455 04 3 4.62 0.36
13 A455 05 1 4.33 0.31
14 A455 05 2 4.29 0.33
15 A455 05 3 4.17 0.25
16 C334 08 1 4.15 0.28
17 C334 08 2 4.21 0.33
18 C334 08 3 4.16 0.19
19 C334 09 1 4.14 0.13
20 C334 09 2 4.11 0.19
21 C334 09 3 4.10 0.27
22 C334 10 1 3.99 0.14
23 C334 10 2 4.24 0.16
24 C334 10 3 4.23 0.14
25 A386 11 1 4.27 0.28
26 A386 11 2 4.70 0.45
27 A386 11 3 4.51 0.45
28 A386 12 1 4.34 0.16
29 A386 12 2 4.38 0.29
30 A386 12 3 4.28 0.24
31 A386 15 1 4.47 0.26
32 A386 15 2 4.31 0.46
33 A386 15 3 4.52 0.33
;
ods graphics off;
symbol v=dot h=3.0 pct;
title 'Control Chart for Diameter Stratified By Machine';
proc shewhart history=Parts;
xchart Diam*Sample (Machine) / stddeviations
nolegend ;
label Sample = 'Sample Number'
DiamX = 'Average Diameter' ;
run;
title 'Control Chart for Diameter Stratified By Machine and Day';
proc shewhart history=Parts;
xchart Diam*Sample (Machine Day) / stddeviations
nolegend
blockpos = 2;
label Sample = 'Sample Number'
DiamX = 'Average Diameter' ;
run;
data Parts2;
length CMachine $8;
set Parts;
if Machine='A386' then CMachine='vlibg' ;
else if Machine='A455' then CMachine='yellow' ;
else if Machine='C334' then CMachine='lipk';
else CMachine='white' ;
run;
title 'Control Chart for Diameter Stratified By Machine and Day';
proc shewhart history=Parts2;
xchart Diam*Sample (Machine Day) / stddeviations
nolegend
blockpos = 3
cblockvar = CMachine;
label Sample = 'Sample Number'
DiamX = 'Average Diameter'
Day = 'Date of Production in June'
Machine = 'Machine in Use';
run;
data Parts3;
length CDay $8;
set Parts2;
if Day='01' then CDay='white';
else if Day='02' then CDay='ligr' ;
else if Day='03' then CDay='white' ;
else if Day='04' then CDay='ligr';
else if Day='05' then CDay='white' ;
else if Day='08' then CDay='ligr' ;
else if Day='09' then CDay='white';
else if Day='10' then CDay='ligr' ;
else if Day='11' then CDay='white' ;
else if Day='12' then CDay='ligr';
else if Day='15' then CDay='white' ;
else CDay='ligr';
run;
title 'Control Chart for Diameter Stratified By Machine and Day';
proc shewhart history=Parts3;
xchart Diam*Sample (Machine Day) /
stddeviations
nolegend
ltmargin = 5
blockpos = 3
blocklabelpos = left
cblockvar = (CMachine CDay);
label Sample = 'Sample Number'
DiamX = 'Average Diameter'
Day = 'June'
Machine = 'Machine';
run;