An R Chart with Probability Limits
/****************************************************************/
/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: SHWREX1 */
/* TITLE: An R Chart with Probability Limits */
/* PRODUCT: QC */
/* SYSTEM: ALL */
/* KEYS: Shewhart Charts, R Charts, Probability Limits, */
/* PROCS: SHEWHART */
/* DATA: */
/* */
/* REF: SAS/QC Software: Usage and Reference, Version 6, */
/* First Edition, Volume 1 and Volume 2 */
/* */
/****************************************************************/
data Disks;
input Lot @;
do i=1 to 6;
input Time @;
output;
end;
drop i;
datalines;
1 8.05 7.90 8.04 8.06 8.01 7.99
2 8.03 8.06 8.02 8.02 7.97 8.03
3 8.00 7.94 7.97 7.95 8.00 8.01
4 8.00 8.06 8.06 7.99 7.97 7.96
5 7.93 8.01 8.00 8.09 8.06 8.02
6 7.98 7.99 8.01 8.09 8.00 7.97
7 8.00 7.94 7.93 8.03 7.93 8.08
8 8.01 7.98 7.98 8.07 8.05 8.09
9 7.97 7.96 8.01 8.11 8.06 8.07
10 7.93 8.03 8.03 8.00 7.93 8.03
11 8.00 8.00 8.02 7.92 7.98 8.01
12 7.98 7.93 8.01 7.97 8.02 8.00
13 8.06 7.93 7.98 7.98 8.02 7.96
14 8.05 7.98 8.05 7.99 7.95 7.99
15 7.94 8.01 7.97 8.04 7.91 8.03
16 8.03 8.03 8.02 8.06 8.00 7.97
17 8.03 7.94 8.05 8.05 8.04 7.94
18 7.99 7.99 7.86 7.99 8.06 8.03
19 7.95 7.96 7.99 7.96 7.94 8.12
20 8.03 8.07 7.98 7.97 8.00 8.04
21 8.04 7.90 8.03 8.02 7.98 7.97
22 7.95 8.05 7.98 8.01 7.97 8.15
23 8.06 8.00 8.03 8.02 7.99 7.95
24 7.97 8.02 8.00 7.96 7.96 8.00
25 8.12 7.97 7.99 8.09 8.05 8.00
;
ods graphics on;
title 'Probability Limits for Disk Drive Test Times';
proc shewhart data=Disks;
rchart Time*Lot / alpha = .01
outlimits = Dlimits
odstitle = title;
run;
title 'Probablity Limits for Disk Drive Test Times';
proc print data=Dlimits noobs;
run;
data Disks2;
input Lot @;
do i=1 to 6;
input Time @;
output;
end;
drop i;
datalines;
26 7.93 7.97 7.89 7.81 7.88 7.92
27 7.86 7.91 7.87 7.89 7.83 7.87
28 7.93 7.95 7.90 7.89 7.88 7.90
29 7.97 8.00 7.86 7.89 7.84 7.78
30 7.91 7.93 7.98 7.93 7.83 7.88
31 7.85 7.94 7.88 7.98 7.96 7.84
32 7.86 8.01 7.88 7.95 7.90 7.89
33 7.87 7.93 7.96 7.89 7.81 8.00
34 7.87 7.97 7.95 7.89 7.92 7.84
35 7.92 7.97 7.90 7.88 7.89 7.86
36 7.96 7.90 7.90 7.84 7.90 8.00
37 7.92 7.90 7.98 7.92 7.94 7.94
38 7.88 7.99 8.02 7.98 7.88 7.92
39 7.89 7.91 7.92 7.90 7.94 7.94
40 7.84 7.88 7.91 7.98 7.87 7.93
41 7.91 7.87 7.96 7.91 7.89 7.92
42 7.96 7.93 7.86 7.93 7.86 7.94
43 7.84 7.82 7.87 7.91 7.91 8.01
44 7.93 7.91 7.92 7.88 7.91 7.86
45 7.95 7.92 7.93 7.90 7.86 8.00
;
title 'Probability Limits Applied to Second Set of Test Times';
proc shewhart data=Disks2 limits=Dlimits;
rchart Time*Lot / readalpha
markers
odstitle = title;
run;