Guidelines for implementation of statistical process control (SPC)

This document describes examples for software validation for SPC software implementing the standards of the ISO 7870 series on control charts and the ISO 22514 series on capability and performance. In detail ISO 7870‑2, ISO 22514‑2 and ISO 22514‑8 are covered. It provides data sets and test results for testing the implementation of the evaluation methods described in these standards. This includes the detection of out of control situations as well as the calculation of sample statistics and process capability indices. The test examples cover the following situations: a) General: — different sample and subgroup sizes, accuracy of calculation for large/small numbers; b) ISO 22514 series: — calculation of sample statistics for location and dispersion; — different distribution models; c) ISO 7870‑2: — calculation of control limits; — visualization of data (histogram, control charts); — detection of out of control situations.

Lignes directrices pour la mise en œuvre de la maîtrise statistique des processus (MSP)

General Information

Status
Published
Publication Date
15-Jun-2020
Current Stage
5060 - Close of voting Proof returned by Secretariat
Start Date
19-May-2020
Completion Date
19-May-2020
Ref Project

Buy Standard

Technical report
ISO/TR 11462-3:2020 - Guidelines for implementation of statistical process control (SPC)
English language
129 pages
sale 15% off
Preview
sale 15% off
Preview
Draft
ISO/PRF TR 11462-3 - Guidelines for implementation of statistical process control (SPC)
English language
129 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

TECHNICAL ISO/TR
REPORT 11462-3
First edition
2020-06
Guidelines for implementation of
statistical process control (SPC) —
Part 3:
Reference data sets for SPC software
validation
Lignes directrices pour la mise en œuvre de la maîtrise statistique des
processus (MSP) —
Partie 3: Jeux de données de référence pour la validation de logiciels
pour MSP
Reference number
ISO/TR 11462-3:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO/TR 11462-3:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/TR 11462-3:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions, and symbols and abbreviated terms ................................................................................. 1

3.1 Terms and definitions ....................................................................................................................................................................... 1

3.2 Symbols and abbreviated terms............................................................................................................................................... 2

4 Overview of the test examples ................................................................................................................................................................ 3

5 Reference data sets description and evaluation ................................................................................................................. 4

5.1 Test data set 1 .......................................................................................................................................................................................... 4

5.1.1 Test data set 1 information ..................................................................................................................................... 4

5.1.2 Test data set 1 results .................................................................................................................................................. 6

5.2 Test data set 2 .......................................................................................................................................................................................13

5.2.1 Test data set 2 information ..................................................................................................................................13

5.2.2 Test data set 2 results ...............................................................................................................................................14

5.3 Test data set 3 .......................................................................................................................................................................................21

5.3.1 Test data set 3 information ..................................................................................................................................21

5.3.2 Test data set 3 results ...............................................................................................................................................23

5.4 Test data set 4 .......................................................................................................................................................................................32

5.4.1 Test data set 4 information ..................................................................................................................................32

5.4.2 Test data set 4 results ...............................................................................................................................................34

5.5 Test data set 5 .......................................................................................................................................................................................43

5.5.1 Test data set 5 information ..................................................................................................................................43

5.5.2 Test data set 5 results ...............................................................................................................................................45

5.6 Test data set 6 .......................................................................................................................................................................................53

5.6.1 Test data set 6 information ..................................................................................................................................53

5.6.2 Test data set 6 results ...............................................................................................................................................55

5.7 Test data set 7 .......................................................................................................................................................................................63

5.7.1 Test data set 7 information ..................................................................................................................................63

5.7.2 Test data set 7 results ...............................................................................................................................................65

5.8 Test data set 8 .......................................................................................................................................................................................73

5.8.1 Test data set 8 information ..................................................................................................................................73

5.8.2 Test data set 8 results ...............................................................................................................................................75

5.9 Test data set 9 .......................................................................................................................................................................................82

5.9.1 Test data set 9 information ..................................................................................................................................82

5.9.2 Test data set 9 results ...............................................................................................................................................85

5.10 Test data set 10 ....................................................................................................................................................................................92

5.10.1 Test data set 10 information ...............................................................................................................................92

5.10.2 Test data set 10 results ............................................................................................................................................95

5.11 Test data set 11 .................................................................................................................................................................................102

5.11.1 Test data set 11 information ............................................................................................................................102

5.11.2 Test data set 11 results .........................................................................................................................................103

Annex A (informative) Test data values ......................................................................................................................................................105

Bibliography .........................................................................................................................................................................................................................129

© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/TR 11462-3:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 69, Applications of statistical methods,

Subcommittee SC 4, Applications of statistical methods in process management.
A list of all parts in the ISO 11462 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/TR 11462-3:2020(E)
Introduction

The test examples given in this document were developed for the assessment of statistical process

control (SPC) systems. They allow SPC software developers to evaluate their systems. Thus, the

end user of those systems can be sure that the data sets are evaluated correctly with a high level of

reliability. In order to cover the widest possible spectrum, suitable data sets were prepared individually

for various constellations. The evaluation results of those data sets are documented and commented on

the following pages.

The results were verified multiple times using different computer programs. This turns the data sets

and the results into references for validation of the software. The data sets are listed in Annex A. An

electronic version is available at https:// standards .iso .org/ iso/ tr/ 11462/ -3/ ed -1/ en/ .

© ISO 2020 – All rights reserved v
---------------------- Page: 5 ----------------------
TECHNICAL REPORT ISO/TR 11462-3:2020(E)
Guidelines for implementation of statistical process
control (SPC) —
Part 3:
Reference data sets for SPC software validation
1 Scope

This document describes examples for software validation for SPC software implementing the standards

of the ISO 7870 series on control charts and the ISO 22514 series on capability and performance. In

detail ISO 7870-2, ISO 22514-2 and ISO 22514-8 are covered.

It provides data sets and test results for testing the implementation of the evaluation methods described

in these standards. This includes the detection of out of control situations as well as the calculation of

sample statistics and process capability indices.
The test examples cover the following situations:
a) General:

— different sample and subgroup sizes, accuracy of calculation for large/small numbers;

b) ISO 22514 series:
— calculation of sample statistics for location and dispersion;
— different distribution models;
c) ISO 7870-2:
— calculation of control limits;
— visualization of data (histogram, control charts);
— detection of out of control situations.
2 Normative references
There are no normative references in this document.
3 Terms and definitions, and symbols and abbreviated terms
3.1 Terms and definitions
No terms and definitions are listed in this document.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
© ISO 2020 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO/TR 11462-3:2020(E)
3.2 Symbols and abbreviated terms

Symbols used in this document are identical to the symbols used in ISO 22514-2 and ISO 7870-2:

C process capability index
C minimum process capability index
C upper process capability index
pkU
C lower process capability index
pkL
U upper control limit
L lower control limit
m number of subgroups
n sample size of each subgroup
P machine performance index
P minimum machine performance index
P upper machine performance index
mkU
P lower machine performance index
mkL
P process performance index
P minimum process performance index
P upper process performance index
pkU
P lower process performance index
pkL

T Centreline (target value) for the respective characteristic in the control charts

U upper specification limit
L lower specification limit
U upper specification limit, transformed values
L lower specification limit, transformed values
Abbreviated terms:
SPC statistical process control
2 © ISO 2020 – All rights reserved
---------------------- Page: 7 ----------------------
ISO/TR 11462-3:2020(E)
4 Overview of the test examples
See Table 1 for an overview of the test examples.
Table 1 — Overview of test examples
Test data Distri- Resulting Total Subgroup
Decimal
set Subclause bution distribu- sample sample Description of data set
points
number model tion size size
Data follows a normal distribu-
1 5.1 A1 normal 4 125 5
tion with no outliers
Correct calculations for a
2 5.2 A2 Weibull 3 600 3 sample following a Weibull
distribution
Normal distribution with time
3 5.3 B non-normal 2 1 000 5
dependent shift of mean
Location: random normally dis-
4 5.4 C1 normal 2 1 000 5
tributed; dispersion: constant
Location: random non-nor-
mally distributed; dispersion:
5 5.5 C2 non-normal 2 1 000 5
constant; resulting distribu-
tion: non-normal
Capability indices for trend
6 5.6 C3 non-normal 2 600 6
production (tool wear)
Capability indices for fix tool-
7 5.7 C4 non-normal 2 500 5
ing (tool change)
Systematic and random chang-
8 5.8 D non-normal 3 500 5 es in location and dispersion
- non-normal
Correct calculations for a
9 5.9 A2 Rayleigh 3 500 5 sample following a Rayleigh
distribution
Correct calculations for a
10 5.10 A2 Weibull 0 200 5 sample following a Weibull
distribution
ISO 22514-8 capability of mul-
11 5.11 C2 normal 1 30 (10)
ti-state production processes
NOTE

— The decision which distribution model fits the data and its use is up to the statistical expert. Within this

document distribution models for each example are therefore assumed. The procedure to select a statistical

distribution is not part of this document.

— According to ISO 22514-2 the calculation method d = 5 for the dispersion is not suited for non-normal

distributions. It is calculated and given in this document even for non-normal distributions for the purpose

of validating the implementation of the calculation method of d = 5.

— The resulting distributions for test 2, 9 and 10 are pre-selected models and with no means the "best natural"

resulting distribution models for the same reason no goodness of fit statistics are given, knowing they will

lead to reject H for the pre-selected distribution models.

— Two more decimal places for sample statistics and control limits than digits of the input values. Resulting

values are rounded (ISO/IEC/IEEE 60559, rounded-to-the-nearest).
— Capability index are always given with 2 digits (rounded).
© ISO 2020 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO/TR 11462-3:2020(E)
— Control limits were calculated using all values in the test data set.

— All control limits were calculated using tabulated correction factors in ISO 7870-2. Using the exact quantiles

of the corresponding distribution functions instead can lead to a deviation in the results <0,1 %.

— The centrelines for the control charts were chosen according to the respective statistics given by

ISO 7870-2:2013, 6.1 to 6.3

— The histogram plot is not part of the validation, since the procedure is not specified in ISO 7870 series nor in

ISO 22514 series. Histograms are for visualization purposes only.
— No units are given, no unit conversion has to be done.
— Time-dependent distribution models A-D are specified in ISO 22514-2.

— Internally a precision of 15 digits is used, when already calculated values are used again in further calculations.

— If the data are not normal distributed an individual chart and a MR chart cannot be used.

5 Reference data sets description and evaluation
5.1 Test data set 1
5.1.1 Test data set 1 information

This set of test data is taken from a process following a normal distribution and is for checking the

accuracy of calculation for control limits, sample statistics and process capabilities. A description of

test data set 1 is given in Table 2. Figure 1 shows a histogram and Figure 2 a probability plot of the test

data set 1 with the purpose of data visualization.
Table 2 — Description of test data set 1
Description of data input
Distribution model A1 Resulting distribution Normal
Data set Annex A, Table A.1 decimal points 4
Total sample size 125 U 14,075
Size of subgroups 5 L 14,060
4 © ISO 2020 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/TR 11462-3:2020(E)
Key
X value
Y1 absolute frequency
Y2 relative frequency in %
Figure 1 — Histogram of test data set 1
© ISO 2020 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO/TR 11462-3:2020(E)
Key
X value
Y1 probability in %
Y2 1-probability in %
Figure 2 — Probability plot of test data set 1
NOTE The width of the class intervals is 0,000 7.

The class interval with the highest frequency of values is from 14,067 95 to 14,068 02.

The density plot is based on the assumption of normality and estimated parameters l = 1, d = 5.

5.1.2 Test data set 1 results
5.1.2.1 List of sample statistics

Table 3 lists all sample statistics which are necessary to calculate the target values and control limits

for the control charts described in ISO 7870-2 as well as the estimators for location and dispersion

given in ISO 22514-2 for the calculation of the process capability indices.
Table 3 — List of sample statistics for test data set 1
Statistic Value Reference
Location
x (l = 1) 14,067 958 ISO 22514-2:2017, Formula (11)
 14,068 000 ISO 22514-2:2017, Formula (12)
x (l = 2)
14,067 958 ISO 22514-2:2017, Formula (13)
x (l = 3)
14,067 828 ISO 22514-2:2017, Formula (14)
x (l = 4)
6 © ISO 2020 – All rights reserved
---------------------- Page: 11 ----------------------
ISO/TR 11462-3:2020(E)
Table 3 (continued)
Statistic Value Reference
Dispersion
0,007 240 (normal distribution) ISO 22514-2:2017: Formula (15)
Δ (d = 1)
σˆ (d = 2) 0,001 187 ISO 22514-2:2017, Formula (16)
ˆ 0,001 200 ISO 22514-2:2017, Formula (17)
σ (d = 3)
σˆ (d = 4) 0,001 180 ISO 22514-2:2017, Formula (18)
σˆ (d = 5) 0,001 207 ISO 22514-2:2017, Formula (19)
s 0,001 128 ISO 7870-2:2013, 3.2
0,005 900 ISO 7870-2:2013, 3.2
0,002 744 ISO 7870-2:2013, 3.2
R 0,001 379 ISO 7870-2:2013, 3.2
5.1.2.2 x chart

The xcontrol chart calculated according to ISO 7870-2:2013, 6.1, is shown in Figure 3.

Key
X number of subgroup
Y mean value
Figure 3 — Mean control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 1, using s ):
L = 14,066 349
U = 14,069 568
© ISO 2020 – All rights reserved 7
---------------------- Page: 12 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.3 X chart

The individuals control chart calculated according to ISO 7870-2:2013, 6.2, is shown in Figure 4.

Key
X value number
Y individuals
Figure 4 — Individuals control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 3):
L = 14,064 29
U = 14,071 63
8 © ISO 2020 – All rights reserved
---------------------- Page: 13 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.4 x chart

The median control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 5.

Key
X subgroup number
Y median value
Figure 5 — Median control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 4):
L = 14,065 93
U = 14,069 72
Out of control situations are given in Table 4.

Table 4 — Results of pattern tests for the median control chart and test data set 1

Out of control situations
Subgroup Result/violation Subgroup Result/violation
6 Violation of L
© ISO 2020 – All rights reserved 9
---------------------- Page: 14 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.5 s chart

The s control chart calculated according to ISO 7870-2:2013, 6.1, is shown in Figure 6.

Key
X subgroup number
Y empirical standard deviation s value
Figure 6 — s control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 1):
L = 0
U = 0,002 356
10 © ISO 2020 – All rights reserved
---------------------- Page: 15 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.6 R chart

The R control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 7.

Key
X subgroup number
Y range R value
Figure 7 — R control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 1):
L = 0
U = 0,005 801
© ISO 2020 – All rights reserved 11
---------------------- Page: 16 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.7 Moving range chart

The moving range control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 8.

Key
X individuals number
Y moving range value
Figure 8 — Moving range control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 3):
L = 0
U = 0,004 51
Out of control situations are given in Table 5.

Table 5 — Results of pattern tests for the moving range control chart and test data set 1

Out of control situations
Value Result/violation Value Result/violation
77 to 84 run below centreline
12 © ISO 2020 – All rights reserved
---------------------- Page: 17 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.8 Process capability

The process capability is calculated according to ISO 22514-2:2017, Clause 6, with calculation method

l = 3 for the location estimator and calculation method d = 5 for the dispersion estimator.

Capability indices (calculation method M )
3,5
Process is stable (mean, R - chart) - C /C is used
p pk
C 2,07 C 1,95
p pk
C 2,20 C 1,95
pkL pkU
5.2 Test data set 2
5.2.1 Test data set 2 information

This set of test data is taken from a process following a non-normal distribution and is for checking the

accuracy of calculation for control limits, sample statistics and process capabilities. A description of

test data set 2 is given in Table 6. Figure 9 shows a histogram and Figure 10 a probability plot of the test

data set 2 with the purpose of data visualization.
Table 6 — Description of test data set 2
Description of data input
Distribution model A2 Resulting distribution Weibull
Data set Annex A, Table A.1 decimal points 3
Total sample size 600 U 0,04
Size of subgroups 3 L 0
Key
X value
Y1 absolute frequency
Y2 relative frequency in %
Figure 9 — Histogram of test data set 2
© ISO 2020 – All rights reserved 13
---------------------- Page: 18 ----------------------
ISO/TR 11462-3:2020(E)
Key
X value
Y1 probability in %
Y2 1-probability in %
Figure 10 — Probability plot of test data set 2
NOTE The width of the class intervals is 0,003.

The class interval with the highest frequency of values is from 0,003 5 to 0,006 5.

The density plot is based on the assumption of a two parametric Weibull distribution with estimated parameters

scale a = 0,009 39 and shape b = 1,897 82. Both estimators have been calculated using the method of Maximum

Likelihood.

The 0,135 %- and the 99,865 %-percentiles are calculated using the inverse distribution function of the Weibull

distribution
Fp()|,ab =×ap[]−−ln()1
X = 0,000 29
0,135 %
X = 0,025 39
99,865 %
5.2.2 Test data set 2 results
5.2.2.1 List of sample statistics

Table 7 lists all sample statistics which are necessary to calculate the target values and control limits

for the control charts described in ISO 7870-2 as well as the estimators for location and dispersion

given in ISO 22514-2 for the calculation of the process capability indices.
14 © ISO 2020 – All rights reserved
---------------------- Page: 19 ----------------------
ISO/TR 11462-3:2020(E)
Table 7 — List of sample statistics for test data set 2
Statistic Value Reference
Location
x (l = 1) 0,008 29 ISO 22514-2:2017, Formula (11)
x (l = 2) 0,007 00 ISO 22514-2:2017, Formula (12)
0,008 29 ISO 22514-2:2017, Formula (13)
x (l = 3)
0,007 51 ISO 22514-2:2017, Formula (14)
x (l = 4)
Dispersion
0,025 11 (Weibull using parameters in 5.2.1) ISO 22514-2:2017, Formula (15)
Δ (d = 1)
σˆ (d = 2) 0,004 88 ISO 22514-2:2017, Formula (16)
σˆ (d = 3) 0,004 87 ISO 22514-2:2017, Formula (17)
ˆ 0,004 81 ISO 22514-2:2017, Formula (18)
σ (d = 4)
σˆ (d = 5) 0,004 67 ISO 22514-2:2017, Formula (19)
s 0,004 32 ISO 7870-2:2013, 3.2
R 0,026 00 ISO 7870-2:2013, 3.2
0,008 13 ISO 7870-2:2013, 3.2
R 0,005 14 ISO 7870-2:2013, 3.2
5.2.2.2 x chart

The xcontrol chart calculated according to ISO 7870-2:2013, 6.1, is shown in Figure 11.

Key
X number of subgroup
Y mean value
Figure 11 — Mean control chart for test data set 2
The control limits are (see ISO 7870-2:2013, Table 1, using s ):
© ISO 2020 – All rights reserved 15
---------------------- Page: 20 ----------------------
ISO/TR 11462-3:2020(E)

L = −0,000 15 (The calculated lower control limit is negative and the dataset is one-sided against

0 limited characteristic. Therefore, the lower control limit is not shown, L = ----)

U = 0,016 72
5.2.2.3 X chart

The individuals control chart calculated according to ISO 7870-2:2013, 6.2, is shown in Figure 12.

Key
X value number
Y individuals
Figure 12 — Individuals control chart for test data set 2
The control limits are (see ISO 7870-2:2013, Table 3):
L = −0,005 39
U = 0,021 96
Out of control situations are given in Table 8.

Table 8 — Results of pattern tests for the individuals control chart and test data set 2

Out of control situations
Value Result/violation Value Result/violation
75 violation of U 433 violation of U
CL CL
155 to 163 run below centreline 435 to 441 run below centreline
222 to 228 run below centreline 464 violation of U
367 violation of U 468 violation of U
CL CL
16 © ISO 2020 – All rights reserved
---------------------- Page: 21 ----------------------
ISO/TR 11462-3:2020(E)
5.2.2.4 x chart

The median control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 13.

Key
X subgroup number
Y median value
Figure 13 — Median control chart for test data set 2
The control limits are (see ISO 7870-2:2013, Table 4):
L = −0,002 15
U = 0,017 17
Out of control situations are given in Table 9.

Table 9 — Results of pattern tests for the median control chart and test data set 2

Out of control situations
Subgroup Result/violation Subgroup Result/violation
91 to 97 run below centreline 155 violation of U
© ISO 2020 – All rights reserved 17
---------------------- Page: 22 ----------------------
ISO/TR 11462-3:2020(E)
5.2.2.5 s
...

TECHNICAL ISO/TR
REPORT 11462-3
First edition
Guidelines for implementation of
statistical process control (SPC) —
Part 3:
Reference data sets for SPC software
validation
Lignes directrices pour la mise en œuvre de la maîtrise statistique des
processus (MSP) —
Partie 3: Jeux de données de référence pour la validation de logiciels
pour MSP
PROOF/ÉPREUVE
Reference number
ISO/TR 11462-3:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO/TR 11462-3:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/TR 11462-3:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions, and symbols and abbreviated terms ................................................................................. 1

3.1 Terms and definitions ....................................................................................................................................................................... 1

3.2 Symbols and abbreviated terms............................................................................................................................................... 2

4 Overview of the test examples ................................................................................................................................................................ 3

4.1 Overview ...................................................................................................................................................................................................... 3

5 Reference data sets description and evaluation ................................................................................................................. 4

5.1 Test data set 1 .......................................................................................................................................................................................... 4

5.1.1 Test data set 1 information ..................................................................................................................................... 4

5.1.2 Test data set 1 results .................................................................................................................................................. 6

5.2 Test data set 2 .......................................................................................................................................................................................13

5.2.1 Test data set 2 information ..................................................................................................................................13

5.2.2 Test data set 2 results ...............................................................................................................................................14

5.3 Test data set 3 .......................................................................................................................................................................................21

5.3.1 Test data set 3 information ..................................................................................................................................21

5.3.2 Test data set 3 results ...............................................................................................................................................23

5.4 Test data set 4 .......................................................................................................................................................................................32

5.4.1 Test data set 4 information ..................................................................................................................................32

5.4.2 Test data set 4 results ...............................................................................................................................................34

5.5 Test data set 5 .......................................................................................................................................................................................43

5.5.1 Test data set 5 information ..................................................................................................................................43

5.5.2 Test data set 5 results ...............................................................................................................................................45

5.6 Test data set 6 .......................................................................................................................................................................................53

5.6.1 Test data set 6 information ..................................................................................................................................53

5.6.2 Test data set 6 results ...............................................................................................................................................55

5.7 Test data set 7 .......................................................................................................................................................................................63

5.7.1 Test data set 7 information ..................................................................................................................................63

5.7.2 Test data set 7 results ...............................................................................................................................................65

5.8 Test data set 8 .......................................................................................................................................................................................73

5.8.1 Test data set 8 information ..................................................................................................................................73

5.8.2 Test data set 8 results ...............................................................................................................................................75

5.9 Test data set 9 .......................................................................................................................................................................................82

5.9.1 Test data set 9 information ..................................................................................................................................82

5.9.2 Test data set 9 results ...............................................................................................................................................85

5.10 Test data set 10 ....................................................................................................................................................................................92

5.10.1 Test data set 10 information ...............................................................................................................................92

5.10.2 Test data set 10 results ............................................................................................................................................95

5.11 Test data set 11 .................................................................................................................................................................................102

5.11.1 Test data set 11 information ............................................................................................................................102

5.11.2 Test data set 11 results .........................................................................................................................................103

Annex A (normative) Test data values .........................................................................................................................................................105

Bibliography .........................................................................................................................................................................................................................129

© ISO 2020 – All rights reserved PROOF/ÉPREUVE iii
---------------------- Page: 3 ----------------------
ISO/TR 11462-3:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 69, Applications of statistical methods,

Subcommittee SC 4, Applications of statistical methods in process management.
A list of all parts in the ISO 11462 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/TR 11462-3:2020(E)
Introduction

The test examples given in this document were developed for the assessment of SPC systems. They

allow SPC software developers to evaluate their systems. Thus, the end user of those systems can be

sure that the data sets are evaluated correctly with a high level of reliability. In order to cover as wide

a spectrum as possible, suitable data sets were prepared individually for various constellations. The

evaluation results of those data sets are documented and commented on the following pages.

The results were verified multiple times using different computer programs. This turns the data sets

and the results into references for validation of the software. The data sets are listed in Annex A.

© ISO 2020 – All rights reserved PROOF/ÉPREUVE v
---------------------- Page: 5 ----------------------
TECHNICAL REPORT ISO/TR 11462-3:2020(E)
Guidelines for implementation of statistical process
control (SPC) —
Part 3:
Reference data sets for SPC software validation
1 Scope

This document describes examples for software validation for SPC software implementing the standards

of the ISO 7870 series on control charts and the ISO 22514 series on capability and performance. In

detail ISO 7870-2, ISO 22514-2 and ISO 22514-8 are covered.

It provides data sets and test results for testing the implementation of the evaluation methods described

in these standards. This includes the detection of out of control situations as well as the calculation of

sample statistics and process capability indices.
The test examples cover the following situations:
a) General:

— different sample and subgroup sizes accuracy of calculation for large/small numbers;

b) ISO 22514 series:
— calculation of sample statistics for location and dispersion;
— different distribution models;
c) ISO 7870-2:
— calculation of control limits;
— visualization of data (histogram, control charts);
— detection of out of control situations.
2 Normative references
There are no normative references in this document.
3 Terms and definitions, and symbols and abbreviated terms
3.1 Terms and definitions
No terms and definitions are listed in this document.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 1
---------------------- Page: 6 ----------------------
ISO/TR 11462-3:2020(E)
3.2 Symbols and abbreviated terms

Symbols used in this document are identical to the symbols used in ISO 22514-2 and ISO 7870-2:

C process capability index
C minimum process capability index
C upper process capability index
pkU
C lower process capability index
pkL
U upper control limit
L lower control limit
m number of subgroups
n sample size of each subgroup
P machine performance index
P minimum machine performance index
P upper machine performance index
mkU
P lower machine performance index
mkL
P process performance index
P minimum process performance index
P upper process performance index
pkU
P lower process performance index
pkL

T Centreline (target value) for the respective characteristic in the control charts

U upper specification limit
L lower specification limit
U upper specification limit, transformed values
L lower specification limit, transformed values
Abbreviated terms:
SPC statistical process control
2 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 7 ----------------------
ISO/TR 11462-3:2020(E)
4 Overview of the test examples
4.1 Overview
See Table 1 for an overview of the test examples.
Table 1 — Overview of test examples
Test data Distri- Resulting Total Subgroup
Decimal
set Subclause bution distribu- sample sample Description of data set
points
number model tion size size
Data follows a normal distribu-
1 5.1 A1 normal 4 125 5
tion with no outliers
Correct calculations for a
2 5.2 A2 Weibull 3 600 3 sample following a Weibull
distribution
Normal distribution with time
3 5.3 B non-normal 2 1 000 5
dependent shift of mean
Location: random normally dis-
4 5.4 C1 normal 2 1 000 5
tributed; dispersion: constant
Location random non-normally
distributed; dispersion con-
5 5.5 C2 non-normal 2 1 000 5
stant; resulting distribution
non-normal
Capability indices for trend
6 5.6 C3 non-normal 2 600 6
production (tool wear)
Capability indices for fix tool-
7 5.7 C4 non-normal 2 500 5
ing (tool change)
Systematic and random chang-
8 5.8 D non-normal 3 500 5 es in location and dispersion
- non-normal
Correct calculations for a
9 5.9 A2 Rayleigh 3 500 5 sample following a Rayleigh
distribution
Correct calculations for a
10 5.10 A2 Weibull 0 200 5 sample following a Weibull
distribution
ISO 22514-8 capability of mul-
11 5.11 C2 normal 1 30 (10)
ti-state production processes
NOTE

— The decision which distribution model fits the data and is used is up to the statistical expert. Within this

document distribution models for each example are therefore assumed. The procedure to select a statistical

distribution is not part of this document.

— According to ISO 22514-2 the calculation method d = 5 for the dispersion is not suited for non-normal

distributions. It is calculated and given in this document even for non-normal distributions for the purpose

of validating the implementation of the calculation method of d = 5.

— The resulting distributions for test 2, 9 and 10 are pre-selected models and with no means the "best natural"

resulting distribution models for the same reason no goodness of fit statistics are given, knowing they will

lead to reject H for the pre-selected distribution models.

— Two more decimal places for sample statistics and control limits than digits of the input values. Resulting

values are rounded (ISO/IEC/IEEE 60559, rounded-to-the-nearest).
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 3
---------------------- Page: 8 ----------------------
ISO/TR 11462-3:2020(E)
— Capability index are always given with 2 digits (rounded).
— Control limits were calculated using all values in the test data set.

— All control limits were calculated using tabulated correction factors in ISO 7870-2. Using the exact quantiles

of the corresponding distribution functions instead can lead to a deviation in the results <0,1 %.

— The centrelines for the control charts were chosen according to the respective statistics given by

ISO 7870-2:2013, 6.1 to 6.3

— The histogram plot is not part of the validation, since the procedure is not specified in ISO 7870 series nor in

ISO 22514 series. Histograms are for visualization purposes only.
— No units are given, no unit conversion has to be done.
— Time-dependent distribution models A-D are specified in ISO 22514-2.

— Internally a precision of 15 digits is used, when already calculated values are used again in further calculations.

— If the data are not normal distributed an individual chart and a MR chart cannot be used.

5 Reference data sets description and evaluation
5.1 Test data set 1
5.1.1 Test data set 1 information

This set of test data is taken from a process following a normal distribution and is for checking the

accuracy of calculation for control limits, sample statistics and process capabilities. A description of

test data set 1 is given in Table 2. Figure 1 shows a histogram and Figure 2 a probability plot of the test

data set 1 with the purpose of data visualization.
Table 2 — Description of test data set 1
Description of data input
Distribution model A1 Resulting distribution Normal
Data set Annex A, Table A.1 decimal points 4
Total sample size 125 U 14,075
Size of subgroups 5 L 14,060
4 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/TR 11462-3:2020(E)
Key
X value
Y1 absolute frequency
Y2 relative frequency in %
Figure 1 — Histogram of test data set 1
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 5
---------------------- Page: 10 ----------------------
ISO/TR 11462-3:2020(E)
Key
X value
Y1 probability in %
Y2 1-probability in %
Figure 2 — Probability plot of test data set 1
NOTE The width of the class intervals is 0,000 7.

The class interval with the highest frequency of values is from 14,067 95 to 14,068 02.

The density plot is based on the assumption of normality and estimated parameters l = 1, d = 5.

5.1.2 Test data set 1 results
5.1.2.1 List of sample statistics

Table 3 lists all sample statistics which are necessary to calculate the target values and control limits

for the control charts described in ISO 7870-2 as well as the estimators for location and dispersion

given in ISO 22514-2 for the calculation of the process capability indices.
Table 3 — List of sample statistics for test data set 1
Statistic Value Reference
Location
x (l = 1) 14,067 958 ISO 22514-2:2017, Formula (11)
 14,068 000 ISO 22514-2:2017, Formula (12)
x , (l = 2)
14,067 958 ISO 22514-2:2017, Formula (13)
x (l = 3)
14,067 828 ISO 22514-2:2017, Formula (14)
x (l = 4)
6 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 11 ----------------------
ISO/TR 11462-3:2020(E)
Table 3 (continued)
Statistic Value Reference
Dispersion
0,007 240 (normal distribution) ISO 22514-2:2017: Formula (15)
Δ (d = 1)
σˆ (d = 2) 0,001 187 ISO 22514-2:2017, Formula (16)
ˆ 0,001 200 ISO 22514-2:2017, Formula (17)
σ (d = 3)
σˆ (d = 4) 0,001 180 ISO 22514-2:2017, Formula (18)
σˆ (d = 5) 0,001 207 ISO 22514-2:2017, Formula (19)
s 0,001 128 ISO 7870-2:2013, 3.2
0,005 900 ISO 7870-2:2013, 3.2
0,002 744 ISO 7870-2:2013, 3.2
R 0,001 379 ISO 7870-2:2013, 3.2
5.1.2.2 x chart

The xcontrol chart calculated according to ISO 7870-2:2013, 6.1, is shown in Figure 3.

Key
X number of subgroup
Y mean value
Figure 3 — Mean control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 1, using s ):
L = 14,066 349
U = 14,069 568
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 7
---------------------- Page: 12 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.3 X chart

The individuals control chart calculated according to ISO 7870-2:2013, 6.2, is shown in Figure 4.

Key
X value number
Y individuals
Figure 4 — Individuals control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 3):
L = 14,064 29
U = 14,071 63
8 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 13 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.4 x chart

The median control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 5.

Key
X subgroup number
Y median value
Figure 5 — Median control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 4):
L = 14,065 93
U = 14,069 72
Out of control situations are given in Table 4.

Table 4 — Results of pattern tests for the median control chart and test data set 1

Out of control situations
Subgroup Result/violation Subgroup Result/violation
6 Violation of L
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 9
---------------------- Page: 14 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.5 s chart

The s control chart calculated according to ISO 7870-2:2013, 6.1, is shown in Figure 6.

Key
X subgroup number
Y empirical standard deviation s value
Figure 6 — s control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 1):
L = 0
U = 0,002 356
10 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 15 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.6 R chart

The R control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 7.

Key
X subgroup number
Y range R value
Figure 7 — R control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 1):
L = 0
U = 0,005 801
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 11
---------------------- Page: 16 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.7 Moving range chart

The moving range control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 8.

Key
X individuals number
Y moving range value
Figure 8 — Moving range control chart for test data set 1
The control limits are (see ISO 7870-2:2013, Table 3):
L = 0
U = 0,004 51
Out of control situations are given in Table 5.

Table 5 — Results of pattern tests for the moving range control chart and test data set 1

Out of control situations
Value Result/violation Value Result/violation
77 to 84 run below centreline
12 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 17 ----------------------
ISO/TR 11462-3:2020(E)
5.1.2.8 Process capability

The process capability is calculated according to ISO 22514-2:2017, Clause 6, with calculation method

l = 3 for the location estimator and calculation method d = 5 for the dispersion estimator.

Capability indices (calculation method M )
3,5
Process is stable (mean, R - chart) - C /C is used
p pk
C 2,07 C 1,95
p pk
C 2,20 C 1,95
pkL pkU
5.2 Test data set 2
5.2.1 Test data set 2 information

This set of test data is taken from a process following a non-normal distribution and is for checking the

accuracy of calculation for control limits, sample statistics and process capabilities. A description of

test data set 2 is given in Table 6. Figure 9 shows a histogram and Figure 10 a probability plot of the test

data set 2 with the purpose of data visualization.
Table 6 — Description of test data set 2
Description of data input
Distribution model A2 Resulting distribution Weibull
Data set Annex A, Table A.1 decimal points 3
Total sample size 600 U 0,04
Size of subgroups 3 L 0
Key
X value
Y1 absolute frequency
Y2 relative frequency in %
Figure 9 — Histogram of test data set 2
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 13
---------------------- Page: 18 ----------------------
ISO/TR 11462-3:2020(E)
Key
X value
Y1 probability in %
Y2 1-probability in %
Figure 10 — Probability plot of test data set 2
NOTE The width of the class intervals is 0,003.

The class interval with the highest frequency of values is from 0,003 5 to 0,006 5.

The density plot is based on the assumption of a two parametric Weibull distribution with estimated parameters

scale a = 0,009 39 and shape b = 1,897 82. Both estimators have been calculated using the method of Maximum

Likelihood.

The 0,135 %- and the 99,865 %-percentiles are calculated using the inverse distribution function of the Weibull

distribution
Fp()|,ab =×ap[]−−ln()1
X = 0,000 29
0,135 %
X = 0,025 39
99,865 %
5.2.2 Test data set 2 results
5.2.2.1 List of sample statistics

Table 7 lists all sample statistics which are necessary to calculate the target values and control limits

for the control charts described in ISO 7870-2 as well as the estimators for location and dispersion

given in ISO 22514-2 for the calculation of the process capability indices.
14 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 19 ----------------------
ISO/TR 11462-3:2020(E)
Table 7 — List of sample statistics for test data set 2
Statistic Value Reference
Location
x (l = 1) 0,008 29 ISO 22514-2:2017, Formula (11)
x , (l = 2) 0,007 00 ISO 22514-2:2017, Formula (12)
0,008 29 ISO 22514-2:2017, Formula (13)
x , (l = 3)
0,007 51 ISO 22514-2:2017, Formula (14)
x , (l = 4)
Dispersion
0,025 11 (Weibull using parameters in 5.2.1) ISO 22514-2:2017, Formula (15)
Δ (d = 1)
σˆ (d = 2) 0,004 88 ISO 22514-2:2017, Formula (16)
σˆ (d = 3) 0,004 87 ISO 22514-2:2017, Formula (17)
ˆ 0,004 81 ISO 22514-2:2017, Formula (18)
σ (d = 4)
σˆ (d = 5) 0,004 67 ISO 22514-2:2017, Formula (19)
s 0,004 32 ISO 7870-2:2013, 3.2
R 0,026 00 ISO 7870-2:2013, 3.2
0,008 13 ISO 7870-2:2013, 3.2
R 0,005 14 ISO 7870-2:2013, 3.2
5.2.2.2 x chart

The xcontrol chart calculated according to ISO 7870-2:2013, 6.1, is shown in Figure 11.

Key
X number of subgroup
Y mean value
Figure 11 — Mean control chart for test data set 2
The control limits are (see ISO 7870-2:2013, Table 1, using s ):
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 15
---------------------- Page: 20 ----------------------
ISO/TR 11462-3:2020(E)

L = −0,000 15 (The calculated lower control limit is negative and the dataset is one-sided against

0 limited characteristic. Therefore, the lower control limit is not shown, L = ----)

U = 0,016 72
5.2.2.3 X chart

The individuals control chart calculated according to ISO 7870-2:2013, 6.2, is shown in Figure 12.

Key
X value number
Y individuals
Figure 12 — Individuals control chart for test data set 2
The control limits are (see ISO 7870-2:2013, Table 3):
L = −0,005 39
U = 0,021 96
Out of control situations are given in Table 8.

Table 8 — Results of pattern tests for the individuals control chart and test data set 2

Out of control situations
Value Result/violation Value Result/violation
75 violation of U 433 violation of U
CL CL
155 to 163 run below centreline 435 to 441 run below centreline
222 to 228 run below centreline 464 violation of U
367 violation of U 468 violation of U
CL CL
16 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 21 ----------------------
ISO/TR 11462-3:2020(E)
5.2.2.4 x chart

The median control chart calculated according to ISO 7870-2:2013, 6.3, is shown in Figure 13.

Key
X subgroup number
Y median value
Figure 13 — Median control chart for test data set 2
The control limits are (see ISO 7870-2:2013, Table 4):
L = −0,002 15
U = 0,017 17
Out o
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.