EN 61069-4:1997

SLOVENSKI STANDARD
01-november-1998
Industrial process measurement and control - Evaluation of system properties for
the purpose of system assessment - Part 4: Assessment of system performance
(IEC 61069-4:1997)
Industrial process measurement and control - Evaluation of system properties for the
purpose of system assessment -- Part 4: Assessment of system performance
Leittechnik für industrielle Prozesse - Ermittlung der Systemeigenschaften zum Zweck
der Eignungsbeurteilung eines Systems -- Teil 4: Eignungsbeurteilung des
Systembetriebsverhaltens
Mesure et commande dans les processus industriels - Appréciation des propriétés d'un
système en vue de son évaluation -- Partie 4: Evaluation des caractéristiques de
fonctionnement d'un système
Ta slovenski standard je istoveten z: EN 61069-4:1997
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
35.240.50 Uporabniške rešitve IT v IT applications in industry
industriji
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
61069-4
INTERNATIONAL
Première édition
STANDARD
First edition
1997-08
Mesure et commande dans les
processus industriels –
Appréciation des propriétés d’un système
en vue de son évaluation –
Partie 4:
Evaluation des caractéristiques
de fonctionnement d’un système
Industrial process measurement and control –
Evaluation of system properties for the purpose
of system assessment –
Part 4:
Assessment of system performance
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61069-4 © IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 5
INTRODUCTION . 9
Clause
1 Scope. 13
2 Normative references . 13
3 Definitions . 15
4 Performance properties . 15
4.1 General . 15
4.2 Performance. 17
4.3 Accuracy . 19
4.4 Response time. 19
4.5 Capacity . 19
5 Review of system requirements document (SRD) . 21
6 Analysis of system specification document (SSD). 23
7 Assessment procedure . 23
7.1 General . 23
7.2 Analysis of the SRD and the SSD. 23
7.3 Designing the assessment programme. 27
7.4 Assessment programme . 29
8 Evaluation techniques. 29
8.1 General . 29
8.2 Analytical evaluation techniques. 31
8.3 Empirical evaluation techniques . 31
8.4 Testing under influencing conditions . 37
9 Execution and reporting of the assessment . 37
Annexes
A Checklist on information to be given in the SRD . 39
B Example documentation of collated information from the SRD and the SSD. 43
C Model of an evaluation. 49
D Bibliography. 69

61069-4 © IEC:1997 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
INDUSTRIAL-PROCESS MEASUREMENT AND CONTROL –
EVALUATION OF SYSTEM PROPERTIES FOR
THE PURPOSE OF SYSTEM ASSESSMENT –
Part 4: Assessment of system performance
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61069-4 has been prepared by subcommittee 65A: System aspects,
of IEC technical committee 65: Industrial-process measurement and control.
The text of this standard is based on the following documents:
FDIS Report on voting
65A/231/FDIS 65A/240/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

61069-4 © IEC:1997 – 7 –
The relation of this part to the other parts of IEC 61069 and the relative place of this part within
this standard is shown in figure 1.
Part 1 provides the overall guidance and as such is intended as a stand-alone publication.
Part 2 details the assessment methodology.
Parts 3 to 8 provide guidance on the assessment of specific groups of properties.
The division of properties in parts 3 to 8 have been chosen so as to group together related
properties.
IEC 61069 consists of the following parts, under the general title: Industrial-process
measurement and control – Evaluation of system properties for the purpose of system
assessment.
Part 1: General considerations and methodology
Part 2: Assessment methodology
Part 3: Assessment of system functionality (under consideration)
Part 4: Assessment of system performance
Part 5: Assessment of system dependability
Part 6: Assessment of system operability (under consideration)
Part 7: Assessment of system safety (under consideration)
Part 8: Assessment of non-task-related system properties (under consideration)
Annexes A, B, C and D are for information only.
The contents of the corrigendum of December 1997 have been included in this copy.

61069-4 © IEC:1997 – 9 –
INTRODUCTION
This part of IEC 61069 deals with the method which should be used to assess the performance
of industrial process measurement and control systems.
Assessment of a system is the judgement, based on evidence, of the system's suitability for a
specific mission or class of missions.
To obtain total evidence would require complete (i.e. under all influencing conditions)
evaluation of all system properties relevant to the specific mission or class of missions.
Since this is rarely practical, the rationale on which an assessment of a system should be
based is:
– to identify the criticality of each of the relevant system properties;
– to plan for evaluation of the relevant system properties with a cost effective dedication of
effort to the various properties.
In conducting an assessment of a system it is crucial to bear in mind the need to gain a
maximum increase in confidence in the suitability of a system within practical cost and time
constraints.
An assessment can only be carried out if a mission has been stated (or given) or if any mission
can be hypothesized. In the absence of a mission, no assessment can be made; however,
evaluations (as defined in IEC 61069-1) can still be specified and be carried out for use in
assessments performed by others.
In such cases, the standard can be used as a guide for planning an evaluation and it provides
procedures for performing evaluations, since evaluations are an integral part of assessment.

61069-4 © IEC:1997 – 11 –
Part 1:
General considerations
and methodology
Scope
Definitions
Basis of assessment
Assessment consideration
The system
Properties
Influencing conditions
Assessment procedure
Definition of the objectives
Design and layout
Part 2:
Methodology
Analysis of objectives
Analysis of system requirements
Analysis of specification
Planning Design of assessment programme
Facilities
Expertise
Time
Funds
Protocol Execution of assessment programme
Monitor and control
Part 3: Functionality
Part 4: Performance
Part 5: Dependability
Part 6: Operability
Part 7: Safety
Part 8: NTR properties
Assessment report
Figure 1 – General layout of IEC 61069

61069-4 © IEC:1997 – 13 –
INDUSTRIAL-PROCESS MEASUREMENT AND CONTROL –
EVALUATION OF SYSTEM PROPERTIES FOR
THE PURPOSE OF SYSTEM ASSESSMENT –
Part 4: Assessment of system performance
1 Scope
This part of IEC 61069 covers the method to be used to systematically assess the performance
of industrial-process measurement and control systems.
The assessment methodology detailed in IEC 61069-2 is applied to obtain the performance
assessment programme.
The subsidiary performance properties are analyzed, and criteria to be taken into account when
assessing performance are described.
References are made to different supplementary performance evaluation techniques.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61069. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on IEC 61069 are encouraged to investigate the possibility of applying the most recent editions
of the normative documents indicated below. Members of IEC and ISO maintain registers of
currently valid International Standards.
IEC 60068,
Environmental testing
IEC 60721, Classification of environmental conditions
IEC 60902: 1987, Industrial-process measurement and control – Terms and definitions
IEC 61000, Electromagnetic compatibility (EMC)
IEC 61069-1: 1991, Industrial-process measurement and control – Evaluation of system
properties for the purpose of system assessment – Part 1: General considerations and
methodology
IEC 61069-2: 1993, Industrial-process measurement and control – Evaluation of system
properties for the purpose of system assessment – Part 2: Assessment methodology
IEC 61298-2: 1995, Process measurement and control devices – General methods and
procedures for evaluating performance – Part 2: Tests under reference conditions

61069-4 © IEC:1997 – 15 –
IEC 61298-3: —, Process measurement and control devices – General metho
...