SIST EN 61069-2:1998

SLOVENSKI STANDARD
SIST EN 61069-2:1998
01-november-1998
Industrial-process measurement and control - Evaluation of system properties for
the purpose of system assessment - Part 2: Assessment methodology (IEC 61069-
2:1993)
Industrial-process measurement and control - Evaluation of system properties for the
purpose of system assessment -- Part 2: Assessment methodology
Leittechnik für industrielle Prozesse - Ermittlung der Systemeigenschaften zum Zweck
der Eignungsbeurteilung eines Systems -- Teil 2: Methodik der Eignungsbeurteilung
Mesure et commande dans les processus industriels - Appréciation des propriétés d'un
système en vue de son évaluation -- Partie 2: Méthodologie à appliquer pour l'évaluation
Ta slovenski standard je istoveten z: EN 61069-2:1994
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
SIST EN 61069-2:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61069-2:1998

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SIST EN 61069-2:1998

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SIST EN 61069-2:1998

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SIST EN 61069-2:1998

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SIST EN 61069-2:1998

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SIST EN 61069-2:1998
NORME CEI
INTERNATIONALE IEC
61069-2
INTERNATIONAL
Première édition
STAN DARD
First edition
1993-03
Mesure et commande dans les processus
industriels –
Appréciation des propriétés d'un système
en vue de son évaluation –
Partie 2:
Méthodologie à appliquer pour l'évaluation
Industrial -
process measurement and control –
Evaluation of system properties for
the purpose of system assessment –
Part 2:
Assessment methodology
© IEC 1993 Droits de reproduction réservés — Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur writing from the publisher.
Internationzl Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
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International Electrotechnical Commission
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vigueur
Pour prix, voir catalogue en
•
For price, see current catalogue

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SIST EN 61069-2:1998
1069-2 © IEC: 1993 — 3 —
CONTENTS
Page
FOREWORD 5
INTRODUCTION 9
Clause
1 Scope 13
2 Normative reference 13
3 Definitions 13
4 Assessment approach 15
5 Analysis of system mission 21
5.1 General 21
5.2 Formulation of system mission 21
5.3 Analysis of system mission into tasks 21
5.4 Assignment of relative importance to tasks 23
5.5 Definition of influencing conditions 23
5.6 Documentation of system requirements 23
6 Specification of system implementation 25
6.1 General 25
6.2 System overview 25
6.3 Definition of system boundaries 25
6.4 Specification of system 27
6.5 Description of system operation 29
6.6 Statement of system implementation rationale 29
6.7 Statement of compliance with system requirements 29
6.8 Documentation of system specification 29
7 Assessment procedure 29
7.1 General 29
7.2 Collation of documented information 31
7.3 Design of assessment programme 31
7.4 Execution and reporting of the assessment 33
Annex A — Bibliography 35

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SIST EN 61069-2:1998
1069-2 © IEC: 1993 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
INDUSTRIAL-PROCESS MEASUREMENT AND CONTROL -
EVALUATION OF SYSTEM PROPERTIES FOR
THE PURPOSE OF SYSTEM ASSESSMENT
Part 2: Assessment methodology
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 cooperation 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, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use 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.
This part of International Standard IEC 1069 has_ been prepared by sub-committee 65A:
System aspects, of IEC technical committee 65: Industrial-process measurement and
control.
The text of this part is based on the following documents:
DIS Report on Voting
65A(CO)30 65A(CO)35
Full information on the voting for the approval of this part can be found in the voting repo rt
indicated in the above table.
The complete standard will consist of a series of publications, of which this is the second pa rt .
Part 1 provides the overall guidance and as such it 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.

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SIST EN 61069-2:1998
1069-2 ©IEC: 1993 – 7 –
The division of properties in Parts 3 to 8 has been chosen so as to group together related
properties.
The complete series will consist of the following titles:
Part 1: General considerations and methodology.
Part 2: Assessment methodology.
Part 3: Assessment of system functionality
(under consideration).
Part 4: Assessment of system pe
rformance (under consideration).
Pa rt 5: Assessment of system dependability
(under consideration).
Pa rt
6: Assessment of system operability (under consideration).
Pa rt
7: Assessment of system safety
(under consideration).
Pa rt
8: Assessment of non-task-related system properties (under consideration).
Annex A is for information only.

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SIST EN 61069-2:1998
1069-2 © I EC: 1993 - 9 -
INTRODUCTION
rt
This pa of IEC 1069 details the methodology needed to systematically assess 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 for an assessment of a system 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 effo rt 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 can still be defined and 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
rt of
provides procedures for performing evaluations, since evaluations are an integral pa
assessment.
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The relation of this pa rt to the other pa rts of IEC 1069 and the relative place of this pa
within the standard is shown in figure 1.

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SIST EN 61069-2:1998
1069-2 © IEC: 1993 - 11 -
Part 1: General considerations
and methodology
Scope
Definitions
Basis of assessment
Assessment considerations
The system
Properties
Influencing conditions
Assessment procedures
Definition of the objectives
Design and layout
Part 2: Methodology
Analysis of objectives
Analysis of system requirements
Analysis of system specification
i
Planning Design assessment programme
Facilities
Expertise
Time
Funds
Execution assessment programme
Protocol
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 International Standard IEC 1069

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SIST EN 61069-2:1998
1069-2 ©
IEC: 1993 - 13 -
INDUSTRIAL-
PROCESS MEASUREMENT AND CONTROL -
EVALUATION OF SYSTEM PROPERTIES FOR
THE PURPOSE OF SYSTEM ASSESSMENT
Part 2: Assessment methodology
1 Scope
This part of IEC 1069 details the assessment methodology of industrial-process
measurement and control systems.
It describes the method for analyzing the objectives given for the assessment, the method
for weighing the relative impo rt
ance of the various system properties and influencing
conditions, and for determining an assessment programme.
2 Normative reference
The following normative document contains provisions which, through reference in this
text, constitute provisions of this pa rt
of IEC 1069. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and parties making
agreements based on this pa rt
of IEC 1069 are encouraged to investigate the possibility of
applying the most recent edition of the normative document indicated below. Members of
IEC and ISO maintain registers of currently valid International Standards.
IEC 1069-1: 1991,
International-process measurement and control - Evaluation of system
properties for the purpose of system assessment - Part 1: General considerations and
methodology.
3 Definitions
For the purpose of this pa rt of IEC 1069, the following definitions apply:
3.1
assessment (of a system): Judgement, based on evidence, of the system's suit-
ability for a specific mission or class of missions.
3.2 evaluation (of a system property):
Attribution of a qualitative or quantitative value
to that system property.
3.3 mission (of a system):
Collective activity assigned to the system to achieve a
defined goal in a defined period under defined conditions.
3.4 task:
Logically complete operation forming a pa rt of the system mission.
3.5 function:
Elementary operation performed by the system which, combined with other
elementary operations (system functions) enables the system to perform a task.

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SIST EN 61069-2:1998
1069-2 ©IEC: 1993 - 15 -
3.6 module: Discrete
unit, capable of performing distinct functions and which can be
easily joined to or arranged with other units.
3.7 element: Any physical part, comprising hardware and/or software, that can be indi-
vidually considered and tested.
4 Assessment approach
Industrial-process measurement and control systems are sufficiently complex, so that a
totally comprehensive assessment inevitably requires an expenditure of effort and time
that is neither practical nor cost-effective.
It is therefore important to analyze and specify the objectives of the assessment carefully,
before an assessment programme is designed.
The objectives of the assessment may differ, being, for example:
- to establish the suitability of a system for a specific mission;
- to establish the suitability of a system for a defined class of missions.
The mission of the system or class of missions is broken down into tasks.
The task(s) which the system shall perform should be defined in terms of its required
properties.
This enables the precise specification of the supporting functions the system should
possess in order to be able to fulfil its task(s).
rt
Some of the properties are, however, not task related, such as documentation, suppo
services, etc. and shall be specified separately.
With the assessment objectives, the system requirements and the system specifications
defined, the assessment programme can be designed.
In general an assessment is executed in phases as shown in figure 2.

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SIST EN 61069-2:1998
1069-2 © I EC: 1993
– 17 –
Application
System
Assessment
Formulation of system
mission(s)
Analysis of mission(s)
into tasks
Assign relative importance
to tasks
Define influencing
conditions
System requirements
(document)
System overview
Specify system to be assessed
Define system boundaries
System specification
(document)
Define boundaries of system
to be assessed
Determine areas of non-compliance
Allocate functions to system
modules/elements
Determine the properties and
influencing conditions to be
assessed
Establish a priori level of
confidence
Determine appropriate assessment
techniques
Determine cost/time for each
assessment activity
Determine assessment priorities
Plan assessment programme
Assessment execution
Reporting the assessment
Figure 2 – Assessment scenario

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SIST EN 61069-2:1998
1069-2 © IEC: 1993 - 19 -
If no mission or class of missions is defined, no assessment can be made.
Evaluations of defined system properties, however, can still be performed for use in
assessments at a later time.
In the latter event, with the evaluation objectives defined and the system and its properties
to be evaluated specified, an appropriate evaluation programme can be designed.
The general assessment layout of figure 2 can still be used, but is then reduced to the
evaluation scenario of figure 3.
Application System Evaluation
Specify system to be evaluated
Define system boundaries
System specification (document)
Define functions to be evaluated
Allocate functions to system modules/
elements
Determine the properties and
influencing conditions to be evaluated
Establish a priori level of confidence
Determine appropriate evaluation
techniques
Determine cost/time for each evaluation
activity
Determine evaluation priorities
Plan evaluation programme
Evaluation execution
Reporting the evaluation
Figure 3 - Evaluation scenario
Structuring the analysis of the mission, the system configuration and the assessment or
evaluation, as indicated, has the adv
...