Standards Development

Scope

This part of the 81346 International Standard, published jointly by IEC and ISO, provides, in combination with IEC 81346-1 and IEC 81346-2, rules and recommendations on the classification of properties related to systems designated by reference designations in any area of technical products and equipment. It provides a classification scheme of properties representing characteristics of objects and systems being designated by function- product- location- or type-specific reference designations. The classes of properties are intended, when combined with a reference designation to provide a clear identification of any property. RDS 81346-8 Properties are based on fundamental quantities and units in accordance with ISO 80000 standard series and standard data element types in accordance with IEC 61360 standard series (CDD) where applicable. This NP is coordinated with IEC SC3D (CDD) which supports this NP. This document will provide a generic set of properties which is fit for purpose in the design phase of systems and make these properties an important relation to the object occurrence (see IEC 81346 -1, 4.9) as distinct from object individuals (see IEC 81346-1, 4.9).

Purpose

The ISO/IEC 81346 standard series (known as “RDS” for Reference Designation System) provides the
rules and tables for creating a reference model for systems, which is a naming convention for systems
used so anyone (humans, tools, documents etc.) can refer to the same object in an unambiguous
manner from anywhere, across any platform.
The 81346 standard series has during the last years developed to be significant in the aim for
digitalization. The reference designation system enables users to create a “neutral” reference model
for all engineering disciplines, which is referrable to/from other systems (e.g. diagramming, 3D, asset
management tools etc.) without conflicting with them.
It is also clear that the 81346 standard series supports systems engineering as defined in ISO 15288
and system architecture as defined in ISO 42010, because systems and system breakdowns in different
aspects as defined by 81346 is a fundamental part of a system architecture.
The 81346 standard series supports the planning, design, utilization and maintenance of system in a
wide range of industry domains. Advantages of designation systems in combination with properties,
which will be more and more important in the future are:
- The reference designation system can be applied in several technical fields in the same
way and is not designed only for one. Aeronautics, mechanical, electrical and process equipment can
be treated the same way which is a basis for companywide synergy effects.
- The reference designation system allows integrating any kind of systems and components
without changing the once defined designations.
- Properties of any system designated by the reference designation system also becomes
unambiguous and thereby referrable from other sources.
- Properties are regarded as an important part of digitalization of requirements related to
systems and system elements.
- The application of different aspects allows, for instance, the designation of functions
independently from realizing products and their location. Properties (in accordance with this proposal)
can be related to any of these aspects.

Rationale
Requirements is an essential part when designing systems, installations and equipment and industrial
products i.e. systems in the scope of the 81346-standard series. As the request to increase
digitalization in the lifecycle of any system is increasing, the need for a common language in this respect of systems. As a part of this framework, the ISO 80000 series plus IEC 61360 was chosen as source
for properties to be sorted in “the RDS way”, including clear definitions for any property identified.
The study demonstrated that properties can be sorted in non-quantitative properties (e.g. colours, taste,
serial numbers) and quantitative properties (QP). QP could then be sub-classified as dimensioned
quantities (e.g. mass, speed, voltage etc. from ISO 80000), dimensionless quantities (e.g. angle,
efficiency), ordinal quantities (Richter scale, Rockwell C hardness etc.) and non -physical quantities.
A total of approximate 260 properties was identified to cover the need for any property, which is
relatively simple compared with other studies, but made possible as the properties was created using
the RDS classification principle; “a door is a door” (with one RDS system code only), and subsequently
“a mass is a mass” (with one RDS property code only). The study also demonstrated that RDS
properties was not in conflict with existing IEC CDD entries and mapping to/from other classification
principles was possible.
In addition to this initial study, it also became clear that most properties are designed to fit products
which has been chosen, and a more generic classification was needed to support from the initial design
phase. As the scope of the 81346 standard is to designate objects (systems) in the full lifecycle by
means of a clear designation between object occurrences and object individuals (see IEC 81346 -1),
the 81346 standard series is in fact designed for exact this life cycle purposes.
The current IEC 81346-1 part has addressed the need to include properties as a part of reference
designations, see IEC 81346-1, 11, but without including a classification scheme for this. The study
demonstrated that properties could be designated “the RDS way”, to support and enrich the common
language provided by the 81346-standard series.
As members of IEC/TC3 as well as ISO/TC10, we (members of the Danish National Committee) have
been asked to propose the new 81346 part 8 for properties. We lately came across the interest ISO
has shown in expanding the IEC CDD database with a more generic collection of properties which are
non-electrical. Based on the collaboration rules between ISO and IEC in common standard series,
either ISO/TC10 or another technical committee of ISO should join the development, but we would
encourage TC’s in both ISO and IEC which is not officially in charge to monitor the development and
contribute with technical knowledge to the extent possible.
This part of the standard will build upon the already well-established knowhow of how to make
classification structure, following the same principles as in 81346-2, -10, -12, -14 (pending) and -50
is evident. The 81346 standard series already provide this common language, however requirements
in the form of properties are not supported, yet it is more and more requested.
It is well known that a lot of different initiatives, also outside IEC and ISO, are working to make a useful
solution for requirements and properties in a digital sense, however none of these projects seems to
follow basic rules for establishing classification systems as defined in ISO 22274. Since 2012 the
ISO/IEC 81346 standard series has followed the rules for classification systems defined in ISO 22274,
and the result of this method has been a simple, yet very powerful, classification of systems both
generic and industry specific.
With the knowhow from the work with 81346 made so far, an initial study was carried out in 2020 to test
if it was possible to establish “RDS 81346 Properties” in the same manner as 81346 handles classes