ISO 22745-1:2010(E)

Annex C
(informative)

Relationship to other standards

C.1 Relationship to ISO 13584

C.1.1 Introduction to ISO 13584

The goal of ISO 13584, Industrial automation systems and integration – Parts library (PLIB), is to define a data model, an exchange format, and an integration mechanism for computerized libraries and catalogues that describe classes of items.

The scope of ISO 13584 is given in ISO 13584-1 as follows:

ISO 13584 provides a representation of parts library information together with the necessary mechanisms and definitions to enable parts library data to be exchanged, used, and updated. The exchange may be between different computer systems and environments associated with the complete life cycle of the products where the library parts may be used, including product design, manufacture, use, maintenance, and disposal. The standard provides a generalized structure for a parts library system and does not define a fully detailed implementable parts library system.

NOTE 1  ISO 13584 is being developed by ISO TC 184/SC 4/WG 2 (WG 2).

Although the term "catalogue" does not appear in ISO 13584-1, there is an assumption that the data needed for a catalogue is a subset of the data needed for a parts library, and the library data model in ISO 13584 can represent catalogues.

Figure C.1 shows the structure of an ISO 13584 library system.


PLIB library system

Figure C.1 — PLIB library system

NOTE 2  Figure C.1 is copied verbatim from Figure 2 of ISO 13584-1:2001, Industrial automation systems and integration — Parts library — Part 1: Overview and fundamental principles.

C.1.2 Similarities between ISO 13584 and ISO 22745

Both ISO 13584 and ISO 22745 provide a data model and exchange format for:

In both standards, characteristic data is described in terms of property value pairs, with reference to a data dictionary entry for each property.

NOTE 1  The term "open technical dictionary" is used within ISO 22745 for ISO 22745's specialization of the general concept of "data dictionary entry".

NOTE 2  ISO 13584 uses the term "dictionary" to refer to a combination of a the ISO 8000-110 notions of "data dictionary" and "data specification".

The data models and exchange formats of both standards provide a mechanism for meeting, in part, the requirements of ISO 8000-110.

Since in ISO 13584, the dictionary and IG are combined, it is possible to represent an ISO 13584 dictionary as an ISO 22745 IG, provided that the terminology in the ISO 13584 dictionary is available through an OTD. This is illustrated in Figure C.2, which contains the EXPRESS-G for the ISO 13584 entity property_DET. ("DET" stands for "data element type".) Table C.1 shows the attributes that would be in a ISO 22745 dictionary:


PLIB property data element type data and relationships

Figure C.2 — Overview of PLIB property data element type data and relationships

NOTE 3  Figure C.2 is copied verbatim from Figure D.8 of ISO 13584-42:1998/Cor.1:2003, Industrial automation systems and integration — Parts library — Part 42: Description methodology: Methodology for structuring part families.

Table C.1 — Common attributes of ISO 13584 and ISO 22745 property definition

ISO 13584 attribute name ISO 22745 attribute name

basic semantic unit (BSU)

concept identifier

definition

definition

note

note (part of definition)

source document of definition

source document of definition

figure

image

name

term

ISO/TS 29002 is being developed to provide for an interface between ISO 22745 and ISO 13584 implementations. Table C.2 shows the correspondence between ISO/TS 29002 parts and ISO 22745 parts.

Table C.2 — Correspondence between ISO 22745 and ISO/TS 29002 parts

Subject ISO/TS 29002 part ISO 22745 part

Identification scheme

5

13

Dictionary terminology

6

14

Catalogue exchange

10

30

Dictionary query

20

14

C.1.3 Differences between ISO 13584 and ISO 22745

This clause describes some of the major differences between ISO 13584 and ISO 22745.

ISO 13584 requires that a property be defined within the context of a class. In ISO 22745, a property is defined independently of any class.

ISO 13584 assumes that classes will be organized into a hierarchy. Although the ISO 13584 data model allows a data provider to "cheat" by creating a flat hierarchy consisting of a single root class, with all other classes directly below it, guidelines that accompany ISO 13584 do not allow this. In ISO 22745, classes are defined independently of any hierarchy.

NOTE   ISO 22745 does allow classes to be linked to externally-defined hierarchies.

In ISO 22745, a concept (e.g., a property) may have more than one definition associated with it, whereas in ISO 13584, there may be only one. In ISO 22745, notes are associated with individual definitions, and there can be more than one note for a definition. A definition in ISO 22745 may have examples as well as notes associated, and the sequence of notes and examples is preserved. ISO/TS 22745-30 uses the PrescribedProperty entity data type to model the specification of how to represent the value of a property within the context of the representation of an item. An ISO/TS 22745-30 PrescribedProperty references an OTD for the terminological definition of the property. ISO 13584 uses the property_DET entity data type to model the specification of how to represent the value of a property within the context of the representation of an item; however, the property_DET includes the terminological definition of the property, rather than referencing a separate data dictionary.

The following attributes would be in an ISO 22745 IG entry for a prescribed property:

The ISO 13584 exchange format for dictionaries is based on ISO 10303-21, Industrial automation systems and integration — Product data representation and exchange — Part 21: Implementation methods: Clear text encoding of the exchange structure. The ISO 22745 exchange formats for OTDs, IGs, and master data is based on XML.

C.2 Relationship to ISO 15926

C.2.1 Introduction to ISO 15926

The purpose of ISO 15926 is to facilitate such integration of data to support the life-cycle activities and processes of oil and gas facilities, process plants and power plants. To do this, ISO 15926 specifies a data model that defines the meaning of the life-cycle information in a single context supporting all the views that process engineers, equipment engineers, operators, maintenance engineers and other specialists may have of the plant. This requires data about components/parts to be available in a computer processable form for incorporation into plant designs and requirements, i.e., such data must be integrated in the same context.

The scope of ISO 15926 is given in ISO 15926-1 as follows:

This International Standard specifies a representation of information associated with engineering, construction and operation of process plants. This representation supports:

The following are within the scope of ISO 15926:

C.2.2 Differences between ISO 15926 and ISO 22745

This clause describes some of the major differences between ISO 15926 and ISO 22745.

The ISO 15926 data model, defined in ISO 15926-2, is extremely general and intended to be an "integration model" that could be used to represent almost anything. Because of the data model's generality, how to represent dictionary, IG, and catalogue data is not clear. A specific data model is not given for dictionaries, IGs, or catalogues. In addition, ISO 15926 does not separate the notions of dictionary and IG. ISO 22745 defines separate, explicit data models for dictionaries, IGs and catalogues.

ISO 15926 requires classes to be organized into a hierarchy.

ISO/TS 15926-4 contains a standard dictionary/IG that all users of ISO 15926 are required to use, although they can extend it with their own classes by creating subclasses of those in the standard dictionary/IG.

At present, no exchange format is defined for ISO 15926 dictionaries/IGs and catalogues. Instead, ISO 15926 dictionaries/IGs and catalogues are exchanged using spreadsheets. ISO 22745 defines XML schemas for dictionaries, IGs, and catalogues.

NOTE   This may be addressed in a future enhancement to ISO 15926.


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