ISO 22745-1:2010(E)

5 Architecture

5.1 First principles

ISO 22745 provides a series of specifications, data formats, and procedures to enable organizations to improve the quality of master data. In particular, ISO 22745 is intended to enable an organization to satisfy the requirements of ISO 8000-110 for exchange of quality characteristic data that is master data.

NOTE   ISO 8000-110 specifies general requirements, but not specific data formats or procedures.

The requirements of ISO 8000-110 are derived from the following general requirements:

  1. ISO 8000-110 requires that a master data message unambiguously state all information necessary for the receiver to determine its meaning and in which context its value is valid.

    ISO/TS 22745-40 specifies a format for representing master data messages in detail. ISO 22745 is based on the notion that all cataloguing concepts are contained in an OTD, and the ISO/TS 22745-40 master data message references cataloguing concepts in the OTD via ISO 22745-13 globally unambiguous identifiers, rather than defining the concepts internally within the master data message, or not defining them at all.

  2. ISO 8000-110 requires that a syntax be specified using a formal notation.

    ISO/TS 22745-40 specifies an Extensible Markup Language (XML) schema (a formal notation) for a master data message.

  3. ISO 8000-110 requires that a data specification be specified using a computer-interpretable language.

    ISO/TS 22745-30 specifies an XML schema for IGs. The notion of "IG" is the ISO 22745 specialization of the ISO 8000-110 notion of "data specification". Using an XML parser built from the ISO/TS 22745-30 XML schema, a computer program can parse a IG. Using Web services built from ISO/TS 22745-14, a computer program can resolve the concept identifiers in a IG to human-readable terminology. Thus, an ISO/TS 22745-30 IG is in a computer-interpretable language.

  4. ISO 8000-110 requires that a master data message refer explicitly both to the data specifications it fulfils and to the formal syntax to which it complies.

    The ISO/TS 22745-40 XML schema contains an attribute with the globally unambiguous identifier for the IG. An XML file conforming to the ISO/TS 22745-40 XML schema will contain a namespace declaration that references the ISO/TS 22745-40 XML schema.

  5. ISO 8000-110 requires that it be possible to check correctness of the master data message against both its formal syntax and its data specification automatically by computer.

    The combination of XML schema for IG (ISO/TS 22745-30), XML schema for master data message (ISO/TS 22745-40), and Web services for resolving identifiers (ISO/TS 22745-14) enables development of a computer program to check correctness of a master data message against both its formal syntax and its data specification.

  6. ISO 8000-110 requires that the identifiers within a master data message belong to an internationally-recognized scheme.

    ISO/TS 22745-30 and ISO/TS 22745-40 use the identification scheme specified in ISO 22745-13, which is based on ISO/IEC 6523-1.

ISO 8000-110 provides two conformance classes: "free encoding" and "fee-based encoding". In order to claim conformance to ISO 22745, the data must conform to the "free encoding" conformance class. This enables an organization to preserve the integrity of intellectual property of the creator of information that has been encoded using identifiers for concepts in a data dictionary.

Figure 1 shows the ISO 22745 data architecture.


ISO 22745 data architecture

Figure 1 — ISO 22745 data architecture

5.2 Dictionary and identification scheme

An OTD consists of a set of concepts. Each concept has one or more terms, one or more definitions, and zero or more images. A globally unambiguous identifier is assigned to each concept, term, definitions, and image. If a concept has more than one term, no preference is given to any specific term. The same holds true for definitions, or images. The following concept types are currently defined:

NOTE   ISO 22745-13 specifies codes for concept types that are used within ISO/TS 29002 parts. The list of concept types specified in ISO 22745-13 can be extended through instances of the concept_type entity data type, which is defined in ISO/TS 22745-10.

The UML model and exchange format for a dictionary are specified in ISO/TS 22745-10.

The identification scheme is specified in ISO 22745-13.

5.3 Identification guide

An IG constrains the use of the dictionary to meet the need of a specific data recipient. The UML model and exchange format for an IG are specified in ISO/TS 22745-30.

NOTE 1  A typical data recipient is a buyer. However, a large supplier can define its own IG in order to specify the format of its own data publications.

An IG specifies which classes may be used in a catalogue, and which properties may be used for each class. If there are multiple terms, definitions, or images associated with a given concept, the IG may specify which one is preferred. An IG specifies the representation (string, measure, currency, etc.) for each property as applied to a given class. Furthermore, an IG may impose constraints on the properties, including the following:

As shown in Figure 1 the following assertions hold:

Different buyers or groups of buyers may agree on terminology but have different requirements for data organization and format. Separating the IG from the dictionary allows the buyer or groups of buyers to receive data in the desired format while still taking advantage of a common dictionary of concepts and terminology.

EXAMPLE 1  Organizations 1 and 2 both buy wire wound fixed resistors. They both require that the test data document be given within the characteristic data of each resistor. Both organizations use the following definition:

test data document

specification, standard, drawing, or similar instrument that specifies environmental and performance requirements or test conditions under which an item is tested and establishes acceptable limits within which the item must conform

Organization 1 requires that the test data document value be given as plain text. Figure 2 illustrates how Organization 1's IG would specify how the value of test data document should be represented in a catalogue.

Organization 2 requires that the test data document value be broken down into the following constituent components:

Figure 3 illustrates how Organization 2's IG would specify how the value of test data document should be represented in a catalogue. In Organization 2's IG, the test data document property is represented as a composite datatype. A composite value consists of one or more fields. Each field is essentially an embedded property value pair, with a property reference.


Test data document represented as a single string

Figure 2 — Identification guide excerpt for Organization 1 — test data document represented as a single string datatype


Test data document broken into components

Figure 3 — Identification guide excerpt for Organization 2 — test data document represented as a composite datatype

EXAMPLE 2  Organizations 1 and 2 both buy wire wound fixed resistors. They both require that the terminal length be given within the characteristic data of each resistor. Organization 1 requires that the terminal length be given in millimetres, and thus uses the following concept definition:

terminal length in millimetres

longest dimension of a terminal, given in millimetres

Since the unit of measure is bound into the concept definition, the property value pair representing terminal length in millimetres in the catalogue should contain only a numeric value. Figure 4 illustrates how Organization 1's IG would specify how the value of test data document should be represented in a catalogue.

Organization 2 requires that the terminal length be given in either millimetres or inches, and uses the following concept definition:

terminal length

longest dimension of a terminal

Since the unit of measure is not bound into the concept definition, it must be given as part of the property value pair Figure 5 illustrates how Organization 2's IG would specify how the value of test data document should be represented in a catalogue. In Organization 2's IG, the terminal length property is represented as a measure datatype. A measure value consists of a unit of measure and a numeric value. The numeric value is represented using a numeric datatype.


Test data document represented as a single string

Figure 4 — Identification guide excerpt for Organization 1 — terminal length represented as a number


Test data document broken into components

Figure 5 — Identification guide excerpt for Organization 2 — terminal length represented as a measure with unit

NOTE 2  The concept identifiers in Figures 2 to 5 are for illustration only, and are not concept identifiers from an actual OTD.

NOTE 3  In Figure 2 to 5, the following simplifications are made:

EXAMPLE 3  Under the scheme in Figures 2 and 5, the concept identifier for wire wound fixed resistor, with version number 1 added, would be "9999-1#01-01#1".

5.4 Catalogue

A catalogue contains a list of descriptions of items. Each item is described by association with a class and by a series of property value pairs. Datatypes for property values include the following:

NOTE 1  ISO/TS 22745-40 contains the normative specification of the datatypes for property values.

A measure value may be qualified (e.g., length = 14.0 cm nominal, plus or minus 0.01 cm). The allowable qualifiers for a measure value for a given property for a given class are specified in the IG.

For each part of the architecture except the identification scheme (dictionary, IG, and catalogue), a Unified Modeling Language (UML) data model has been defined, along with an XML exchange format (see Figure 6).

NOTE 2  Each slate colored box represents a UML data model. Each purple box represents an XML schema.

NOTE 3  Each box in Figure 6 represents a kind of data set, and each arrow represents a reference from one data set to another.

EXAMPLE   A property value pair in a catalogue references a property defined in an OTD. Thus, there is an arrow from the "Catalogue" box to the "Dictionary" box.


Models and schemas

Figure 6 — Models and schemas


© ISO 2010 — All rights reserved