ISO/IEC 11179 (formally known as the ISO/IEC 11179 Metadata Registry (MDR) standard) is an international standard for representing metadata for an organization in a metadata registry.
Today, organizations often want to exchange data quickly and precisely between computer systems using enterprise application integration technologies. Completed transactions are also often transferred to separate data warehouse and business rules systems with structures designed to support data for analysis. The industry de facto standard model for data integration platforms is the Common Warehouse Model (CWM). Data integration is often also solved as a data, rather than a metadata, problem, with the use of so called master data. ISO/IEC 11179 claims that it is a standard for metadata-driven exchange of data in an heterogeneous environment, based on exact definitions of data.
The ISO/IEC 11179 model is a result of two principles of semantic theory, combined with basic principles of data modelling.
The first principle from semantic theory is the thesaurus type relation between wider and more narrow (or specific) concepts, i.e. the wide concept "income" has a relation to the more narrow concept "net income".
The second principle from semantic theory is the relation between a concept and its representation, i.e. "buy" and "purchase" are the same concept even if different terms are used.
The basic principle of data modelling is the combination of an object class and a characteristic. For example, "Person - hair color".
When applied to data modelling, ISO/IEC 11179 combines a wide "concept" with an "object class" to form a more specific "data element concept". For example, the high-level concept "income" is combined with the object class "person" to form the data element concept "net income of person". Note that "net income" is more specific than "income".
The different possible representations of a data element concept are then described with the use of one or more data elements. Differences in representation may be a result of the use of synonyms or different value domains in different data sets in a data holding. A value domain is the permitted range of values for a characteristic of an object class. An example of a value domain for "gender of person" is "M = Male, F = Female, U = Unknown". The letters M, F and U are then the permitted values of gender of person in a particular dataset.
The data element concept "monthly net income of person" may thus have one data element called "monthly net income of individual by 100 dollar groupings" and one called "monthly net income of person range 0-1000 dollars", etc., depending on the heterogeneity of representation that exists within the data holdings covered by one ISO/IEC 11179 registry. Note that these two examples have different terms for the object class (person/individual) and different value sets (a 0-1000 dollar range as opposed to 100 dollar groupings).
The result of this is a catalogue of sorts, in which related data element concepts are grouped by a high-level concept and an object class, and data elements grouped by a shared data element concept. Strictly speaking, this is not a hierarchy, even if it resembles one.
It is worth noting that ISO/IEC 11179 proper does not describe data as it is actually stored. There is no part of the model that caters to the description of physical files, tables and columns. All the ISO/IEC 11179 constructs are "semantic" as opposed to "physical" or "technical".
Since the standard has two main purposes (definition and exchange) the core object is the data element concept, since it defines a concept and, ideally, describes data independent of its representation in any one system, table, column or organisation.
The standard consists of six parts:
Part 1 explains the purpose of each part. Part 3 specifies the metamodel that defines the registry. The other parts specify various aspects of the use of the registry.
The data element is foundational concept in an ISO/IEC 11179 metadata registry. The purpose of the registry is to maintain a semantically precise structure of data elements.
Each Data element in an ISO/IEC 11179 metadata registry:
Data elements that store "Codes" or enumerated values must also specify the semantics of each of the code values with precise definitions.
The poor reception of ISO/IEC 11179 in commercial data warehousing and data integration software suggests that it may not fill real world business needs. Despite the rising demand for efficient data integration solutions, Oracle, the only major commercial supporter of ISO/IEC 11179 has canceled its support for this standard (see below)!
The spread of ISO/IEC 11179 has been more successful in the public sector. However, it is unclear if this is due to different requirements for data exchange in the public sector, since its spread seems to follow the sphere of influence of the participants in the development of the standard, i.e. the reception is with U.S. government agencies, and with a limited group of national and international statistical organisations.
Organizations such as the United Nations and the US Government are large users of 11179 standards.
11179 is strongly recommended on the U.S. government's XML website. US Government's XML web site and is promoted by The OPEN Group as a foundation of the Universal Data Element Framework (UDEF http://www.opengroup.org/udef/). The Open Group is a vendor-neutral and technology-neutral consortium working to enable access to integrated information within and between enterprises based on open standards and global interoperability.
Although the ISO/IEC 11179 metadata registry is a complex standard comprising several hundreds of pages, there are users that are attempting to extend these standards to meet various challenges. For example the XMDR project states its purpose as being: ...concerned with the development of improved standards and technology for storing and retrieving the semantics of data elements, terminologies, and concept structures in metadata registries. It is, however, uncertain as to how active this effort is at present: the XMDR website ([1]) does not list project meetings after October 2007, and also whether it has been able to influence ISO to enhance its standard.
The following metadata registries state that they follow ISO/IEC 11179 guidelines although there have been no formal third party tests developed to test for metadata registry compliance.
Listed alphabetically:
Note that there are no independent agencies that certify ISO/IEC 11179 compliance. The Data Foundations website cited above, for example, states that they use "Custom extensions to the core model" - i.e., proprietary and non-standard extensions. While possibly necessary to address the problems that their customers have encountered in practice, such extensions would interfere with metadata exchange.