BUILDING SMART – IFD

ISO 12006-2 The related standard, OmniClass follows the international framework set out in International Organization for Standardization (ISO) Technical Report 14177 – Classification of information in the construction industry, July 1994. This document was later established as a standard in ISO 12006-2: Organization of Information about Construction Works – Part 2: Framework for Classification of Information. ISO 12006-3 and ICIS In much the same way that ISO 12006-2 has been implemented in the UK in Uniclass and in North America in OmniClass, the object-oriented framework standardized by ISO/PAS 12006-3 has been adopted by ICIS members in the Netherlands with LexiCon and in Norway with the BARBi programs. Following these ISO standards will promote the ability to map between localized classification systems developed worldwide and the object-oriented framework of 12006-3, implemented alongside and in concert with 12006-2-based standards, will multiply the degree of control available over construction information. ISO 12006-3 and ISO 15926 (EPISTLE) EPISTLE is a dictionary development used in the oil and gas industry that has a similar top level structure to ISO 12006-3. While IFD and EPISTLE share much of the same concepts and have the same core structure, the initiatives are different. IFD only defines types of things. EPISTLE will also store instances or individuals. To cover the same functionality as EPISTLE, IFD relies on the IFC standard. Entries in IFD would be for example types of doors while an instance of a door in a particular building project would be established using IFC. IFD does not aim to hold such individual records. For

Following these ISO standards will promote the ability to map between localized classification systems developed worldwide and the object-oriented framework of 12006-3, implemented alongside and in concert with 12006-2-based standards, will multiply the degree of control available over construction information. ISO 12006-3 and ISO 15926 (EPISTLE) EPISTLE is a dictionary development used in the oil and gas industry that has a similar top level structure to ISO 12006-3. While IFD and EPISTLE share much of the same concepts and have the same core structure, the initiatives are different. IFD only defines types of things. EPISTLE will also store instances or individuals. To cover the same functionality as EPISTLE, IFD relies on the IFC standard. Entries in IFD would be for example types of doors while an instance of a door in a particular building project would be established using IFC. IFD does not aim to hold such individual records. For that we rely on the IFC standard. IFD will on the other hand hold all classes or types of concepts that in turn can be used to instantiate individuals.

In other words IFD holds the templates while IFC (or also other standards and conforming databases) are used to fill them in. IFD Library Development Development of the IFD Library is in two primary areas – content and technology. To date the Norwegian and Dutch efforts have independently focused on developing on both fronts. With the creation of the IFD Partners and the release of the IFD API by the Norwegians, all technology development is being focused on this platform which is now in limited release. Efforts are also underway to harmonize all of the content developed to date into the common core context within the IFD. IFD Library Status – Content Content within IFD are of two basic types: 1. Concepts (Labeled through Terms) –something that can be distinguished from other things and that can be recognized as such. One concept can have many labels in different languages or in the same language, still remaining the same concept.

On the other hand a name might be used as a label for several concepts. Names and concepts have their own Ids, and are linked through a naming relationship. IFD Library White Paper 2008-04-10 5 2. Characteristics (Properties) – concepts that cannot be defined using other concepts; their meaning is provided through a description. Subjects are concepts being defined, Characteristics are concepts that define. Characteristics contain values when instantiated in a relationship with a Subject. Characteristics can be distinguished into the following types (in alphabetic order): Behavior, Environmental influence, Function, Measure, Property and Unit. (The list of Characteristics is not extensive. Measure and Unit are used to scale Properties.) Concepts are related to other concepts through objectified relationships. Relationships are collected into contexts based on how they came into the library and where they came from. Concepts can relate to other concepts in multiple contexts. For example, the concept Door might have the following relationships to other concepts depending on the context in which it is being viewed. A context can typically be the relationship structure of one given classification system like OmniClass.

Figure 2: Concepts and Relationships: courtesy Lars Bjørkhaug and Håvard Bell, IFD in a Nutshell, IFD Developers wiki, www.ifd-library.org All concepts are assigned a Global Unique Identifier (GUID) by the IFD to allow them to be readily identified and reused by applications. A goal for entering terms into the IFD Library is to resolve duplicates and synonyms so that multiple entries with the same or similar meaning are not created. The processes and procedures for achieving the common use of terms across multiple contexts are still being refined to help those using the IFD efficiently search for similar terms already in the library. The following graphic illustrates how a concept (window) can be described by a set of characteristics in IFD. The relationship between a concept and its characteristic can also be captured in a context allowing the relationship between the particular use of a concept and its properties in that use to be captured within a given context.