||Engineering Semantics of Model Views for Building Information Model Exchanges Using IFC
||Manu Venugopal, Charles Eastman, Rafael Sacks, Ivan Panushev, Vahideh Aram
||The data schema of the Industry Foundation Classes (IFC) schema is generic, designed to support the full range of model exchanges needed in the construction industry. While it has a rich ontology of building part entities and relationships, it does not impose any fixed structure on the ways in which entities should be aggregated or represented, with the exception of the project-building-space containment hierarchy. Thus the IFC model, in and of it-self, is inadequate for ensuring interoperability between software applications. For any given set of use cases for a sub-domain of building construction, a set of model view definitions (MVD) is required to specify exactly what information should be exchanged, and in what form and structure the IFC entities are to be used. Compiling a model view definition, presently based on human intuition of industry knowledge, is challenging. What should be the level of detail to be included in case of geometry, classification and aggregations, and parts and relationships etc.? IFC, which is based on STEP and is represented in EXPRESS language, is known to be good in expressivity but lacks in a formal definition of its concepts. Thus in preparing a set of MVDs, information modellers must determine the appropriate level of meaning to require and they must define the typing structure to be used. If the structure is too simple, the exchanges will only have value for importing software able to apply some level of expert knowledge to interpret the information. If it is too rigid, then it will only be appropriate for a narrow range of use case exchanges and a large number of model view definitions will be required, which also implies that software companies will need to prepare multiple export and import routines. This paper discusses the spectrum of possibilities, using examples from concrete construction in general and precast concrete construction in particular.
|Year of publication:
||Industry Foundation Classes (IFC), Model View Definitions (MVD), National BIM Standard (NBIMS), Product Modeling, Process Modeling
Manu Venugopal, Charles Eastman, Rafael Sacks, Ivan Panushev, Vahideh Aram (2010).
Engineering Semantics of Model Views for Building Information Model Exchanges Using IFC. CIB W78 2010 - Applications of IT in the AEC Industry,