Model View Definitions (MVD)
Model View Definitions (MVDs) are buildingSMART’s solution to create IFC based standards that can be implemented and tested.
An MVD consists of three main components:
- A set of Concept Templates. These concept templates define additional agreements on how to use the IFC Schema.
- A set of Exchange Requirements. This is a selection of entities and properties from the IFC Schema that are found suitable for a selection of use-cases.
- A description on how Software should deal with the data that are exchanged. For example, can the software use the data as a reference, or should the data be mapped to internal objects during import.
The buildingSMART Software Certification team operating the b-Cert platform (b-cert.org) is using MVDs to test software implementations for conformance.
In the buildingSMART community the term MVD has been mainly used to define exchange requirements in a project. Within the buildingSMART solutions this is however covered with the combination of IDM and IDS.
In principle, everyone can define their own MVD. Without common guidelines it is unlikely that these MVDs will be interoperable with and likely that they will need specific software implementations. A comprehensive overview is on https://blog.buildingsmart.org/blog/the-curious-case-of-the-mvd To avoid these situations buildingSMART is defining a limited amount of ‘base MVDs’. These base MVDs can be extended with custom made sets of exchange requirements but cannot change concept templates and the selection of IFC resources.
This policy supports projects with delivering valid and interoperable exchange requirements for their use-cases, it provides interoperability with existing software implementations, and helps align with Software Certification.
For IFC 5, the concept of MVDs will change. IFC5 will be modular with a shared base. More on this on the Technical Roadmap page.