# OpenBIM: An Enabling Solution for Information Interoperability
## 3 Overview of OpenBIM
### OpenBIM Standards
#### 3.1.1 buildingSMART Standards  
buildingSMART standards, as the most important part of openBIM standards, mainly includes five basic standards, the names and functions of these five basic standards are briefly summarized one by one in Table 2[4]. 1. IFC--Data Standard  
IFC is a common data schema for describing building information model data, which aims to establish a standard method of data representation and storage, so that all kinds of software can import and export building data in this format, thus promoting data sharing among different specialties and different software throughout the whole life cycle. IFC standards can be used to unify the format of information generated by different types of software so as to realize the free conversion of building information [2]. Up to now, the maturity level of each IFC version can be vividly represented in Figure 5. \begin{table}
\begin{tabular}{c c} \hline \hline
**Name** & **What It Does** \\ \hline IFC & Transports information or data \\ Industry Foundation Classes & \\ IDM & Describes processes \\ Information Delivery Manual & \\ DVD & Translates processes into technical requirements \\ Model View Definitions & \\ BCF & \\ BIM Collaboration Format & Change coordination \\ bsDD & \\ buildingSMART Data Dictionary & Defines BIM objects and their attributes \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Brief summary of five basic standards. Figure 5: The maturity levels of Industry Foundation Classes (IFC). IDM--Process Standard  
IDM is a method for capturing and specifying the whole process and information flow during building life cycle, which aims to ensure relevant data is exchanged in a way that can be interpreted by the recipient software. The construction and maintenance of buildings involves many different participants, knowing what information needs to be communicated among them and when it is communicated is important. IDM can facilitate this information communication process by making full use of business process modelling notation (BPMN) and templates for Exchange Requirements [2]. 3. MVD--Process Translation  
The Model View Definition defines a subset of IFC schema that needs to meet one or more exchange requirements in the AEC industry. Together with this subset of IFC schema, a set of implementation instructions and validation rules are issued, and the method of publishing concepts and related rules is mvdXML [5]. The mvdXML is an encoding format, through which MVD can be encoded and allowable values in specific attributes of a specific data type can be defined. In practice, software applications can use mvdXML statically to support specific model views or use it dynamically to support any model view. 4. BIM Collaboration Format (BCF)--Change Coordination  
The BIM collaboration format (BCF) is a simplified and open standard XML format used to encode information which enables workflow communication between different BIM software tools [3]. The development of BCF mainly includes two parts, namely a XML file format and a RESTful web service, in which the open file XML format called bcfXML can support workflow communication in BIM processes; besides, the RESTful web service called bcfAPI can enable software applications to seamlessly exchange BCF data in BIM workflows [6]. 5. buildingSMART Data Dictionary (bsDD)--Standard Library  
buildingSMART Data Dictionary (bsDD), as a reference library based on the IFD standard (ISO 12006-3), is one of a set of buildingSMART standards that enables collaborative work. To understand bsDD standard better, it is necessary to understand the concept of IFD standard. IFD is a terminology library-oriented or ontology-oriented standard, which ensures the accuracy of BIM information exchange and sharing by establishing the mapping relationship between IFC and information representations of different languages and vocabularies, as well as specifying the related conceptual semantics of objects [2].