In the digital built environment, there will not be a single data dictionary which comprises all the definitions which are needed in all BIM domains. Different groups, possibly in different countries, will create or have created separate data dictionaries, specialized for their needs, based on the legislation and culture. For the future of BIM, it is important to ensure that these data dictionaries can be interoperable in tools and applications.
In 2018, France proposed a new ISO standard, ISO/NP 23386 Building information modelling and other digital processes used in construction – Methodology to describe, author and maintain properties in interconnected data dictionaries, within SC 13 "Organization and digitization of information about buildings and civil engineering works, including building information modelling (BIM)" with a methodology that would help ensure the quality and unicity of property descriptions and avoid the creation of duplicates. Furthermore, the standard would address the need to enhance quality of data dictionaries and ensure a seamless communication between all the stakeholders in the construction industry.
The project was approved with a development track of 24 months under the Vienna Agreement with CEN/TC 442 "Building Information Modelling" as lead, meaning that the development takes place in the CEN committee but with contribution from and parallel voting in SC 13.
Purpose and content
The elements of the data dictionaries need to be described by the same attributes. If this is agreed and done by all data dictionary providers, it is quite simple to map properties in one data dictionary to properties in other data dictionaries. This can lead to reuse of properties and to harmonization of properties across data dictionaries. In addition, this is an important step to allow BIM applications to use a set of data dictionaries in a common way. The governance of the data dictionaries needs to follow the same rules with respect to the building and development of the data dictionaries’ content.
The assumption is that the data dictionaries are independent from each other, they are connected in a coordinated network of data dictionaries (again, there may exist several of these networks). Within the network, the data dictionaries are related, which is visible, for instance, using a specific attribute which maps properties and groups of properties of different data dictionaries to each other. Any data dictionary in the network of coordinated data dictionaries is independent, i.e. it has its own processes and committees to control the development and evolution of the data dictionary; meanwhile, they all follow the same description and governance rules described in this document.
The document specifies the attributes to define properties and groups of properties of a single data dictionaries as well as the processes and commissions/roles for the governance of a single data dictionary in a network of coordinated data dictionaries. In the governance processes, it is described how the single data dictionary deals with queries and change requests and the extension of queries to other connected data dictionaries; information of other connected data dictionaries regarding change is an integral part of this process.
The project is currently under FDIS ballot until 3 February. FDIS, which stands for "Final Draft International Standard", is the final ballot before publication. If approved in both CEN and ISO, the standard will become an EN ISO standard, and all the 34 member bodies in CEN will then have to adopt it as a national standard.