Interoperability can not be considered without open standards
There has been real progress in the BIM industry toward open standards; this is confirmed by headlines such as the collaboration agreement announced in June 2016 by Autodesk and Trimble. The two companies have been working together ever since to increase interoperability and offer users greater flexibility in their workflows. Autodesk already did this in 2008, when it launched an API exchange with Bentley Systems in an attempt to optimize its interoperability in space design and infrastructure.
Also last summer, Bentley Systems CEO Greg Bentley explained in an interview with BIM+ what BIM means for a software vendor, emphasizing the issue of interoperability. While Bentley is less of a proponent of concepts like IFC or COBie than its competitors, the company has developed its own solution to address interoperability.
“Interoperability is now provided through collaboration services that work well with our competitors’ software,” Greg explains in the interview. This means that point-to-point compatibility integrations are used for interoperability . And those integrations aren’t based on open APIs. Bentley is promoting the use of its own i-model format generated by design software plugins.
Thus, i-Models are the company’s solution to the challenge posed by interoperability. They can be created using free plugins, both with tools from the company itself (Microstation) and others, such as Autodesk’s Revit. i-Model data is accessible from an ODBC database driver, also from Bentley.
What is interoperability?
Before we delve deeper into the topic, let’s look at the definition of interoperability offered by the AFUL working group : “Interoperability is the ability of a product or system, whose interfaces are completely understood, to work with other existing or future products or systems, without access or implementation restrictions.”
This definition is just a small part of what interoperability can be, but at least we can draw one main conclusion: Interoperability cannot be considered without open standards .
BIM Software and Interoperability
Wikipedia dedicates a subchapter to software interoperability that is a bit more specific in its definition: “With respect to software, interoperability is used to describe the ability of different programs to exchange data through a common set of interchange formats, read and write the same file formats, and use the same protocols.”
One of the key points of software interoperability is that customers have the freedom to switch from one product to another, while keeping their data intact after the transfer . This is especially important for use cases where data will remain in a system for a long time, to avoid vendor lock-in.
In the construction industry, where project teams from different organizations, disciplines, and phases come together, it is desirable for different tools to share information with each other and, if desired, for data generated in one phase to be used in the next without re-entering it. This is the basis for OpenBIM . An OpenBIM workflow is impossible without interoperable software .
https://www.youtube.com/embed/KppDDS3KnnM
Interoperability allows the best professionals in each discipline to work on a project, using the tools with which they feel most comfortable and productive.
Semantic interoperability and BIM
To communicate with each other, systems need to use common data formats and communication protocols . Examples of formats include XML, JSON, SQL, ASCII, and Unicode. Protocols include HTTP, TCP, FTP, and IMAP. When systems are able to communicate with each other using these standards, we speak of syntactic interoperability .
For BIM tools to work together, we need more than just the ability to transfer information . We also need the ability to convey meaning . The information output must be the same as what is understood. To achieve this, both parties must refer to a common reference model for information exchange. We need semantic interoperability .
What interoperability is not
This figure is taken from the AFUL interoperability working group, cited above, and is presented under the heading “Degrees of Interoperability.” However, we could say that the first two categories are not true interoperability . Let’s see what Wikipedia says:
“When a vendor is forced to adapt its system to a dominant one that isn’t based on open standards, it’s not a question of interoperability, but merely of compatibility.”
Plugins for BIM tools are common ways to provide such a compatibility solution.
“The supplier behind that product can choose to ignore any future standards and not cooperate in any standardization process at all, using its near-monopoly to insist that its product sets the default standard because of its dominant market position.”