Opinion

openBIM and buildingSMART International pt 1

 

From BIM Journal. Click Here to Read Issue 1

Kickstarted decades ago by Autodesk as the International Alliance for Interoperability (IAI) although nowadays bolstered by an increasing number of prominent software vendors, buildingSMART International provide the leading neutral forum for consensus that supports the creation, adoption and use of openBIM standards worldwide. As they point out, “openBIM” is the embodiment of open standards that innately contains the open and free exchange of structured information throughout the project lifecycle[2]. In short, they create (and adopt) open international digital standards and they also have a relationship with key standards bodies worldwide, with many of their standards becoming ISO status.

The Basic Standards

BuildingSMART International coordinate the initiatives and goals of the industry and the companies that are pushing for open standards all over the world. Their key standards are identified below and the need for these standards is largely appreciated in most disciplines already, but a reminder of what they are now follows;

The Data Standard: IFC - Industry Foundation Class

The grandfather of them all and by far the one you’re most likely to have heard of, the IFC “file format” is in fact the international open standard for exchanging construction (and facilities management) data across differing software applications. This standard is an official ISO standard (ISO 16739:2013) and something that software vendors need to worry about complying with more than you. That said, to subscribe to openBIM this is the file format to go with during your exports (and element classifications etc) and one that other participants can access and add their information to in any compatible software they choose.

What surprises people here is that even with IFC being available as an import/export option in most software, interoperability is not in fact guaranteed.  This is improving (and IFC is by far the closest we’ve got) but genuine interoperability is down to how the software has utilised the standard in the first place. This is why many (BIM authoring) software vendors have chosen to become “IFC Certified” but as always double check what you want to achieve in trial versions first before you make your final choice.

Very positively however, other initiatives for openness like this exist but take longer to gain popularity so it is genuinely refreshing to see how IFC has grown. I’m speaking mainly of the UK government adoption of the Open Document Format for editable documents instead of proprietary formats (using .odt instead of .doc) so well done again to BuildingSMART there. Industry has certainly bought in.

I feel compelled to at least mention COBie here however, which is said to be a subset of IFC. What this means, very generally, is that “of all the data contained in the IFC, just show me the information that relates to Facilities Management” rather than anything to do with geometry or the like - as this is all that most clients will ever really care about.

The “Language Standard”: IFD - International Framework for Dictionaries.

Using buildingSMARTs own example; think of a door and then the parameters needed to describe that door - the width, the height etc. These exact terms are described in English as you read them here and now... but software should be interactive globally and in all languages, surely?

So what if these parameters were reduced to a number instead? For example “width” could be IFD#2468 and “height” could be IFD#3579. Other languages can then map their terms for these parameters to the same IFD number and hey presto, standardisation of parameter terms the world over. Mapping of terms to numeric references in this manner relies on the use of something called a GUID (Globally Unique Identifier) which will have more significance in many fields as our technologies and overall global ‘connectedness’ evolves.

Of course you would still search and go about your daily business using your native language, but think about the specification potential of this globally, especially for manufacturers to really make sure they are represented in all territories. This helps specifiers and manufacturers all over the world. Indeed a great initiative to really get behind.

The buildingSMART data dictionary (bSDD) is effectively a mapping tool for the above with support for the classification system of your choice.

This is where LEXiCON comes into play also; a tool that is used to share common terminology that is mapped through open standards, again complete with industry support.

The “Coordination Standard”: BCF – BIM Collaboration Format

Originally developed by Tekla and Solibri certain software applications contain the ability to send instant messages, of sorts, to project participants in real time in order to gain rapid feedback. BCF encodes these messages in a certain way and, separate to the IFC data the model contains, enables other BCF compliant software to display the same message to the end user reliably back and forth. Again something for software vendors to worry about but something that will become more prevalent over time.

 The Process Standard: IDM – Information Delivery Manual

Set up to assist software automation and data exchange, this standard seeks to ensure that the flow of activities for a particular business process are described consistently. This then enables software vendors to understand the configuration of activities that make the process work; the actors involved, the information required, when it is required and when it is consumed and produced. That is my brief description anyway.

Process Translation: MVD – Model View Definition

CAD/BIM software applications contain many preset views of the model that are utilised at different stages of the project lifecycle. “Coordination View” and “Structural Analysis View” spring to mind. Model View Definitions (MVDs) define the agreed items (the attributes of the IFC data model) that are necessary to support the data exchange requirements in relation to the views chosen. Again something for software vendors to consider really, but it may ultimately affect you.

continues to part 2...

Read both parts (and more) in BIM Journal