Comparing Pommes and Naranjas
Jerry Laiserin

It's tough enough to compare unlike things, such as apples and oranges, but even harder when we label the comparisands with different names in disparate languages. As building designers, constructors and owner/operators shift their media of description and communication from "CAD" to "the next thing," we face the pommes/naranjas problem—proliferation of names and languages that prevent us from distinguishing meaningful differences and similarities among emerging approaches to software about buildings. I am convinced that the building industry cannot move forward with any of these new tools unless and until we agree on a term to replace "CAD." I am equally convinced that the best term for this purpose is…

Building Information Modeling. Now, before you denounce me for "selling out" via an Autodesk promulgated nomenklatura, let's place the issue in context. Other current contenders include, for starters, single building model, virtual building model, integrated project modeling and project lifecycle management (the cognoscenti among you can play "pin the tag on the vendor"). On one hand, the entire exercise begins to resemble those tongue-in-cheek, three-column collections of buzzwords from which new catchphrases can be randomly assembled ("construction asset modeling" or "project information database" and so on).

On the other hand, it's a deadly serious issue that can stymie meaningful discussion. For example, I was recently invited to help the Public Interest Energy Research project of the California Energy Commission evaluate grant requests for the commercialization of a Green Building XML language (gbXML) for building energy simulation linked to computer-generated building models. Although everyone in the room was an expert—strategistas from leading "CAD" vendors, national researchers in building simulation, the developers of gbXML (energy consultancy GeoPraxis and "CAD" modeler DesignWorkshop from Artifice, Inc.)—nearly half our scheduled discussion time was diverted to defining and differentiating different approaches to 3D modeling versus intelligent modeling, and visualization versus simulation (my role was that of vendor-neutral, technology-agnostic analyst of the market potential for gbXML, something I'll report on in a future issue).

The point is, when even the experts stumble over terminology because "CAD" is no longer sufficiently descriptive of the breadth and depth of the design process, then it is time to concede that the term may have outlived its usefulness. In fact, the term Computer-Aided Design (CAD) was not preordained and is still not universally applied. Early contenders included: Computer-Aided Design and Drafting (CADD) and Computer-Aided Architectural Design (CAAD)—these two linger on; Design Augmented by Computer, as in the long-gone General Motors DAC-1 system; and such collateral variants as Computer-Aided Design and Manufacturing (CADAM or CAD/CAM) and Electronic Design Automation (EDA).

CAD became a convenient umbrella term, specific enough to have some universally understood meanings regarding interface, geometric representation and so on, yet generic enough to suggest and include all specialized and/or collateral variations. In an attempt to denote the increasing "intelligence" of some "CAD" programs in recent years, vendors and pundits have proposed an assortment of replacement terms. Sifting through the possibilities, I find that I prefer the word "building" over "project" because there are many kinds of projects (such as software development) that have nothing to do buildings. At the same time, the word "building" is loose enough to hint at design, construction and operation. Without delving into the semantics of data versus information versus knowledge, I find that "information" is clearly suggestive of software that deals with more than just geometry.

Combined, "building information" implies, to my ear, a strong sense of what the design, construction and operation of buildings is about. It avoids techno-jargon, yet remains evocative of technical goings-on. "Modeling," although a near-jargon word, does connote the mathematical or digital description of objects or systems—we have econometric models and weather models as well as physical models of 3D objects. "Modeling" also implies a process of description or representation that provides the foundation for building performance simulation (essentially, modeling future behavior) and for the management of building information (information models serving as the frameworks in which information is managed).

So, "building information modeling," as a description of the next generation of design software, seems to me to come closer to the winning characteristics evidenced by "CAD" for its generation of tools—specific enough to evoke reasonably clear, common meanings, yet broad enough to encompass a diversity of commercial and technological approaches. The only fly in the ointment is that Autodesk has been using the term for the last few months to describe their building industry strategy. However, Autodesk has not, to my knowledge, asserted any intellectual property rights (service mark or trademark) to the term—as, say, Graphisoft has in the past with "virtual building."

Unlike many in the industry punditry game, my personal business model does not depend on coining unique and proprietary acronymic buzzwords, so "building information modeling" or BIM will do just fine. And, just in time, too, because I've been editing a six-part series on "Design Frontiers" that Susan Smith has written for the LaiserinLetter, and getting one term to apply across all major vendors will make the whole series easier to read (and, yes, easier to edit). The series segments that describe Autodesk's strategy already referred to BIM. The first two segments, dealing with software from Autodesk arch-rival Bentley Systems, were more problematic, hewing to Bentley's "integrated project modeling" terminology.

After a bit of jawboning with Bentley's marketing folks, I got their agreement to use BIM as the top-level descriptive term for their latest design software. With Bentley and Autodesk both humming the BIM tune, we've covered well over 80% of the USA market (as defined by sales of current-generation "CAD" tools). At an 80% tipping point, the dominos should fall into place for the rest of the market.* Now, vendors can compete—and users can judge them—based not on "how many ways we differ from CAD," but on "how well we execute and live up to the promise of BIM." It should be an interesting ride.

*NOTE: At press time, Brad Holz, CEO of mega-analyst firm Cyon Research, with whom I had debated this issue for some time, called to advise that in a soon-to-be-published white paper on Graphisoft, Cyon would—with the assent of Graphisoft—adopt the Building Information Modeling, BIM, terminology. This drives vendor acceptance of the term to substantially more than 90% of the USA market.

In addition, Randall Newton, formerly of the Bentley-owned MSM Online and now editor of the soon-to-be relaunched, Cyon-owned AECnews, has bought into BIM. For a counterpoint, I have received from the irrepressible (and possibly irascible) Martyn Day a letter too long and too funny for this issue. I'll run it next time.

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