Saturday, August 22, 2009

Definition of CAD

CAD or CADD is an extremely generic term that means Computer Aided Design (Drafting).
That's it !
If you use a computer to create design drawings or forms then it's CAD. It doesn't matter if the software uses Parametrics, 2d, 3d, surfaces or solids.
CAD does not stand for 2d or vector based software.
I keep hearing and reading people refer to CAD as an acronym for AutoCAD or the DWG or DGN or even SKP.
For someone to say "The project is done in CAD not BIM". Makes absolutely no sense. You cannot compare the definition of CAD to BIM (Building Information Modeling). CAD is just a big part of BIM.
Spread the word.
CAD means Computer Aided Design. It does not mean 2d or vector based file format.


Gregory Arkin said...

Man, you've opened up a can of worms with this one. I'll get my two cents in early and will delve into other software.

Is MSPaint and Photoshop the same? Notepad and Microsoft Word? Calculator vs Excel? In the end, they all do the same thing. computer Aided Processing. Word Processing, Photo Processing and Number Processing.

After all, it's data processing. We computer data. For that matter, DOS with Visicalc did math 27 years ago. We may as well just use a typewriter for contracts and general ledger paper for requisitions.

How about morse code versus a cellphone. Both are digital communication transmitters. Fax machines for that matter transmit digital data converted to analog sound signals.

I guess we could say that faxing a 20 page contract equals emailing a 20 page Office 2007 Word document. They're both digitally transmitted. Computer Aided Data Transmission.

Bicycles and Motorcycles are both Mechanical Aided Transportation.

Ok, I think I've made my point. You ride your bicycle up the mountain and I'll ride my motorcycle. We'll continue the conversation when you finally make it up the hill exhausted and out of breath.

Google it, xerox it, use a kleenex. We use generic words to describe things, yet were all technology snobs and have our favorite programs, gadgets and electronics. Some of us love Microsoft and other Apple. Some hate them all and just want their mechanical pencil back, but what the point.

I'll fight the nomenclature any day and I say that CAD for BIM is Coordination Analysis and Design. Still CAD, but light years from Computer Aided Drafting.

Kung Fu said...

I think that both of these arguments are compelling unto themselves. But there is a definite fissure between the rationales.

First let's use a term from the closing of the comment. "Nomenclature", accourding to, is defined as follows:

1. a set or system of names or terms, as those used in a particular science or art, by an individual or community, etc.
2. the names or terms comprising a set or system."

"CAD" as an acronym is meaningless without its context. That context materializes in reference to the speaker(s). Without the context of some sort of design environment "cad" means a person who behaves in an ill mannered way. That isn't part of BIM.

When you place the term in the conext of this particular blog (Revit Rocks) it's clear that CAD stands for Computer Aided Design. To that end it is easy to rationalize that CAD is a concept, albeit a large one, that is part of a larger goal. In this case, BIM.

I submit that Mr. Arkin's argument, while also compelling, places the term "CAD" in a different context and therefore it is part of a different nomenclature. In Mr. Arkin's argument CAD is a procedure and/or practice meaning Computer Aided Drafting. This context places it in a world of professional "CAD" drafters who are accustomed to CAD referencing exactly what this blog states it is not.

Neither argument is corrent or incorrect. In a discussion between BIM professionals it natural to assume that CAD is a concept representing any number of practices all of which contribute to the BIM concept. In a discussion among CAD drafters it is natural to assume that CAD is a practice utilizing a commonly accepted category of applications producing a defined file output.

My statements are overarched by the fact that one defines CAD as "Computer Aided Design" and the other as "Computer Aided Drafting". Both are correct but also define different contexts.

Now if you want to talk upset let's discuss whether CAD (drafting that is) professionals are CAD Drafters or CAD Technicians? That is one that gets me worked up all the time.

- Curt Moreno -

Gregory Arkin said...

In that case Curt, I'm changing Revit to Computer Automated Design.

The bottom line is the bottom line. It's not what software you use, it's how you use it. There's no doubt that Revit is a better way to document the construction means and methods necessary for the contractor to build the building for the owner. The benefits of BIM/Revit are well documented and the technology benefits the owner, contractor, subcontractors, manufacturers and facility managers.

There is no comparison. Words are words. Actions speak louder than words. A picture is worth a thousand words. A model is worth a million words.

I look at all of it in the context of coordination, analysis and design. My point was and is, use the best technology to automate the process and increase profitability.

Us BIM fantatics like to differentiate the differences between CAD and BIM. If an owner were to come into your office and you had two screens open, one with AutoCAD and the other with Revit, would you tell him they are both CAD? Maybe, but 10 out of 10 times, he's going for the Revit model.

So, call it whatever you want and we'll call it whatever we want and at the end of the day, the architectural industry is still moving to Revit.

As far as your CAD technicians or CAD operators or CAD drafters, you can call them all unemployed if they don't learn Revit and how buildings go together.

I'm not sure why Daryl made his original post on the subject, but as long as he continues to create his amazing Revit tutorials, I'll blame it on a severe cold or heat wave in Canada, eh?

Gregory Arkin said...
This comment has been removed by the author.
Jason said...

Despite the double-posting, I do have to agree with Gregory on this one.
Technically, yes, with Revit I am using a computer to assist with design (and/or drafting). But the same could be said if I were to take an old Dell workstation and turn it on its side and use it as a drafting board, and certainly no one would make that distinction or claim (but man, it would be hilarious).
A less smart alleck example would be, InDesign. If you follow the post's original logic, InDesign is now CAD. I am using a computer to help my design of a layout. Or if I drew something in Photoshop. That's now CAD, too. But I would be laughed at if I called folks in our marketing department CAD users.
If we step back from the universally accepted definition of the phrase, then many many many other things are now CAD. Just so we don't all go crazy, we have to keep the original accepted definition of a phrase or concept.
BIM and CAD are HUGELY different concepts. To counter the first sentence and basis for entire post, CAD is NOT a hugely generic term (but I have always liked the double-d CADD more). One is not a subset of the other. CAD was and always has been an electronic replacement for pen and paper. It is a pencil that you plug into the wall. BIM is a modelling and sequencing and data organization structure and process.
I too am curious about the motivation behind the original posting. That might be more insightful than the posting itself.

RobiNZ said...

I agree with Daryl: BIM is CAD.

The most important concept is "aided". Computers or software don't design, they help people design.


Vincent Cadoret said...

BIM is not CAD. It's a form of advanced CAM (computer assisted modelling). Generalizing the term CAD is unfair for both sides because CAD is more of an art while BIM is a science (I know because I have done both).

To illustrate what will happen look at wood sculpting: at one time in history Totems were an important way of communication but not anymore. It still exists today but we don't use it to communicate with the next village over.

Basically what I'm saying is that BIM is a natural progression/evolution of CAD. It's not BAD to be CAD, just SAD to have an emotional attachment to a tool.

JT said...

To state the obvious, BIM encompasses a much broader definition and spectrum of information than CAD (design/drafting)...but you are correct in assuming that CAD is a BIM attribute. I actually prefer limiting the term CAD to 2D legacy software/ design, as it draws a line in the sand that is easily comprehended by those in and outside the industry. Many words/terms/acronyms definitions morph....doesn’t bother me in the slightest. Besides, I think this topic is pretty much cooked and kind of like trying to stop the ocean tide...good luck with that!

Jay Polding said...

People think the company name of Autodesk is 'AutoCAD'. They call Architectural Desktop 'Autodesk' which is now AutoCAD Architecture. Because AutoCAD has the 'word' CAD in it, people call it CAD. Revit has been proclaimed BIM. In a way this has hurt Revit because some assume that you can’t use it for drafting (cadding) or making precise details which is far from the truth.

Jay Polding said...

JT nailed it, we can't stop this one. CAD is AutoCAD, Revit is BIM. Even if I was 'Dr CAD' in another life, :-(. Dr BIM just doesn't have that ring to it. ha ha.

Gregory Arkin said...

Jay, I actually own and, so Dr CAD vs Dr BIM would be like being a chiropractor vs a neurosurgeon. They're both doctors aren't they?

For them to be equal, I'd love for someone to explain why all of the contractors are running to Revit and Navisworks but never touched AutoCAD. Why has the GSA mandated BIM? Why did Archicad never take over AutoCAD if it was so great and the first BIM product.

Why was Navisworks ever paired with AutoCAD. If AutoCAD and Revit are equal and on the same level, why are the largest architecture firms in the world all moving to Revit.

Yeah, it's a non issue. Why do we even waste time justifying the nomenclature and differences. Anyone who calls them the same, has never used Revit and wants CAD to equal BIM so they don't have to explain why they haven't switched and become irrelevant.

Jay Polding said...

Dr.CAD is probably more of an archaeologist...Dr.BIM is certainly as condescending as a neurosurgeon.

Daryl Gregoire said...

Times may have changed and the term 'BIM' was not even around when 'CAD' moved us off the drafting boards but that is all irrelevant in my opinion.

CAD is any kind of design or drafting done with a computer. It's that simply. It has nothing to do with 2d or 3d or parametrics?

You can call it 2d CAD or 3D CAD or Vector based CAD or Solid Modeling CAD or Parametric CAD but to simply decide that the term CAD now means AutoCAD or DWG or DGN or NON REVIT is just lazy.

When REVIT came out is was most definitely refered to as CAD.

Maybe we need to find another term but you cannot just change the meaning of a term out of convenience or lack of better word.

I just can't get used to someone saying, "That project was done in 'CAD' when they really mean 'AutoCAD' or any other vector based program.

On the other hand, BIM has nothing to do with 2d or 3d. It kills me when someone says "That project was done in 'BIM'", when they really mean it was done in REVIT.

BIM is an all encompassing, integrated design process that contains 2d, 3d, green build, solor studies, budgets, material take-offs, construction, building life cycle, LEEDS . . . . etc. etc.

Is REVIT a big part of BIM, yes it is. Does REVIT = BIM, absolutely not.