Issue #1,072 | 2 November 1020 | The Business of CAD
I work in the food service design industry. We design commercial food service facilities for restaurants, schools, hotels, and so on. Back in the 1980s, a group of forward-thinking food service designers developed a layering standard for AutoCAD, which we still use. Having a standard made our lives much easier.
There are over 400 manufacturers in our industry. A food service designer may use equipment from dozens of manufacturers in a kitchen design. We simply don’t have the time to edit Revit families from all these sources to work together in our Revit projects. So we applied the same thinking to Revit, and food service designers have been using a common Revit Shared Parameter file since 2010.
Our Shared Parameter file covers all the utilities that one may find in a kitchen: gas, water supply, voltages, drainage, and so on. By and large, it has been working very well. Now our group has expanded to develop these standards for international food service design. I’ll keep you posted on our progress.
- Truman Donoho
Foodservice Equipment Symbols
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I don’t see how you can have BIM-to-CAM when there is insufficient resolution/fidelity in the BIM to start with. It’s easy to degrade resolution, but how do you add it?
- Robin Capper
New Zealand
The editor replies: The idea is to have CAM-level details in the BIM model, which I think is referred to as LOD 5 (level of detail 5). This is the level at which screws are modeled.
The problem is how to get to LOD 5, as lighter models already overwhelm BIM hardware and software systems. So this is the gap that exists between doing the design and being able to manufacture it.
Martyn Day of AEC Magazine wrote about the BIM-can't-CAM problem, but I can't find that article; sorry! Traditional BIM vendors are making enough money from selling regular BIM that they haven't bothered fixing the CAM part. Autodesk, which went overboard on buying construction management software, doesn't have a way to get from Revit to the construction site. Bricsys proposes adding intimate details through "AI," where the software predicts the details needed, and then adds them automatically.
Mr Capper responds: I think the real issue is that BIM is often more ‘design intent’ than actually constructible. I thought Autodesk’s Quantum concept, demo’ed at AU a few years ago, was an interesting approach to that.
The detail modeler, say curtain wall fabricator, just pulled critical control points from the architect's model (live, and refreshed at agreed-to intervals) and served back as a lightweight placeholder. Seems to have ‘gone dark’; I wonder if it was abandoned or retreated into secret development?
The editor replies: It was abandoned after several years of development. It was known as Project Quantum and was specific to AEC. Autodesk is replacing it with the all-encompassing Project Plasma, and apparently will announce more at Autodesk University later this year.
You can read more about the history of these two initiatives in "What Comes After Revit?" at aecmag.com/technology-mainmenu-35/1821-beyond-revit-autodesk-seeks-to-reinvent-collaborative-bim
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The discussion of Revit and BIM are very interesting, even though it's totally different world than the mechanical one that I inhabit.
Occasionally, I read things that make me realize that the building construction world is intensely striving to achieve the level of documentation that is considered completely normal and routine in the manufacturing world. The problem is that they have to do it for a "product" that is more complex in terms of the number of different parts involved (generally) and, instead of being built in a single factory, with all components purchased by a single purchasing department, there are many, many companies involved, each with their own systems of part numbering, naming, modeling, purchasing, warehousing, issuing, inventorying, and accounting.
So they can look to the manufacturing world for some guidance, but no manufacturing system is going to stretch to fit the construction of a large building by fifty subcontractors.
The article noted that "The Shared Parameter GUID ensures each Shared Parameter in existence has its own unique 32-bit identifier number, which is the only thing Revit really cares about with any parameter you create."
This is called a "part number" in my world. And I have occasionally had to explain and convince small manufacturers that it's important to assign a unique number to every component they make. I can only imagine how hard it would be to convince everyone involved in a large building project, from the architect to the electrician, that having consistent names for things is essential.
Thanks for your continued insights into this world.
- Jess Davis, president
Davis Precision Design, Inc.
The editor replies: You hit the nail on the head, to borrow a phrase from construction. As someone once put it, think of assembling an Boeing 747, but in a muddy field miles from the factory, and each one plane being made with a different set of plans.
The BIM software world has, in the last year, just started to notice that they have a great problem in failing to connect with construction, except experimentally. It is all well and good for industry critics to complain that construction has only progressed 1% in efficiency over the last couple of decades, but there can be no automation when there is no data to input into the automation.
Mr Davis responds: It's kind of fun to explain manufacturing to a carpenter.
"Yeah, that 2x4 you just cut and nailed in place? See, we would have a drawing for that."
"Why would I need a drawing to cut that?"
"Oh, you wouldn't cut it. A supplier would cut it, and you'd just have to find it in those two semi-loads of pallets that got unloaded during the last rainstorm. It'll be marked with a cardboard tag."
The editor replies: ROTFL
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Dave has an elegant solution to the parameter mess, although it would require some admin. Bizarrely, it is implemented for some items in that old, non-BIM product called AutoCAD Architecture, that in some ways is more sophisticated at managing BIM standards.
Revit has a similar concept in its CAD export maps (object keys to layer names), but AutoCAD Architecture's Layer Key system addresses the same problem. The list of AEC Objects is consistent, but there is no standardization across the industry for layers.
So an object 'DOOR' can be mapped to 'A-Door' in one key, or '32-Door' or 'Bld_Door' or whatever you assign in the different keys. Open a generic file; hit Remap; all the layers and properties update; start work. This means you have one template, one parameter in the library, potentially serving hundreds of client standards.
Using a key to build names has massive advantages, with the only real disadvantage of having to administer the keys:
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It enforces company standards by allowing users to only select pre-set values when naming content. For Revit, imagine when creating parameters (to use Matt's example) you could only choose ‘Width’ as part of the parameter name, because the BIM standard has set it . This eliminates creative naming or typos ("witdth").
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It would allow mapping of multiple values to your standard, so my ‘FurnLength = Desk Width | Width of desk | witdth’ in ‘foreign’ content or linked files.
As an aside I only have Length (X), Depth (Y) and Height (Z) but no ‘Width’ in my shared parameters as I found this avoids confusion. If you want to have a ‘Width,’ it has to update the relevant X, Y, or Z shared parameter used for tracking object volumes. I can do that with our content, but not any foreign stuff. -
It would allow you to have per-project or client Key Tables. If they are consistent with naming (and often they are consistently different), just link the content, apply the map, done.
I would not like a parameter creation standard or mapping key to control everything, but it should be able to manage consistent information crucial to information sharing and basic data entry (Width, not widTH, Witdh etc). In some ways the shared parameters do that, but still depend on users complying with a standard while making them!
The other thing is, and sorely lacking in Revit, Layer Keys -- like every other AEC Object, Display, Material and Property Set (Parameters) -- have both Style and Instance GUIDs and can be updated (from a standards file) automatically or with a prompt on first access, or manually any time. If the BIM Manager updates a key to reflect a client’s requirements or a change in standards, then every project will acquire that update when it’s next edited. So I wish Revit had that!
I even have found using Schedule Keys (combinations of parameters tied to a single selectable key value) for things like rooms, area, and space properties works very well in a Revit Project, but is challenging to standardize across multiple projects, even with third party tools.
For instance, I have a master Schedule Key in my Standards project, update it (add a value, or change some of the existing key sub-parameters), but then update the same key schedule in existing projects. It’s a basic requirement in using BIM for lifecycle management, not just build and run.
- Robin Caper
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Another excellent eZine from my man Ralph! A reader wrote, “What I proposed (many, many years ago) was a Linked Parameter Mapping Table.”
That’s a ‘no-brainer’! Any idiot could see that as the only solution for a changing world. I’ve said as much to Autodesk in the past, but my wishlist suggestions always fell on deaf bureaucratic-guarded investor pocketbooks.
It’s too late to fix the screw-up of data in the CAD world. The only way it will get fixed is if we impose upon ourselves a global CAD dictatorship! Cheers,
- Chris Cadman
The editor replies: Data exchange is a problem that stays problematic, even as brilliant programmers find solutions.
And in Other News
Hexagon reported total Q3 revenues of €940 million (US$1.1 billion) — flat both on organic and constant currency bases from a year ago, following five quarters of declines. Despite this, the company has so far this year made ten acquisitions, including a third line of CAM [computer-aided manufacturing] software through last week’s purchase of ESPRIT owner DP Technology.
CEO Ola Rollén said the company needs also to get more into AEC. Details from Monica Schnitger at schnitgercorp.com/2020/10/28/hexagons-q3-was-flat-year-year-on-an-organic-constant-currency-basis/.
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Contact Software releases its PLM software Elements v15.5 as an LTS [long term support] edition, so that customers will receive support for years to come.
The software helps manufacturers offer variations on products quickly through rule-based family models linked to ERP [enterprise resource planning] systems. contact-software.com/en/news/2020/10/contact-elements-155/
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OnScale Solve’s cloud engineering simulation platform offers multi-physics solvers. The current version has mechanical, thermal, and coupled thermal-mechanical analyses; in the future, the site plans to add dynamic mechanical, nonlinear mechanics, thermal-fluid, fluid-structure interactions, and acoustic analysis.
The company is offering free private accounts to anyone of 500 core-hours/year. The software runs on its own at onscale.com, as well as inside Onshape.
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