People wave their hands and talk about BIM, Model-Based software, and Model-Based design. What do these words really mean to civil engineers and surveyors? Where does the rubber hit the road?
Maybe the answer is simple. Maybe not.
It sure appears to take a while for people to get to the unexpected consequences.
Model-Based is Simple and Elegant
We build a "reasonably realistic" model of what we want BEFORE we attempt to actually construct it. The phrase "reasonably realistic" means "suitable" from my perspective. Suitable is probably a good subject for another post.
Hopefully, our AutoCAD Civil 3D model building isn't too time-consuming. At first, learning the model-based structures and processes unquestionably make our model building consume more project man-hours up front.
If that doesn't change pretty quickly, you are probably doing some basic things "wrong" or at least incorrectly.
If it keeps happening, please get some help and a change of perspective.
It's really not supposed to be or work that way.
The Money Pit
Hopefully, our model is good enough and the design software is also robust enough to actually help us construct, quality assure, and publish the model in multiple ways too.
All three parts are essential and equally significant to our real world success.
All of the following are put to the test throughout these processes:
- Our personal and corporate skill and experience
- Our understanding of the design discipline(s) standards and real world systems
- AND our AutoCAD Civil 3D usage skills
More Ain't a Joke
The problem of multiple processes going on at once isn't a joke. Simultaneous multiple processes confuse us both personally and corporately.
- They upset our old school CAD workflows, and our habitual way of working (what always worked before) most of all.
- Personal task accountabilities get all mashed up and mixed together in new, and perhaps, unforeseen ways in the new environment.
- The basic questions and answers to What, Where, When, and How simply are not the same anymore.
- Those uncomfortable and overwhelming facts can and do produce negative results and bad expectations.
Maybe we REALLY didn't want anything to change in the first place. But it did, it will, and it must. Complex socio-economical realities we don't and cannot control make that so.
We Can and Do Miss the Forest for the Trees
At the beating heart of "model-based" design is the core concept that the model and it's managed "data" will produce the published results we will require.
Yippee! The end of drudgery is on site!
Civil 3D actually can do this remarkably well today. But on a practical level, to many Civil 3D users and organizations it sometimes feels like Elvis left the building or never showed up at all.
The model building and publishing problem and the complexity of the output publishing processes can easily become a beast all by itself in these multi-process muddied waters.
Our decades of previous CAD experience teach us to go back and focus ALL the time on the details present in the "model" to solve the problem. That makes sense because this focus was absolutely necessary when the CAD software was primitive based NOT Feature or data-based (model-based). Put another way...
We won't and can't throw away our previous "investments" even when they may no longer apply or actually require some additional investment to again become even more useful.
All the time I hear the telling example of this kind thinking, "All our details are in CTB format so we can't use STB or we have to "convert them all". They employ old school .shx font files in the details; have their own internal detail Layer scheme; historic hatch patterns, etc.
Converting all that to the any other standards will "take forever" and be a waste of resources that are currently "in short supply". So…
"We'll have to keep doings things the same way."
Aside from the fact that there are a number of ways to automate and/or systematize a conversion process for this kind of stuff, (They do own AutoCAD Map 3D and AutoCAD after all) there is another significant issue.
Ask The Other Question
"What are you publishing? Are you really handing over digital "drawings", your complete project models (Yes there can be more than one), or just submitting a dwg based plan set?"
To them their "project", the "drawings", the "model", and even their deliverables are all the same thing.
To be honest, they probably DO know better, but that CAD reality has been their world since who knows when.
They "know" AutoCAD Civil 3D is different, but they still can't quite break the old mold and reengineer the new machine they need.
At some deep mental and mindset level AutoCAD Civil 3D is just replacing the AutoCAD software.
Changing how and what they produce as work isn't being questioned in any real depth by anyone. Ok. Maybe some of their customers are shouting. Are those folks were just tired of converting the dwgs to get backgrounds to use in their own deliverable plan sets.
The Critical Issue and Our focus must be
Make Publish on Demand Real
The model is the Model. That is all it is.
Good models don't and shouldn't care what they "look like" in a Feature (data) based world. The model and its data structure(s) should be stable, but remain malleable, flexible, and able to be validated first and foremost. Civil 3D is NOT perfect at this without some informed user hand-holding, a known project|data structure, and some organizational maintenance and publishing processes in place.
Historically, CAD looked like it could do Publish on Demand too. Software vendors promised that (and even continue to promise it) today. Technically, CAD by itself could NOT perform because of its fundamental CAD primitive only definitions that are built into it by design.
“CAD is like stacking concrete blocks on the ground and saying or thinking you've constructed a retaining wall.”
Ordered pictures of parts by themselves do not make systems. However, the old school CAD "device" did allow us to create an acceptable illusion of the real world system(s).
Please note that you have to work on the PARTS and their careful arrangement in detail to make the end published illusion work.
Is it still called "AutoCAD" Civil 3D for a reason?
We know Civil 3D employs Feature (model-based) "representations” to display and annotate the data buried in a Model's Features. Yes, if you explode the Features you'll get simple CAD primitives. Dumbing down to CAD into any format is not rocket science today, but that is only practically useful if you view the acts as a linear publishing one way output process. That means that the "Export to" process REALLY is a separate and discrete process triggered by a known event and performed from a known checklist.
All forms publish and reporting processes in Civil 3D need to be seen and dealt with this way. This mindset maximizes the use of your real world resources to do this. The more you can move and concentrate publish details into a one-way OUTPUT process the faster it works, the easier it is to maintain, and the cheaper it becomes to perform. That is basic process engineering and mechanics 101.
Work the Same and Publish on Demand or NOT
Intelligent Publish on Demand (iPOD) is something you must work on ALL the time in your project. You will and MUST fail at that to learn and improve to get better at it. This is iterative engineering.
How Do You Do That?
The specifics and details of the output iPOD process must NOT get mixed up with the model building, QA process, etc either. This is HARD to do because of our detail centric CAD experience is focused on what we see NOW or in other words - the CURRENT state of MY drawing.
In a model-based world, ALL publishing ALWAYS happens from an OUTPUT drawing specifically built and designed to help us perform the specifics of our Publish On Demand process.
That means there WILL be more than one Publish On Demand drawing doesn't it?
That also means that our MODEL should eventually become the replaceable and almost disposable object in our project structures. Read that sentence again. This is the TEST.
That is what "Model-Based", "Feature-based", and/or "Data-based" really means.
Now if we want to talk about BIM in a substantive way, we must introduce continuous feedback loops into those external publish processes too. We must have those basic loop structures and methods already in our internal processes to get to functional Publish on Demand and do our internal QA well anyway.
Practical real world BIM is all about the suitable quality of the information published.
The architect, the contractor, and the owner all really do need different things.
Can you say, "How would you like your Surface, Alignment, Parcels, etc. today?"
Flip the Mindset
Yes. I first published a version of this post 5 years ago. I'd guess that makes the point too.