The chicken or the egg.

[Bill Harper]

We are really being pressured to provide BIM content from our customers. My confusion is, when are they placing these in the BIM models. After we supply the as built? We will still continue to work from our end as usual. Usually that invloves many revisions prior to fabrication.

We don't plan on providing our as built based on the 3D BIM model, would like to. Just wondering why they have so many problems. It seems that there is a major delay in updating the BIM models. I thought that was the whole reason for BIM, to find these problems in advance.

[JonathanHerrera]

"We are really being pressured to provide BIM content from our customers. My confusion is, when are they placing these in the BIM models. After we supply the as built? We will still continue to work from our end as usual. Usually that invloves many revisions prior to fabrication.

We don't plan on providing our as built based on the 3D BIM model, would like to. Just wondering why they have so many problems. It seems that there is a major delay in updating the BIM models. I thought that was the whole reason for BIM, to find these problems in advance."

Well from my experience this all comes down to two things, the workflow and quality in which the Building Information Model will be provided. In regards to quality, how are families being created? Parametric? Fixed? If parametric, you have a better chance of achieving a true as-built, hence a couple parameter values would need to be changed an voila, done. Whereas, if using "Fixed" families, you would basically need to recreate them almost from scratch depending on the extent of the changes. Another big factor that takes play is the trust you have over the project team. And by trust I mean this, will they create the model & content required in the most efficient way possible for the long run/entire length of the project? I know it does take a bit longer to setup a model to be efficient for the long run, but trust me it's completely worth it. Any model with a LOD below 300 would in reality not be worth updating to LOD 500 (shop drawing quality), because it'd be too expensive.

In regards to the workflow, is the model being provided at the correct LOD at every submittal? LOD 100 at SD, LOD 200 at DD, etc. If so, you have a greater chance of achieving true shop drawings without having to spend so much time working on them.

Having a complete and coordinated BIM Execution Plan is also something you might want to look into.

-Jonathan

[garethace]

I'm simply suggesting that whatever you provide as a deliverable be complete or you shouldn't provide it. Therefore issuing the entire model requires more time because there is no way to limit the model, as it is a digital version of reality and you are now responsible for the accuracy of your digital version of reality... instead of plans and specifications that give you instructions on how to get to reality. Those are 2 very different conditions.

I'm only chipping in here briefly and I haven't read through all contributions from all contributors here. But I am glad that Silverado in this case, has made the above point. It is very important, when working for any Employer in the construction, to understand what rules he or she are willing to make, what level of reality they are willing to risk their job with, and what kind of deliverable they believe they can get by with.

It causes no end of problems for employees, especially younger ones, in the construction industry who try to argue the case to their Employer that they may have fallen short of requirements, in terms of providing the virtual representation of reality, needed in many new BIM softwares.

I could quite confidently argue, that more than 50% of practitioners out there who operate and build on a regular basis, have no regard for what kind of digital tool their drafting staff are using, and what level of reality that the software is capable of providing. A big block of Employers in the construction industry, would be happier if BIM software never existed, and we still lived in a world that was limited by two dimensions.

I would compare it to the movie starring Al Gore, The Inconvenient Truth. The inconvenient truth for many very experienced Employers and Designers in the construction industry, is the growing presence of BIM in the industry. I am only glad that someone else such as Silverado, has admitted to something like this, and is aware of the reality of working conditions for a lot of young employees in the industry.

Regards, Brian O' Hanlon

[garethace]

Just wondering why they have so many problems. It seems that there is a major delay in updating the BIM models. I thought that was the whole reason for BIM, to find these problems in advance.

Bill, apologises here again, if I am just jumping in. I haven't following the exact thread of this discussion, and I am only responding to some of the individual comments.

I had some exchanges with a BIM manager working in the Asian market at the moment. He raised exactly the same point, about delay in updating the BIM model. His job in the contract was as BIM manager, running all clash detection between the different speciality professionals supplying information into the BIM.

He discovered to his dismay, that even when he ran the clash detection and notified the engineers involved of clashes that needed to be addressed, that still they were VERY slow to make any model changes. In the end, he resolved this problem and it is too detailed to go into here. But it is still an ongoing problem for him, as a BIM manager on nearly every project. You can listen to the lecture he gave to us here, if you ever find a spare hour.
http://www.youtube.com/watch?v=xl4cR9OO97U

Regards, Brian O' Hanlon.

[Hammer.John.J]

Which comes first, the BIM model or the fabrication drawings?

I work for an HVAC manufacture. We work with contractors that use BIM. We do not use or see the BIM models. It seems that these contractors always have issues with collision. We fix them and move on. My question is, do they build the BIM model after fabrication and installation? Is this the way it should be?

I am was thinking that the BIM models should be done prior to fabrication to avoid these type problems. Is this correct?

Is this the flow of BIM?

1. Manufacture supply BIM content.

2. BIM content placed in model.

3. Collision is detected and fixed.

4. Product is release for fabrication.

You can avoid collisions using modeling software and drafting software neither is right or wrong. BIM attempts to replicate the built environment in 3 dimensions, but that requires far more input than maybe necessary if you have limited potential for conflicts. BIM tool for creating plans, specs, and estimates. I am not aware of any formal replacement of the document to bid to build environment. If you are issuing models for construction, i don't want to be your attorney

[garethace]

BIM attempts to replicate the built environment in 3 dimensions, but that requires far more input than maybe necessary if you have limited potential for conflicts.

Quite so. In initial stages, it would be helpful if we focussed on using our valuable BIM trained human resources in areas, where BIM really does offer significant paybacks for the effort involved.

From a Consultants point of view, where he or she, is responsible for supervision of a number of junior drafting employees - the two dimensional playing field can be a much easier one to be in, from a supervisor's role point of view. If one is in a situation, where one cannot 100% trust one's junior case, then my instinct would be to steer away from 3d models.

I would be criticised by many for making that suggestion.

But if one does simple maths. If a junior employee is capable of generating say two serious errors per month, which I as a supervisor need to catch, using a two dimensional process. Then that same junior employee, may be capable of producing ten errors on average per month, which I also need to catch, using a three dimensional model process.

Now, is it easier or more difficult to 'catch' the two errors, or the ten errors per month? That is, if my labour resource pool in my area doesn't offer me an opportunity to employ better staff, or for whatever reason the project budgets do not allow for hiring better BIM trained staff.

The fact remains, that many employers out there, cut down on staffing costs, and 'get by' as best they can with people who are inferior from a point of view of CAD or BIM skills. It just works out that way a lot of the time, that employers who hire staff, have already factored in their own time, into the equation, that they will need to double-check everything produced by the 'cheaper' staff hire.

When the employer does the mathematics in their brain, they will weigh up, which option is best for them. To hire really expensive staff who can generate zero errors on average per month, and require less hand holding. Or, alternatively, hire less capable staff, who do require a lot of hand holding.

In a large number of cases, the small to medium sized employers, who are not really that enthusiastic about their clients and the work they have on the drawing board, at a given time, will let go all of their good staff, and simply keep their company ticking off with cheaper staff, who fill seats. In that arena, the two dimensional process is king - and I suspect that is what has allowed the two dimensional process to hang on, as long as it has done. To be honest, the 3d software and computer capabilities were there ten years ago, no problem. But for some reason, today, two dimensional process still abound.

[Bill Harper]

This is more what I am looking at.

Autodesk Fabrication FABmep
http://www.youtube.com/watch?v=s0UzUgjyvZw

Autodesk Fabrication CAMduct
http://www.youtube.com/watch?v=Sc18ZFxzXHc

Quickpen has some stuff similar to this.