Breaking up the Revit model

[mbeham]

Ok everyone out there i need a quick response to this for a meeting Thursday morning that i did not get wind of until 20 min ago..normally how it works here. The question is why should you not split up a Revit model. Everywhere says not to do it however nothing says why....i can name some reasons off but i'd like to get more input from other people. im not talking splitting them once they are 300MB. Our normal work files currently are all under 130MB so they are managable files. We are being asked this question by management because of course that is how Bentley does it. Please any response available will be a great help.

[sbrown]

Because thats NOT how Revit works. Revit is a building information model. Its meant to be one model. Linking was originally created for campus plans, its been expanded to allow some cross documentation, but it adds alot of management with little if no performance gain when the models are all loaded in. There are cases where linking makes sense but they are limited. If you don't have a performance issue or need to work from different locations it will just be a headache.

1. You have to manage view graphics from multiple models, ie create views for your linked views.
2. Not all annotations show up, so if you want to create interior elevation views your stuck, you can either create them in the host and not beable to adjust the model, tag etc. or you can create it in the child but not see the ref. So for all practical documentation reasons it becomes a liability.
3. Levels, Levels, Levels, Grids Grids Grids. these things will start to show up everywhere and without a strict management policy you will be constantly dealing with setting up views for new views of the model. (note this can be dealt with, its just not direct editing).
4. Schedule performance and editability - you can only edit fields in the active model. So you have to go to the other model, fill out all its schedules and then just "view" them in your host model.

There are more reasons I don't like linking. But workflow and management are the main ones.

[violet78]

How about asking them why you _should_ separate them? :P I can't think of any good reason to do that except on bigger files.

With all pieces in one model, it's much more efficient to make changes. Say you have exterior walls in one model, interior in another. Building shrinks. You change all the outside walls, then move to a second file to change inside walls, then back to the first and reload so everything looks right.

It's impossible to join geometry between pieces in separate models. If you need to do a door schedule, how do get one schedule if you have doors in multiple files? How do you make sure line types, family types, etc., stay consistent across files? Too many questions to make it reasonable, in my opinion.

[dkiewig]

All the reasons stated previously are good ones, but not better than this:

-Tell management that Bentley s$cks!!!

[twiceroadsfool]

I think it needs to be evaluated on a case by case basis. On very large projects, using File Links is absolutely the way to go. You can workset a project to the hilt, it wont matter if the project is so massive that youve got 400MB Central files.

It is always a decision to be made evaluating the stage and the complexity and the size of the project.

Does linked files mean more management strategy is necessary? Absolutely! Thats just part of the gig now, IMHO...

[cliff collins]

If you are using Revit Architecture, Revit Structure and Revit MEP for a fully
coordinated BIM project, then you will absolutely be linking (splitting up)
the model.

At our firm, we have a "Shell and Core" model, and the "Interiors" model
which are linked together, for large hospitality projects. This enables our architectural and interiors departments to work independently--and not "step on each others' toes".

But Scott is correct when he states that Revit is designed to function as a single-model
BIM solution.

Until the hardware catches up with the software's abilities--some "splitting up"
may be required for performance/management on large ( 200Mb or larger )
projects. 64 bit OS and additional RAM and faster processors help.

Cheers.....

[cdatechguy]

Take away their trade magazines....(Dilbert Reference...with Point Haired Boss....alas...cannot find comic to link in...)

[mbeham]

Thank you everyone for your timely responses. This just helps me to back up my opinions a lot better. I agree with all of it! We have been doing each discipline in one central file so 4 files one Arch, Mech, Struc, Elec. We have not had a model over 150 MB. Thanks again. Please feel free to continue to post i think a lot of people get this question and just like the idea of more peoples thoughts on this process.

[twiceroadsfool]

People will always have different ways to skin a cat... But File Linking is not the devil it is often made out to be.

This file has two models in it, and it makes editing the entire building insanely fast. A few design options, one link, and a View Template makes the whole thing much easier to manipulate than if the entire thing was in one model...

EDIT:

I should mention the point of the 2 models is that theres only one "floor" modeled. But this is just one reason for using links. Ive used them on large buildings too, simply to minimize the load on lesser workstations. I break them at expansion joints, just like the building itself, or i pick a location and CLEARLY delineate the process to the entire project team...

[sbrown]

Would you eleborate on how your are setting up your room and door schedules, interior elevations and referencing. I'd love to speak with you if you don't mind. Will you be at AU? Please PM me with your contact info if you don't mind. I've done one job where ID was linked into Arch and that worked ok but still some hurdles that didn't work well.

Thanks.

[twiceroadsfool]

Yeha, im gonna be there... (If youre talking to me). The only aspect (so far) thats been a pain in the ***, is rendering. Because light sources dont cross over. But, i have Max so i suppose i should learn to use it. :)

email: armaller@gmail.com
MSN: armaller@gmail.com

Im on my way out the door, but ill come back and tlak about schedules and views... Though theyre all standard issue protocol, there arent many tricks. Its a little work to manage it all, but thats what we do now, lol...

[mbeham]

If you are doing schedules across two arch models i'd also like to hear about that. Its something we are probably going to be doing very soon since we are starting to model everything in the building now rather than just casework we are placing every piece of equipment in. I will be at AU as well.

[mbeham]

The whole reason breaking the model is coming up is because of overseas offices that our company is wanting to share with. I've made a post here http://forums.augi.com/showthread.php?t=81530&highlight=sharing+with+other+offices discussing what we have looked at. What i am wondering is does anyone out there have experience with this. Have they shared with an office overseas, if so how did they do it and what was the outcome. We are really being pushed now to do this and its something we would rather be leading as a research and development group rather than cleaning up after.

[mzabritski]

Just to jump in here....

We are also getting ready to do our largest project to date (about 500,000s.f.) and we are looking at ways to break up the project with worksets and/or linked models. This project will be split between our offices with some IPD workflow aspects involved. We've already started moving our workstations to 64bit Revit and have Riverbeds and Riverbed Mobile controllers in place.

Love to talk about previous experiences with other users here. I will also be at AU this year. Anyone looking to get a hold of me:

email: LSUWEST@HOTMAIL.COM
MSN Messenger: LSUWEST@HOTMAIL.COM

Thanks,
Michael

[jandajanda]

how to create a central file project .i need the steaps

[mbeham]

For those are at AU from this discussion. I was wondering if you would all be interested in a sit down maybe at breakfast or lunch to discuss what issues we have and what each one of us is doing to get it out on the table. Let me know and we can maybe arrange this.

[sbrown]

For those are at AU from this discussion. I was wondering if you would all be interested in a sit down maybe at breakfast or lunch to discuss what issues we have and what each one of us is doing to get it out on the table. Let me know and we can maybe arrange this.

Yes, when is good?

[mbeham]

How about 11:30 Wednesday right outside the Lunch room Hall C then we can go in and sit down and discuss. Please feel free to invite anyone you think will help.

[twiceroadsfool]

I just saw the update on the post. 11:30 tomorow sounds good. You cant miss me, my badge has like... 5 of the little flair stripes on it. hahaha...