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Assembly Model Structure


Hi Guys,


We have assembly models comprising of over 2500 parts which have various optional sub-assemblies. Things get a bit challenging when trying to show these components in Spare Parts Listings (exploded views) as they want options detailed separately - showing multiple assembly levels.


We're interested in hearing how you structure your models. We've tried both multiple sub-assemblies and flat structures.


I prefer multiple sub-assemblies as components are easily shown / hidden / updated etc... If the sub-assembly is used more than once (in top level) there's only one update to make. Others are in favour of flat structure where we group components or create configurations - downside being people so not always re-group or configure when carrying out updates.


Both have pro's and con's. I'm happy to share some of our model tree's etc... if this helps?




Re: Assembly Model Structure


Obviously I don't know what kind of thing you're designing but I can't see how a flat structure makes any sense for anything but trival assemblies. For an assembly of 2500 parts it's absolute madness!


We also have extreamly large assemblies in 5-8 layers of sub assemblies - this makes fabrication and assembly drawings and sub-assembly re-use very clear and easy.


You must spend most of your day managing views, part groupings and mates etc.  I suggest you tell your spare parts people to let the designers worry about the model.  Anyway, surely it must be easier for them to do parts lists and exploded views of smaller chunks?

Re: Assembly Model Structure

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

I think that usually organizations organize parts as closely as possible to how they are fabricated and assembled and not to faciltate spares documentation.

And it seems to me there are still ways to display the top assembly via configurations and list control in parts lists to serve the needs of spares if necessary.

But I agree with @Alex_H that a flat structure will likely give you headaches (more of them anyway) in the long run.

Bruce Shand
ST10 MP7 - Insight - Win10 - K4200

Re: Assembly Model Structure


We do it as such.

We make valves, typically large for hot service 900-2300F



     >Body.asm                  (multi part objects, fabricated, machined etc.)





     >bolting.par usually place one stud and 2 nuts and pattern per flange, can be hundreds to thousands of bolts.





The body.asm is comprised of 3 asm for the 3 main subcomponents and then in the main body.asm other things like refractory anchors and refractory are done. Such is similar for other parts of the valve.



When it comes to displaying a single part the item numbering has been a headache as we rely on the auto generated parent child numbering system of 1.1, 1.2 1.3.1, 1.3.2, 1.4, 2.1, 2.2.1, 2.2.2.. etc but once you just pull that single sub assembly you lose the top parent and get truncated down to 1, 2, 3.1, 3.2. The only solution thus far is to make a new top level assembly placeholder to suck up that parent spot.



Re: Assembly Model Structure

Honored Contributor
Honored Contributor

I organize assemblies based on what drawings are needed for fabrication.


Part+Part +Part -----welded=one sub-assembly (welment)

Part+Part+Part-------bolts=one sub-assembly


How the sub-assemblies are moved, managed, stocked, sold, or assembled are the break points.


If part numbers or names are assigned as some level can also control.

Re: Assembly Model Structure


Thank you for your replies, really appreciate them.

Alex_H - We design and manufacture PTO / Tractor driven lawn mowers (Trimax Mowing Systems). I agree, flat structures are incredibly time consuming to update and manage so I'm completely against them in most cases. It is easier to generate small exploded views (sub-assemblies) and in this instance we've done as you suggested by dictating what Spare Parts receive (drawing wise).

bshand - This is generally what we've done in the past (assemble models as we would in reality - fabrications, assemblies including fasteners etc.)

nanan00 - Very similar to how we currently structure models, thanks for providing this info. Unfortunately I don't have a solution to your challenges when displaying single parts etc... We use our own numbering and revision system which is done manually, but works really well. I'm happy to share details if you would like me to elaborate.

12GAGE - This is what we do, but it presents challenges for spares wanting parts shown in multiple sub-assemblies. It’s possible of course, buy can be very time consuming to update.

We will reach an agreement (for model structures) prior to starting out next project. Spares may have to work with what we give them. Thanks again for your feedback.

I've asked this question around the place and it was suggested we try Family of Assembly. Is anyone familiar with this or currently using it (haven't had a chance to research it yet).

Re: Assembly Model Structure


I think Family Of assemblies would only help if you have a flat assembly structure.

If you are using sub assemblies and not all the parts within them are spares you would have to create a FOA for every one.


Could you use a file property to define a spare - possibly in the category or keyword property?

That would only work though if a part is always a spare. Maybe an enhancement request coming here for an assembly defined property ie. a custom occurrence property defined at assembly level.


I would think assembly configurations are your best bet - create a 'spares' view config and you can explode them, show them in a drawing and create a parts list containing just the spares.

HP Z420 16GB RAM
Quadro K4000
ST10 MP6 on Windows 10 Pro 64.