Assembly Occurrence Properties - Do Not Display at Next level

[beachcomber]

Hello all,
We have assembly models where 'background' information has been added to enable the drawing to show where/how parts are located in the assembly.
This has been done by adding the appropriate assemblies then setting the occirrence properties to 'Do Not Display at Next Level'
It is my belief that this can have a serious affect on overall performance when the assemblies are very large, and it has been done on several assemblies that are used in the main GA assembly model.
Does anyone else have any views on this?

bc.
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[HDS]

I can not answer if this method requires more ram or resources but I will share my views.

Was it done only to show more information for drawing views or was it done to allow the model to be constrained & designed around the other assembly?

If it was only done for the drawing then those views could be recreated using the higher level assembly. You will have links to more than one file in a drawing (and more than one drawing linked to the main .asm file).

We have done this for design purposes before or to allow two people to work on different parts of the main assembly. In that case it was too much work to remove the extra parts and reconstrain the entire model. It might be better than lots of links and interpart copies if they were needed to build the models around those other assemblies for design purposes.

 

[beachcomber]

Hi HDS,
Unfortunately the company I work for do not use a stage-by-stage assembly structure.
What they do is what I call 'Zone' assemblies, which are then all brought together in a GA assembly. The advantage of this is that you don't really have to worry about build sequence in your modelling.
The disadvantage is that you never have the previous level parts to refer and constrain things to.
What I found was that several of the zone assemblies had one of the machine frame assemblies (comprising hundreds of parts) for reference. The frame assembly was then also used at GA level.
Another zone assembly used at GA level had so much reference information that it almost contained another GA.
By the time we had finished investigating what was attached to what, we had at least 16 frame assemblies at GA level(although occurrence properties meant only the correct 4 displayed).
It really isn't practical to generate all our zone assembly drawings from the GA. What we are now doing is creating a zone assembly containing just the parts for that zone. We then create another assembly containing this zone assembly and any other reference models and use the same filename but with -DFT on the end. This is then used for the zone arrangement drawing.
It isn't perfect but in the past it has certainly helped performance-wise.

Just as a test I added a small zone assembly to a new assembly model. Then I added the -DFT model to a new assembly (remembering to set occurence properties to not display at next level) - hope you are following this.
Timings for opening them from a fresh restart of SE were 4 seconds and 39 seconds, and the memory usage was much higher for the DFT model.
Exactly the same amount of data was displayed in each case so my conclusion is setting the occurrence properties asc described only really affects display times.

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

Where would we be without sat-nav?

 

[HDS]

What you are doing seems cumbersome but it sounds like it offers some advantages for the way you need to work. The part I don't understand is if the zone assembly has all the parts and is fully constrained why is the -DFT assembly the one used to build the GA? Is it so everyone can work separately on their parts of the project?

You could try changing the settings for what is active and use display configurations or zones to control that. However if it isn't displayed I don't know if it will change anything. Simplified assemblies and Zones are supposed to help with this. However, I have never tried either one.

BTW what does GA mean?

 

[beachcomber]

GA = General Arrangement or General Assembly.
In other words the Top Level assembly.

No, the -DFT assembly is purely for creating the drawing with background/reference information. It does not go into the top level assembly. The zone assembly goes into top level.

There are other problems here also, to do with system performance. It takes an age to return to a big assembly when you in-place edit or open a part.
We have just tried to clean up the models by removing any attachments that are not requred at higher levels to give orselves a chance of actually getting some work done.
I remember last time I was here I had to bring a book to read while I was creating drawing views. The workstations are a bit better but as usual are bogged down with non-cad stuff. One or two people have 64-bit workstations that ONLY have cad on them and they are significantly faster.

Simplified assemblies, in my opinion, are a complete waste of time. They don't update automatically, they bloat the assembly file size and have faces missing all over the place.
The 'Zones' function will make no difference to the problems we have.

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

Where would we be without sat-nav?

 

[HDS]

I didn't think any of those would really help like they are advertised to.

We have seen similar problems with VERY slow assemblies and blame it mostly on the network because we don't have PDM. I try to limit my time on the internet to when I am waiting on assemblies to save or drafts to update.

Some people have found that broken links can be one of the causes. There is a command in revision manger to look for them in all the files in a folder. There is a utility someone wrote and posted to the GTAC forums that will look for broken links to bitmaps in face styles. If those are there they are hard to find but can cause big issues.

 

[KENAT]

beach, while I've done plenty with big assy's and pushing the machine limits, I don't think most of the ones I dealt with had large assy's set to not show at next level.

However, I seem to recall maybe being warned about this, though it may have been you or someone else on here that warned me.

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[beachcomber]

Kenat,
Quite possible it was me. I've been through this exercise for this company before and once we had got rid of all these attachments we saw a big improvement in performance.
Now I've done it on this project I can see an improvement yet again.
There shouldn't be any broken links because these models were created recently from another project using revision manager, so we are sure they are all 'clean'.
I'm sure the rest is down to network and workstation quality.
Another factor is that many of the parts are simplified, although on these models it has been done in an efficient way so file sizes are not increased that much.
I found some years ago that opening a massive assembly took longer with simplified parts displayed rather than as-designed. The trade off is that view manipulation is quicker with simplified parts.
Thanks for your input.

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

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[KENAT]

I don't think it was one of the things that came up on a session regarding large assy's at the conference back in 06, however your experience suggests it is a factor.

Also, as you hint at, there are many aspects to 'performance'. Changes that enhance one factor may negatively affect another.

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[Nodski]

Hi,
Slightly different angle here....seems whatever you do with solid edge or probably at a guess with any Cad system there is are always advantages & disadvantages of whatever do ! The obvious thing to do is experiments...
I would suggest not to do the following !
1) use interpart copies
2) use family of parts
Reason being potentially so many links...have a look in revision manager to check these links. Before i joined the company i work for now they used family of parts for fasteners, ouch how many links..we tediously replaced these. Everyone can open our top level assemblies now !
Set your default open settings to inactivate & hide all.
Use configurations that you have saved previously so you can carry on working with what you were on 'yesterday'.
Simplified assemblies...hmm the file size is larger when simplified most of the time... So better in .asm's, group parts and assemblies that you only need to see some times so you can hide them with a couple of clicks.
Well there is more, but i dont know if this satisfies your requirements. Oh yes simplified assemblies lead to un balloon referenceable ( if there is such a word ) in .dft if the simplified option is used in .dft.
That will do for now.

Nodski
Hope someone answers my question ! lol

 

[KENAT]

Lots of assembly levels with relatively few items in each assy is preferable to a 'flatter' assy structure.

Unfortunately, it flows in the face of what our manufacturing like, and although there are ways to trick it to some extent in SE I don't like doing anything fancy I don't have to because so many of the folks round here using SE are nothing like expert.

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[beachcomber]

Some great points Nodski and I have to agree with all of them.
Kenat, I'd never really thought of the assembly structure that way, I've always just modelled from a product point of view.
I suppose the flat structure could potentially require more positioning constraints in a single file.

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

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[beachcomber]

Just to let you guys know, I have just opened the top level assembly in view and markup which reports that there are 1738 unique parts with a total of 108827 occurrences.
Now that's a big assembly!

Considering we only have 3GB of ram in 32-bit systems I think we are not doing too bad.

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

Where would we be without sat-nav?

 

[KENAT]

I'm afraid my memory is fuzzy on the details but supposedly keeping each assy small and having more subassy instead helps - I think like you say it's because there are less constraints to take care of. I've actually restructured some top level interface type assy's to try and take advantage of this and I think it helps but I haven't done double blind testing or anything!

You're doing OK, I can't remember how big our model got before we finally had to get 64 bit with lots of RAM. Even then, the model could be opened on 32 bit machines it was just slow and prone to crashing, it was the need to create drafts of the top level assy's that pushed us over the edge.

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[beachcomber]

Something that struck me a few moments ago - before cleaning we must have had close on 220K parts !!!

For drafts of this size assembly I tend to set up a view by selecting 'Visible Parts' then 'Show Only' and save it as a view configuration.
That way you only process the required information.

bc.
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[HDS]

With lots of constraints in a file it can be nearly impossible to figure out which one to fix when they start to go bad after a part has changed.

We have had some top level assembly drawings that required each sheet to be in a separate file.

 

[beachcomber]

HDS,
We do the same thing with very large assemblies.
One file per drawing sheet.

bc.
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[KENAT]

For assemblies, using all low quality draft views works very well since you don't normally have dimensions, or not many.

However, for the type of foot print drawings we had to do they needed lots of drawing views & dimensions and for reasons based on our own doc control limitations one file was better, with as vew sheets as possible.

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