Alternate Assemblies vs Family of Assemblies

Also, the Family of Assemblies term seems to be used interchangeably with Alternate Assemblies. And the name of that pane seems to have changed recently. Am I getting that right?

I don’t think the terms are interchangeable. I think FOA is a type of Alternate Assembly. FOA saves each different assembly as an embedded object in the file. The other type of AA is for alternate positions, where the parts are all the same just with different relationships.

Here’s a PDF that I think clarifies it. It’s from ST4 so could be dated.

https://support.industrysoftware.automation.siemens.com/training/se/en/ST4/pdf/spse01685-s-1040_en.pdf

Thanks, but that’s really dated. It looks to me that the FOA and AA have been merged. The pane that shows in most of the youtube videos with the heading Alternate Assemblies is now called Family Of Assemblies. When I use the Command Finder, it highlights the Family of Assemblies pane for Alternate Assemblies.
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Ben is right. Alternate Assemblies is a term used to describe assemblies that contain different states (or configurations, for SWX people). FOA and Alternate Position Assemblies are two types of Alternate Assemblies. That is fact. How the commands in SE are called and what the tabs are named can be a little misleading IMO.

Ok, I got an answer from one of the top technical guys at SE. According to him,

  • Family of Assemblies – gives you the ability to control everything for each member. This could be parts added/removed, different assembly relationships, part positions etc.

  • Alternate Positions of the Assembly – only allows you to control part positions for each member and nothing else.

So if you want a SW equivalent of assembly configs, use FOA, if you want to limit it to changing positions (mates/relationships), use AA.

Matt, these have always been under the one “Edge Bar” pane which is currently called “Family of Assemblies” even though it can be used for either.

When you initially create the first “member”, you have to make a decision… Family of Assemblies or Alternate Position. This locks you in to that type for all members and cannot be changed.

General rule of thumb:

  • Alternate Position - 1 Assembly with all parts the same and only move states (i.e Open/Close, extended/non-extended)


  • Family of Assemblies - Different assemblies with different parts and thus different parts lists

It sounds like everything you can do with AA you can also do with FOA. Or am I reading the tech guy wrong? So why would you choose AA? Just curious. Is this functionality possibly in transition, on the way to being consolidated?

And now I find this in an official doc:

Alternate assemblies in Solid Edge include both Alternate Position Assemblies and Family of Assemblies.

Is this a terminology disaster or am I on crack? And I still have to figure out how “adjustable assemblies” figure in to this.

Every time we tried FOA it bit us in the butt. Costing thousands of $ of lost time doing rework/fixing. I get the feeling that the Alternate position assemblies were implemented much simpler than a FOA, smaller file size too.

I don’t recall much with Alternat Position Assemblies. Instead, we used edit: flexible adjustable assemblies to get the motion needed as every assembly that moved had multiple where used. But we still had clowns that liked to apply that mate to the intentional degree of freedom and blow-up dozens to hundreds of other assemblies. We were gaining trust in the new Over Ride Relaion feature before going to the dark side. When using flexible the build times go up and mating to base planes in the sub-assemblies is an absolute no-no. I’m digressing from the topic of AA though…

Ok, this appears to be the answer:

Alternate Assemblies is the top level designation.
Alternate position assemblies and family of assemblies come under the Alt Assy heading.

However, it still looks like FOA covers the same territory as APA, so WTF?

Actually, seeing it spelled out like that makes sense, even if I’d still just torch the whole thing and call it all FOA.

To make the mud clearer, here’s the basic hierarchy:

-Alternate Assemblies
…FOA
…you can configure parts and sub-assemblies
…you can configure relationships and variables
…each member has its own set of file properties

…APA
…you can configure relationships and variables

(periods are intended as indents, forum software doesn’t like spaces…???)

Yeah, I think that’s a good summary, but again, why use APA at all, if FOA does all of that and more? Is there a reason you would want to lock out other capabilities?

I don’t think there’s any functionality “locked out” its in the implementation. APA just doesn’t possess the ability to have different BOMs for example, there’s only one BOM per APA. FOA is literally a bunch of separate assemblies saved in one assembly file with some UI to automate the differences between them.

My understanding is FOA has much more overhead than APA. It’s always a compromise between one big tool that supposedly does everything vs a lean and elegant tool that is effective and reliable. I don’t drive a semi everywhere I go, don’t even drive a pickup; even though it can get me to work and back “and more.” I don’t want all the extra hassle that comes with driving a semi if all I want is get to work and back home.

Ok, thanks. That makes sense of it.

You guys are starting to make SolidWorks assembly configurations look easy.

No, it’s just getting one good explanation of the terminology. The actual function is easy.

Sounds like it creates a bunch of files, which is kind of weird for alternate position assemblies. Guess I need to play around wit it.

SolidWorks lets you create configurations all willy nilly, which is good and bad.

Just to clarify, SE does NOT create extra files for Alternate Position Assemblies. For FOA it creates embedded states inside an assembly (displayed as Assembly1.asm!Member2). If you’re in a managed environment like Teamcenter you have the option to publish members to their own datasets and maintain associativity to the parent. Otherwise, all members are embedded into the parent file kind of like configurations in SWX.

See screenshot below. (Arrow points to the publish button because tooltips aren’t captured in screenshots inside a VM.)
2021-11-23 04_46_53-Window.png

In that screenshot, Isn’t there a separate .par file for each variant (Long, Short)?

I was reading through the help file and it sounds like “Alternate Assemblies” is either “FOA” or “Alternate positions”. It says once you pick one, you can’t convert to the other. Can you have both?

FOA does not create multiple assemblies. FOP creates multiple parts.

It turns out that FOA does everything Alternate Positions does and more, but it seems that FOA is more resource intensive, and if all you need is to show alternate positions (assembly relationship offsets), and not swapping out parts, then Alternate Positions option would be the way to go to save on assembly bloat.

It would be if SW had an option for lighter assembly configurations. This has been my central question for this thread.