BOM Stability

[SWISGR8]

Please dont shun me, but we currently dont use SW BOM's yet (I cant stand it) but when I have played with them I noticed a concerning "stability" issue. Let's say you have you SW BOM setup and have the basic situation of where you have selected to use the "Follow Assembly Order" for Item Nubmers. Now if you go and change anything WRT order in the actual assy, then affected items will change. There could be many other scenarios such as maybe you choose not to use "Follow Assembly Order" to avoid this, but then you could accidentally select it and then everything changes and if you dont catch it, then you're in a time-wasting recovery mode. To me the ideal thing here is to not use this option, but to enhance that, I would like to be able to disable the "Follow Assembly Order" control all together (ie gray it out), is there a way to do this. I realize there are working conventions that can be set up etc (such as "dont use this"), but it can still happen and then you're wasting a bunch of time going back and fixing or not catching until too late and end up with a documentation debacle, especially when dealing with revs and you dont catch until too late.

Any ideas or enlightenments to my understanding of this?

Thanks,
Mike

 

[drawoh]

SWISGR8,

I systematically set SolidWorks' BOM to Follow Assembly Order. On earlier versions of SolidWorks, I determined that the no-reuse features and the cross-out features were not reliable. The feature that crossed out unused item will fail if the parts list is copied to a plain text file or are other tool that does not support font features.

Also, I keep related components close together in the assembly tree in the model, re-arranging them if necessary. This imposes some rules, procedures and understandings at the drawing level...

[ol]
[li]Do not write notes refering to item numbers. Item numbers change, randomly.[/li]
[li]Do create unique names for each component in the assembly and use these in any notes. You should not have five different parts called BRACKET.[/li]
[li]We create external parts lists from the SolidWorks data. These have a note stating this, and stating that manual changes to the parts list will be lost.[/li]
[li]Any SolidWorks drawing that has somehow degenerated into a piece of crap can and will be redone. It does not take long. Any automatic history you built into the drawing will be broken.[/li]
[li]The Excel parts lists each are attached to drawing views, which you may delete and re-do from time to time.[/li]
[/ol]

Probably, I missed something important, but you can see my point. SolidWorks' parts lists work very well, but you need to be methodical with them.

JHG

 

[handleman]

I've never used "follow assembly order," but I've never "accidentally" clicked on it either. There are a lot of commands in SW that are potentially devastating if they are used and then the file is saved before you notice. However, I think the ability to enable/disable commands willy-nilly would cause more harm than good.

 

[SWISGR8]

I hear you JHG, and that's what I'm hoping to customize I guess by eliminating some of the control that would not pertain to how we want to use it. We create the external PLs as well and to me those are much easier to create and maintain when driven by the SW BOM. I dont like the excel-based BOM (they do some crazy things), and for some reason I cant remember why, but it was something quite a while ago and I decided they are too limited and even more unstable, and worse the instability was in a random way.

I hear all of your point though, I just feel a huge benefit to SW BOM is to not have to put a lot of dbl checking into the BOM. And it's almost like the time you save up front by having it create the BOM gets used up again by having to check it more thoroughly down the line.

Also, with the Follow Assy Order(FAO)if you use subassys that arent really subassys in terms of part number (just for ease of modelling) so therefore if you say to use a Parts Only BOM style, the parts changing withing that subassy will change the itemization in the main assy BOM (ie you design evolves to not need a certain item or has 1 or more added).

I know my posts show (and it is true) we need to have some procedures in place and those to some degree are unavoidable with a parametric software such as SW, it's just I want to eliminate the dependency on procedures as much as possible, or at least to minimize the effect/penalty of missing a step.

Mike

 

[SWISGR8]

Yeah, I hear you Handle, and looks like you are with me as I see you use the word "devastating". I know the "accidental" would be pretty rare if at all, but the fact that it could happen means more care has to be put into the maintenance of the BOMs. More than anything, I was wondering if there was a fairly easy way to address it as I would like to. But if not, then we have to work around it.

Thanks,
Mike

 

[CorBlimeyLimey]

Stick a piece of masking tape over the position where the FAO option appears.

 

[SWISGR8]

What a card, you here all week ... then my question would be what tape is best ?

 

[drawoh]

SWISGR8,

Also, with the Follow Assy Order(FAO)if you use subassys that arent really subassys in terms of part number (just for ease of modelling) so therefore if you say to use a Parts Only BOM style, the parts changing withing that subassy will change the itemization in the main assy BOM (ie you design evolves to not need a certain item or has 1 or more added).

You have a choice. You can create sub-assemblies for the hell of it and use the indented BOM. Or, you can accurately model your assembly tree, and let the parts list show the top level parts only. I go for the accurate model of the assembly tree. I do not just create sub-assemblies. Most of my fabricated parts are aluminium, and I create these as assemblies. That way, I can add thread inserts and dowel pins to the fabrication drawing, and let the fabricator manage them.

Perhaps I was not clear enough before. I turn "Follow Assembly Order" on. If these is any possibility that SolidWorks will change item numbers, you have to follow my rules, above. I recommend doing this, regardless of how you set your BOM.

JHG

 

[SWISGR8]

JHG, I understood your method and I appreciate it (not knocking it if that was your interpretation), just added some of my own findings. With Rule 2 though, that to me is a no-brainer, parts should all have a p/n and therefore that should be their name, if for some strange reason a purchased component could have the same p/n as a purch comp from another mfg, then add mfg names, etc; my blood curdles when I see people naming models with a generic descriptor.

Back to BOMs, I havent really seen them change randomly though, there's usually a reason (when I've seen it), it's just that as with all things in a parametric environment, sometimes the reason isnt right in front of you. We dont make subassy's "for the hell of it" though, we end up with some very large models with a lot of mates and components as a whole and sometimes the subassy is the only way to keep from bogging the system down, BUT at the same time the appropriate way to create that particular subassy might not really fit into the mfg scheme, so it is basically in existence as a virtual subassy only. Not to mention that there are some ways of taking advantage of design tables and commonly assembled parts that also do not lend themselves to mfg. I get you though maybe we need to establish more "rules" than I'd like, but hopefully SW adds more customization control such as what I mention, not with "willy-nilly" access, but more likely through an advanced, external-to-SW access. There's always a way to do it without compromising software integrity, they just need to do it.

Anyways, I guess it's on to the rules. Thanks.