Redesigning part - BOM change
Redesigning part - BOM change
(OP)
My question is similar to an earlier post - thread1103-185128: Assembly Drawing BOM Change Question. My situation is this, I am redesigning a part that is a welded assembly. It's form is changing slightly, but it's fit and function are not, therefore, I want to keep the same part number. However, several pieces are being added, and several other pieces are being removed. Is it standard practice to remove the pieces from the BOM that are being removed, and add new item numbers for the pieces being added, or is it acceptable to simply exchange item numbers in the BOM? The parts being exchanged serve completely different functions to the assembly, so I'm inclined to make new item numbers for them. I do not intend to renumber any parts, and agree with the advice from the earlier mentioned post for keeping the item number in the BOM if removed. I just wonder if it's standard practice to replace items with new items that have different functions. I can see how that could be confusing to craftsman used to welding the assembly.





RE: Redesigning part - BOM change
If your company requires to make it a new rev - same part, then I would remove the parts from the BOM, add "removed" and add the new parts to a new BOM item #.
Chris
SolidWorks 07 3.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)
RE: Redesigning part - BOM change
RE: Redesigning part - BOM change
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RE: Redesigning part - BOM change
RE: Redesigning part - BOM change
Chris
SolidWorks 07 3.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)
RE: Redesigning part - BOM change
If you are changing parts within the weldment, then your form changes are not slight. I would recommend pulling a new number for the weldment. Since you opted against this option, it might be best to not do anything else that you feel is going to be confusing. Exchanging item numbers on the BOM could be confusing, particular since you don't have a PLM system in place.
Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group
RE: Redesigning part - BOM change
RE: Redesigning part - BOM change
Here's a good general rule:
Good luck with your task.
Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group
RE: Redesigning part - BOM change
More important than just 'function form or fit' is effectively whether it is interchangeable - forward/backward compatible. Assessing function form and fit are ways to help judge this.
If it is interchangeable then you'll probably get away with the same number and just a rev change.
Function, Form and Fit are defined in I think it is ASME Y14.35 revision of drawings (or something like that).
Out of interest anyone know in which US standard it talks about when something can be a rev and when it needs to be a new part number, especially for non government work. I thought it would be Y14.35 but it didn't jump out at me when I looked. In the UK it was in a Def Stan (equivalent of Mil Std) for the government programs I was working on.
Ideally I wouldn't change the item numbers once assigned, so would do what Ctopher suggests, but in some CAD systems this is easier said than done.
RE: Redesigning part - BOM change
Where possible, I personally do try to keep the same number. In the case of draftsmandon's situation (as described), I would likely pull a new number since the part/process used to make the part substantially changed. First, it was no longer capabiable (fit) with the previous components draftsmandon removed from it. Second, several parts that did go into it (form) where completely different. It could confuse the welders and make BOM changes very complex and hard to follow. Even worse, if this was a fastened assembly, if a part needed to be replaced in a repair activity, the older components would be useless on a new rev, and the newer components would be useless on the old rev. However, there may be some room for forgiveness since this is a weldment. In my experience, based on what draftsmandon has mentioned, I say the save bet is to pull a new part number for the weldment.
Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group