Subcomponent Revisions on Assembly Drawing BOM Table
Subcomponent Revisions on Assembly Drawing BOM Table
(OP)
My company is looking at the pros and cons of including a revision column to assembly drawings to reflect the subcomponent revision. On typical projects we have 4-5 levels in our top-level assembly. We are starting to get into using more components on multiple projects. Top-level system revisions aren't a concern to them nor is revising every assembly drawing between subcomponent to top-level drawings.
I'm looking for input as to the pro's and con's of such a system. What type of impact, other than time (because time isn't important o.O), could this type of change make? By what other means could revision information be transfered to vendors (that make assemblies) to show them exactly what has changed?
Thanks
I'm looking for input as to the pro's and con's of such a system. What type of impact, other than time (because time isn't important o.O), could this type of change make? By what other means could revision information be transfered to vendors (that make assemblies) to show them exactly what has changed?
Thanks





RE: Subcomponent Revisions on Assembly Drawing BOM Table
You will have someone requesting part 435 rev A component for assembly 123, when the latest rev of part 435 is F, just because the 123 drawing says use rev A.
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
RE: Subcomponent Revisions on Assembly Drawing BOM Table
There should be a document and data control process that forwards changed drawings to whomever would require them. Listing all component revisions on the top assembly drawings is a nightmare waiting to happen.
RE: Subcomponent Revisions on Assembly Drawing BOM Table
RE: Subcomponent Revisions on Assembly Drawing BOM Table
RE: Subcomponent Revisions on Assembly Drawing BOM Table
However, if you want to keep track of drawing revisions as part of the drawing pack, rather than just in some ERP or config control software/database then I have a suggestion.
On government contracts in UK the way this was done was to have a drawing list.
For the top level 'deliverable' (or sometimes major sub assemblies) a drawing list was created This had a list of drawings of all the parts used to make the relevant assembly (including sub assemblies unless they had their own DL) with their revision listed.
It had the same number as the top level drawing but with DL prefix (or maybe suffix, I can't recall).
You may be able to set this up in Excel (to allow find & replace) or if you have a parametric CAD (such as Solid Edge) there may even be a way to do it more or less automatically, generate a report from the top level assy or something showing revs of all parts.
It will take some time effort but it was the main tool we used for configuration control and while at the time my colleagues and I had concerns, having seen what other places do(including US defense contractors), and the end result, it wasn't that bad.
In terms of letting vendors know what has changed, how about giving them a copy of the ECO or are you ECO not that detailed?
KENAT, probably the least qualified checker you'll ever meet...
RE: Subcomponent Revisions on Assembly Drawing BOM Table
RE: Subcomponent Revisions on Assembly Drawing BOM Table
With your current system are the part revision levels the same as the drawing revision levels?
If so, the top level assembly will get a revision every time the drawing for any part used in any sub-assembly has a drawing that gets revised. This could also apply to commercial parts that do not have drawings but do have purchase specifications.
If the Director does not paying for the manhours required to make so many revisions you should point out that if customers are aware of the revision level of the product they purchase from you they will question why there are so many revisions to the product. While there are no design changes to the product it will appear to customers that you are still in the development phase and do not have a final design. If my company was purchasing a product that always had a new revision we would be likely to find an new supplier that appeared to have a stable design.
Louis