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Drawing / BOM Revisions

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Drawing / BOM Revisions | 2 August, 2019

Hello All,

I am a few months in with a new employer, spending much of my time with AS9102B First Article Inspections. This company is a Micro-Chip and PCA OEM but also designs, develops and manufactures products for a handful of customers, as well.

One thing I recently learned, that I have never seen before, is a Product (mechanical and assembly) Drawing that does not contain a Parts-List or a reference to a BOM-Rev. The BOMs are loaded into the ERP System with revision control, but changes to the BOM do not effect the final Product Revision.

Is this a common practice? I've spent time doing FQE work on the west-coast, visiting and approving FAIs for hundreds of suppliers, and I have never come across a BOM change that did not rev-up the Product Drawing.

Thanks in advance,


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Drawing / BOM Revisions | 2 August, 2019

It's not that uncommon.

I've seen AS9100 certified companies use different revisions for the BOM, assembly drawing, and the product itself.

In this case the product revision may be affected by either a BOM or a drawing revision, while the other remains the same.

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Drawing / BOM Revisions | 2 August, 2019

Thank you for the reply.

My concern isn't with each doc having different Revs.

I believe the part that I'm struggling the most with is that the product drawings contain no mention of components or a BOM whatsoever. It's as if there is nothing to tie the 2 documents together... literally, every component on the BOM could change and you would have no clue a change was made by looking at a product drawing.

If this is common practice, I will just need to educate myself to their system.

Thanks again, Aaron

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Drawing / BOM Revisions | 2 August, 2019

Sorry, I guess I missed the point originally but yes, in the case of separate drawings and BOMs, the drawing wouldn't have to change unless the form or fit changed enough to justify a change.

Obviously if the only BOM is the one on the drawing, then the drawing revision would typically change if the BOM changed. I'm assuming that this is the case in your scenario.

We have some customers that do it this way for simple products with just a few line items, but their other products with many line items have separate BOMs/drawings.

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Drawing / BOM Revisions | 2 August, 2019

Thank you for the clarification.

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