Incoming Inspection Details on Drawings 1

[Michael_Michael_Motorcycle]

Currently our engineering detail drawings that we send to vendors to manufacture components, we have the following included under "Inspection".

(1) Visual and dimensional inspection requirements for the vendor making the part
(2) In-house incoming inspection requirements (checking certificate of conformance, measuring certain dimensions, etc)

I am of the opinion that we should not have (2) on our drawings and that information should go on a separate document because only information relevant to the vendor should be on the drawing that goes to the vendor.

There are others in the company that believe (2) should be on the drawing because it is necessary to fully define the part and that as much information relevant to the part as possible should be coalesced into the drawing.

Is there a standard or principle that dictates what the standard operating procedure should be here?

Thank you

 

[3DDave]

The drawing is usually part of a contract. If you want to put on the drawing those things that are usually in the purchase agreement, then why not?

I think putting such information on the drawing is unusual, but if your suppliers don't care, why do you care what the supplier sees that does not apply to them?

 

[Michael_Michael_Motorcycle]

To be clear, "In-house incoming inspection requirements" is for internal use when we receive the parts made by the vendor. It would not be in the purchase agreement.

 

[3DDave]

"why do you care what the supplier sees that does not apply to them?"

 

[Michael_Michael_Motorcycle]

"why do you care what the supplier sees that does not apply to them?" Ultimately I don't, but the way our documentation is set up I think it makes no sense to put our incoming inspection on the drawing, and I would prefer if everything we do at the company flows in a logical way. For additional context, we have a separate "spec sheet" for our parts that contains other things we have to do to the parts in house when we receive them (cleaning, packaging, etc). I think it makes more sense for our internal inspection procedure to go on that sheet.

 

[3DDave]

Talk to your management. There aren't drawing police who will come and put your management in jail for doing what they are doing. If anyone will see a problem it will be your legal department/lawyers who may have concerns over the presentation of contractual information.

The model-based definition systems will have all of this information in a single fat file, at least as envisioned for unmanned, lights-out manufacturing.

 

[ewh]

I have butted my head against similar issues when moving to a smaller, more manufacturing-oriented company... the value isn't seen by management as far as the bottom line, so much in-house process info that would otherwise be documented separately is combined with the base engineering definition and sent out to suppliers. As has been noted, it doesn't seem to bother the suppliers.

"Know the rules well, so you can break them effectively."
-Dalai Lama XIV

 

[pmarc]

If I were the vendor, the information than only some specific dimensions are going to be checked by my customer as a part of their in-house incoming inspection could be quite valuable and I wouldn't necessary want to admit it to the customer ;-)

 

[Michael_Michael_Motorcycle]

"If I were the vendor, the information than only some specific dimensions are going to be checked by my customer as a part of their in-house incoming inspection could be quite valuable and I wouldn't necessary want to admit it to the customer"

That is a compelling point...

 

[jassco]

Hi, 3M:

I would use method 1.

Below is Fundamental Rule #3 from ASME Y14.5-2018, Section 4.1 (page 12).

(c) Each [highlight #FCE94F]necessary dimension[/highlight] of an end product shall
be shown or defined by model data. [highlight #FCE94F]No more dimensions
than those necessary[/highlight] for complete definition shall be
given. The use of reference dimensions on a drawing
should be minimized.

Your In-house incoming inspection requirements should not be part of the definition.

Best regards,

Alex

 

[3DDave]

Rule #3c probably doesn't apply. They apparently aren't dimensions. Not sure about the OP, but many places put markers next to dimensions indicating which ones are to be inspected and often addressed with a note telling how often and by what method.

 

[Michael_Michael_Motorcycle]

Correct, they aren't dimensions. Just instructions about how our internal team should perform inspection on the part that we receive.

 

[jassco]

You can put anything on your print as long as they are provided as definition of the product. Instructions on how to measure and how to use the product should be kept out of the print.

Best regards,

Alex

 

[3DDave]

An advantage to this is it may limit those nuisance calls where the item doesn't meet some internal inspection. It can inform the buyer that this is a particularly important characteristic and, depending on the detail on the drawing, encourage them to get more information about how the inspection will be done so they can better conform to that requirement.

In an ideal world everyone would simply follow the drawing exactly but that doesn't always happen and getting parts in, counting on them going into the production line, and not being able to - that's an unhappy situation. Then comes arguments over details that could have been hashed out before the first piece was made, and the delay in getting new parts or reworking the ones the purchaser QC did not accept.

 

[MintJulep]

It would not be in the purchase agreement.

Most purchase agreements have something like "we want stuff as shown on the drawing."

Do you really want to go down the path of some stuff on the drawing applies and some doesn't?

Just instructions about how our internal team should perform inspection on the part that we receive.

If your internal inspection is less strict than what the vendor's in-process or final inspection "should be", then the vendor will apply the less strict requirements. Is that OK?

 

[jassco]

I agree with MinJulep. Everything on a print is considered specification regardless it is a dimension or a general note. The vendor is required to meet the specification. If you don't want your vendor to meet it, you need to remove it.

In automobile industry, if you send a print like this, your vendor will need to report this specification on the PPAP document.

Best regards,

Alex

 

[Prometheus21]

Coming from a company that has for almost a 100 years manufactured stuff in-house, and have just recently (last 7 years) started buying certain components normally produced in-house from vendors, I do understand your predicament, as my company had the same discussion back in the day.

For those components we decided to keep every product specification on the drawing as is, with a minor modification.

As for any technical drawing we have a general notes section (Stuff like deburring, rounding, general surface roughness, standard references ect).
Now our technical drawings also specify a strict degreasing procedure per our internal company standard (located right below the general notes section - e.g. O-43.005.170 - internal document number, made up number but you get the gist) as well as reference to internal documents describing specific deburring tools and inspection requirements to be used before part installation.

The vendors were told to disregard those specifications and requirements, and the sections were stamped "INTERNAL" before the drawing was released to the vendor. We have yet to receive a question or complaint from any vendor.

"I am of the opinion that we should not have (2) on our drawings and that information should go on a separate document because only information relevant to the vendor should be on the drawing that goes to the vendor." - agreed. And then reference that internal document number on the drawing. You will thank me if you ever reach 30-40k + drawings active/archived company drawings.

"There are others in the company that believe (2) should be on the drawing because it is necessary to fully define the part and that as much information relevant to the part as possible should be coalesced into the drawing." - If In-house incoming inspection requirements is necessary to fully describe the part then the drawing is...incomplete. The part and its function should be fully defined by what is printed on the drawing alone. The inspection requirements is there to only verify that the part is, in fact, made according to what is on the drawing.

 

[jassco]

Well, it does not matter who is going to make the part (in-house or purchased), or how it is inspected, or where it is used. The print should remain the same.

Best regards,

Alex

 

[Prometheus21]

The print should remain the same, but to avoid potential confusion with vendors it is beneficial to stamp in-house references (e.g. document numbers) as "INTERNAL" or something similar (like references to specific degreasing protocols, in-house measuring protocols, surface treatments ect. again; in my opinion)
I would personally avoid listing extensive In-house inspection requirements directly on the print like the plague. It causes clutter and detracts from an otherwise good drawing. List it on a separate document and reference that instead; using 1 line instead of 20.

 

[ctopher]

The drawing only needs the info needed to make the part. Some dimensions can be made as critical/inspections dimensions.
From my experience, add any more info on a drawing, price goes up from the vendor.

Chris, CSWP
SolidWorks
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