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Superceded specs

Superceded specs

Superceded specs

I have received a PO and print with a spec, my material supplier says that spec has been superseded by another. is it industry standard to accept superseded specs or do I have to get prior approval to deviate from the PO and print requirements?

RE: Superceded specs

Usually it makes no difference, but there are just enough cases where the revision matters that you have to watch out.
Without knowing which spec you're talking about, I won't know for sure.

If it's AMS-QQ-A-250/5 Aluminum 2024 clad sheet versus QQ-A-250/5 Aluminum 2024 clad sheet, no problem.
If the old spec has been significantly modified by the superseding spec, then this could affect the intended result.
You won't know unless you compare the two or refer the matter to your customer who issued you the PO.

At least you supplier told you about it before shipping!


RE: Superceded specs

There are many bureaucratic reasons why an updated spec might not be acceptable, particularly if substantive changes have been made. Typically, if such a spec were changed, the system that uses this component would be forced into a re-qualification, which would be very expensive and probably unnecessary. We have a product that is still being produced to MIL-STD-461C, because that's what it was designed to, and it may be OK under MIL-STD-461F, but we'd have to spent more than a few shekels to prove it.

This is where you need to find out from the customer whether there's a material impact to using the updated spec.

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RE: Superceded specs

The PO should provide a description of requirements for the delivered product, including the associated engineering drawing release. Before taking any action, you need to carefully review all of the related documentation listed on the engineering drawing and PO. Also make sure the customer provided all related change documentation such as advance ECNs that may not be listed on the drawing. If you dig down deep enough in the customer's process documentation, you might find something that allows this type of material substitution.

On the other hand, as IRstuff noted, if this part is used on a product whose design was certified based on specific material properties for that part, you should not use an alternate material without authorization. The correct approach would be to submit a written request to the customer for a formal design change or an allowance to use a substitute material for the existing purchase contract. If you deliver the finished part with non-conforming material certs, it is quite likely the customer's receiving QA will reject the parts, and your company will have to eat the cost.

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