Qualification Samples Preparation

Guest

Hi,

Would like claification on performing qualification tests:

1 My understanding to prepare samples for qualification tests, the built of the samples has to be of same material batch built and built at same period, is this correct?

2. If the built is at 2 different times [ built months apart ] and from 2 separate batches, and each built samples is used for different stress tests, what are the consequences if one batch the test pass and the other batch happens to fail?

Thank Q

Posted: Tue Oct 04, 2026 1:43 pm Post subject:

Hi RelQAFA,

In the company that I used to work for before, the policy is basically to use samples that 'represent the manufacturing process being qualified.'

Ideally, one should get qual samples for all rel tests from at least three different lots. Getting samples from different lots increases one's confidence in the rel data, so it is not true that qual samples should only come from one batch. In fact, getting samples from different lots is a better way to 'represent' your manufacturing process.

I think your question stems from the fact that you're dealing with samples from different lots for different rel tests. This is acceptable in my opinion, especially if there's a genuine lack of samples due to reasons beyond your control.

If all rel tests are passed by these samples, then you're ok, as long as you understand how your sampling scheme relates to the qual you're doing.

If not, then you'll have to confirm the rel failures whether valid or not by doing full FA on the failures. The FA should be able to determine if the failures are related to the qual being done or not.

If the failures are qual-related, then you have to reengineer your process and start a new qual again. If they're not related to the qual, then you simply need to get more samples and rerun the failed tests again. You certainly need to have 'passing' data for all rel tests to complete your qual.

EE

Guest

Hi EE,

Thanks for providing the answer.

Regards,
RELQAFA