How often is test equipment the source of your errors?

Question

I'm a technician at a large aerospace company. I work on systems with BOM costs in the 6 figures that sell for 7 figures. Despite this, our test equipment is horribly maintained. During testing, if we encounter a non-conformance, the immediate reaction from me or my co-workers is to suspect that it's a test software or hardware issue.Be it the cables used, the test software, the test hardware itself, or the unreleased customer software that's loaded on the device to be tested, we have to rule out the equipment before we suspect that it's something wrong with the product. I'm just wondering if it is common in large companies to neglect preventative maintenance. Thank you.

klausnrooster · Accepted Answer

100% of the time, test equipment contributes some error. Usually the magnitude is small and the cause is unassignable - if you maintain the equipment. Whether your tests are destructive (to the sample) or not, you should be doing weekly or even daily Verification testing (of the same batch of whatever) and Control Charting the results. You should be doing MSA (Measurement Systems Analysis) and probably Uncertainty Budgets. Does your lab have ISO-17025 Accreditation? I hope so. But even if you do all the above, you will still be asked to retest. A test error is the best thing! If it's test error, then maybe there is no problem with materials, process, and sampling that produced the sample you are testing. No need to reject and/or rework - just correct the test! But if you get your test equipment under control, that mindset in the people above you will make sarcasm your constant companion.

bdavis___ · Answer

Never. Test Equipment goes to the Cal lab on a periodic basis. They keep the gear working. Test cables, probes, etc. are user replaced and don't cost much.I have seen o'scopes and signal generators working well 40+ years old.