FMEA
FMEA
(OP)
I am currently conducting an fmea on a system and am a bit confused on the design verification column. If there are calculations and existing test procedures that have been carried out at the design stage. Does this necessarily mean that you have to fill in the recommended action columns?





RE: FMEA
RE: FMEA
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DFMEA must account for parts being made incorrectly only as far as the part's design not being fully specified (i.e. omissions in a drawing).
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If so, my recollection is that there are supposed to be corrective measures taken to reduce the criticality and effect of the failure modes you've identified
TTFN
RE: FMEA
RE: FMEA
ChemE, M.E. EIT
"The only constant in life is change." -Bruce Lee
RE: FMEA
I fully agree with aspearin1, "machine malfunction" is NOT a single mode. Every instance where a machine designer / builder will place a sensor is a 'corrective action' preventing a failure mode. Every hard stop, every safety feature, every poke-a-yoke are there to head off potential failure.
A lot of these items are built in under a 'common sense' umbrella, but should be given consideration on the PFMEA. Otherwise, down the road, some hot-shot newbie will come along and "improve" an operation by removing or defeating a feature that has no apparent function and doesn't appear to be a corrective action as per the PFMEA.
So many products outlive the original launch team and the PFMEA is one of the living documents that should be there to guide future tinkerers.
regards,
Hydroformer
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If you are only "a bit confused" then you're doing better than most. ISO 9000 has new definitions now for design verification vs. design validation:
Subclause 4.4.7, Design Verification, states that design verification must be carried out at appropriate stages of design and must ensure that "design stage output meets the design stage input requirements."
Subclause 4.4.8, Design Validation, is new and is in addition to "design verification." Design validation must ensure that the product conforms to defined user needs or requirements. This is in addition to design verification which must ensure that design stage output meets design stage input requirements. Design validation follows successful design verification and is normally performed on the final product.
The design stage output typically would be drawings, specifications, ie. paperwork. Does the paperwork invoke, enforce, or implement the original design input requirements? In otherwords (according to this old designer's brain) are the drawing details and calculations checked, maybe independently checked, and properly signed off and documented and archived? That would be design verifcation.
Design validation then would be testing or demonstration of the final product (hardware) to assure that it meets the originally intended performance, appearance, dimensions, reliability, etc.
RE: FMEA
As for the 5M's, they are used in cause and effect analysis as a tool for root cause identification. What causes could cause a specific effect?