B
JSW05 said:
The page you posted addresses receiving verification. I advise our suppliers to stick with potential failures that are caused in the operation in question. In other words, insofar as the PFMEA is concerned, I'm not especially interested in sub-supplier errors because they are not controlled by the receiving verification process. I want to see what can potentially go wrong in my supplier's process. In this case, it's possible that "bad" material may be accepted, or "good" material may be rejected. Depending on materials procedures, it's also possible to misidentify incoming material. I want to see the controls in place for those possibilities.
The other thing I noticed is that the potential causes listed are essentially the same as the modes. For example, the potential failure mode of "Sow chemistry inaccurate" is essentially repeated as the cause--"Supplier sent out of spec material." The first rule of thumb in PFMEA construction is that failures don't cause themselves. The problem here also speaks to my first observation; it's not possible to identify the cause because it's a sub-tier error; what I want to know is how that material is kept from being accepted (the potential failure mode of your process).
The other thing I noticed is that the potential causes listed are essentially the same as the modes. For example, the potential failure mode of "Sow chemistry inaccurate" is essentially repeated as the cause--"Supplier sent out of spec material." The first rule of thumb in PFMEA construction is that failures don't cause themselves. The problem here also speaks to my first observation; it's not possible to identify the cause because it's a sub-tier error; what I want to know is how that material is kept from being accepted (the potential failure mode of your process).
It took me a while to see what you meant by the Failure Mode "repeating itself" as the Cause. I guess I never looked at it that way. Nice observation - and Thanks. I've attached a couple of more pages showing the "two column" approach and how we have addressed "preventive" controls for process parameters in our casting operation.
I, also, would be interested in reading your article. Some of our suppliers have had issues following the AIAG format. I, typically, do not get very critical of whatever format they employ - as long as they can show they have performed some sort of process analysis and documented improvements to "protect" us from receiving noncoforming material. Of course, if my customer demands one of my suppliers' PFMEAs in the AIAG format, I will try to work with the supplier to get it done that way.
Attachments
-
104.9 KB Views: 1,321