Re: Final inspection as proces step in PFMEA
There are differing opinions on the subject of including inspection operations on the PFD and PFMEA. There is no specific requirement to do so in the AIAG manual, but I tend to think it should be included because it does (A) have the potential to result in delays and customer dissatisfaction and (B) have its own potential failure modes.
How you deal with the issue with your suppliers is a matter of choice on your part.
There are differing opinions on the subject of including inspection operations on the PFD and PFMEA. There is no specific requirement to do so in the AIAG manual, but I tend to think it should be included because it does (A) have the potential to result in delays and customer dissatisfaction and (B) have its own potential failure modes.
How you deal with the issue with your suppliers is a matter of choice on your part.
Kales Veggie
People: The Vital Few
D
David Bear - 2010
My experience has shown that if a step is important enough to include on the process flow diagram, it should be included on the PFMEA and Control Plan. It is not always necessary to include final inspection (depending on how your process is structured), but your PFMEA and Control Plan should include the steps listed on the flow diagram.
Kees,
Would an MSA conducted on the devices + parts mitigate some of the risks associated with final inspection?
What do you think?
Jan.
D
David DeLong
Re: Final inspection as proces step in PFMEA
Jim and I disagree on this point.
I would suggest following the outline in the AIAG manual which which states that one should ask "How can the process/part fail to meet requirements? Regardless of engineering specification, what would a customer consider objectionable?"
I always remember presenting a seminar on this subject in one company and they reflected one Process FMEA that they had spent countless hours developing. It included Receiving Inspection, fork lift moving, storage, dock audit, etc. It was huge and they were about ready to give up.
Most inspection is now performed by the Operator at the job site. I wonder how this should be approached if we do include inspection? Do we really have one process step or two process steps when the inspection in integrated? The inspection at a process step or after a process has occurred is called the Current Process Controls Detection or Prevention method.
I would suggest that a process step is one that is costed into the product which does comply with the AIAG outline. If a final inspection was costed rather than included in overhead, include it but in most cases, it isn't.
At least 50% of the Process FMEA are faked. There is 1 person, usually from the Quality group, sitting in a corner dreaming up stuff and then making sure that the RPN is lower than the Customer requirement.This usually occurs a day prior to sample submission. Does this really help reduce defects?
We need to really perform then in product families with a small group of department representatives contributing to preventing non-conforming product and defects.
Although I do respect Jim's opinion, I would not include final inspection as a process step but as a control method.
Jim and I disagree on this point.
I would suggest following the outline in the AIAG manual which which states that one should ask "How can the process/part fail to meet requirements? Regardless of engineering specification, what would a customer consider objectionable?"
I always remember presenting a seminar on this subject in one company and they reflected one Process FMEA that they had spent countless hours developing. It included Receiving Inspection, fork lift moving, storage, dock audit, etc. It was huge and they were about ready to give up.
Most inspection is now performed by the Operator at the job site. I wonder how this should be approached if we do include inspection? Do we really have one process step or two process steps when the inspection in integrated? The inspection at a process step or after a process has occurred is called the Current Process Controls Detection or Prevention method.
I would suggest that a process step is one that is costed into the product which does comply with the AIAG outline. If a final inspection was costed rather than included in overhead, include it but in most cases, it isn't.
At least 50% of the Process FMEA are faked. There is 1 person, usually from the Quality group, sitting in a corner dreaming up stuff and then making sure that the RPN is lower than the Customer requirement.This usually occurs a day prior to sample submission. Does this really help reduce defects?
We need to really perform then in product families with a small group of department representatives contributing to preventing non-conforming product and defects.
Although I do respect Jim's opinion, I would not include final inspection as a process step but as a control method.
It would mitigate some risk, but not all. The level of risk (which varies depending on circumstances) should be considered in all cases, and there's no single best answer to the question at hand.
Re: Final inspection as proces step in PFMEA
As usual - the correct answer to any question is it depends. For some products, it is a control, and there are no real issues from its inclusion in the process flow and may have nothing to offer in the FMEA.
BUT, on other products, the additional handling in final inspection can create problems - sometimes with frequencies that can be quite significant. For example, it may be that a final inspector is far from the production line, and on the line they take every effort to protect the threads. But at final inspection they measure a characteristic or two, and toss them into a box (unaware of all of the controls put in to avoid that defect - as determined in the FMEA and transferred to the control plan and work instructions - on the previous operations), nicking the threads and creating scrap. That is scrap that will not be detected until the customer opens up the box. Once you get that rejection, it will end up on the FMEA anyway, so it was likely worthwhile putting it in and considering the issues.
As usual - the correct answer to any question is it depends. For some products, it is a control, and there are no real issues from its inclusion in the process flow and may have nothing to offer in the FMEA.
BUT, on other products, the additional handling in final inspection can create problems - sometimes with frequencies that can be quite significant. For example, it may be that a final inspector is far from the production line, and on the line they take every effort to protect the threads. But at final inspection they measure a characteristic or two, and toss them into a box (unaware of all of the controls put in to avoid that defect - as determined in the FMEA and transferred to the control plan and work instructions - on the previous operations), nicking the threads and creating scrap. That is scrap that will not be detected until the customer opens up the box. Once you get that rejection, it will end up on the FMEA anyway, so it was likely worthwhile putting it in and considering the issues.
I think the issue depends on how your company define what a "process" is. In my org., everyone used to include final inspection into the process flowchart so every doc hereafter has the process "Final inspection". In fact, in most of the time, it is the inspection being done right after the last production operation. So instead of writing it to the control part of the last operation (in control plan), we simply put the control points to an individual process at the end of the flow.
Personally i don't think much help to separate out a final inspection if all the control points are in fact being done right at the site of the last operation. (But the reality is many customers do not find a production process "completed" without having a final or outgoing inspection) 100% inspection is however frequently be treated as a process itself.
b.rgds
Personally i don't think much help to separate out a final inspection if all the control points are in fact being done right at the site of the last operation. (But the reality is many customers do not find a production process "completed" without having a final or outgoing inspection) 100% inspection is however frequently be treated as a process itself.
b.rgds
T
tlars
Is it possible that an inspection step should not be scored in an FMEA?
One's first instinct is that EVERY step should be evaluated for failure mode. Under this guise, the inspection step should not be skipped.
I would propose that the inspection step IS A RESULT of a previous process step in the FMEA. The inspection step has been added to increase the likelihood of detection for a previous process step. The failure modes for that previous process should have already been captured.
Just my $0.02.
Thad
One's first instinct is that EVERY step should be evaluated for failure mode. Under this guise, the inspection step should not be skipped.
I would propose that the inspection step IS A RESULT of a previous process step in the FMEA. The inspection step has been added to increase the likelihood of detection for a previous process step. The failure modes for that previous process should have already been captured.
Just my $0.02.
Thad
