PFMEAs and Inspection Process - Feasibility Analysis

[Nattapong]

PFMEAs and Inspection Process

The PFMEA only applies to to the mfg processes. Does your feasibility analysis include problem solving for processes? If so, then those problem areas that have been solved will show up as low RPN numbers on the PFMEA.Although not required, IMO, it is best to address each step of the process during when preparing FMEA.

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Sam Goody

I agree with you Sam, PFMEA should be evaluated on a value added process (e.g. Manufacturing Process)...According to its concept "Before- Event" Right? But my CB asking for "Inspection Process" too...
That was make me confused how to idendify the "Detection" number (Detection Performance of faulty detection)...I think it doesn't make sense to applies PFMEA on Inspection Process.
Sam or anybody, please advice me the referenced documents which clearly identify that "PFMEA shall (or should) be applied on only Manufacturing Process".
Will be greatly appreciate.

 

[Randy Stewart]

I don't think you will find anything that states that. Inspection has processes and therefore can have PFMEA applied. We use PFMEA on our design processes along with design FMEAs. Remember you're focused on the process not what you are inspecting. Detection is being applied to a process failure. Identify your "Desired" inputs (gage R&R, travelers, fixtures, etc.) and "Required" outputs (SPC report, PIST, etc.) and be specific. Look at how the gage R&R result is used, training of the inspectors, etc. You may want to look at equipment FMEAs for CMMs.

 

[Bill Ryan - 2007]

Just an addition to Randy's post:
Accepting nonconforming product and Rejecting conforming product are a couple of other "Inspection Process" Failure Modes we have included in our PFMEAs.

Bill

 

[Sam]

In the context for which the "Potential Failure Mode and Effects Analysis" manual was written it applies to the design and manufacture of products and manufacturing processes.
Can you use it for other areas such as MArketing, Sales Customer Service, Quality,etc. Sure you can, but it is not required to be included as a part of thje D/PFMEA as described in the manual.
As far as evaluating the inspection process; You are making that evaluation when assigning the detection rating?
Value added processes is the key wording.

 

[Bill Ryan - 2007]

FWIW - Here's my sopabox delivery of the day:

I look at the PFMEA as a means to document our efforts to ensure shipping conforming product to our customers. IMO - It is also a good place to document the dreaded Corrective Action/Continuous Improvement activities. The comment of only needing to be "value added" bothers me. Are transportation or storage steps "value added"? Yet can they cause nonconformities?

Inspection processes, to me anyway, are pretty significant steps in our Manufacturing Process Flow. Improvements on/to the process can't be made without "good" data. Doesn't it make sense that an evaluation ensuring (or at least attempting to ensure) "good" data would be a valuable step? Is it "value added"? That has been hashed out in a different thread.

I don't quite agree with Sam's "question" that you've "evaluated" your inspection process through the Detection values. All you've done is assessed you're ability to "catch" a nonconformance assuming you have "good" MSA studies, everyone is doing their job correctly, etc.

I guess I'm saying that I'm in agreement with your CB, Nattapong (which concerns me ). I've found that including "Failure Modes" of the Inspection step(s) with the PFMEA discipline have shown us shortcomings in our methods/practices and we have improved that area of our process significantly.

I hope that makes sense and sort of helps you out. I think Randy has put some very good examples of what a Failure Mode is and, at minimum, should get the thought process going to help pacify your CB (if you decide to go that route). But keep in mind, pacifying the CB should not be your primary goal - improving the process overall should be the goal.

Enough for now.

Bill

 

[Diana Cadwalader]

PFMEA is not only applicable to manufacturing processes but is VERY applicable to business processes. For instance, the process of packing and shipping - - one of the highest areas of "soft" defects in product. OR consider the order entry process - - mistake proof it by doing a FMEA on it. - -

Just areas that I know from experience are areas that are greatly enhanced by using this tool - -