Special Characteristics on DFMEAs - KPC's on the Design FMEA?

[Kerry]

Special Characteristics on DFMEAs

I am having a great deal of trouble identifying/understanding the requirements for identifying special characteristics, eg. KPC's, on the Design FMEA. I've been through the QS manual, the FMEA manual, and the APQP manual looking for clear definition of the requirements and have been unable to find what I'm looking for. Can anyone help me?

 

[Paul Alexander]

Kerry,

Do you mean "Special Characteristics" or "Significant Characteristics"?

Paul

 

[Marc]

If you take a read through this Presentation you will find within (near the front of the presentation) several pages which give many company definitions of both. To some companies a special characteristic is the same as a critical characteristic is to another company. Be careful here.

 

[Kerry]

Here's where I'm coming from: The QS manual section 4.2.3.2 refers to "Special Characteristics" and then directs us to Appendix C for further explanation of what constitues a special characteristic. Looking at Appendix C there is a table defining Standard Characteristics and Special Characteristics and Symbols for each of the Big 3 OEMs. My question pertains to the Special Characteristics as defined in Appendix C, regardless of the customer.

I am looking for any documented requirement that specifically states that these characteristics are required on the Design FMEA.

 

[Marc]

->I am looking for any documented requirement that
->specifically states that these characteristics are
->required on the Design FMEA.

Look at the Design FMEA Severity Ratings and you will see the expectation is that you determine critical / special characteristics. When I was involved in air restraints at Delphi and ICI Explosives, our design FMEAs had the rating of 10 described as "...prossible / probable death of occupant..."

It may not be said, but it is overtly (my opinion implied that all critical / special characteristics be identified and addressed in the DFMEA.

I really think 4.2.3.2 is aimed at the PFMEA more than the DFMEA., but none the less...

My question to you is: What critical or special characteristic you want to leave off your DFMEA and why?

 

[Sam]

->I am looking for any documented requirement that
->specifically states that these characteristics are
->required on the Design FMEA.

Refer to 4.4.5 Design Output and 4.4.5.1 Design Output - Supplemental.

 

[D.Scott]

Kerry - I may be missing your point here but 4.2.3.2 simply means that when your customer identifies a key/special characteristic with for example an inverted delta (Ford's symbol for a critical characteristic), you must be sure that your paperwork (FMEA, CP, WI) have the same symbol (or your own equivalent). You will notice from Appendix C that no symbol need be used for general characteristics. Therefore if there are no Key/Special identified on the print (or otherwise) there is no requirement for you to use a symbol in your documents.
Hope I didn't just confuse the issue more.
Dave

 

[Kerry]

I don't want to leave any special characteristics of the DFMEA. I have a long standing battle going on with my Product Engineering department. I feel, and I believe I am correct, that all special characteristics should be identified on the DFMEA. As input to the DFMEA the voice of the customer should be considered. So, that obviously means that any customer-designated special characteristics must be included. Another input would be similar products & lessons learned from previous programs. So, I would think that any known special characteristics from similar products that could be applicable should also be included in the DFMEA. Finally, the DFMEA is a living document (contrary to what my engineers may think). As they continue through the design phase additional characteristics may be identified as "special" - these should be added to the DFMEA.

The only thing my engineers agree with me on is the requirement for customer-designated special characteristics.

I have asked my registrar, who has provided me with his interpretation in writing, and have presented his answer to the engineers. They responded to me that that was just his "interpretation" and that if you asked someone else their interpretation may be different. I felt like I was in the Clinton hearings (it all depends on what your definition of "is" is). But, I digress.

The only way I am going to be able to resolve this issue is to either find a requirement in writing or just wait until they get a nonconformance, which I'd rather not do.

 

[Al Dyer]

Originally posted by Kerry:
Another input would be similar products & lessons learned from previous programs. So, I would think that any known special characteristics from similar products that could be applicable should also be included in the DFMEA.

Let's keep it simple here,

If you have a print with SC's include them in the DFMEA.

Are you required to put SC's from similar products on the DFMEA? No, like processes do not mean like products/product specifications.

ASD...

 

[TOMO]

So, what if I have a characteristic that I consider both proprietary, and significant?

You may call me cynical. But, I cannot trust my customer with proprietary information. It has been "Leaked" to my competitors in the past. I think that APQP requires me to allow my customer access to my Design FMEA. So, I am hesitant to include ALL Key/significant characteristics in a Design FMEA.