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View Full Version : Special Characteristics on DFMEAs - KPC's on the Design FMEA?


Kerry
22nd February 2001, 02:14 PM
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
23rd February 2001, 04:03 AM
Kerry,

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

Paul

Marc
23rd February 2001, 07:16 AM
If you take a read through this Presentation (http://Elsmar.com/FMEA/) 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
23rd February 2001, 09:31 AM
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
26th February 2001, 10:11 AM
->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 (http://Elsmar.com/FMEA/) 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
26th February 2001, 11:25 AM
->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
26th February 2001, 04:27 PM
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
1st March 2001, 11:56 AM
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
4th April 2001, 09:29 PM
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
22nd May 2001, 04:01 PM
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.

Al Dyer
22nd May 2001, 07:32 PM
TOMO:

Are you a design responsible supplier to the Big 3? If so, how was the determination made and what type of documentation is issued by your big 3 customer to designate you as design responsible?

Just curious!

ASD...

Kerry
23rd May 2001, 09:11 AM
Al -

Could you please clarify your reasoning for the question to TOMO listed below?

Originally posted by Al Dyer:
TOMO:

Are you a design responsible supplier to the Big 3? If so, how was the determination made and what type of documentation is issued by your big 3 customer to designate you as design responsible?

Just curious!

ASD...

Al Dyer
23rd May 2001, 09:54 AM
Originally posted by Kerry:
Al -

Could you please clarify your reasoning for the question to TOMO listed below?




I am refering to QS-9000 3rd edition element 4.4, where it notes that a supplier is design responsible if they have the authority to establish new or change existing product specification. Just looking for any info as to how the big 3 determine this and how they document it to the supplier.

Kerry
23rd May 2001, 10:49 AM
I'm kind of getting off the topic of this forum, but are suppliers required to have something in writing from the Big 3 stating whether or not they are design-responsible? Would this be something that would be included in a contract, or would it be a separate document?

TOMO
23rd May 2001, 11:55 AM
Al,

I am curious as to the relevance of your question to the topic.

The OEM communicates performance requirements for the systems we provide via an RFQ/technical specification. We provide a design proposal to meet the requirements. Being a working level engineer, I am not aware of any official documented declaration of design resposibility. But I do know that we are legally responsible for any design weaknesses, etc.

I am not sure if this answers your question. But, then, I am not sure what relevance your question has to the topic, either.

TOMO

Al Dyer
23rd May 2001, 12:59 PM
The relevence is to provoke some discussion between companies mis-understanding the difference between being a "design responsible" supplier to the big 3 and using a DFMEA as an internal tool.

Is there a requirement in QS-9000 that companies shall use DFMEA? No

The AIAG FMEA manual is not an auditable document, only a reference manual.

On page 67 of QS-9000 3rd Edition, Ford outlines that when a supplier is "design responsible" they shall prepare a DFMEA.

Page 4 of the AIAG PPAP manual(auditable) states that if a supplier is "design responsible" they shall prepare a DFMEA.

The same in TS-16949, only different wording.

Personal opinion, if you are not "design responsible", a FMEA is a FMEA.

This topic is very interesting but realize that the intent of an interesting topic can waver over its course. If you feel I should generate it under another topic I have no problem moving it!

Keep up the posts!

ASD...

TOMO
23rd May 2001, 05:44 PM
I see!

Where I'm coming from is driven by customer requests for quote. Inevitably, there is an entry in the text of the RFQ mandating that we conduct Design FMEA's and invite/share results with the customer.

Whether QS generically requires a DFMEA or not is kind of a moot point as the customer mandate in an RFQ/SOR/SOW, etc. for a DFMEA specifically makes it required. This is even further put to bed by our specific procedures which make FMEA's a requirement (as Martha would say, "It's a good thing").

My concerns are related to ramifications of referencing "Special characteristics" in the Design FMEA. There are often commercial/confidentiality, specificity issues involved.

I am in definite agreement that if the customer has specific characteristics that he/she wants referenced on the salable item under contract, they could indeed, be included in the Design FMEA.

I am not convinced that anything is accomplished by including all special characteristics of every sub-asm and component. I am, however, convinced that it could have detrimental effects.

TOMO

Kerry
31st May 2001, 11:26 AM
Originally posted by Al Dyer:
Is there a requirement in QS-9000 that companies shall use DFMEA? No


ASD...

Al -

Under 4.4.5.1, Design Output - Supplemental the QS standard states "The supplier's design output shall be the result of a process that includes:" among other things "Use of Design FMEAs"

But again, I digress. I do appreciate everyone's input.

Al Dyer
4th June 2001, 09:22 AM
Kerry:

I agree, if the company is design responsible. That is why I like to ask how companies document that they are design responsible as stated in the 1st paragraph of element 4.4.

Are there any truly "Design Responsible" suppliers that can shed some light?

ASD...

Sam
4th June 2001, 10:20 AM
Al, This is the second (maybe more) time that you have asked this question concerning design responsibility. Where are you going with this? What is your interpretation of the note? Please elaborate.