Basic PFMEA (Process Failure Mode Effects and Analysis) Questions

[sushant_kulkarni]

Dear all,

1) Does it true that FMEA is made once for any product( Process not

consider) after that not revised atall ?

2) Does it true that Inward inspection not required FMEA only control plan?

3) As all of you know sev., occurance as well as detection decide the RPN

value.

But for Process inprovement purpose we have to revised RPN no. but only

DETECTION matrix we have authority to change other two factor

sev. & occurance we canot change.

Can any one give me exact idea about the same.?

And if anybody change all three factor too?

 

[Manix]

Re: FMEA - some questions?

1) No, FMEA is a live document and should be updated throughout the products life cycle. Your aim is to reduce RPNs to the minimum possible, and in line with a commitment to Continual Improvement, this will be reflected in your FMEA. This can apply to process, product or system. Though a DFMEA is usually considered optimum once you have finished the design phase (because your design phase should aim to get it all right first time, but in reality this is sometimes not the case). Plus your DFMEA will be an input into future projects.

2) We include incoming inspection on our FMEAs. I know some may not. I would, because how is this different from any other process? There is still the potential for things to go wrong and you need to identify and mitigate this risk. In fact, is this not the most important process to get right? Failures here have a knock on effect down the process chain, and the earlier you identify them, the cheaper it will be!

3) I find that Severity is the hardest to change on a PFMEA. I find this because the severity of an identified effect is usually just as serious no matter what you do in the process. This is where we talk about a process failing leading to a failure of the product/service (customer effect). E.g. if someone does not secure a component correctly in the process, the effect will be potential lethal projectile within the passenger compartment of a vehicle. The severity of the effect will not change no matter what controls you instigate to prevent the failure of the process. However, some things the severity can be reduced. If the effect of a certain failure is the fact that an operator may breath in toxic fumes (manufacturing effect) and you actually take measures to reduce the toxicity, then this would reduce the severity, from the operator becoming seriously ill to perhaps them just getting a cough! Occurrence and detection can easily be reduced depending on the controls you put in place. Preventative measures will reduce the occurrence and detection type measures will obviously change the detection rating.

 

[Manix]

Re: FMEA - some questions?

Also check out this thread which has just come back to life! (thanks Stijloor)

PFMEA - RPN - Severity, Occurrence and Detection - Which one does not change?

 

[Stijloor]

Re: FMEA - some questions?

"Severity" keeps people that are interested in FMEA excited! It's like a toy, can't get enough of it!

Stijloor.

 

[rdd007]

Re: FMEA - some questions?

FMEA for incoming inspection imo is absolutely needed. We include it and every step right through putting it on the truck. I have a customer who would probably want us to put purchasing on there as well ... if it could go wrong, it will, and needs to be thought through/responded to.

 

[David DeLong]

Re: Basic FMEA Questions

Process FMEAs should be performed on all process steps that are costed into your process of producing the product.

Is Receiving Inspection costed in? Do you produce a product at Receiving Inspection? The only thing you do is a small amount of inspection; that is it. How can your company make improvements in producing the supplied product if you have no control in its production? You can't!!

You supplier should be performing the process FMEA and their products and not your company. Beware that a lot of suppliers might "fake it" though.

I remember one time when I was presenting FMEA training in an automotive supplier and they reflected a huge, huge FMEA of a product. It had Receiving Inspection, fork lift driving, stacking, etc. What a mess. Look at the example in the AIAG standard.

Keep your FMEAs to the processes where you have full control in making the product and keep out of the indirect actions in your plant that are covered in your overhead, including Receiving Inspection.

 

[D.Scott]

Re: Basic FMEA Questions

Process FMEAs should be performed on all process steps that are costed into your process of producing the product.

Is Receiving Inspection costed in? Do you produce a product at Receiving Inspection? The only thing you do is a small amount of inspection; that is it. How can your company make improvements in producing the supplied product if you have no control in its production? You can't!!

You supplier should be performing the process FMEA and their products and not your company. Beware that a lot of suppliers might "fake it" though.

I remember one time when I was presenting FMEA training in an automotive supplier and they reflected a huge, huge FMEA of a product. It had Receiving Inspection, fork lift driving, stacking, etc. What a mess. Look at the example in the AIAG standard.

Keep your FMEAs to the processes where you have full control in making the product and keep out of the indirect actions in your plant that are covered in your overhead, including Receiving Inspection.

I am sure there are varying methods of developing an FMEA. I respectfully disagree that an FMEA should be based on process steps being "costed in". I also don't believe the "production of a product" applies. The controlling question should be "Is there a possibility of failure in this step?". If there is, IMHO it should be included in your FMEA.

In our company there is certainly a possibility of failure in receiving. The customer may have sent the wrong parts to be processed or perhaps there may be a defect in the parts as received. There is the possibility that raw materials received may be nonconforming in some way. The possibility of affecting the process has to be considered and a resulting control developed.

Your point about overkill is certainly valid. I have seen a lot of line items that could probably be eliminated with good team analysis. The AIAG FMEA reference manual is certainly a good place for any FMEA team to start but please remember the examples there are not meant to be inclusive of all process steps. The manual often refers to a team of representatives from all affected areas. It specifically mentions "manufacturing, materials, quality, service and suppliers". The idea given is to develop a summary of the team's thoughts, including an analysis of items that could go wrong.

The intent of an FMEA is to determine where problems could occur in your process and develop controls to prevent them from happening. If you recognize receiving as a potential failure, the team should list it and make a determination as to what they will do about it. The FMEA should reflect a knowledge of your process and identify all your risks. What I see as a risk may not be a problem at your company. If we all shared the same risks there would be no need to sit down and do an analysis.

In the new AIAG CQI-12 Special Process Assessment question 1.3 (Requirements and Guidance) states "The organization shall incorporate the use of a documented FMEA .... for each process. In any case they shall address all process steps from part receipt to part shipment .....". Granted, this is written for fasteners but it reflects a preference by AIAG.

Boil it all down and you are right back to whatever the customer accepts works for me. If they don't require potential receiving failures, don't put them in the FMEA.

Dave

 

[Jim Wynne]

Re: Basic FMEA Questions

Process FMEAs should be performed on all process steps that are costed into your process of producing the product.

Is Receiving Inspection costed in? Do you produce a product at Receiving Inspection? The only thing you do is a small amount of inspection; that is it. How can your company make improvements in producing the supplied product if you have no control in its production? You can't!!

All process steps that have the potential to affect product quality should be included in PFMEAs, regardless of whether or not they're "costed in." The point could be made that incoming inspection should be eliminated wherever possible, but that's not the question here.

One point of confusion I've seen regarding inspection processes has to do with the AIAG PFMEA manual requirement for each step in the process to assume that the material coming into that step is conforming, and to focus on the potential failure modes for that process alone. This does not apply to inspection, for obvious reasons, and it's unfortunate that the manual doesn't address the distinction. Inspection processes, incoming or otherwise, have their own set of potential failure modes. For example, it's possible to approve nonconforming material, or reject conforming material. It's also possible to mislabel the inspection status of the material. There are other possibilities, but you get the idea.

Again, if the process has the potential to affect product quality, it should be included.

 

[Jim Wynne]

Re: Basic FMEA Questions

Boil it all down and you are right back to whatever the customer accepts works for me. If they don't require potential receiving failures, don't put them in the FMEA.
Dave

I was with you 100% until the last sentence. Whether or not a customer requires attention to a given process shouldn't necessarily be a good reason to eliminate it from consideration. If there is potential for costs (or customer dissatisfaction) to be incurred due to failure, the process should be included whether the customer requires it or not.

 

[D.Scott]

Re: Basic FMEA Questions

I was with you 100% until the last sentence. Whether or not a customer requires attention to a given process shouldn't necessarily be a good reason to eliminate it from consideration. If there is potential for costs (or customer dissatisfaction) to be incurred due to failure, the process should be included whether the customer requires it or not.

I agree.

Dave