Process FMEA (PFMEA) RPN Corrective Action Plan

[sxbalasu]

Where will you start implementing corrective actions. Meaning
will you choose a characteristic with a RPN number greater than say 200 and above and take corrective actions or where to start. I know there are customers and auditors asking to start corrective actions for characteristics with RPN number greater than 50. My opinion is that start with may be 250 or three hundred and implement corrective actions review your FMEA and go down in RPN number. I think this is a cyclic process.
Please give your opinion on this.
thanks

 

[tomvehoski]

I had a QS auditor with a client a couple years ago about to write a nonconformance because we did not pre-define an action RPN value. The FMEA manual states you SHOULD NOT do so (can't remember exactly where right now) so I argued the point and won that battle.

I would caution against setting a firm number that will require action for all FMEAs for several reasons:

Since the severity, occurrence and detection ratings are somewhat subjective, there will be variation among FMEAs. Each one should be evaluated from high RPNs to lowest.


It may not be practical to take action for every item, and lower RPNs may be easy to fix. Example: Issue 1 RPN = 400, Issue 2 RPN = 350. Issue 1 costs $1,000,000 to fix and will require redesign of the product. Issue 2 can be improved with a $5,000 investment in 30 days. I ran into this with an Environmental FMEA. The 14001 auditor wanted to know why we implemented battery recycling with a very low RPN value before another project. Reason - it was free and took 10 minutes.

I would also be concerned that if there was a "target" number the FMEA team may try to work backwards to be below it to avoid action.

I usually run my FMEA workshops by having clients brainstorm everything they can think of and we put it into a spreadsheet project on the wall. After we have set RPNs we go back starting with the highest RPN and brainstorm:
1. What can we do about this issue.
2. Is is possible to improve.
3. What will it cost, do we have the time, will the customer allow, etc.

Just make sure you enter something onto the FMEA if you are not going to take action to explain to others. If you have a high RPN with recommended action "None" you will have more problems with outsiders than if you enter "Not feasible to improve at this time. Requires capital expenditure, customer approval, changing laws of physics, act of Congress, etc." If you have an RPN of 5, you don't need to justify.

Hope this helps,

Tom

 

[Sam]

Tom,
That is a process I can live with. I will insert this into our process flow as part of the FMEA review.

 

[IceZebra]

As I mentioned in another thread earlier, the IATF is trying to move away from focusing on RPN and move towards focusing on the high severity failures and getting the occurence and detection values down to 1 (if possible).

This is something that should be done as part of your preventive action process. This process should prioritize first which FMEA you will be reviewing and then how to go about selecting which failure modes to address.

I offer the following example:
If you have a failure mode with a severity ranking of 10 and an occurence value of 2 and a detection value of 2, then this item may not show up using the traditional methods of attacking high RPN's. But this is definitely where you would want to focus because the fact that the severity is a 10 could mean potential lawsuits down the road (due to injury or death).

Conversely, if you have a failure mode with a low severity ranking but it occurs often and you detect it every time it happens, then you might consider leaving that one alone until you have addressed other, more severe failure modes.

This is just food for thought but the point I am trying to make, and it has been reiterated by Tom and even the FMEA manual, is that the focus shouldn't just be on RPN values. You need to consider all failure modes with priority on severity, then maybe use the RPN value to prioritize any actions (taking into account the other items noted by Tom).

However you want to do it though, it is important to note that it is considered preventive action following the above noted process and not corrective action. To answer the question that started this thread, you only need to take corrective action when something has gone wrong.

Sorry for the long winded reply but I hope this helps too.

Ice

 

[sxbalasu]

FMEA Corrective action plan

Ice and Tom;
Your points are very well noted and the gist of both of yours is attack those characteristics which has higher severity rating because that might affect the customer and also give importance to detection and occurrence.
May be someone else also can share their ideas onthis.
thanks
siv

 

[lday38]

no qs-9000 requirment that on FMEA??

Am I understanding corretcly that there is no requirment of qs-9000 or TS16949 that a company must record recomended actions on RPN's, severity, high occurences or detections ?
I had a minor nonconformance in that when I recoreded my recomended actions, I put the action in the wrong space and the severity number down wrong.
This led me to defining the entire process and establishing proof of review of FMEA. My boss wanted me to put down we record recomended actions on the FMEA greater than 80, I took it a little further >7 severity , >7 detection,etc...
I relaly thought that this RPN number was a little high and that all
actions should be on the FMEA form.
what do you all think?

 

[Bill Ryan - 2007]

Iday38

Regardless of whether there is a "requirement" or not, one of the great benefits of an FMEA is documenting all recommended actions to improve the chance of not producing/shipping nonconforming product. It is one of the best ways to avoid "Corporate Amnesia" . As far as "putting things in the wrong places" there are numerous softwares which help reduce the chances of doing that. A few of the programs I have reviewed will put the recommended actions "across the board" for all parts having that specific Failure Mode. This has led us to improving certain things on nuymerous parts with only one RA.

Bill

Hope all of our members had a safe and happy holiday season!!!