Recalculating RPN (FMEA Risk Priority Number) - Customer Request

Moncia

Quite Involved in Discussions
#1
HI All

I have a question which might seem trivial to some. As i mentioned before i am new to the PPAP stuff

This is only my Second PPAP - first i did back in 2008 and remember nothing

so we submitted our PPAP
all good - customer liked it

oops - i am looking at the FMEA book and i just answered my own question

i wanted to ask you - when customer asked us to recalculate RPN - which number to lower - Severity, Occurrence or Detection

but i see in the example in the book - they lowered Occurrence

so i know you lower Occurrence - but why??

who knows PPAP - who can explain it to me
or direct me to some reading material - classes
anything

i have no idea what i'm doing and i have to do two more PPAPs within next month

:frust:
 
Elsmar Forum Sponsor

Englishman Abroad

Involved In Discussions
#2
Monica,

Very briefly

Whether you revise the severity, occurence or detection will depend on what you have changed in your process.

If you have changed the design of the part to reduce the effect of failure (e.g. from an effect of product safety, to making a undesirable noise) you could revised the Severity rating.

If you have improved the manufacturing process capability, to make less bad parts then the problem will occur less, and so you should revise the occurence rating.

If you have invested in an automatic 100% inspection machine instead of your half blind human inspector then you should revise the detection rating as you will be more sure that the defective parts will be detected.

You should put the changes and revised ratings on the right hand side of the FMEA form.

You should in general not revise the severity on the PFMEA unless the design has been changed to change the effects of the failure.
 

Moncia

Quite Involved in Discussions
#3
thank you
that makes sense

so this is a process FMEA and we improved the process so in this case i will lower the occurrence

thank you
 

Moncia

Quite Involved in Discussions
#5
ok

thank you

now that i know what to lower - do i recalculate all the RPN or only the highest ones

my FMEA is for a simple process - chemical reaction
and most of our RPNs are below 50

but i have one scenario when the RPN is 72 - but the occurrence is 1 already

what to do with this one ???
 

Jen Kirley

Quality and Auditing Expert
Staff member
Admin
#6
ok

thank you

now that i know what to lower - do i recalculate all the RPN or only the highest ones

my FMEA is for a simple process - chemical reaction
and most of our RPNs are below 50

but i have one scenario when the RPN is 72 - but the occurrence is 1 already

what to do with this one ???
We can only recalculate the RPNs for FMEA line items in which there has been intervention. We can decide on interventions based on RPN but are also free - and indeed encouraged to do so for other reasons as well; high Severity ratings make good targets for intervention.

It is possible that a single intervention can affect multiple line items, especially when the intervention is one of engineering improvements which can lower Severity. However, we can only recalculate the line items actually affected by the change.

It is difficult to imagine lowering Occurrence to less than 1.
 

Moncia

Quite Involved in Discussions
#7
oki

next question

i am sorry to be such a pain - but i still have no idea what im doing

so - the fmea i just ask you about

we put actions in place and i recalculated RPN

iam doing new FMEA but the process is exactly the same as the previous FMEA

so - i pretty much have it but - do i send it as it is to the customer - minus the obvious changes as the name - date- etc

or do i revise it with the new RPN

i probably make no sense - but the controls and actions we put in place for the first fmea - they will also be follow / used in this process
so do i put recommended actions as current contorls - have the lower occurrence - consequently lower RPN and as new recommended actions - none needed

or i just send the old fmea as it is

do i make sense ???? probably not
 

Moncia

Quite Involved in Discussions
#9
thank you

i've been reading a lot of previous cove posts so i pretty much know what i have to do

thank you guys for posting such a helpful discussions
 

Englishman Abroad

Involved In Discussions
#10
Moncia,

If I understand correctly from your post;
"iam doing new FMEA but the process is exactly the same as the previous FMEA

so - i pretty much have it but - do i send it as it is to the customer - minus the obvious changes as the name - date- etc

or do i revise it with the new RPN

i probably make no sense - but the controls and actions we put in place for the first fmea - they will also be follow / used in this process
so do i put recommended actions as current contorls - have the lower occurrence - consequently lower RPN and as new recommended actions - none needed

or i just send the old fmea as it is"

You are creating a new FMEA for a new PPAP, based on a existing FMEA. However the new part PPAP uses the same process
as covered in the old FMEA.

FMEAs are linked to manufacturing processes, you do not need to create a new Process FMEA for a new product on the same manufacturing process. You should review if the current Process FMEA is still valid (severity effects are the same, etc) for your new product.

Also if your addtional process controls and actions that you have added on the right hand side of the FMEA have now become the standard process control, then you are correct to move them to the current process control column and revise the rating. - So that the RPN will be lower and the actions column will be blank.

On a different subject, in Europe at least it is not usual to send the PFMEA with the PPAP package to the Customer. It is accepted that the PFMEA is core to your business, and can be considered confidential; Normally it is accepted that the Customer Quality or Design engineer can review it with you on site, but can not take a copy. (They could give the PFMEA to a low cost supplier in Elbonia to make your products!!).
 
Thread starter Similar threads Forum Replies Date
W Is the RPN (risk priority number) in the PFMEA really a RPN without the detectability ISO 14971 - Medical Device Risk Management 4
N Timing for Closing High FMEA RPN Items FMEA and Control Plans 4
M Requiring action on factors alone of RPN in FMEA APQP and PPAP 7
C PFMEA RPN - Feedback regarding adjusted RPN FMEA and Control Plans 3
N How to reduce RPN of Visual Inspection Process FMEA and Control Plans 6
S PFMEA RPN - At what RPN level do you take actions in the FMEA? APQP and PPAP 4
C How to handle Action Results in a new FMEA Review once we have a new RPN? FMEA and Control Plans 1
L FMEA - Calculating RPN = S*O*D FMEA and Control Plans 3
I RPN without Recommendation neither corrective actions FMEA and Control Plans 2
Q Why is the FMEA RPN = S*O*D? FMEA and Control Plans 10
G Determining the "Detection" Number Component of the FMEA RPN FMEA and Control Plans 5
K How do you determine what is acceptable base on an FMEA RPN FMEA and Control Plans 6
M Changing PFMEA (Process FMEA) RPN Values based on a Rejection FMEA and Control Plans 4
I PFMEA RPN Numbers Medical Device Risk Management FMEA and Control Plans 1
A PFMEA (Process FMEA) Detection Rating - Actions to Reduce RPN FMEA and Control Plans 3
K Do you have to use RPN in Medical Device Risk Analysis? Identification of Hazards ISO 14971 - Medical Device Risk Management 6
R When to take action if an FMEA RPN number is high? FMEA and Control Plans 43
G Relation b/n Process Failure Mode RPN Value and the associated Process Failure Cost FMEA and Control Plans 3
B Formula to calculate the Process Sigma from an RPN Six Sigma 17
E FMEA Action Plan Threshold (RPN) - Auditor says Action Plan for an RPN > 84 IATF 16949 - Automotive Quality Systems Standard 21
Howard Atkins FMEA RPN Reduction Process FMEA and Control Plans 4
M FMEA RPN Recalculation after Actions are (or are not) Taken FMEA and Control Plans 6
C PFMEA RPN rankings - Preventative action must be opened if RPN over 100 ISO 14971 - Medical Device Risk Management 9
R If two processes have same RPN NUMBER - which should have priority over the other? FMEA and Control Plans 3
T RPN of Action Results per the AIAG FMEA manual FMEA and Control Plans 5
N How to Calculate RPN in Design FMEA (DFMEA) vs. Process FMEA (PFMEA) FMEA and Control Plans 9
F What is a usual RPN level for requiring actions? FMEA and Control Plans 4
V Emphasizing Severity more than Occurrence and Detection vs. Overall RPN FMEA and Control Plans 20
L PFMEA (Process FMEA) issue about lower RPN - AIAG 3rd edition page 55 FMEA and Control Plans 13
B Corrective Actions Priority - Process FMEA (PFMEA) RPN Limits - Recommended Actions FMEA and Control Plans 20
R FMEA review, RPN reduction - Any "rule of thumb" as to what makes an RPN too high? FMEA and Control Plans 12
K RPN reduction - Occurrance Reduction - Reducing occurance of defect on line FMEA and Control Plans 1
A Does anyone actually do a Pareto of the Top 5 (highest) RPN's of PFMEA? FMEA and Control Plans 8
A Is there an established RPN number or score for a DFMEA? FMEA and Control Plans 1
S RPN Ranking - Put a formula in an access database or Excel .xls spreadsheet Excel .xls Spreadsheet Templates and Tools 12
G Assignation of RPN rating (Detection) on Visual Inspection where subsequent operation FMEA and Control Plans 18
D Ranking Audit Effectiveness with RPN General Auditing Discussions 3
R PFMEA - RPN - Severity, Occurrence and Detection - Which one does not change? FMEA and Control Plans 67
A Quick question about RPNs - Any RPN over 100 should be actioned? FMEA and Control Plans 9
J FMEA RPN Number and When to Recommend to Take Action FMEA and Control Plans 3
T Process FMEA (Failure Modes Effects Analysis) Severity Rating and RPN IATF 16949 - Automotive Quality Systems Standard 17
S FMEA - Reject a PPAP because the RPN number is not shown? QS-9000 - American Automotive Manufacturers Standard 6
S Process FMEA (PFMEA) RPN Corrective Action Plan FMEA and Control Plans 6
S FMEA RPN Corrective Action Plan QS-9000 - American Automotive Manufacturers Standard 1
R Defining the RPN cut off number - Working on the top 3- 5 high RPNs? FMEA and Control Plans 4
Kevin Mader FMEA Severity Index - Leading contributor to the RPN value FMEA and Control Plans 9
J RPN numbers in FMEA - It is not correct to go only by the RPN numbers when doing FMEA FMEA and Control Plans 12
J FMEA Handbook 2019 IATF 16949 - Automotive Quality Systems Standard 3
J Process FMEA Template with examples - Cold and Hot Forged components FMEA and Control Plans 4
B Why the Greek god Hephaestus should have done a design FMEA (DFMEA) on his giant robot APQP and PPAP 1

Similar threads

Top Bottom