Severity Occurrence Detection Ranking Scale - 1 to 10 vs. 1 to 5

B

bgwiehle

#11
kurisuoriari said:
...A couple of years ago we reviewed our Severity Occurence Detection Ranking.
A broad difference existed in using scales of 1 to 10.
As a improvement the scales were refined to 1 to 5.

Thus I have a Max RPN of 125.
This has worked fine and provides good repeatability of classification for different users and team members...
Out of curiosity and because it isn't clear from your initial post, are your criteria equivalent to the full range of the ratings suggested in the FMEA manual? Or do your criteria not use the full range, on the basis that your products would never use the higher values?
Re-worded: Are your "5" ratings the same description as "10" in the FMEA manual or are your "5" ratings the same as the "5" in the manual?

B.G. Wiehle
 
Elsmar Forum Sponsor
R

Randy Stewart

#12
Jconlake,

You know, I didn't have to look at your info to tell you were from MI. There is something about the people in the auto industry in MI that has them, shall we say, a little on edge? I don't know if it is due to working near the Headquarters or just being in the Motor City grind (especially without hockey) that sets the tone.

Would not recognize their own part if they saw it in production.
I once had a customer argue with me over that very issue. He came out to witness a run, I told them we were running his parts on a particular line and he told me straight up that those were not his parts. It turned out he had never seen the parts unpainted before.
 
T

tomvehoski

#13
I could see why your customer would have issues with this in the automotive world. While I don't agree with many things the big 3 have done, standardizing the approach to several quality tools is a help. If I'm the customer and managing 20 suppliers, I don't want to have to learn 20 different ways to review a FMEA. The FMEA manual has a pretty good guideline for ranking severity, and as I recall, a 9 or 10 basically means somebody dies. If you stop your ranking at 5, it is saying worst case you have a squeak/rattle/bad radio. I'm taking those examples from memory, so I could be off on the actual severity result. For example:

Failure mode: Airbag fails to deploy, occupant dies - two suppliers make two components that can cause this.

Your component: S 5, O 2, D 2 RPN = 20
Supplier B: S 10, O 2, D 2 RPN = 40

In both cases the exact same result (dead driver) with the same occurrence & detection ratings, but different RPNs.

I agree there should be no trigger number to act on an RPN. I would take action on RPN 10 over RPN 100 if RPN 10 was free to fix and RPN 100 was $10,000,000 (and low risk, not safety related)

One of my biggest headaches right now is developing a corrective action system that can address multiple customers - big 3, Europe, truck...... The 8D is one document that has not been standardized by the automotive industry. How confusing would it be if we had 3 FMEA methods, 5 warrants, 8 control plan formats ....
 
K

kurisuoriari

#14
Spot On

JSW05 said:
This isn't actually a FMEA question, it's a customer-requirements question. The question is: how can I deal with customer requirements that don't make sense?..... You can just accept the nonsensical requirement and move on.
Yep thats spot on.
I have a follow up review with the Auditor at the OEM site Fri am.
I will outline my strategy for corrective actions and tentatively approach this subject.

It may be the case that I have to accept this as a customer requirement.

uumm..How about a scale of rankings of 1 to 10 where by some magic nobody ever uses odd numbers ?

I will post up the result of my review with the auditor.

Cheers

Chris
 
K

kurisuoriari

#15
Spot on again..there is hope

dokes said:
Interesting situation. I wonder if there is any evidence of the reliability of a 10 point scale versus a 5 point scale. Frankly there is not a big difference between a 9 or 10 in a 10 point scale, both of which a 5 would cover on a 5 point scale.
Yes exactly so my 9 & 10 rankings are grouped as 5, 7 & 8 as 4 etc.
This means I treat a 9 as a 10 in my rating and action is taken with equally priority on 9 & 10 as this is a 5 ?

The slight difference clogged up team reviews arguing over the numbers.
As many have said here it not the numbers that count really anyway and I insist on action on anything over 12 in scale.

Good to get views from like minded people.
I have dealt with one Major OEM customer for 15 Years.

This place is great find. Thanks to all for your post's on this.

Chris
 
K

kurisuoriari

#16
Yep

Rob Nix said:
...if your customer requires it, then that's the way it is (unless you can convince them otherwise).
I agree and will have a go with the convincing first. If that don't work I do what he says. But I could still have some magic nobody ever uses the odd numbers ?

Cheers

Chris
 
K

kurisuoriari

#17
Wey Hey

Bill Ryan said:
I haven't vented in a while..... so here goes :mad:

....other than through the AIAG manual..... 1-5 scale would actually help stop that kind of activity as you mentioned with the "good repeatability of classification" comment.
(Wow, am I wound up this morning ;) )
Wey Hey me new here and second post goes bonkers with moderators getting mad.

I have decided to fight the good fight I will tell him to stick.... Er I will prove by statistical analysis that my ranking is suitably effective and moreover efficient.

I will keep my 1 to 5 Ranking...whatever..I mean he can't make me do it.

Cheers

Chris
 
K

kurisuoriari

#18
Fair Point

D.Scott said:
I don't buy that a reduction of the scale from 1 to 10 is an improvement. By dropping from an RPN of 1000 to 125 would look great on paper but what did you actually do? The "nice looking" 125 is still the same "worst case" it would be at 1000 so what was accomplished?

The idea of a FMEA is to identify where the problems might be, not to grade the quality supplied to the customer. The FMEA is simply a tool to look at potential problems that might appear anywhere in processing.

There is a good chance that whatever you are making/processing is only a component of a larger "end" product. If that's the case, the information supplied by you for your portion of the process should be as compatible and understandable as possible with and to the others involved in the realization of the product.

For this reason alone, it is understandable that the scale of 1 to 10 was established and published as a guide for determining RPNs. When viewed as a piece of the "big" FEMA, your changes in formatting or calculations could be causing a problem up the line that you may not be thinking about. For the sake of uniformity and customer satisfaction, I would revert to the 1 to 10 scale. My honest opinion is if you insist on pushing it, you will find you are flogging a dead horse. This is not one of the "battles-to-pick".

Dave
Thanks Dave,

I appreciate your comments and your disagreement..no really I do.

Accomplishments of my scale are repeatable scoring which resulted in quick team reviews and focus on actual actions required. Actioned were quickly implemented during APQP and I run with all supplied product from my plant with a RPN of less than 12.

The plant is 800 meters from the Main OEM customer and ships 400,000 parts a day.

Again I appreciate you comments. However I have decided to "Push-it" as I think its a real breakthrough all the team members internally have indicated that they think it would be a backward step. It has real results.

Cheers

Chris
 
K

kurisuoriari

#19
Superb

Jconlake said:
Better yet, give the customer blank pages and tell them it was prepared with invisible ink to protect their valuable info. It can only be read by holding the paper over an open flame.
I opened my TS Audit back in 2003 by presenting the Auditor with our company Policy, Objectives, and Manual in.....Japanese.....I answered his questions at first in Japanese.....

Hey did'nt he check the customer requirements for the audit ?

He was our long standing ISO Auditor and appreciated the joke.

Cheers

Chris
 
K

kurisuoriari

#20
bgwiehle said:
Out of curiosity and because it isn't clear from your initial post, are your criteria equivalent to the full range of the ratings suggested in the FMEA manual? Or do your criteria not use the full range, on the basis that your products would never use the higher values?
Re-worded: Are your "5" ratings the same description as "10" in the FMEA manual or are your "5" ratings the same as the "5" in the manual?

B.G. Wiehle
Basically my 9 & 10 are both a 5. The wording in my Procedure is adjusted from the Manual for my product range.

Cheers

Chris
 
Thread starter Similar threads Forum Replies Date
D How to fill a Process FMEA - Three columns - Severity, occurrence and Detection FMEA and Control Plans 16
R DFMEA Severity 9-10 with Occurrence 3 and Detection 3 - Actions FMEA and Control Plans 3
K 4th Edition AIAG FMEA Occurrence, Severity and Detection Criteria for Plastics FMEA and Control Plans 1
L FMEA Occurrence, Severity and Detection Criteria FMEA and Control Plans 3
Y Severity, Occurrence and Detection FMEA Ranking Tables - Guidelines? FMEA and Control Plans 8
V Emphasizing Severity more than Occurrence and Detection vs. Overall RPN FMEA and Control Plans 20
E FMEA Severity, Occurrence, and Detection Rating - I am in need of some examples FMEA and Control Plans 19
R PFMEA - RPN - Severity, Occurrence and Detection - Which one does not change? FMEA and Control Plans 67
E Risk Management selection Probability of Occurrence and Severity ISO 14971 - Medical Device Risk Management 24
D Severity or Occurrence? Performing an FMEA on Motorcycle Operation FMEA and Control Plans 9
I Ford FMEA requirements for Severity and Occurrence Rankings Customer and Company Specific Requirements 1
R DFMEA/PFMEA mitigation of high severity (9-10) in low volume products IATF 16949 - Automotive Quality Systems Standard 1
silentmonkey How to measure severity if my product is designed for emergency use and failure would result in death? ISO 14971 - Medical Device Risk Management 9
J On PFMEA for danger labels - Label always should be assigned severity 10 ? FMEA and Control Plans 3
S The Severity of a Medical Device Hazard - Risk Analysis Clarification ISO 14971 - Medical Device Risk Management 6
MrTetris Informational Risk Register - Same hazardous situation, different severity of harms ISO 14971 - Medical Device Risk Management 7
A PFMEA severity score different applications FMEA and Control Plans 11
X Customer Service FMEA - Specifically Customer Care / Severity Rankings Service Industry Specific Topics 3
S What should the FMEA Severity for SC & CC Characteristics be? FMEA and Control Plans 4
N AIAG 4th ed. FMEA Manual "Fit" Changed to "Appearance" - Fit severity? FMEA and Control Plans 2
G Severity in Process FMEA for Rework Process FMEA and Control Plans 1
O PFMEA - Reducing Severity (S) Ranking - Manufacturing Process Design Changes FMEA and Control Plans 4
S FMEA's - Severity and Classification of Print Characteristics FMEA and Control Plans 1
N Risk Severity Estimation for Medical Devices as per ISO 14971 ISO 14971 - Medical Device Risk Management 12
C Determining PFMEA Severity for Armored Parts FMEA and Control Plans 5
C FMEA DOGMA about Severity - Am I right or Wrong? FMEA and Control Plans 2
F Risk = Likelihood * Severity - Can we mitigate the Severity? Occupational Health & Safety Management Standards 44
M Severity Reduction in a Design FMEA (DFMEA) FMEA and Control Plans 25
S Severity of 9 or 10 should be identified as Special characteristic? FMEA and Control Plans 10
G Internal vs. External PFMEA Severity Rankings FMEA and Control Plans 12
R Risks which must be Distinctly Identified - Harm, Hazard, Severity ISO 14971 - Medical Device Risk Management 7
C Severity of Effect on Process (Manufacturing/Assembly Effect) Scrap or Reworking FMEA and Control Plans 3
W Severity Rating CORRECTIVE ACTIONS - Opinions Wanted Please Nonconformance and Corrective Action 15
H DFMEA Severity Ranking of Non-Compliance to EMC Standards FMEA and Control Plans 2
P Chemical Purity Testing - FMEA Severity Scale FMEA and Control Plans 2
T FMEA Severity 9 &10 - Example of "with warning?" FMEA and Control Plans 6
E Harms Severity Scoring - Combination of Hazards ISO 14971 - Medical Device Risk Management 4
B The Distribution that represents the Severity of Nonconformances Nonconformance and Corrective Action 2
A AIAG Design FMEA Severity Rankings - Noncompliance Government Regulation? FMEA and Control Plans 9
G FMEA Severity Ranking for an Automotive Audio System FMEA and Control Plans 9
Chennaiite FMEA Severity Rating for Potential Manufacturing Effect mentioned in the FMEA manual FMEA and Control Plans 9
kedarg6500 FMEA Severity Scale - Higher for Failure at Customer's or End-Customer's place? FMEA and Control Plans 19
M FMEA Severity Ratings for Health Care Information System FMEA and Control Plans 10
C Does the PFMEA Severity have to match the DFMEA Severity? FMEA and Control Plans 3
P Measuring Severity of Construction Nonconformance Report Nonconformance and Corrective Action 3
L Standard for process control level depending on gravity (severity)? FMEA and Control Plans 7
I Defining a Severity Level of a non-conformance Nonconformance and Corrective Action 13
L FMEA - Should a severity of 9 or 10 be always followed by recommended actions? FMEA and Control Plans 2
J Severity of Finding for "Past Due Gage" found on the shop floor General Measurement Device and Calibration Topics 40
S FMEA Severity of 9 or 10 - Shower does not operate FMEA and Control Plans 13

Similar threads

Top Bottom