Javier Garcia - Verdugo Sanchez - Six Sigma Training - W1 Failure Mode and Effect Analysis (FMEA)
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Transcript of Javier Garcia - Verdugo Sanchez - Six Sigma Training - W1 Failure Mode and Effect Analysis (FMEA)
FMEAFMEA
Week 1
Knorr-Bremse Group
About the FMEA
The FMEA is a structured method for:• Recognizing and rating of potential failures of a
product or processp p• Allocation and rating of various factors which
causes these failures• Rating of the possibility how bad or good a failure
or cause can be detected
• Furthermore the FMEA gives you the possibility to define and prioritize actions in order to reduce the occurrence of failures (causes) or improve the detection of fail res (ca ses) in others ords adetection of failures (causes), in others words a risk reduction of potential failures
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 2/36
The Content of this Module
• Definition and historical backgroundg
• Areas for application
• Connection with other tools
• Preparation of a process FMEA• Preparation of a process FMEA
• Definition of improvements
• Application examples
P ti l i• Practical exercise
• Design FMEAg
• Summary
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 3/36
Definition FMEA
• FMEA stands for Failure-Mode and Effect-AnalysisAnalysis
• The FMEA is a formalized, analytical method for a systematic registration and avoidance of potential failures. It can be used for the development of new
d t d f l iproducts and for process planning
• The potential failure, the consequences for the p , qcustomer, the potential failure causes and the possible failure detection will be shown and quantitative rated.q
• Based on the rating, actions will be defined in order to avoid the potential failuresavoid the potential failures.
• Of course, this tool can be used for the investigation of
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 4/36
existing processes as well.
History
Developed in the 1960’s in the Aerospace industry during the Apollo missionsthe Apollo missions
In 1974 the US Navy developed MIL-STD-1629 with the use of FMEAuse of FMEA
In the late 1970’s, automotive applications driven by li bilit t b t i t th FMEA i t thliability costs, began to incorporate the FMEA into the management of their processes
Many companies involved in the management of hazardous materials and potentially dangerous
h d th i i l d l iprocesses, have used the same principals underlying FMEA in issues of risk management
The automotive industry requires the FMEA for all processes of suppliers since years
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 5/36
FMEA within the DMAIC Cycle
ControlMaintain
DefineMaintain
ImprovementsSPC
Control Plans
Project charter (SMART)
Business Score CardQFD VOC
D Documentation QFD + VOC
Strategic GoalsProject strategy
C M
MeasureB li A l iImprove
AIBaseline Analysis
Process MapC + E Matrix
M t S tAnalyze
ImproveAdjustment to the
Optimum
FMEA Measurement SystemProcess Capability
Definition of critical Inputs
FMEA
FMEAStatistical Tests
Simulation FMEAStatistical Tests
Multi-Vari StudiesRegression
Tolerancing
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 6/36
g
Purpose of the FMEA
The early rocognition of failure risks and the reduction y gof occurrence to a minimum.
The avoidance of the possibility of liability claimsThe avoidance of the possibility of liability claims.
The reduction of costs
• for a change caused due to the failures
• for additional work (non value added) due to rejects / scrap• for additional work (non value added) due to rejects / scrap or rework
• For warranty claims in external areas• For warranty claims in external areas
The FMEA is an efficient tool for preventive quality assurance
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 7/36
quality assurance
The FMEA Form Sheet
Process Potential Failure Mode Potential Failure Effects
SE Potential Causes
OC Current Controls
DE
RP
Step/FunctionPotential Failure Mode Potential Failure Effects E
VPotential Causes C
CCurrent Controls E
TPN
What is the process step/ function under
In what way could the process step/function potentially fail to meet
What is the impact on the Key Output Variables (Customer Requirements) or e
is t
he
t to
the
to
mer
? What are the causes of this Failure Mode? Typical failure cause result from process c
ause
oc
cur? What are the existing controls
and procedures (inspection and test) that prevent the cause or the an
you
or
FM
?
function under investigation?
potentially fail to meet process requirements or intent?
(Customer Requirements) or internal requirements?
How
Sev
ere
effe
ccu
s t cause result from process inputs.
How
oft
en d
oes
or F
M test) that prevent the cause or the
Failure Mode? Should include an SOP number.
How
wel
l cde
tect
cau
se o
H
RPN
Actions Recommended
Resp. Actions TakenSEV
OCC
DET
RPN
What are the actions for reducing the
occurrance of the Cause, or improving d t ti ? Sh ld
Whose Responsible
for the recommende
d ti ?
What are the completed actions taken with the recalculated RPN? Be
sure to include l tidetection? Should
have actions only on high RPN's or easy
fixes.
d action? completion month/year
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 8/36
Comparison of Theory and Praxis
The FMEA is a very helpful tool. However, the FMEA itself failed in several applications already. Why?
• The FMEA as a single “island” solution
In these cases, teams used the FMEA to investigate a product or service for potential risks. Very complex paper work is often the result, they are very difficult to maintain and to understand for people outside the actual teams.
• The external FMEA
These FMEA often stops with the rating of what the customer sees (e.g. after all control and inspection steps). The real risks will be not discovered. This gives a picture of fewer risks than there actually may befewer risks than there actually may be.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 9/36
The Connection with other Tools
• Prüfergebnis• Regelkreisinfo an
SMD/Siebdruckggf. Linienstop
•Regelkarte•Lotpastenhöhe •Rüstkontrolldaten •Lötqualität
• Prüfergebnis• Regelkreisinfo an
SMD/Siebdruckggf. Linienstop
•Regelkarte•Lotpastenhöhe •Rüstkontrolldaten •Lötqualität•Regelkarte•Lotpastenhöhe •Rüstkontrolldaten •Lötqualität
Rating of Importance to Customer
9 9 7 10 10 9 3 2 6
C & E MatrixProcess Map
Lotpasten-druck
SMT-Bestückung
Reflow-Löten
SPC-Prüfung
M LeiterplatteS LP-MarkenM LotpasteA ArbeitsanweisungS SchabloneS Temperatur
M BauteileK BestückprogrammK BE NachversorgungA ArbeitsanweisungS DruckluftS Wartungszustand
K Lötprofil ProgrammS HilfsstoffeS WartungszustandS Ofenverschmutzung
S Regelkreis-information
A KontrollfolieA Prüfanweisung
G /
Lotpasten-druck
SMT-Bestückung
Reflow-Löten
SPC-Prüfung
M LeiterplatteS LP-MarkenM LotpasteA ArbeitsanweisungS SchabloneS Temperatur
M BauteileK BestückprogrammK BE NachversorgungA ArbeitsanweisungS DruckluftS Wartungszustand
K Lötprofil ProgrammS HilfsstoffeS WartungszustandS Ofenverschmutzung
S Regelkreis-information
A KontrollfolieA Prüfanweisung
G /
Lotpasten-druck
SMT-Bestückung
Reflow-Löten
SPC-Prüfung
M LeiterplatteS LP-MarkenM LotpasteA ArbeitsanweisungS SchabloneS Temperatur
M BauteileK BestückprogrammK BE NachversorgungA ArbeitsanweisungS DruckluftS Wartungszustand
K Lötprofil ProgrammS HilfsstoffeS WartungszustandS Ofenverschmutzung
S Regelkreis-information
A KontrollfolieA Prüfanweisung
G /
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Process Inputs Ge
l Tim
e
Vis
cosi
ty
Cle
an
line
ss
Co
lor
Ho
mo
ge
ne
ity
Co
nsi
ste
ncy
Dig
ets
Tim
e
Te
mp
era
ture
So
lids
Total
1Scales Accuracy
9 8 2 1 1 9 1 1 8 321
2Preheating DICY TK
1 1 1 1 1 1 1 1 1 65
THT-Bestückung
End-Prüfung
Schwall-Löten
M BauteileA Roy.- ProgrammA BestückanweisungS Training
A LötparameterM HilfsstoffeM LötmaskeS Wartungszustand
A PrüfprogrammS AdapterS Netzwerk
•Bestückqualität •Lotwellenparameter •Go / no go•Fehleranzahl•Fehlerzettel•DiagnoseTHT-
BestückungEnd-
PrüfungSchwall-
Löten
M BauteileA Roy.- ProgrammA BestückanweisungS Training
A LötparameterM HilfsstoffeM LötmaskeS Wartungszustand
A PrüfprogrammS AdapterS Netzwerk
•Bestückqualität •Lotwellenparameter •Go / no go•Fehleranzahl•Fehlerzettel•DiagnoseTHT-
BestückungEnd-
PrüfungSchwall-
Löten
M BauteileA Roy.- ProgrammA BestückanweisungS Training
A LötparameterM HilfsstoffeM LötmaskeS Wartungszustand
A PrüfprogrammS AdapterS Netzwerk
•Bestückqualität •Lotwellenparameter •Go / no go•Fehleranzahl•Fehlerzettel•Diagnose
3DMF Load Accuracy
3 8 1 1 1 8 1 3 8 255
4DMF Cleanliness
1 1 4 2 1 2 1 1 1 105
5DMF Raw Materials
1 1 1 1 1 2 1 1 1 74
6DICY Load Accuracy
9 7 1 1 1 9 1 1 2 269
7DICY Envir. Factors
8 5 3 1 1 8 1 1 2 247
8DICY Raw Materials
8 5 1 1 1 9 1 1 2 242
FMEA9DICY Mixer Speecd
1 1 1 1 7 1 1 1 1 125 FMEA
Process/Product Failure Modes and Effects Analysis
(FMEA)
Capability of Process and Measurement System
Process or Product Name:
Prepared by:
Responsible: FMEA Date (Orig) ______________ (Rev) ___
Process Step/Part Number Potential Failure Mode Potential Failure Effects
SEV Potential Causes
OCC Current Controls
DET
RPN
Spin Draw Process
Fiber Breakouts Undersized package, High SD panel-hours lost 2
Dirty Spinneret8
Visual Detection of Wraps and broken Filaments 9 144
Filament motion Visual Sight-glass
USLLSL
y
5Filament motion
2Visual Sight glass
8 80
8Polymer defects
2Fuzzball Light
9 144
0
33323130292827
ProzeßschrittErgebnis ( Output)
Spezifikation Faktor ( Input)
Control strategy
33323130292827 SpezifikationOSG
ZielUSG
FahigkeitCp
CpkMuster
AnzahlHäüfigkeit
Messmittel
Faktor ( Input)
SpezifikationOSG
ZielUSG
FahigkeitCp
CpkMuster
AnzahlHäüfigkeit
MaßnahmenWas
VerantwrtlichAbgeschlossen
Wirksamkeit
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 10/36
% R & R% P/T
HäüfigkeitMessmittel
% R & R% P/T Datum
Bewertet durch
FMEA Types
• System – used for analyzing systems or subsystems in early concept or design stages. Concentration on possible y p g g pfailure modes along with the function of the system caused by the design.
• Design – used to analyze a product design before production releaseproduction release.
Process used to analyze manufacturing and assemblyProcess – used to analyze manufacturing and assembly processes.
• In a modified form the FMEA will be applied for risk analysis in the area of health and safety and for important projects.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 11/36
Process FMEA
In the product development process the design FMEA will be applied before the process FMEA.
We will turn the order and discuss the process FMEA first.
Then we will discuss the design FMEA.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 12/36
Process FMEA
• Important tool for process engineering or teams looking at preventive process improvements (beforelooking at preventive process improvements (before a failure occurs).
• Will be used for the determination of priorities of• Will be used for the determination of priorities of process improvement efforts, to ensure that it is beneficial for the customer and raise attention.
• Will be used to document the finalization of projects and the resulting improvements of the risk gcalculation.
• It should be a live document, which requires a frequent review and updates.
• It is a key tool in the DMAIC cycle.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 13/36
Process FMEA
Further applications
• Supports the analysis of new manufacturing processes
• Guides the development of a new manufacturing process by helping process design engineers in the
l d t di f th k f th tearly understanding of the weaknesses of the current process.
• Will help at the evaluation of risks due to process• Will help at the evaluation of risks due to process changes.
• Identification of gaps in the process control plan so• Identification of gaps in the process control plan, so that action for improvement can be taken.
• Identification of potential variables which can be• Identification of potential variables, which can be considered for further investigations with Mulitvari and DOE studies.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 14/36
Process FMEA
• Initiation:
– Early in the process improvement investigation after aEarly in the process improvement investigation after a process map is available
– When a new process are being designedp g g
– When existing processes are being changed
– After process function are defined but before specificAfter process function are defined, but before specific hardware is selected or released to manufacturing
• Update/review:Update/review:
– Whenever a change is being considered to manufacturing / assembly processesassembly processes
– After review of action items completion
Recalculation of RPNs– Recalculation of RPNs
– To develop actions and assign responsibilities to the new highest ranking RPNs
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 15/36
highest ranking RPNs
Basic Definition of Defects
A product is defective if:− they differ from the determined condition due to the production
− they don’t fulfill the safety regulation due to design deficiencies, although they may be defect free.although they may be defect free.
− they don’t reach the specified performance level
− they are dangerous because warning notes and procedures are missing
Design defects:have an effect for the complete production line− have an effect for the complete production line
Manufacturing defects:raw materials have deficiencies− raw materials have deficiencies
− failures during the production itself
Service defects− service does not fulfill the criteria which have been defined by the
design and the customer
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 16/36
Failure Mode, Effect and Detection
Failure mode 1 Eff t 11
Failure mode 2
Effect 1
Failure mode Effect 11
Effect 2
F il dFailure mode 1
Failure mode 2
Effect 1Detection 1
Detection 22
Its getting very complex easily
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 17/36
Its getting very complex, easily…
Sources of the Complexity of a Product
Safety SOP`s− A high priority factor
Effect on the production stop and yield− What affects the production stop and the yield?
− Preventive maintenance - repairs while the process is still going on or when it is stoppedor when it is stopped
− Process control
− Actions to correct the programp g
Repair plan− repair time, ease of maintenance, repair costs and toolsp , , p
Access− Access difficulties to the repairing partp g p
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 18/36
The Risk Priority Number (RPN)
The result of a FMEA is the product of three quantitative ratings, in relation to failure effect, cause frequency and detection capability
Effect Cause Control RPNEffect
1.........10
Cause
1........10
Control
1........10
RPN
1.....1000
Capability to detect the failure
How often the cause occurs
How bad will it be for the customer
RPN= Importance x Occurrence x Detection
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 19/36
RPN= Importance x Occurrence x Detection
Definition of RPN Terms
• Severity (of Effect) - importance of possible effect on customer requirements - could also concern safety and q yother risks if a failure occurs (1=Not Severe, 10=Very Severe)
• Occurrence (of Cause) - frequency with which a given cause occurs and creates Failure Mode Cancause occurs and creates Failure Mode. Can sometimes refer to the frequency of a Failure Mode (1=Not Likely, 10=Very Likely)(1 Not Likely, 10 Very Likely)
• Detection (capability of Current Controls) - ability of current control scheme to detect: the causes beforecurrent control scheme to detect: the causes before creating failure mode and or the failure modes before causing effect (1=Likely to Detect 10=Not Likely to
D t il f th ti di f th d l
causing effect (1=Likely to Detect, 10=Not Likely to Detect)
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 20/36
Details for the rating see appendix of the module
Failure Mode, Effect and Detection
Example: Spraying of a wax layer
Process Step/Input
Potential Failure Mode Potential Failure EffectsSEV
Potential CausesOCC
Current ControlsDET
RPN
What is the In what ways does the Key What is the impact on the Key he
er? What causes the Key Input to se
ur
? What are the existing controls and ou
M?
process step/ Input under
investigation?
Input go wrong? Output Variables (Customer Requirements) or internal requirements?
How
Sev
ere
is th
to th
e cu
sotm
e go wrong?
ofte
n do
es c
aus
or F
M o
ccu
procedures (inspection and test) that prevent eith the cause or the Failure Mode? Should include an SOP number.
How
wel
l can
yo
ect c
ause
or
FM
Hef
fect
How
det
Apply wax layer Not enough wax low corrosion protection 7 Viscosity to high 5 5 175
Check spray pattern 1 /Apply wax layer Not enough wax low corrosion protection 7 Temperature to low 5 5 175
Apply wax layer Not enough wax low corrosion protection 7 Spray pressure to low 5 5 175
Check spray pattern 1 / layer, periodical spray
head cleaning
If a prepared process map and/or C&E matrix is available, you can start with the inputs (causes) which are responsible for thecan start with the inputs (causes) which are responsible for the failure modes. The start at the failure modes without pre-work is
more difficult and results in more complex FMEA.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 21/36
p
Step by Step Create a FMEA
2. Define process flow
3. Define Inputs Outputs
4. Create C & E Matrix
1. Build Team for project p p
5. Identify the way for each input how it can change – these are the causes Note: one input may have several causes
p j
causes. Note: one input may have several causes.
6. Identify effects for each cause. This should come directly from the y yC & E matrix. Note: one cause may have several effects.
7 D fi th f il d f h bi ti f / ff t Th7. Define the failure mode for each combination of cause / effect. The failure mode, driven by the cause, will have an effect for the customer.
8. List the current controls for detection of failure mode or cause.
9. Rating of effect, occurrence and detection. Calculation of the risk priority number (RPN).
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 22/36
Step by Step Create a FMEA
10. Rank the all combinations creating the RPN
11. Define possible actions for combinations of RPN values >100
12. Calculate potential effects on the RPN for the defined actions
13. Start the actions with impact and / or quick to realize
14. Documentation of all conducted actions
15. Post rating of the RPN after the actions
A decision matrix is helpful to establish an action plan. The matrix includes the factors: effect on RPN, cost, time and resources.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 23/36
, ,
Exercise
• For this assignment you need the results from the exercise process map and C&E matrix.
• Form the same teams.
• Create a FMEA for 3-5 cause – effect relations.
• What could be the actions to reduce the occurrence or to improve the possibility for p p ydetection. Recalculate the RPNs!
• Use the flipchart with “Post its” or the form sheetUse the flipchart with Post its or the form sheet FMEA.xls.
Present your results in 45 minutes
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 24/36
Design FMEA
• System – used for analyzing systems or subsystems in early concept or design y y p gphases. Concentration on possible failure modes, caused due to the design, in linkage with the function of the systemlinkage with the function of the system.
Design – used to analyze a productDesign – used to analyze a product design before production release
• Process – used to analyze manufacturing and production processes.
• In a modified form the FMEA will be• In a modified form the FMEA will be applied for the risk analysis in the area work safety and for important projects.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 25/36
Purpose of the Design FMEA
Recognize functional failure modes of the product very early in the design phase.
Recognize potential safety and environment problems to eliminate doubts.p
Set priorities for design improvement.
Help with the development of a detailed test toHelp with the development of a detailed test to check the design.
Help with the identification of potential criticalHelp with the identification of potential critical inputs and outputs.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 26/36
Philosophical Approach
Mainly concentrate on safety aspects and potential regress or complaint topicsregress or complaint topics
2 different points of view:
Suppose the material is perfect but the processSuppose the material is perfect, but the process is poor.
S th i f t b t th t i lSuppose the process is perfect, but the material is poor.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 27/36
Inputs/Outputs of a Design FMEA
Inputs− customer requirements, safety regulations and legal
instructions
− Already known failure modes of the system
− list of the product functions
Outputs− Recommended design activities on product level
− Design controls or tests to rate design failure modes
− Potential failure modes converted into effects and transmitted to the process FMEAtransmitted to the process FMEA
− Potential causes converted into failure modes and transmitted to the process FMEAtransmitted to the process FMEA
− Potential critical variables
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 28/36
Design FMEA Form Sheet
Functional Potential Failure
SPotential Causes/
O Current Design D RProduct
RequirementPotential Failure Mode
Potential Failure Effects
EV
Potential Causes/ Mechanisms
CC
Evaluation or Control
ET
PN
fect
to
d th
at
ur?
dete
ct
mod
e?
mb
er
ET
)
What is the functional product requirement under
consideration?
In what ways could the functional product
requirement fail to be fully met?
What would be the impact of failure mode
on the customer (internal or external)?
ever
e is
the
eff
he c
usto
mer
?
What could cause the failure mode to occur?
s th
e lik
elih
ood
caus
e w
ill o
cc What methods, tools, or measures will
discover the cause before design
release? iffic
ult
is it
to d
use
of fa
ilure
m
Pri
ori
ty N
um
V X
OC
C X
DE
How
se th
Wha
t is
the
c
How
dth
e ca
u
Ris
k (S
EV
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 29/36
Design FMEA and Process FMEA
Design FMEA
F il d Eff t CFailure mode Effect Cause
One important t t i bl f
Effect on the customer -ti fi d RTY COPQ
One important i t i bloutput variable of
the product is not correct
unsatisfied, RTY, COPQ or C-P are being influenced
input variable is not correct.
Process FMEA
correct influenced
Process FMEA
Failure mode Effect CauseOne important input variable is not correct (further
One important output variable of the product is not correct (further
Cause of the KPIV problems
correct (further details will be added)
not correct (further details will be added)
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 30/36
)
Example: Oxidation Process
Design FMEA
F il d Eff t CFailure mode Effect Cause
Viscosity is on the t id f
Affects yield and it I t t
Flow rate is too hi h t loutside of
specificationcapacity. Important output of QFD
high or too low
Process FMEAProcess FMEA
Failure mode Effect CauseFlow rate is too high
Viscosity crosses the upper limit
Flow rate meter is not calibratedcalibrated
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 31/36
Summary
• Definition and historical backgroundg
• Areas for application
• Connection with other tools
• Preparation of a process FMEA• Preparation of a process FMEA
• Definition of improvements
• Application examples
P ti l i• Practical exercise
• Design FMEAg
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 32/36
Appendix for the Appendix for the
FMEAFMEA
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 33/36
Rating: Severity of the EffectConsequences
Effects Criteria: Meaning of the consequences
Rating number
Dangerous withoutCan endanger the operator or the equipment. Very high classification of the meaning, if possible
Dangerous withoutwarning
10failure consequences or failure to comply with regulations affects the safety during use/operation.Failure occurs without warning
9Dangerous with
warning
Can endanger the operator or the equipment. Very high classification of the meaning, if possible failure consequences or failure to comply with regulations affects the safety during use/operation
Very high
M i l di ti f th d ti P d t h t b t d t d tl d Th
Serious interruption of the production. 100% of the products have to be scrapped. Products or servicesare not functional. The customer is very unsatisfied and complaints usually
8
warning q p y g y g pFailure occurs with warning
HighMarginal disruption of the production. Products may have to be sorted out and partly scrapped. Theproduct or service is restricted functional. Customer unsatisfied 7
6MediumMarginal disruption of the production. Products may have to be sorted out and partly scrapped. Theproduct or service is restricted functional. Customer feels discomfort.
Low 5
Very low 4
Marginal disruption of the production. Products may have to be sorted and reworked. The product orservice is restricted functional. Customer feels discomfort.
Marginal disruption of the production. Products may have to be reworked. The product or service Very low 4
Minor 3
has defects which will be recognized by the customer in the most cases
Marginal disruption of the production. Products may have to be reworked during running production.The product or service has defects which will be recognized by the average customer.
Very Minor 2
None No
consequences
1
Marginal disruption of the production. Products may have to be reworked during running production.The product or service has defects which will be recognized by single customer.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 34/36
q
Rating of the Occurrence
Failure probability Failure portionRating number
33% 9Very high, failure is almost inevitable
number
50% 10
5% 7
High, general similar to processes with high failureprobability
13% 8
Medium, general similar to processes with occasional failures but never in a higher degree 0,25% 2500ppm 5
1,30% 6
Low, sporadic failures at similar processes 50ppm 3
g g
0,05% 500ppm 4
5ppm 2
Minimal: in fact free of failure 0,5ppm 1
Very low, sporadic failures at constant processes
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 35/36
Rating of the Detection
DetectionCriteria: Probability that the existence of a failure before processing of delivery
can be detected due to appropriate measures
Absoluteimprobable
No controls for failure detection available. 10
Rating number
improbable
Very unlikely, that current controls will detect the possible failure. 9
Unlikely, that current controls will detect the possible failure. 8
Veryimprobable
Improbable
Very low Very low probability that the current controls will detect the possible failure. 7
Low 6
Moderate 5
Low probability that the current controls will detect the possible failure.
Moderate probability that the current controls will detect the possible failureModerate 5
4
3
Moderate probability that the current controls will detect the possible failure.
Moderate high Moderate high probability that the current controls will detect the possible failure.
High probability that the current controls will detect the possible failure.High
In every case 1
Very high 2Very high probability that the current controls will detect the possible failure.
Current controls will detect the possible failure in every case.
Knorr-Bremse Group 09 BB W1 FMEA 06, D. Szemkus/H. Winkler Page 36/36