FMEA Failure Mode and Effects Analysis PDF

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FMEA Failure Mode and Effects Analysis What is FMEA? ??? What can go wrong in flights? Do you think that in your flight might come something wrong? –  What are the risks that comes to mind? –  Why do these risks come to your mind firstly? Murphy’s Law: Anything that can go wrong will go wrong (at the fir...

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FMEA Failure Mode and Effects Analysis

What is FMEA? ??? What can go wrong in flights? Do you think that in your flight might come something wrong? –  What are the risks that comes to mind? –  Why do these risks come to your mind firstly? Murphy’s Law: Anything that can go wrong will go wrong (at the first possible Cme) FMEA can also be defined as 'proacCve risk assessment'. PrevenCon! 2

What is FMEA? •  A tool used to idenCfy and evaluate failure modes in a process or design, and help o determine the causes of those failures. •  Designed to prioriCze potenCal failures based on risk. •  Designed to reduce the chances of failure by driving acCons for improvement. •  Presents only the failure modes and does not solve problems on its own.

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Why do we apply FMEA? Toyota History's Biggest Product Recall Toyota made the greatest product recallof its history with a total of approximately 9 million vehicles withdrawn from the market in 2009-2010 following a fatal accident in 2009, which is very important to the quality of the product, but the leading companies in the sector. The main two reasons for recall are: •  The portable mop on the driver's side is stuck together to prevent the brake pedal from funcConing •  Uncontrolled acceleraCon of vehicle due to mechanical sCffness of gas pedal 4

Why do we apply FMEA? •  The result is fatal when both condiCons occur; why these possibiliCes were not considered before? •  This product recall scandal is not the first and will not be the last. The record product recall cases are: –  Ford Motor 21 million (1980) –  GM 13 million (2014) –  Ford Motor 7,9 million (1996) –  Ford Motor 4,5 million (2005) –  Ford Motor 4 million (1972) 5

History of FMEA •  It was developed by the American army in the late 1940s to increase the credibility of military equipment. •  It was used by the rapidly developing aircraa industry in the 1960s. •  It was begun to be used by NASA in 1963 and was applied in 1969 when Apollo 11 was sent to the Moon. •  In the 1970s, first industrial applicaCons started in Japan. •  It was spread in the automoCve sector in the 1980s. –  Ford Motor Company was the forefront to implement.

•  The spread in other sectors did not last long.

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FMEA Process Map Map Process

IdenCfy all potenCal failure models

Describe and record effects of failure

Determine severity of failure

Determine the causes of failure

Determine how oaen the failure occurs

Re-evaluate failure mode

Review results

Evaluate acCon plan for correcCon

Calculate the RPN

Evaluate controls for process and determine detectability

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When to use FMEA? •  New process development •  New product development •  Changes in man, machine, method, materials or environment

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FMEA Success Factors •  •  •  • 

A team approach is imperaCve Accurate data Background knowledge of the process Experienced personnel

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Process Analysis •  Find and review exisCng process maps, SIPOC analysis, value stream maps etc. •  Team must fully understand the how, when and why of each process involved (What is the point of the process?) –  Walk through the enCre process, step-by-step –  Encourage quesCons –  Uncover data and hidden process steps

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What is Failure? •  The condiCon or fact of not achieving the desired result or outcome; insufficient or non-performing. Note: Evaluate processes and understand the point for each process step.

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What is Failure Mode? •  The manner in which a process, equipment or machine can potenCally fail. –  A descripCon of the potenCal opportunity for nonconformance at a specific point in Cme. –  Such as – premature operaCon; failure to operate at a predescribed Cme; operaConal failure; or resultant failure (as from a bad set-up)

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Examples of Failure Modes (Think 8 wastes) •  •  •  •  •  •  •  • 

Incorrect informaCon DeformaCon Cracks Dirty Under-performing Stratched Dented Out of round

•  •  •  •  •  • 

Undersized Late/early İncomplete Missing Ripped Unreadable

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What is Effect? •  To determine effect, consider impact on customer –  Customer could be: end user, subsequent operaCon or downstream process or document •  There can be more than one effect for each failure mode •  Think about difference in perspecCve between each type of customer: internal – vs – external.

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Take AcCon! •  When –  An effect of failure has a severity of 8 or higher –  The product of severity & occurrence is high –  When the RPN is high •  > 75 or whatever your business decides •  The RPN is calculated for the enCre process or design first •  Failure modes with the highest RPN = Highest Priority!

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Suggested AcCons •  Minimize severity through –  Design modificaCons or process modificaCons •  Reduce the likelihood of occurrence by –  Design or process improvement •  Improve detecCon –  Poor acCon but may be necessary

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AcCons for Improvement •  •  •  • 

IdenCfy the high RPN’s Determine what to do to achieve an improvement Implement the improvement acCon Recalculate the RPN

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Failure Priority DetecCon •  Severity •  Occurance •  DetecCon

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Severity in FMEA What is the size of the potenCal error detected? –  You forgot to set the clock when you were sleeping in the evening. –  When you go out for a holiday, you forget the oven on.

•  Severity is the level of significance of the effect of the potenCal failure mode Two factors should be taken into account when determining the severity: 1.  Causes that the problem creates within the company –  Quality problems –  The next process will have adverse effects

2.  Reflected on the outside (customer/paCent) –  Does the customer/ paCent noCce? –  will it cause dissaCsfacCon? 19

Severity Ranking 1

low impact, very unlikely to be noCced by the customer

2

low impact, likely to be noCced by the customer

3

the low impact is likely to be noCced by the customer

4-5

may lead to customer dissaCsfacCon, though not criCcal to product quality

6-7

high customer dissaCsfacCon risk, but no vital consequences such as injury / contravenCon of laws

8 9 10

there is a risk of injury / contravenCon of the law will most likely cause undesirable consequences such as injury / contravenCon of the law will result in unintended consequences such as injury / contravenCon of the law 20

Occurance in FMEA •  Is the frequency a specific failure cause is likely to arise: –  Review similar processes or products and the failure modes associated with them –  If similar items not available, use the FMEA team to assess the items subjecCvely and then develop guidelines. •  How oaen could it be? –  Every minute/hour/day/month/year? –  It used to be once as old as you can not remember the date.

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Occurance Ranking 1

a very weak probability of error / problem arising

2-3

error / problem occurs with a weak probability

4-5

rarely observed errors / problems

6-8

repeCCve trending errors / problems

9 10

error / problem almost inevitable error / problem will definitely arise

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DetecCon in FMEA •  Considering the current control mechanisms on the system/ equipment/process, the problem is: –  Can we detect it in some way? –  Can we prevent the customer/paCent from being noCced or exposed?

•  Is the assessment of the likelihood of finding the failure mode before: –  The failure occurs –  The next downstream process –  Leaving the factory/facility

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DetecCon Ranking 1 2 3 4-5 6-8 9 10

Absolutely detectable Although the probability of detecCon is not certain, it is extremely high It is likely that it will be detected Maybe it is possible to detect Unlikely to be detected It is probably not detectable DetecCon is not possible

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Risk Priority Number (RPN) •  The output of an FMEA is the RPN •  The RPN is calculated based on informaCon from –  The potenCal failure modes; –  Their effects & causes; –  The current ability of the process to detect the failures before they reach the customer •  Is calculated as the product of three quanCtaCve raCngs, each one related to the effects, causes and controls. •  The RPN’s are then sorted&acCons are recommended for the top issues. RPN = Severity * Occurrence * DetecNon 25

RPN CalculaCons Earthquake Blackout





Severity Occurance DetecCon RPN

→ High → Low → High → Medium High





Severity Occurance DetecCon RPN

→ Low → Medium → Medium → Low – Medium 26

FMEA Form

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FMEA Exercise - Withdraw money from the ATM Process Step/ PotenNal Error/ PotenNal Effects of Severity Equipment Failure Factor Failure Withdraw money from the ATM at the amount ATM is not requested by paying the customer

The ATM gives more money than requested

Customer dissaCsfacCon (high level) Incorrect entryto demand deposit system

Possible Causes Occurrence of Failure

ExisNng Controls (to detect the problem)

DetecNon

RPN

There is not enough money at the ATM.

5

Low cash alarm / warning

5

200

Money stuck in ATM

3

CongesCon alarm / warning

10

240

Inconsistency in accounts

Power interrupCon during operaCon

2

None

10

160

The bank loses money

Banknotes stuck together

2

7

84

Banknotes are misplaced

3

4

72

System slow

7

None

10

210

Power interrupCon during operaCon

2

None

10

60

8

6

Inconsistency in accounts

It takes too long Customer to withdraw dissaCsfacCon money from the (medium level) ATM

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Loading procedure (pusng the edges of the bundles together) Visual control of two persons

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Types of FMEA & ApplicaCon Fields Design FMEA – Primary focus is product. Process FMEA – Primary focus is the process. System FMEA – Primary focus is equipment.

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Process FMEA The process starts with the IPO and flow diagrams of the process being examined. If the IPO and flow diagram are not available, they are removed from the FMEA preparatory phase. Process FMEA pracCce usually requires mulCdisciplinary teamwork. •  Aaer the process steps have been idenCfied, error/failure factors, effects, probable causes and idenCfied controls are recorded. •  FMEA can be applied periodically not only for designing new processes but also for 'conCnuous improvement' in exisCng processes. –  It provides very useful process informaCon. The acquired process informaCon is also reflected in similar processes to prevent failures before they occur. –  The rouCne applicaCon of FMEA in the process reduces the cost of poor quality. 30

Design FMEA What kind of faults can arise in a product / service due to the problems in design? Can we get away with it before it has emerged or the customer has not noCced it yet? Product FMEA is applied to ensure 'first Cme right' quality in new products, especially for the first Cme on the market. –  product specificaCons, producCon condiCons and processes. –  guarantee early availability of specified product specificaCons. •  The product FMEA is long-lasCng in the market and it is successful in products with quality problems.

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System FMEA •  System FMEA makes it possible for criCcal systems to be examined by subdividing them into sub-systems in detail at the design stage. •  The system can be applied to FMEA management systems as well as technical equipment. –  educaCon system, documentaCon system, performance evaluaCon system, informaCon management system, etc. –  plant / building management systems –  venClaCon / water / heaCng / cooling systems and so on. System X Sub-systems (S1,S2, S3…)

Complex systems break down into subsystems when analyzed by FMEA

Components 32

Other ApplicaCon Fields of FMEA

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