basics of fmea book

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THE BASICS OF

FMEA


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Robin E. McDermott

Raymond J. Mikulak

Michael R. Beauregard

2nd Edition

THE BASICS OF

FMEA


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Productivity PressTaylor & Francis Group270 Madison AvenueNew York, NY 10016

2009 by Taylor & Francis Group, LLCProductivity Press is an imprint of Taylor & Francis Group, an Informa business

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Contents

Introduction. ix

Chapter 1 What.Is.an.FMEA?. 1Te History o FMEAs ...........................................................................1

Chapter 2 What.Is.the.Purpose.o.an.FMEA?. 3Part o a Comprehensive Quality System ................................................3FMEAs and Bottom-Line Results ...........................................................4

Example 1 ..........................................................................................4

Example 2 ..........................................................................................4Example 3 ..........................................................................................5

Chapter 3 ISO.9000,.ISO/S.16949,.and.FMEAs. 7

Chapter 4 Te.FMEA.Process. 9Evaluating the Risk o Failure ............................................................... 10

Assessing the Risk Priority Number ...................................................... 10

Chapter 5 Te.FMEA.eam. 11FMEA eam Size.................................................................................. 11FMEA eam Membership .................................................................... 12FMEA eam Leader .............................................................................12Te Role o the Process Expert .............................................................. 12raining the FMEA eam ....................................................................13

Chapter 6 FMEA.Boundaries.o.Freedom. 15FMEA Scope ........................................................................................ 16FMEA Start-Up Worksheet .................................................................. 17

Chapter 7 Product/Design.versus.Process.FMEAs. 19Product/Design..................................................................................... 19Process ..................................................................................................20


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i Contents

Chapter 8 en.Steps.or.an.FMEA. 23Te FMEA Worksheet ..........................................................................23

Step 1: Review the Process or Product ................................................25Step 2: Brainstorm Potential Failure Modes ........................................25Step 3: List Potential Eects or Each Failure Mode ...........................26Steps 46: Assigning Severity, Occurrence, and Detection Rankings .....26

Step 4: Assign a Severity Ranking or Each Eect ........................... 31Step 5: Assign an Occurrence Ranking or Each Failure Mode .......36Step 6: Assign a Detection Ranking or Each Failure Mode

and/or Eect .......................................................................36Step 7: Calculate the Risk Priority Number or Each

Failure Mode ...........................................................................36Step 8: Prioritize the Failure Modes or Action ...................................37Step 9: ake Action to Eliminate or Reduce the High-Risk

Failure Modes .........................................................................38Step 10: Calculate the Resulting RPN as the Failure Modes

Are Reduced............................................................................38

Chapter 9 FMEA.Case.Study. 41Case Study Step 1: Review the Process ...............................................41

Case Study Step 2: Brainstorm Potential Failure Modes .....................42Case Study Step 3: List Potential Eects o Each Failure Mode .........42Case Study Step 4: Assign a Severity Ranking or Each Eect ...........46Case Study Step 5: Assign an Occurrence Ranking or Each

Failure Mode ........................................................46Case Study Step 6: Assign a Detection Ranking or Each Failure

Mode and/or Eect ..............................................46Case Study Step 7: Calculate the Risk Priority Number or Each

Failure Mode ........................................................46

Case Study Step 8: Prioritize the Failure Modes or Action ................47Case Study Step 9: ake Action to Eliminate or Reduce the

High-Risk Failure Modes .....................................47Case Study Step 10: Calculate the Resulting RPN as the Failure

Modes Are Reduced or Eliminated ......................47

Chapter 10When.and.Where.to.Use.FMEAs. 49Saety ....................................................................................................49

Accounting/Finance .............................................................................50

Sotware Design ...................................................................................50Inormation Systems/echnology .........................................................50Marketing ............................................................................................. 51Human Resources ................................................................................. 51Purchasing ............................................................................................ 51


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Contents ii

Appendix 1 Creating.a.Process.Flowchart. 53

Appendix 2 Brainstorming. 57Brainstorming Rules .............................................................................57

Appendix 3 Reaching.Consensus.on.Severity,.Occurrence,.and.Detection.Rankings. 59

eam Voting ......................................................................................... 59Get the Process Expert Involved ...........................................................60Deer to One o the eam Members .....................................................60Rank Failures and Eects within a Ranking Category .........................60

alking It Out ...................................................................................... 61Use the Higher Ranking ....................................................................... 61

Appendix 4 Examples.o.Custom.Ranking.Scales. 63

Appendix 5 Process.Improvement.echniques. 73Mistake Proong .................................................................................. 73Design o Experiments .......................................................................... 74Statistical Process Control .................................................................... 74eam Problem Solving Using CI ools ................................................. 75

Appendix 6 ISO/S.16949.Requirements.Reerencing.FMEAs. 77

Appendix 7 Alternative.FMEA.Worksheets. 81

FMEA Glossary o Terms. 85

Index. 87


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ix

Introduction

Failure Mode and Eect Analysis (FMEA) techniques have been around or over40 years. It was only in the late twentieth century, however, that FMEAs gained

widespread appeal outside the saety arena. Tis was thanks in large part tothe U.S. automotive industry with its QS-9000 supplier requirements that wereestablished in 1996 and global eorts by the International Automotive askForce (IAF) to build on QS-9000 (and other international quality standards)

with the development o ISO/S 16949.Te 2002 revision o ISO/S 16949 incorporates ISO 9001:2000 and denes

the quality system requirements (and application o ISO 9001) or automotive

production and relevant service part organizations.Te ISO/S 16949 standard requires that suppliers to the automotive indus-

try conduct product/design and process FMEAs in an eort to prevent ailuresbeore they happen.

Unlike many quality improvement tools, FMEAs do not require compli-cated statistics, yet they can yield signicant savings or a company while at thesame time reducing the potential costly liability o a process or product that doesnot perorm as promised.

FMEAs do take time and people resources. Because FMEAs are team based,several people need to be involved in the process. Te oundation o FMEAsis the FMEA team members and their input during the FMEA process. Com-panies must be prepared to allow the team enough time to do a thorough

job. Eective FMEAs cannot be done by one person alone sitting in an ocelling out the FMEA orms. Automotive customers and ISO auditors todaycan easily spot an FMEA that was done just to appease the customer and ulllstandards requirements.

Tis booklet was designed to help shorten the learning curve or FMEA

teams and to help them conduct eective and ecient FMEAs, even i it is theirvery rst FMEA. Te books easy-to-use reerence ormat makes it an invaluableresource or FMEA teams.


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1

Chapter 1

What Is an FMEA?

An FMEA (Failure Mode and Eect Analysis) is a systematic method o identi-ying and preventing product and process problems beore they occur. FMEAsare ocused on preventing deects, enhancing saety, and increasing customer

satisaction. Ideally, FMEAs are conducted in the product design or processdevelopment stages, although conducting an FMEA on existing products andprocesses can also yield substantial benets.

The History o FMEAs

Te rst ormal FMEAs were conducted in the aerospace industry in the mid-1960sand were specically ocused on saety issues. Beore long, FMEAs became a key

tool or improving saety, especially in the chemical process industries. Te goalwith saety FMEAs was, and remains today, to prevent saety accidents and inci-dents rom occurring.

While engineers have always analyzed processes and products or potentialailures, the FMEA process standardizes the approach and establishes a commonlanguage that can be used both within and between companies. It can also beused by nontechnical as well as technical employees o all levels.

Te automotive industry adapted the FMEA technique or use as a qualityimprovement tool.


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3

Chapter 2

What Is the Purpose oan FMEA?

Preventing process and product problems beore they occur is the purposeo Failure Mode and Eect Analysis (FMEA). Used in both the design andmanuacturing processes, they substantially reduce costs by identiying prod-uct and process improvements early in the develop process when changes arerelatively easy and inexpensive to make. Te result is a more robust processbecause the need or ater-the-act corrective action and late change crises arereduced or eliminated.

Part o a Comprehensie Quality SystemA ormal FMEA process should be a part o a comprehensive quality system.While FMEAs can be eectively used alone, a company will not get maximumbenet without systems to support conducting FMEAs and implementingimprovements that are a result o the FMEAs. For example, one element o acomprehensive quality system is eective use o data and inormation. Withoutreliable product or process data the FMEA becomes a guessing game based onopinions rather than actual acts. Te result may be that the FMEA team ocuses

on the wrong ailure modes, missing signicant opportunities to improve theailure modes that are the biggest problems. Another example that supportsthe need or a comprehensive quality system is documentation o procedures.


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4 The Basics of FMEA

Tis is especially critical with a process FMEA. In the absence o documentedprocedures, people working in the process could be introducing signicant

variation into it by operating it slightly dierently each time the process is run.In this case, the FMEA is aiming at a moving target because each time the pro-cess is run, it produces dierent results.

Tere are many dierent models or quality systems, including ISO 9000,ISO/S 16949, and the Malcolm Baldrige National Quality Award. Te bestmodel or a company depends on the type o business, the requirements othe customers o the business, and the current quality systems that are alreadyin place.

FMEAs and Bottom-Line Results

Eective use o FMEAs can have a positive impact on an organizations bottomline because o their preventive nature. Here are three real examples.

Example 1

Ford required a manuacturer o automobile liquid-level foats to conduct botha design/product FMEA and a process FMEA. Te manuacturer establishedthree FMEA teams, each tasked with a dierent aspect o the process/product.Tree team leaders were assigned and were responsible or ensuring the teamseorts were coordinated.

The Results

Te combined eorts o the teams resulted in a decrease in deectives to0.2 part per million.Te equipment uptime increased rom 74 percent to 89 percent.Customer complaints dropped rom an average o two per year to none.Productivity per labor hour increased by 22 percent.

Example 2

An aircrat engine manuacturer conducted an FMEA on its engine assemblyoperation. A cross-unctional team was ormed that included individuals romoutside o the assembly department, although all were amiliar with assembly tosome extent.


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What Is the Purpose of an FMEA? 5

The Results

Te team identied the biggest risk o ailure and mistake-prooed theprocess to the point where there was no chance o it recurring.Internal ailures dropped to one-third o what they had been, eliminatingproblems that had existed or years but were not high enough a priority toaddress until the FMEA.Te manuacturer saved $6,000 per month on engine teardowns.

Example 3

A small printed circuit board manuacturer with thirty-ve employees ormedan FMEA team. While the manager was a team member, his role was to keepnotes, not to lead the team. Ater a brie FMEA training session, the teamdecided to collect data and inormation rom other operators that were not onthe team. With that inormation, they were able to complete the FMEA in ourtwo-hour sessions.

The Results

Te highest-priority items were associated with the wave-soldering operation.Te team discovered that many o the ailure modes were related to preven-tive maintenance o the soldering unit.

Ater establishing and implementing a preventive maintenance program,the team decreased solder deects on the complex boards they manuac-tured rom an average o eleven per board to an average o one per board.Te team continues to work to urther reduce the deects.


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7

Chapter 3

ISO 9000, ISO/TS 16949,and FMEAs

ISO 9000 is a amily o standards or quality management systems. When an organization achieves ISO 9000 certication, that organization

has developed, instituted, and uses systems capable o controlling processes thatdetermine the acceptability o its product or services. ISO 9001:2000, whichcombined the earlier standards o ISO 9001, 9002, and 9003, denes the require-ments o a comprehensive quality management system.

ISO/S 16949:2002 takes ISO 9001 one step urther with an emphasis on aprocess approach. While ISO/S 16949:2002 is based on ISO 9001, it containscomplementary automotive industry-specic requirements adding to the standard

both a process orientation and a ocus on the customer.Specic actions required to ulll ISO are dened throughout the ISO/S 16949standard, particularly in Sections 5 (Management Responsibility), 6 (ResourceManagement), and 7 (Product Realization). Most o the reerences to FMEAsare in Section 7.

See Appendix 6 or a listing o FMEA-related reerences in ISO/S 16949.


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9

Chapter 4

The FMEA Process

Te objective o an FMEA is to look or all o the ways a process or product canail. A product ailure occurs when the product does not unction as it shouldor when it malunctions in some way. Even the simplest products have many

opportunities or ailure. For example, a drip coeemakera relatively simplehousehold appliancecould have several things ail that would render thecoeemaker inoperable. Here are some possible ways the coeemaker can ail:

Te heating element does not heat water to sucient temperature tobrew coee.Te pump does not pump water into the lter basket.Te coeemaker does not turn on automatically by the clock.Te clock stops working or runs too ast or too slow.

Calcium deposits rom impure water clog up the brewing process.Tere is either not enough or too much coee used.Tere is a short in the electrical cord.

Failures are not limited to problems with the product. Because ailures alsocan occur when the user makes a mistake, those types o ailures should also beincluded in the FMEA. Anything that can be done to ensure the product workscorrectly, regardless o how the user operates it, will move the product closer to100 percent total customer satisaction.

Ways in which a product or process can ail are called ailure modes. Eachailure mode has a potential eect, and some eects are more likely to occurthan others. In addition, each potential eect has a relative risk associated with


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it. Te FMEA process is a way to identiy the ailures, eects, and risks within aprocess or product, and then eliminate or reduce them.

Ealuating the Risk o Failure

Te relative risk o a ailure and its eects is determined by three actors:

SeverityTe consequence o the ailure should it occur.OccurrenceTe probability or requency o the ailure occurring.DetectionTe probability o the ailure being detected beore theimpact o the eect is realized.

Assessing the Risk Priority Number

Using the data and knowledge o the process or product, each potential ailuremode and eect is rated in each o these three actors on a scale ranging rom1 to 10, low to high.

By multiplying the ranking or the three actors (severity occurrence detection), a risk priority number (RPN) will be determined or each potentialailure mode and eect.

Te risk priority number (which will range rom 1 to 1,000 or each ailuremode) is used to rank the need or corrective actions to eliminate or reduce thepotential ailure modes. Tose ailure modes with the highest RPNs should beattended to rst, although special attention should be given when the severityranking is high (9 or 10) regardless o the RPN.

Once corrective action has been taken, a new RPN or the ailure is deter-

mined by reevaluating the severity, occurrence, and detection rankings. Tisnew RPN is called the resulting RPN. Improvement and corrective actionmust continue until the resulting RPN is at an acceptable level or all potentialailure modes.


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11

Chapter 5

The FMEA Team

Although one person typically is responsible or coordinating the FMEA process,all FMEA projects are team based. Te purpose or an FMEA team is to bring avariety o perspectives and experiences to the project.

Because each FMEA is unique in dealing with dierent aspects o the prod-uct or process, FMEA teams are ormed when needed and disbanded once theFMEA is complete. In act, it would be inappropriate to establish a permanentFMEA team because the composition o the team is dictated by the specic taskor objective. In cases where several FMEAs are needed to cover one process orproduct, it is good practice to have some overlap o members between the teams,but there also should be some members who serve on only one or two o theteams to ensure a resh perspective o the potential problems and solutions.

FMEA Team Size

Te best size or the team is usually our to six people, but the minimum numbero people will be dictated by the number o areas that are aected by the FMEA.Each area (or example, manuacturing, engineering, maintenance, materials,and technical service) should be represented on the team. Te customer o theprocess, whether internal or external to the organization, can add another uniqueperspective as well and should be considered or team membership.


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FMEA Team Membership

It is helpul also to have people on the team who have dierent levels o amil-iarity with the product or process. Tose who are most amiliar with it willhave valuable insights, but may overlook some o the most obvious potentialproblems. Tose who are less amiliar with the process or product will bringunbiased, objective ideas into the FMEA process. Be aware that those with anemotional investment in the process or product may be overly sensitive duringthe critiquing process and may become deensive. Deciding whether to includethese emotionally invested people on the team must involve weighing the dis-advantages against the advantages that their experience and knowledge will

bring to the process.

FMEA Team Leader

An FMEA team leader should be appointed by management or selected by theteam as soon as it is assembled. Te team leader is responsible or coordinatingthe FMEA process, including:

Setting up and acilitating meetingsEnsuring the team has the necessary resources availableMaking sure the team is progressing toward the completion o the FMEA

Te team leader should not dominate the team and does not normally havethe nal word on team decisions. Te team leaders role is more like that o aacilitator than a decision maker.

Arrangements should be made or someone to be responsible or taking

meeting minutes and maintaining the FMEA records. Te scribes role is otenrotated among all team members, except the team leader. Tis spreads theburden o recording the meeting equally among all participants.

The Role o the Process Expert

A point that is oten debated with FMEAs is what role the process expert playson the FMEA team. A person with expertise in the process (or example, thedesign engineer in a design FMEA or the process engineer in a process FMEA)can bring tremendous insight to the team and can help speed the process. Inmany ways he or she can be a real asset to the team. On the other hand, a processexpert can also slow down the FMEA process.


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The FMEA Team 13

An FMEA is a critical look at a product or process. People on the FMEAteam who have a stake in the product or process being examined cannot allow

their egos to get in the way o the FMEA. Tis is especially dicult or theprocess expert. Most likely he or she has a huge investment in the process orproduct, in terms o both time and personal integrity. Te purpose o an FMEA,in essence, is to nd faws in that persons work. Tis can be a dicult processor an individual to go through and may result in several dierent types oreactions, including deensiveness, anger, and decreased sel-esteem, all o whichare counterproductive or both the team and process expert.

Training the FMEA Team

While it is helpul or FMEA team members to have some understanding o theFMEA process beore starting the project (such as reading through this bookand having it handy as a reerence), extensive training is not necessary i teammembers have previous experience working on problem-solving teams. A teamleader or acilitator who is well versed in the FMEA process can easily guide theteam through the process as they are actually perorming the FMEA. Tis means

that there is not a need or extensive classroom training. Instead, the FMEAteam can be immediately productive working on a real FMEA project and at thesame time benet rom the most powerul orm o trainingexperience.

It is important, however, that FMEA team members know the basicso working on a team because they will be using those skills as FMEA teammembers. Knowledge o consensus-building techniques, team project documen-tation, and idea-generating techniques such as brainstorming are all necessaryor FMEA team members. In addition, team members should be comortableusing continuous-improvement problem-solving tools, such as fowcharts, data

analysis, and graphing techniques.


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Chapter 6

FMEA Boundarieso Freedom

It is important that the FMEA team has clearly dened boundaries within whichthey are ree to conduct the FMEA and suggest and implement improvements.For example:

Is the team responsible only or conducting the analysis, are they tomake recommendations or improvements, and/or are they to implementthe improvements?

What is their spending budget?What other resources do they have at their disposal?

Does the team ace a deadline or other time constraints?What process must they ollow i they need to expand beyond the denedboundaries?

What and how should they communicate the FMEA process and resultsto others in the organization?

Management is responsible or dening the boundaries o reedom. Someo the boundaries o reedom can be standing guidelines or all FMEA teams.For example, a standard procedure can be established to dene the process that

teams must ollow i they need to go beyond the normal boundaries, and thisprocedure can apply to all FMEA teams. Te same holds true or the process thatthe team should use to communicate the FMEA results to others in the organi-zation. Other boundaries will need to be set or each FMEA and will depend on


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the type o FMEA (design/product or process), the scope o the FMEA, and thepeople on the FMEA team.

While management is responsible or dening the boundaries o reedom,the FMEA team members have equal responsibility in making sure these bound-aries are dened beore the project gets under way. I the team members do notknow what the boundaries are or i they are unclear about any o the boundaries,they should get clarication beore proceeding with the FMEA. Tis will helpthe team avoid problems and conficts later in the process.

FMEA Scope

Te scope o the FMEA must be well dened. Tis denition usually comes romthe leader o the unction responsible or the FMEA. I the FMEA is ocused onthe design o a product, the head o the design unction should clearly dene thescope o the project. For a process FMEA, the leader o the manuacturing ormanuacturing-engineering unction would most likely dene the scope.

A specic and clear denition o the process or product to be studied shouldbe written and understood by everyone on the team. eam members should havean opportunity to clariy their understanding o the scope, i necessary, and

those clarications should be documented. Tis will help prevent the team romocusing on the wrong aspect o the product or process during the FMEA.

For example, i your team is working on a product FMEA or a new dripcoeemaker that your company has just developed, your denition o the productto be studied might be:

Our team will conduct an FMEA on the new RS-100 coeemakerand the glass carae or that coeemaker. Te FMEA will not includeany parts o this coeemaker that are common to other coeemakersin our product line, such as the electronic clock, the electrical cordand wiring into the coeemaker, and the gold cone coee lter.

A specic and clear denition is even more important with process FMEAsbecause they can encompass so many dierent aspects o the process manuac-turing chain, rom the raw materials to components, to the actual manuactur-ing and assembly, to the shipping, and everything in between. While each parto the chain plays an important role in the quality o a product, it may help touse a narrow denition o the process to ensure that the FMEA project is com-pleted in a timely manner.

Because large processes may be dicult to work on in their entirety, breakthem into subprocesses when possible and attend to them one at a time, or haveseveral teams working at the same time on dierent subprocesses.


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FMEA Boundaries of Freedom 17

FMEA Start-Up WorksheetTe FMEA Start-Up Worksheet, shown in Figure 6.1, can help the members oa team make sure they have a clear understanding o their boundaries o reedomand their roles and responsibilities beore the project gets under way.

FMEA Number: Date Started:

Date Completed:TeamMembers:

Leader:

Who will take minutes and maintain records?

1. What is the scope of the FMEA? Include a clear definition of the process(PFMEA) or product (DFMEA) to be studied. (Attach the Scope Worksheet.)

2. Are all affected areas represented? (circle one)

YES NO

YES NO

YES NO

3. Are different levels and types of knowledge represented on the team? (circle one)

4. Are customers or suppliers involved? (circle one)

Action:

Action:

Action:

Boundaries of Freedom

5. What aspect of the FMEA is the team responsible for? (circle one)

6. What is the budget for the FMEA?

7. Does the project have a deadline?

8. Do team members have specific timeconstraints?

9. What is the procedure if the team needs toexpand beyond these boundaries?

10. How should the FMEA be communicated toothers?

FMEA Analysis Recommendations forImprovement

Implementation ofImprovements

FMEA Team Start-Up Worksheet

Figure 6.1 FMEA Team Start-Up Worksheet.


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19

Chapter 7

Product/Design ersusProcess FMEAs

Te principles and steps behind all FMEAs, whether they are ocused on theproduct or the process, are the same even though the objectives may dier.

Product/Design

Te objective or a product or design FMEA is to uncover problems withthe product that will result in saety hazards, product malunctions, or ashortened product lie. As consumers, we are all too amiliar with examples

o these types o problems, such as an air bag in a car that may not workproperly or a paint job that cracks and dulls within the rst three or ouryears that you own the car.Product FMEAs can be conducted at each phase in the design process(preliminary design, prototype, or nal design), or they can be used onproducts that are already in production. Te key question asked in designFMEAs is: How can the product ail?See Figure 7.1 or a sample worksheet or dening the scope o a designFMEA study.


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Process

Process FMEAs uncover process problems related to the manuacture othe product. For example, a piece o automated assembly equipment maymiseed parts, resulting in products not being assembled correctly. Or, ina chemical manuacturing process, temperature and mixing time could besources o potential ailures, resulting in an unusable product.It is helpul when conducting a process FMEA to think in terms o the veelements o a process: people, materials, equipment, methods, and environ-ment. With these ve elements in mind, ask: How can process ailureaect the product, processing eciency, or saety?See Figure 7.2 or a sample worksheet or dening the scope o a processFMEA study.

Design FMEA Scope Worksheet

Product: Date: Scope defined by:

Part 1: Who is the customer?

Part 2: What are the product features and characteristics?

Part 3: What are the product benefits?

Part 4: Study the entire product or only components or subassemblies?

Part 5: Include consideration of raw material failures?

Part 6: Include packaging, storage, and transit?

Part 7: What are the operational process requirements and constraints?

Figure 7.1 Design FMEA Scope Worksheet.


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Ten Steps for an FMEA 25

Some organizations have their own ormat or the FMEA worksheet. Others willadapt this orm to meet their needs.

Te worksheet is easiest to work with when enlarged to 11 17 inches in sizeor when put on to a large poster or projected rom a computer or use during theteam meeting.

A numbering system to track and access FMEA previously conductedprojects is helpul. Te numbering system should enable cross-reerencing tosimilar FMEAs as well as other improvement activities dealing with the sameproduct or process.

Copies o all FMEAs should be kept in a central location so they are easilyaccessible during audits or internal process and product reviews.

Step 1: Reiew the Process or ProductTe team should review a blueprint (or engineering drawing) o the product ithey are considering a product FMEA or a detailed fowchart o the operationi they are conducting a process FMEA. Tis will help ensure that everyone onthe FMEA team has the same understanding o the product or process that isbeing worked on.

I a blueprint or fowchart is not available, the team will need to create oneprior to starting the FMEA process. (Inormation on creating a fowchart canbe ound in Appendix 1.)

With the blueprint or fowchart in hand, the team members should amiliar-ize themselves with the product or process. For a product FMEA, they shouldphysically see the product or a prototype o it. For a process FMEA, the teamshould physically walk through the process exactly as the process fows.

It is helpul to have an expert on the product or process available to answerany questions the team might have.

Step 2: Brainstorm Potential Failure ModesOnce everyone on the team has an understanding o the process (or product), teammembers can begin thinking about potential ailure modes that could aect themanuacturing process or the product quality. A brainstorming session will get allo those ideas out on the table. eam members should come to the brainstormingmeeting with a list o their ideas. In addition to the ideas members bring to themeeting, others will be generated as a result o the synergy o the group process.

Because o the complexity o most manuactured products and manuac-turing processes, it is best to conduct a series o brainstorming sessions, eachocused on a dierent element (i.e., people, methods, equipment, materials, and


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the environment) o the product or process. Focusing on the elements one at atime will result in a more thorough list o potential ailure modes.

It is not unusual to generate dozens o ideas rom the brainstorming process.In act, that is the objective!

Once the brainstorming is complete, the ideas should be organized by group-ing them into like categories. Your team must decide the best categories orgrouping, as there are many dierent ways to group ailure modes. You can groupthem by the type o ailure (e.g., electrical, mechanical, user created), where onthe product or process the ailure occurs, or the seriousness (at least the teams bestguess at this point) o the ailure. Grouping the ailures will make the FMEA pro-cess easier to work through. Without the grouping step, the team may invest a loto energy jumping rom one aspect o the product to a completely dierent aspecto the product and then back again. An easy way to work through the groupingprocess is to put all o the ailure modes onto sel-stick notes and post them on a

wall so they are easy to see and move around as they are being grouped.Te grouping also gives the team a chance to consider whether some ailure

modes should be combined, because they are the same or very similar to eachother. When the ailure modes have been grouped and combined, i appropriate,they should be transerred onto the FMEA sheet. Te example in Figure 8.2

shows how each component (part o the process or piece o the product) andits intended unction are listed, and next to each you can see the potential ail-ure modes associated with each item. Note that there are usually several ailuremodes or each component.

Step 3: List Potential Eects or Each Failure Mode

With the ailure modes listed on the FMEA Worksheet, the FMEA team reviews

each ailure mode and identies the potential eects o the ailure should itoccur. For some o the ailure modes, there may be only one eect, while orother modes there may be several eects.

Tis step must be thorough because this inormation will eed into theassignment o risk rankings or each o the ailures. It is helpul to think o thisstep as an i-then process: Ithe ailure occurs, then what are the consequences?

Steps 46: Assigning Seerity, Occurrence, andDetection RankingsEach o these three rankings is based on a 10-point scale, with 1 being the lowestranking and 10 the highest.


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Ten Steps for an FMEA 29

Ta

ble8

.2b

(Generic

)Pro

cess

FMEASeeri

tyEalu

ation

Cri

teria

C

riteria:

Criteria:

Severit

yofEffecton

Rank

Effect

SeverityofEffecton

Effect

P

roduct

Process

(CustomerEffect)

(Manufacturing/AssemblyEffect

Failureto

Potentialfailuremo

deaffectssafevehicle

Mayendangeroperator(machineor

MeetSafety

operationand/orin

volvesnoncompliance

10

Failureto

assembly)w

ithoutwarning.

and/or

withgovernmentre

gulationswithoutwarning.

MeetSafety

Regulatory

Potentialfailuremo

deaffectssafevehicle

and/or

Mayendangeroperator(machineor

Requirements

operationand/orin

volvesnoncompliance

9

Regulatory

assembly)w

ithwarning.

withgovernmentre

gulationswithwarning.

Requirements

Lossofprimaryfun

ction(vehicleinoperable

,

8

Major

100%ofpro

ductmayhavetobescrapped.

Lossor

doesnotaffectsafe

vehicleoperation).

Disruption

Lineshutdo

wnorstopship

.

Degradation

Degradationofprim

aryfunction(vehicle

Aportiono

ftheproductionrunmayhaveto

ofPrimary

operable

,butatred

ucedlevelof

7

Significant

bescrapped

.Deviationfromprimary

Function

performance).

Disruption

processincludingdecreasedlinespeedor

addedmanpower.

Lossofsecondaryfunction(vehicle

100%ofpro

ductionrunmayhavetobe

Lossor

inoperablebutcom

fort/convenience

6

reworkedo

fflineandaccepted

.

Degradation

functionsinoperable).

Moderate

ofSecondary

Degradationofseco

ndaryfunction(vehicle

Disruption

Aportiono


Function

inoperablebutcom

fort/convenience

5

bereworkedofflineandaccepted

.

functionsatareduc

edlevelofperformance}.

AppearanceorAud

ibleNoise,vehicle

100%ofpro

ductionrunmayhavetobe

operable

,itemdoes

notconformandnoticed

4

reworkedin-s

tationbeforeitisprocessed.

bymostcustomers

(>75%).

Moderate

AppearanceorAud

ibleNoise,vehicle

Disruption

Aportiono


Annoyance

operable

,itemdoes


3

bereworkedin-s

tationbeforeitisprocessed.

bymanycustomers

(50%).

AppearanceorAud

ibleNoise,vehicle

Slightincon

veniencetoprocess,o

peration,

operable

,itemdoes


2

Minor

oroperator

bydiscriminatingcustomers( 2.00

ExampleRanking

10

9

8

7

6

54

3

2

1

Occurrence: DFMEA Custom Ranking, Piece-BasedExamples


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66 Appendix 4

No design rules used.

Design protocols are formalized.

Design rules are specified in initial design criteria.

Design reviews held to ensure compliance to design rules.

Checklist used to ensure design rules are followed.

Purchasing systems do not allow selection of nonstandardcomponents.

Early supplier involvement so all relevant knowledge about inputmaterials and compliance to design needs are understood.

Design software signals compliance issues.

Design software ensures compliance to the relevant industrystandards.

Design software prevents use of nonstandard dimensions, spacing,and tolerances.

ExampleRanking

10

9

8

7

6

5

4

3

2

1

Detection: DFMEA Custom Ranking, Design Rule Examples

No consideration given for DFA/DFM.

Te number of components has been minimized.

Only standard components have been used.

Ergonomic assembly techniques have been incorporated.

Modular designs used.

Easy-fastening devices (snap fits or quick fastening devices such asquarter-turn screw, twist locks, spring clips, latches) used.

Self-testing or self-diagnosis has been built-in.

Self-aligning surface, grooves, and guides used.

Asymmetrical features used to mistake-proof assembly.

Design elements such as pad sizes, wire gauge, and fasteners havebeen standardized throughout the design.

ExampleRanking

10

9

8

7

6

5

4

3

2

1

Detection: DFMEA Custom Ranking, DFA/DFM (Design forAssembly/Design for Manufacturability) Examples


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Examples of Custom Ranking Scales 67

No verification testing used.

GO/NOGO tests used to ensure dimensional requirements.

Partial functionality of prototype tested before release.

Full Alpha tests conducted; no Beta testing.

Untested computer model used to simulate product performance.

Accelerated life testing of final design before release; lab simulation.

Alpha and Beta testing used before release to ensure design meetsneeds.

Product tested for full functionality in customers application.

Finite element analysis to highlight stress concentrations requiringdesign changes early in the design stages.

Computer modeling to ensure form and fit of mating components.

ExampleRanking

10

9

8

7

6

5

4

3

2

1

Detection: DFMEA Custom Ranking, Simulations &Verification Testing Examples

In-service failure that threatens safety.

Extensive product recall.

Unscheduled engine removal.

Premature (unscheduled) component replacement.

Oil leak but system still operational.

Air-conditioning system not operating properly.

Interior panel rattles.

Variation in seat colors.

Door plugs missing.

Scratch on interior of housing.

ExampleRanking

10

9

8

7

6

5

4

3

2

1

Severity: PFMEA Custom Ranking, Customer SatisfactionExamples


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68 Appendix 4

Critical process equipment damaged and unusable ordestroyed.

ExampleRanking

10

9

8

7

6

54

3

2

1

Severity: PFMEA Custom Ranking, Operational Examples

ExampleRanking

10

9

8

7

65

4

3

2

1

Severity: PFMEA Custom Ranking, EH&S (Environmental,Health and Safety) Examples

Loss of customer due to late delivery.

Entire lot of top-level assembly product scrapped.

Full assembly line (or bottleneck operation) down morethan 1 week.

Rework full lot of top-level assemblies.

Scrap full lot of sub-level assemblies.Technical (engineering) resources required to get lineoperational.

Rework sub-level assemblies off-line.

Equipment down for more than 1 hour.

Engineering disposition.

Loss of life, serious injury.

Large hazardous material spill or release.

OSHA recordable injury.

Personnel exposure above PEL.

Moderate hazardous material spill or release.Fail internal ISO 14001 audit.

Injury requiring first aid.

Spill of nonhazardous material.

Minor (nonhazardous) coolant spill.

Poor housekeeping.


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1:2 events (or complex assemblies)

1:10

1:25

1:50

1:500

1:1,000

1:5,000

1:10,000

2.00

ExampleRanking

10

9

8

7

6

54

3

2

1

Occurrence: PFMEA Custom Ranking, Piece-BasedExamples


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70 Appendix 4

1 per occurrence per shift

1 per occurrence per day

1 per 2-3 days

1 per week

1 per month1 per quarter

1 per half-year

1 per year


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Does not apply.

No monitoring, measurement, or sampling.

Acceptable Quality Level (AQL) sampling plan used forFinal Inspection.

100% visual inspection.

100% visual inspection with visual standards.

Statistical Process Control (SPC) used in-process withCpk 1.33 or higher.

SPC used in-process with Cpk 1.67 or higher.

100% manually inspected using GO/NOGO gauges.

ExampleRanking

10

9

8

7

6

5

4

3

2

1

Detection (Control): PFMEA Custom Ranking, ManualDetection Examples

Does not apply.

ExampleRanking

10

9

8

7

6

5

4

3

2

1

Detection (Control): PFMEA Custom Ranking, GaugingExamples

Periodic Non Destructive Testing (NDT).

Periodic in-line variable gauging.

Periodic in-line GO/NOGO gauging.

In-line GO/NOGO gauge on all parts exiting process.

Automated inspection on first piece.

Dimensions of input materials confirmed with in-processaccept/reject gauging.

100% automated inspection of 100% of product.

Does not apply.


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73

Appendix 5

Process ImproementTechniques

Organizations have a wide variety o approaches to improvement available tothem once an improvement opportunity has been identied. Te improvementopportunities identied through an FMEA are no exception. Some eectivetechniques or ollowing through on identied opportunities are describedbriefy below.

Mistake Proofng

Mistake-proong techniques, when implemented properly, make it virtuallyimpossible to have a ailure. An excellent example o mistake-proong is a carthat will not start unless the clutch pedal is depressed. Tis prevents the car romlurching orward when it is started. Beore this was mistake-prooed, a drivercould try to start the car while it was in gear, causing it to jump orward intoother cars, objects, and even people.

Mistake-proong techniques include ways to make it impossible to makemistakes in both the manuacture and use o products. Limit switches, electriceyes, bar coding, and counting techniques can all be used to mistake-proo

processes and products.


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74 Appendix 5

Examples o mistake-proong we experience every day include the ollowing:

Electric heaters that turn o i they all overCar lights that shut o automaticallyOverwrite protection tabs on audio- and videotapes and computer disksIrons that shut o ater being unused or a set number o minutes

Automatic seat belts

Design o Experiments

Design o experiments (DOE) is a amily o statistical techniques that rst helpidentiy the key variables in a process and then determine the optimum process-ing parameters or the highest quality. Design o experiments is eective in bothcontinuous and discrete processes. DOE can be used in the product developmentstage as well.

Tere are many types o DOEs. Full actorials, ractional actorials, responsesurace methodology, and evolutionary operations (EVOP) are some. Perhapsthe most powerul type o DOE is the amily o extreme ractional actorial

designs called screening experiments.Using a screening experiment, it is possible to vary several process variables

at the same time and statistically determine which variables or combinationo variables have the greatest impact on the process outcomes. Once these keyvariables are known, the FMEA team can ocus its eorts just on these variables,saving time, eort, and money.

Statistical Process ControlStatistical process control (SPC), another statistical technique, is a tool that canbe used to monitor processes to make sure they have not changed or to comparethe output o a process to the specication. One SPC technique, control charting,enables operators to monitor key process variables and adjust the process when itchanges, beore it goes out o control and produces a bad product.

Te FMEA team can use control charts to get a real-time view o the process.When a ailure occurs in the process, the control charts will signal a change. Byquickly reacting to the signal, the team can work to nd the root cause o theailure beore the trail gets cold. Once the root cause is ound, mistake-proongcan be used to eliminate the ailure mode, taking the resulting RPN to essen-tially zero.


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Process Improvement Techniques 75

Team Problem Soling Using CI Tools

Many processes and products can be improved using basic continuousimprovement (CI) tools and the brain power o the improvement team. Basicwell-known improvement tools include brainstorming, fowcharting, data collec-tion and analysis, voting and ranking, Pareto analysis, cause-and-eect analysis,and action planning.


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77

Appendix 6

ISO/TS 16949RequirementsReerencing FMEAs

ISO/S 16949 is the quality standard or the automotive industry. It is based onISO 9000 and builds on QS-9000, which was the quality systems requirementoriginally developed by the Chrysler/Ford/General Motors Supplier QualityRequirements ask Force. Teir goal was to develop a undamental quality systemthat provides or continuous improvement, emphasizing deect prevention andthe reduction o waste in the supply chain. ISO/S 16949 incorporates a processapproach to the quality system requirements originally presented in QS-9000.

Te requirements o Section 7.3 o ISO/S 16949, Design and Develop-ment, include product and manuacturing process design and development. Testandard ocuses on error prevention rather than detection and species the useo FMEAs as part o this eort. Specic clauses citing use o FMEA include:

7.3.1.1 Multidisciplinary approach

Te organization shall use a multidisciplinary approach to prepare orproduct realization, including

- development/nalization and monitoring o special characteristics,- development and review o FMEAs, including actions to reduce

potential risks, and- development and review o control plans.


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78 Appendix 6

7.3.2.3 Special characteristics

Te organization shall identiy special characteristics [see 7.3.3 d)] and

- include all special characteristics in the control plan,- comply with customer-specied denitions and symbols, and- identiy process control documents including drawings, FMEAs,

control plans, and operator instructions with the customersspecial characteristic symbol or the organizations equivalentsymbol or notation to include those process steps that aectspecial characteristics.

Note: Special characteristics can include product characteristics andprocess parameters.

7.3.3.1 Product design outputsSupplemental

Te product design output shall be expressed in terms that can beveried and validated against product design input requirements.

Te product design output shall include

- design FMEA, reliability results,- product special characteristics and specications,- product error-proong, as appropriate,- product denition including drawings or mathematically based data,- product design reviews results, and- diagnostic guidelines where applicable.

7.3.3.2 Manuacturing process design output

Te manuacturing process design output shall be expressed in termsthat can be veried against manuacturing process design inputrequirements and validated.

Te manuacturing process design output shall include

- specications and drawings,- manuacturing process fow chart/layout,- manuacturing process FMEAs,- control plan (see 7.5.1.1),- work instructions,- process approval acceptance criteria,- data or quality, reliability, maintainability and measurability,


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ISO/TS 16949 Requirements Referencing FMEAs 79

- results o error-proong activities, as appropriate, and- methods o rapid detection and eedback o product/manuacturing

process nonconormities.

Section 7.5, Production and service provision, ocuses on the require-ment to plan and carry out production and services under controlled conditionsthrough use o a documented control plan. Reerences to FMEAs ollow:

7.5.1.1 Control plan

Te organization shall

- develop control plans (see annex A) at the system, subsystem,component and/or material level or the product supplied, includingthose or processes producing bulk materials as well as parts, and

- have a control plan or pre-launch and production that takes intoaccount the design FMEA and manuacturing process FMEAoutputs.

Te control plan shall

- list the controls used or the manuacturing process control,- include methods or monitoring o control exercised over special

characteristics (see 7.3.2.3) dened by both the customer and theorganization,

- include the customer-required inormation, i any, and- initiate the specied reaction plan (see 8.2.3.1) when the process

becomes unstable or not statistically capable.

Control plans shall be reviewed and updated when any change occurs

aecting product, manuacturing process, measurement, logistics,supply sources or FMEA (see 7.1.4).

Note: Section 7.1.4 relates to change control.

Reprinted rom ISO/TS 16949:2002 Manualwith permission o the InternationalAutomotive ask Force. For more inormation contact AIAG (www.aiag.org).


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81

Appendix 7

Alternatie FMEAWorksheets

Te Fourth Edition (2008) o the Potential Failure Mode and Eects AnalysisManual (by DaimlerChrysler, Ford and GM Supplier Quality Requirementsask Force) introduced alternative ormats or the Design FMEA and ProcessFMEA Worksheets. Alternative worksheets are included as able A7.1 (Alter-native Design FMEA Worksheet) and able A7.2 (Alternative Process FMEA

Worksheet) annotated with a brie explanation o the major (optional) changes.


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82 Appendix 7

DesignFailureModeandEffectsAnalysisWorksheet(AlternativeVersion:majorchangesnoted.)

Product:_________________________

ModelYear/Program:_____________________________

DFMEANumber:_____

__

DFMEA

CoreTeam:_________________________

DF

MEADate:(Original)___________________

T

eamLeader:_________________________

DesignResponsibility:___

__________________________

(Revised)__________________

_

Page:

of

DFME

AAnalysisResults

ActionResults

Cur

rentDesign

Item(Component)

andFu

nction

Requirement

Potential

Failure

Mode

Potential

E

ffect(s)

ofFailure

Severity

Classification

Potential

Cause(s)of

Failure

Current

Design

Controls,

Prevention

Current

Design

Controls,

Detection

Detection

RPNRecommended

Action

Responsibility

andTarget

Completion

Date

Action

Taken

and

Completion

Date

Severity

Occurrence

Detection

RPN

Occurence

TableA

.7.1

Alterna

tie

Design

FMEAWorkshee

t


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Alternative FMEA Worksheets 83

Process

FailureModeandEffectsAnalysisWorksheet(AlternativeVersion:majorchangesnoted.)

Process:_________________________

ModelYear/Program:_____________________________

PFMEANumber:_____

__

PFMEA

CoreTeam:_________________________

PF

MEADate:(Original)___________________

T

eamLeader:_________________________

ProcessResponsibility:___

__________________________

(Revised)__________________

_

Page:

of

PFMEAAnalysisResults

ActionResults

Curren

tProcess

ProcessStep

(Component)

and

Function

Requirement

Potential

Failure

Mode

Potential

Effect(s)

ofFa

ilure

Severity

Classification

Potential

Cause(s)of

Failure

Current

Controls,

Prevention

Current

Controls,

Detection

Detection

RPN

Recommended

Action

R

esponsibility

andTarget

Completion

Date

ActionTaken

and

Completion

Date

Severity

Occurrence

Detection

RPN

Occurence

TableA

.7.2

Alterna

tie

Proces

sFMEAWorkshee

t


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85

FMEA Glossary o Terms

AIAG: Automotive Industry Action Group.Design.o.experiments.(DOE): Series o statistical techniques used to intro-

duce controlled change into a process and to study the eect o thechange on the process outcomes.

Detection: FMEA ranking scale that denes the likelihood o detecting aailure or the eect o the ailure beore it occurs.

FMEA: Failure Mode and Eect Analysis. A systematic, structured approach

to process improvement in the design and process development stage.ISO.9000: International quality standards or product design, manuacture,

and distribution.Mistake-proofng: Making the process so robust that it cannot ail; also called

error-proong.Occurrence: FMEA ranking scale that denes the requency o a ailure mode.QS-9000: Automotive sector-specic quality requirements made optional with

the introduction o ISO/S 16949.Resulting.RPN: Risk priority number o a ailure mode and its corresponding

eects ater improvements.Risk.priority.number.(RPN): Risk priority number o a ailure mode and its

eects beore improvement.Severity: FMEA ranking scale that denes the seriousness and severity o the

eect o the ailure, should it occur.Statistical.process.control.(SPC): Statistical technique used to monitor pro-

cesses, usually involving the use o control charts.otal.RPN: Calculated by adding together all o the risk priority numbers or

an FMEA. Tis number alone is meaningless, but can serve as a gaugeto compare the revised total RPN once the recommended actions havebeen instituted.


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86 FMEA Glossary of Terms

S.16949: Also known as ISO/S 16949, this standard is based on ISO 9001but contains complementary automotive industry-specic require-

ments adding to the standard both a process orientation and a ocuson the customer.


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87

Index

AAerospace industry, 1

Aircrat engine manuacturer, 4Alternative worksheet, 8183

design FMEA worksheet, 82

process FMEA worksheet, 83Applications, seeUsesAutomotive industry, 1

BBlank FMEA worksheet, 24

Boundaries o reedom, 1517responsibility o management, 15scope, 16start-up worksheet, 17

Brainstorming, 13, 57ailure modes, 2526piggybacking o ideas, 57potential ailure modes, 42

round-robin approach, 57rules, 57team, 25

CCase study, 4147

brainstorm o potential ailure modes, 42calculation o resulting RPN as ailure

modes are reduced, 47

calculation o risk priority number or eachailure mode, 46

detection ranking or each ailure mode, 46eliminating or reducing high-risk ailure

modes, 47Fire Extinguisher FMEA eam, 41FMEA analysis worksheet, 4445FMEA team start-up worksheet, 43occurrence ranking or each ailure mode,

46potential eects o each ailure mode, 42prioritizing ailure modes or action, 47review o process, 4142severity ranking or each eect, 46team boundaries, 41

Chrysler/Ford/General Motors SupplierQuality Requirements ask Force,77

CI, seeContinuous improvement

Consensus-building techniques, 13Consensus-reaching tool, 60, see also Severity,

occurrence, and detectionrankings, reaching consensus on

Continuous improvement (CI), 75Customer

credit history, 50eect, 28obligation to, 50perspective on FMEA team, 11satisaction examples, ranking scales, 63, 67-specied symbols, 78

Custom ranking scales, examples o, 6371customer satisaction examples, 63design or assembly/design or

manuacturability examples, 66


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88 Index

design rule examples, 66environmental, health, and saety examples,

64, 68event-based occurrence examples, 69event-based ranking examples, 64gauging examples, 71manual detection examples, 71mistake-proong examples, 70

operational examples, 68piece-based examples, 65, 69simulation and verication testing

examples, 67time-based examples, 70

DDesign

occurrence evaluation criteria, 30scope worksheet, 20

severity evaluation criteria, 28worksheet, alternative, 82

Design o experiments (DOE), 74Detection rankings, seeSeverity, occurrence,

and detection rankings, reachingconsensus on

DOE, seeDesign o experiments

E

Environmental, health, and saety examples,ranking scales, 64, 68Event-based ranking examples, 64Evolutionary operations (EVOP), 74EVOP, seeEvolutionary operations

FFailure(s)

data collection on, 46detectability o, 38eects o, 46

Failure mode(s), 9brainstorming o, 2526, 42

calculation o risk priority number or, 36detection ranking or, 46high-risk, eliminating or reducing, 38, 47occurrence ranking or, 46Pareto diagram, 47potential eects or, 26, 42potential or, 39prioritizing o or action, 37, 47risk priority number or, 46

Failure Mode and Eect Analysis, seeFMEAFMEA (Failure Mode and Eect Analysis), 1, 3

common language, 49denition o, 1rst development o, 49history o, 1objective o, 9

GGlossary o terms, 8586

HHuman resources, 51

IIdea(s)

brainstorming, 26, 57categories, 26-generating techniques, 13piggybacking o, 57

Improvement opportunities, 73

International Automotive ask Force, 79ISO 9000, 4, 7ISO/S 16949, 4, 7ISO/S 16949 requirements reerencing

FMEAs, 7779

Chrysler/Ford/General Motors SupplierQuality Requirements ask Force,

77control plan, 79International Automotive ask Force, 79


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Index 89

manuacturing process design output,

7879

multidisciplinary approach, 77product design outputs, 78

QS-9000, 77

special characteristics, 78

LLAN, seeLocal area network

Local area network (LAN), 50

MMalcolm Baldrige National Quality Award, 4

Manuacturing saety FMEAs, 49

Marketing, 51

Mistake-proong techniques, 73

Models, quality systems, 4

OOccurrence, seeSeverity, occurrence, and

detection rankings, reaching

consensus on

PPareto diagram

ailure modes, 47

rankings, 37

Piece-based examples, 65

Potential Failure Mode and Eects Analysis

Manual, 81

Printed circuit board manuacturer, 5

Process, 910

assessing risk priority number, 10denition, 16

documentation, 23

elements o, 20

evaluating risk o ailure, 10

expertinvolvement o, 60role o, 1213

actors determining risk o ailure, 10FMEAs, seeProduct/design versus process

FMEAsmanuacturing chain, 16problems, 20review o, 25, 4142scope worksheet, 21severity evaluation criteria, 29worksheet, alternative, 83

Process fowchart, creation o, 5355

best way to create fowchart, 53fowchart symbols, 54symbols assigned, 53top-down fowchart, 53, 55

Process improvement techniques, 7375continuous improvement, 75design o experiments, 74evolutionary operations, 74improvement opportunities, 73mistake proong, 7374

statistical process control, 74team problem solving using CI tools, 75

Productblueprint, 25ailure, 9review o, 25

Product/design versus process FMEAs, 1921design FMEA scope worksheet, 20examples o problems, 19process, 2021

process elements, 20process FMEA scope worksheet, 21product/design, 19ranking scales, 21

Purchasing, 51Purpose o FMEA, 35

bottom-line results, 45comprehensive quality system, 34examples, 45ailure modes, 3ISO 9000, 4

ISO/S 16949, 4Malcolm Baldrige National Quality

Award, 4models or quality systems, 4training session, 5


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90 Index

QQS-9000, 77

RRank failures, 60

Ranking scales, see Custom ranking scales,

examples of

Risk priority number (RPN), 10

calculation of for each failure mode, 36

calculation of as failure modes are

reduced, 3839, 47

resulting, 10

RPN, see Risk priority number

SScreening experiments, 74

Severity, occurrence, and detection rankings,reaching consensus on, 5961

consensus-reaching tool, 60

deerring to team member, 60

getting process expert involved, 60

mean ranking, 59

rank ailures and eects within ranking

category, 60

talking it out, 61

team voting, 5960

use o higher ranking, 61Sotware quality assurance, 50

SPC, seeStatistical process control

Start-up worksheet, 17

Statistical process control (SPC), 74

Steps, 2339

assigning severity, occurrence, and

detection rankings, 2636

Band-Aid approaches, 38

blank FMEA worksheet, 24

brainstorming o potential ailure modes,2526

calculation o resulting RPN as ailure

modes are reduced, 3839

calculation o risk priority number oreach ailure mode, 36

communication tool, 23design FMEA occurrence evaluation

criteria, 30design FMEA prevention/detection

evaluation criteria, 3233design FMEA severity evaluation criteria,

28detection ranking, 35eliminating or reducing high-risk ailure

modes, 38generic ranking system, 27

idea categories, 26list o, 23numbering system, 25occurrence ranking, 35Pareto diagram o rankings, 37partially completed FMEA worksheet, 27potential eects or each ailure mode, 26prioritizing o ailure modes or action, 37process documentation, 23process FMEA detection evaluation

criteria, 3435process FMEA occurrence evaluation

criteria, 31process FMEA severity evaluation criteria,

29product blueprint, 25review o process o product, 25severity ranking, 31specic actions to reduce rankings, 39worksheet, 23

Team, 1113

brainstorming, 13consensus-building techniques, 13customer perspective, 11disagreements, 59emotionally invested people, 12

idea-generating techniques, 13role o process expert, 1213team leader, 12team membership, 12


102/104

Index 91

team size, 11training, 13voting, 5960

elecommunication systems, 50op-down fowchart, 53, 55

UUses, 4952

accounting/nance, 50human resources, 51

inormation systems/technology, 50local area network, 50manuacturing saety FMEAs, 49marketing, 51purchasing, 51saety, 4950

sotware design, 50

telecommunication systems, 50

WWorksheet(s)

alternative, 8183

design FMEA worksheet, 82

process FMEA worksheet, 83

blank, 24

design FMEA scope worksheet, 20FMEA analysis worksheet, 4445

FMEA team start-up worksheet, 43

partially completed FMEA worksheet, 27

process FMEA scope worksheet, 21

start-up, 17


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basics of fmea book

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