fmea fta reliability

Upload: yashar2500

Post on 02-Jun-2018

232 views

Category:

Documents


0 download

TRANSCRIPT

  • 8/10/2019 FMEA FTA Reliability

    1/76

    TAun

    )srl',

    Q

    crolo"'-

    UNIVERSITYF

    WOLVERHAMPTON

    i .

    lee{o't'4--

    School f Engineeringnd he

    Built

    Environment

    ; , i

    t - l - .

    / \ t

    -

    l-- ' '

    BCI{TECTUNE

    ANO FNODUCT OggION

    ET3008

    Colloborative

    esign

    Module uide

    @Th6Univsrsilyol Wolverhamplon

    Schoolor

    ngineeing nd

    is

    BuiltEnvircnmenl

    ModulsGuide

    006-07

    10la

  • 8/10/2019 FMEA FTA Reliability

    2/76

    Module

    uide

    t{oduleTitler

    CollaborotiveDesign

    i{odule

    Code: ET3008

    Pre-requisites: ETZOO3

    r CV2009 r

    CN20O3

    Co-requisit"si None

    Semaster/Acadenic

    eorr

    Semester 2@7/Og

    credii

    Voluer

    15

    Level

    of study:

    li\oduleLeadcr:

    6rohan Ooks

    Phoner

    +4419Q2

    ?3888

    Foxr

    +441902

    322754

    E-moiL [email protected]

    Internal Aioderotorr K?vin

    arnr

    1 Rolionole

    The

    principol

    im of

    ihis

    module

    s

    to

    provide

    underslanding

    nd

    knowledge

    f the

    principles

    f Colloboroliveesign.

    his

    ncludes

    he

    opplicoiion

    f ossociated

    omputer osed

    ools ond

    methodologies

    reloted o distributed esign evelopmant.hemodule ims o review

    modern

    oycpproaches

    o New

    Product

    Development

    nd

    nnovotion. he

    module

    ill

    provide

    ihorough

    nsighto the complex

    ssues

    urrounding

    3

    Dimensional

    AD

    Dato

    Exchcnge, esign

    eoms

    nd

    mportontlyn

    -

    todoy's

    ncreosinglyitigious ociety,Design

    ssunonce.

    2

    Leorning

    ouicomes

    By

    successfulompletion

    f the moduletudentswill

    be oble o showr

    @Th6 niveGilyl Wolvrhampton

    Schoolol

    Enginee gand he

    BuihEnvironmenl

    Moduls uide

    006-07

    2alA

  • 8/10/2019 FMEA FTA Reliability

    3/76

    2.1

    Krowledge

    ndUnderstohdihg

    KU)

    1

    The

    woy

    in

    which

    Quolity

    Assurqnce

    echniques

    nfluence he

    design

    rocess

    nd

    how hey

    might

    be oppliedo evoluote

    esign

    solutions.

    2 Fociors thot need to be drown into the desiqn

    developmeni/reolisotion

    rocess.

    2.2 SubjecfSpecificSkills

    sss)

    1

    Dehonstrote

    qn qworeness

    f rnonogemeni/enterPrise

    ssues

    within

    he Design

    nvironment

    2.3 IntellcctuolSkills

    I5)

    2.4 Keyskills

    Ks).

    1 Communicoie

    Showobility o discuss

    ncludingisfening nd

    receiving:e oble o moke

    presenioiion,

    o reqdond o write.

    2 Workwith others

    be oble1o

    plon

    wofk,work owords

    bjeciives,

    reviewwork

    3

    Wcckly

    opic

    aulde

    (Pleos

    oie

    hot onoccosion

    t

    moy

    necessdry

    o omendhe schedule)

    oThe University J

    wolverhampion

    SchoololEngineerngnd h

    Bu t Environmenl

    Module ulde 006-07

    W..k

    No

    WG.k

    conncncinq

    Indicotiv.ModulcProgromm.

    1 ?4'^Sept07 fniroduction

    o

    nodule

    Foilure

    Modes

    qnd

    Effects

    Anolysis nd Fouli

    Tree

    Anolysis

    ncluding

    pplicotions

    o typicol design

    situotions.

    1'rOcI 07 f ntroductiono

    Reliobility

    3 I'h oct 07

    RiskAnolysis

    n

    he collaborqtive

    nvironment

    15'h ct 07

    f

    nclusive esiqn

    ndSusioinobility

    5

    22nnOd 07 6eneric

    roduct

    iobility

    29th

    oct

    07 Thedesiqner'sesponsibility ith

    cose tudies.

    7

    5'h Nov 07

    Borrierso communicotion.

    The

    voice

    f the customer.

    Quolity

    equiraments

    'filness

    for

    purpose"

    8 12rhNov 07 Exqminoiionnto he stroteqic role of CAD.

    3ofB

  • 8/10/2019 FMEA FTA Reliability

    4/76

    9

    19th

    Nov

    07

    Desion

    ocurnentotion

    nd

    ocilities

    monoqement.

    10

    26ih

    Nov

    07

    Investigotion

    nio

    ihe use of Disiribuied snd

    Colloborqtiveesiqn

    11 3'd

    Dec

    07 Computer

    qseddesiqn

    knowledqe

    ystems

    12 101h

    ec

    07

    The

    New ProductDeveloDment

    rocess

    nd

    Electronic

    Doto Exchonoe

    Christmos

    ocotion

    3 weeks

    7rh

    Jon

    08

    Finol

    ummotive

    ssessnent

    or

    semester

    14 14th

    qn

    08

    Morkinq

    Week

    15

    z - Jon 08

    Feedbock

    ndocodemic dviceweek

    You shouldolso efer to the

    Acodemic olendor

    or furiher

    informoiion

    n

    teqching

    ndossessmenieeksi

    hitpr,/,/qsp2.wlv.oc.uk/webteom/obout/uninf

    /req-qco-cql0708.doc

    4 SpcciolistRcsourccs

    School

    rovidcd)

    WoLF

    qnd

    appropriote

    ofiwore,

    or

    exomple

    but

    nol exclusively)

    utocAD.

    5 Spcciolisi

    Rgsources

    Studcniprovided

    with cost

    ndicoted)

    None

    6 Indicotiv. Rcodirg ndL?orhingupportList

    DIETEP

    G E, Engineering

    esign,McarowHill.

    CATHER , MORRISS

    , PHILIPM,

    ROSE

    C. Design ngineering

    ulterworth

    Heinemonn

    RIBBENS,

    .

    (2000)

    Sinultaneous ngineeringor

    NewProductDevelopnenf.

    JohnWiley

    Sonsnc.

    O'CONNER,

    .

    2OO2)

    ractical

    el

    abilityEngineering.ohnWiley

    ondsons

    Ltd,

    SKALAK,S.

    (2OOZ)

    nplenenting Concuffenl Engineering

    n

    Snall Conpanies.

    MorcelDekker

    td

    LEE,K.

    1999\

    Principles

    f

    CAD/CAtuI/CAE

    ysfens,

    Addison

    Wesley

    WRI6HT,

    L

    (Morch

    1998)

    Design Uethods

    n

    Engineering

    nd Product Design.

    Mc6row-Hill

    ublishingo.

    Sludv Skills

    TiDs voilobleo downloodrohl

    httpi//osp.wlv.oc.uk/Level3.osp?UserTvpe=6&Level3=542

    subjeci specific resource

    nformo+ion onolsobe

    fouhd

    ot the Subject Storting Pointl

    httD://osD-wlv-oc.uk/Level4.osD2UserTvDe=4dLevel4=683

    OTheUniversity

    f Wolvefiampton

    SchoololEngneer

    g

    and

    heBuiltEnvimnmonl

    Modute uide 006-07

  • 8/10/2019 FMEA FTA Reliability

    5/76

    7 Teochingond Ledrning

    {eihods

    The Schoolof Et\gineering

    nd the

    Built

    Environmenf's

    eochingond eorning

    philosophy

    s io develophe whole

    fudeni

    .e.

    o

    provide ou

    with

    chollenging

    ociivities

    qnd

    ossignnenishot require

    ou

    o develop nd

    hprove killsos well

    os ncreqsenowledgendunderstondingf yoursubjectspeciolistn.

    This

    volue-odded

    pproochmeons

    hot

    you

    need o be

    provided

    wiih

    the

    opportunityo develop

    kills hrough he noture

    onddesign f ihe cosestudy.

    The lecture

    progrommes designedo bridge he

    gop

    between

    our

    current

    knowledge,nderstonding

    nd

    evelof skillsond hose equired

    y

    q

    designern

    your

    hosen

    rofession.

    Tutoriqls,

    procficols

    snd seminor

    octivity will

    involve ou in investigofions,

    presentotions,iscussionsnd/or exercises

    n set topicsond noy

    nvolve elf

    qnd

    peer

    ossessment.

    Thisopproochees he leorning Eeds5 he focusof the leorning ctivitywith

    the understonding

    hot

    you

    will

    needo tokeonsomeesponsibilityor

    your

    own

    leorning.

    8 Asscssmnt

    8.1 ,{elhods

    ord

    Weightiirgsr

    Cohponent

    ,Assignmeniosed pon'Design

    ssuronce'oPics

    component

    , Assignnent osedupon New

    product

    ntroduction/definitionnd

    CADdotoboses

    8-2

    Asscssment

    DESCRIPTION

    KU

    K5

    2

    F

    -

    D

    tr

    >

    SUBIAISSION

    \ryEEK

    1

    Componenl

    1

    Individuol echnicolreport on

    o selecteddesign

    ollfion sing

    oppropriote

    techhiqus

    for

    ossuring esign ompliohce

    nd

    fitness or

    purpose

    I

    1

    I

    50'?6

    Conpohent

    Prociicol ossessmen+

    bosed

    eilher on Dolo Exchonge

    or

    Doto

    Attribltes. 6roup reporf

    with

    ihdividuol riliques.

    I

    50%

    10

    @TheUniveBity

    of Wolvehampton

    School i EnglnBing

    nd he BulltEnvironmenl

    Module uide 006-07

    5or8

  • 8/10/2019 FMEA FTA Reliability

    6/76

    To

    poss

    he module

    ou

    must

    qchieve

    minimum

    rode

    f

    D5 or

    ggqb

    otnponenl

    of ossessment.

    Key

    o

    Leorning

    utcomes:

    KU . KnowledgendUnderstonding

    SSS

    =

    Subject peciflc kil ls

    15

    =

    Ihtellectuolki l ls

    Ks

    =

    Key

    kil ls

    8.3 lilorking

    Critrio

    Full detoils

    of the

    morking

    criteriq will

    be issued

    to

    you

    qs

    port

    of fhe

    ossignmeht rief ot the

    slort of the module.

    8.4 Subnission

    of Coursework

    ThEossignmentshouldbe hondedn qt the City Compus tudenf Registry

    (MI

    024) ondo receipt

    obtoined.

    8.5

    Exi?nsiohs

    Extensionswill

    onlybe ollowed

    n exceptionol ircumstonces nd

    you

    nust

    hoveo

    volid couse

    (normolly

    covered.

    for

    exomple,

    by

    o medicol cerfificoie),

    Applicotions

    or

    exfensions eed o be hode using he stqndord

    orm

    obtoinoble

    from

    heCityCompustudent

    egisiry,

    tu\Io24).

    Assignm?nisubmitlcd

    ote withoui

    q

    sqnctionedxtension ill be norkcd

    FN

    ff

    you

    ore

    unobleo submit

    our

    work

    by fhe deodlina r wiihin onyExtension

    gronted;

    or

    if

    you

    consider

    our

    perfornonce

    hos been offected by some

    exceptionql circumstonces

    you

    should consider

    opplying

    for

    Exienuoting/Mitigoting

    ircumsionces.

    n

    suchcqses

    ou

    should onsult

    our

    Personoluior or o

    University ounsellor

    or

    odvice.

    8.6

    Returnof Coursewor.k

    The

    pink

    copy

    of ihe Student

    Assessmenl

    orm will

    nornrolly e reiurned

    o you

    within hree working

    weeks. tudentwork

    s not normollyeturnedond

    you

    ore

    odvisedo keep ourownhordondsoft copy f onyworksubhitted.

    8-7 Retrievol f Failure

    The

    etrievol

    pportunity

    or

    exohinotionsn this

    module ill

    be duringweek

    conmencrnoJ

    urv uuo.

    Retrievolwork reloting

    o ossignments ust be token

    qt

    the next

    ovoiloble

    opportunity. For setnester

    ne rnodulesesit work shouldbe honded

    n by

    Fridoy

    14th

    Morch

    2008.

    For

    semesterwo

    modules

    esit

    work

    should e honded

    in

    by Fridoy

    11th

    uly

    2008.

    OThUniversity

    i Wolvedampton

    Schooot Enginer

    gand heBuiltEnvimnmenl

    Module uide 006-07

    6 ol8

  • 8/10/2019 FMEA FTA Reliability

    7/76

    Retrievol

    work

    reloiing to

    ossignmenis ill

    be

    posted

    n WOLF,under he topic

    SEBEStudentNoiice

    boord.

    f

    you

    choose ot o toke his

    opportunity

    ou

    will

    be required

    o retoke the wholemodule

    t the

    next opporlunily.

    you

    ore

    odvised o discuss

    our

    retrievol oplionswith

    your

    Personol

    uior.

    Regulotions

    overning

    elrievol

    of

    foilure

    vory depending

    on

    your

    oword,

    in

    porticuloruponwhetheryou ore studying or o degreeor o highernotionol

    quqlificotion.

    Pleose efer

    to

    your

    Course

    Guideor the Undergroduote tudenf

    Hondbook

    007108.

    Student

    Conduclond

    Behoviour

    Students

    ore expecled

    o complywith ihe

    SEBE tudenf Code

    or

    Bahoviour

    ond

    Attendonce.

    his s

    published

    nWOLF

    SEBE

    tudentNotice

    oord) nd

    on the school otice

    boords. tudents

    who do noi conduct

    hemselves

    n

    qccordonce

    ith hiscode

    ndwho redisruptive

    n closs

    moy

    eexcluded

    rom

    ihe module

    nd

    moy

    esubleci

    o lhe Universilyf Wolverhompton

    isciPlinory

    procedures.

    9.1

    Altsndqnce

    n Closs

    fn the

    interestof courtesy

    o

    fellow

    students

    nd

    stoff, students re r?minded

    ihot

    it is

    expected

    hey will be

    puncfuol

    norrivolot clqss

    nd

    n

    good

    ime

    for

    the

    beginningf the

    ecture.

    9.2

    obilcPhones

    fn the interest of courtesyo fellowstudentsqndstoff Pleose nsure hqt

    mobile

    hones

    re switched

    ff during ectures nd tutoriol

    closses. n

    exceptionolircumstonces

    he module

    eoder

    qy

    ollow

    ndividuol

    hones

    o be

    kept

    on

    if

    o volid eoson

    s

    given.Anystudent

    who

    considershey

    hqve

    o

    volid

    reosonmust

    discusshis wiih

    the lecturer

    rior

    o the lecture iofting.

    f

    permission

    s

    gronted

    he

    phonehould e

    put n

    o'silent ode'.

    9.3

    Plogiorismnd

    Collusion

    Plogiorism

    ndcollusion

    re

    veryserious ffenceshot

    con esult

    n

    expulsion

    from

    he

    Universiiy.

    his s becousehose

    ound

    uilty

    f

    plogiorism

    r collusion

    will

    not onlyhove itenpted o rapresent orneonelsesworkos heir ownbut

    hqve lso oughto

    gqin

    nunfoircdvqntqge

    ver heir

    fellow

    students.

    9.3.1

    Avoidinglogiorismnd

    Collusion

    1. In the coseof

    group

    work

    you

    ore ocfively

    encourogedo work

    n o teom.

    Howevet

    he sections

    f the ossignment

    hot

    you

    onswer nusibe

    your

    own

    individuol

    ork.

    2. You hould oke

    t verycleorwhot

    sourcesf

    inforhqtion ove een sed;

    whercmolerial/informotion

    rom

    hese

    sourcess

    quofed t

    musl

    be

    cleorly

    referenced sing he HqrvordReferencingystem.Detoils onbe obtoined

    OThUn

    v6ilyoi Wolverhamplon

    schooloiEnginesring

    nd heBuiltEnvironment

    Mod leGuide 006-07

  • 8/10/2019 FMEA FTA Reliability

    8/76

    from

    Leorning

    Cenlres

    or on-linevio the LeorningCentre Home

    Poget

    http://qsp.wlv.oc.uk/Level5.osp?UserTypc4&Level5:3

    65).

    3. Neverotiehpt to copy

    r

    porophrose

    nother tudenfswork.

    9-4 The StudentVoic

    The involvehenfof students

    n

    lhe

    qssessment

    f course

    quolity

    is

    on

    esloblished

    ori

    of ihe

    University's

    rocedures.he

    Students'

    Union nd

    your

    Pothwoy

    eoders

    will

    be

    qble

    o tell

    you

    obout he representotiveoles

    qvqiloble

    io students

    nd

    he communicotion

    rocesses

    n

    he

    School. hese re

    mportont

    roles hot benefit

    you

    ondother studenls.Further

    nformotion bouistudent

    representotion

    nd the

    Student Voice

    s

    svqiloble

    t

    the Sfudents'

    Union

    websiter

    10 R"glstrqllon

    you

    ore reminded

    hot only

    students who hove

    formolly

    registered

    os

    porticipants

    no

    module

    illbe oble o

    goin

    redits. tudenis re resPonsible

    for

    checking ndomending

    heir |noduleegistrofion

    fotuseither ihroughe-

    vision,

    r the Studenf

    Registry,

    1l CourseHqndbook

    ndAcodemic egulollons

    or

    sfudcnls

    This

    module

    uide

    hould e reod

    n

    conjunctionith

    he termsond onditions

    contoined

    n

    your'course

    6uide'ond he

    University'sUndergroduoietudent

    Hondbookor

    StudEnts

    OOT/08.

    12 Module

    qrliclponls

    l{odulcLeodcr:

    Nomc

    GrqhqmOskes

    Universily f Wolverhompton

    Phoner

    +441902

    323888

    Foxr

    +441902

    22754

    E-moil:

    [email protected]

    OThUnive6ity

    of Wolvefiamplon

    SchooloJ nginering

    nd heBuiltEnvimnmenl

    [,rodure u]de 006-07

    8 018

  • 8/10/2019 FMEA FTA Reliability

    9/76

    Pca*:t

    ,

    J .*

    |

    IJNIVERSITY

    OF

    WOL 'EREAMPTON

    SEBE

    Department

    f

    Architecture

    fld

    Product

    Design

    ASSIGNMENI

    I

    -

    Individual

    wirh r6Dect

    ro the

    hct that

    ;ciety

    is

    grsduallymoving owards

    a more

    itigious

    *"itontti.*,

    legislation

    n

    the United

    Kingdom

    and he

    European

    canomic0ornmunity

    *ouU

    impo.e

    s-euere

    enalties n

    companies

    rising

    rom design

    errors

    and defects

    In order

    o

    meet his

    challenge

    ompalies

    ned o

    identify

    potential ources

    fhilue

    in

    theirproductsand use his infonnationn a design ssurance

    ense

    L

    With rdpeot

    to

    the above,

    rom a team

    collaborative

    esign

    oint

    ofview,

    disclss

    the

    ollowing

    eohniques

    f

    hazard

    nalysis:

    1.3FaultTreeArlabsis.

    Yourarrwers

    o 1.2and

    1.3should

    nclude

    nanalysis

    fa domstic

    pplisncd

    DIY

    dornestio

    roducl hat

    you

    are amiliar

    with c.g.

    microwave ve4

    hedge

    trinrner.

    2.

    Discuss

    ow the

    ollowing

    opics

    woutdbe considered

    ndaddressed

    n

    your

    ohosen

    roduct:

    2.1 Reliability,

    2.2Safery.

    Use

    diagrams

    ndor

    sketches

    o illustrate

    our

    answer.

    Assi$ment

    weighting

    =

    50%

    Issuedat;

    4' October

    2007

    Hand n date:

    23d

    November

    007

    1.1

    Preliminsry

    azard

    t1"ir.rr/

    /

    i

    1,ffi",T"1

    Ir

    I,,",",/

  • 8/10/2019 FMEA FTA Reliability

    10/76

    a ,J uNtvERslrY

    F

    V\VI WOLVERHAMPTON

    s"rroftt

    r

    elgin"edng

    nd

    he

    Built

    nvironment

    ASSESSMENT

    RIEF

    ModulTitler

    COLLABORATIVEDESIGN

    Module

    ode:

    ET3008

    ComDonnt I

    ^r

    t

    Element

    Not

    il;6;;

    Numbefl

    appllcabr

    Wiqhting:

    50%

    component

    Failuro

    Modes

    nd

    E fects

    Analysi3,

    autt

    ru'

    Analysb'

    Rrliablllty

    End

    Safety

    Leaming utc.omeso b6assessd:

    Knowledge

    nd

    unde6tanding

    fi

    Th

    way

    n whlchQuallty

    ssurance

    echnlques

    nfluenc

    hsdslgn

    rocess

    nd

    how

    heymlght

    e

    eppliedo

    evluate

    esignollllons

    Faclors

    hatneod

    o be

    drswnnto

    hsdslgn

    evElopm9nurosllstlon

    pocess.

    aubjectpclfickllls:

    Demonstrate

    n awarensss

    f managsmenuentrpr lse

    ssues

    ithinhe

    design

    nvlronment

    KeY

    Skillsl

    Communicate

    show

    bilityo dlscuss

    ncludlng

    lsteningnd ecelvlng;

    e

    abl o mako

    presentatlon'o rad nd

    owrits

    Llarking

    rltefia:

    leas

    eferto

    ttached

    het

    o ThUnlv.Elty ol Wolv.rhampton

    school f Engineedng

    nd tho BuiltEnvkonmonl

    School

    6366mnt

    andbook

  • 8/10/2019 FMEA FTA Reliability

    11/76

    Hazard

    nalysis

    a

    genel broad

    ntrcduction

    o hazard

    nalysrs

    AoDlication

    f

    FIVIEA

    nd

    FTA

    methodologies

    0 he

    chosen

    roducl

    How

    Reliabilily

    ssues

    ave

    been

    onsidered

    n the

    chosen

    Product

    g

    choice

    f

    ."asuiemeniunits;

    cvcles'

    ou|s.

    and

    method

    f testing

    or

    Reliability

    How

    Safety

    ssues

    ave

    been

    considered

    n

    he chosen

    roduct

    g

    rflethods

    f

    safety

    assessmentnd esting-

    Th6

    minimum

    ass

    malkforthls

    omponenl

    s

    D5

    Assignment

    anded

    ut:

    4tnoc{ober

    007

    Latest

    ate

    or

    submissioh:

    23'd

    November

    007

    Assignmenb

    ubmitted

    frer

    h.

    deadlne

    ndwthout

    n

    allhorised

    'xtnslon

    oftime

    willbe

    maR6dF0

    Please

    mark

    your

    assignment

    or

    the

    aftentlon

    of: Graham

    Oakes

    SEBE

    Room

    tA109b

    You holld

    make

    vry

    arwhatsources

    lintotmation

    ave

    en

    Eediwhra

    'lrlal/lnformalion

    iom.

    h's

    i.',i,JiJ-rj

    r"tii

    i,"i,t u..rearty

    6fe,enc.d

    .rns

    heHaruard

    efer.ncrns

    Frem.

    D.tallEcan

    obtain.d

    rom

    The

    assignm6nt

    usl

    be handed

    n o

    studnt

    Registry'

    Ml Block

    City

    campus'

    A

    signed

    eceipt

    ust

    e

    obtained

    hen

    heassignments

    resubmitted

    oushould

    eep

    your.receiptn

    a saf

    Place.

    Youare

    advised

    o

    keep

    our

    wn

    electronic

    hard'

    opy

    f anywork

    ubmltted'

    Comments

    Thiswork

    s

    echnical

    n content

    nd hould

    esuitably

    onstructed

    nd

    presented'

    The

    SEBE ord

    ariffforthis

    ype

    of assessment

    ndweighting

    s approximately

    000

    *orai. wnicn

    mav

    oe

    enhanc;d

    y he

    nclusion

    ftechnical

    eviews'

    ews

    lippings'

    caiestudlesnd-oiagrams

    ll

    ofwhich

    hould e

    clearlyeferenced,

    itld

    nddiscussed

    in

    youf

    main

    oxt,

    o the Unive6ity fWoLverhamPlon

    school

    f Engineeing

    nd

    he81]ilt

    nvironment

    school

    ssessmen

    andbook

  • 8/10/2019 FMEA FTA Reliability

    12/76

    ATl

    t>e

    i-

    School

    f Engineering

    nd

    heBuilt

    Environment

    ASSESSMENTBRIEF

    '

    ,

    I te'r

    '

    '-'v_J'

    Module

    Trtle:

    Collabor.tive

    llesign

    Module odo:

    E

    3006

    Componenl

    umbe[

    2 of 2

    Weighling:50%

    CAD

    Cu3tomi.ation/Exlraction

    Leaming

    Outcomeso

    be sssessed

    y his

    component.

    Knowlcdge

    md U lerrtrndhg

    of:

    Fecto$ lil

    noed o bedrawl

    imo hedesign

    evelopmeltEalisatiotl

    ocess'

    SubictSoccifDc

    ldll :

    o.doostria ao

    "tartoos

    ofnanagemcs/elrsFisessucswithio trcDesiSnovilonmel|l

    Ker Sldllr:

    WJrk witn orhers

    be

    ablc10

    plan

    wodq

    work

    owsrds

    bjectives,

    eview

    wo*'

    Ma*ing

    Crited$

    Assignment

    andcd

    uti

    Lat6t

    dat

    for lubmisaion:

    fta assiEmdl

    brief

    hasbad

    esiS d

    o

    Fovidr

    a

    patbwsy

    o acbicviry

    a succcsfil

    $bmission

    anA ou

    are

    atvisea

    o urtte

    lbc assigrunq[

    thcordet

    a wNch

    t

    is

    pr$d'd ThassigrmFnt

    Joria conoeocc

    wio anover

    architrg

    ssig&rnt

    lEoducriotr

    trdcoDclude

    it'hbdlel

    point

    conilusions

    nd

    bibliography/tcfctEoces

    vidence fbockgrould

    eadiry?Id

    rrratchwill bc

    UNIVERSITY

    F

    WOLVERHAMPTON

    Element

    \t

    Bl6c

    \.

    UIl\

    \),-+-

    )

    jl

    , (

    r--I

    tootea

    oratong io

    6c uo

    of CAD

    basc (aluplcs

    3 ogql"d

    tiftnt the

    s8lun.[t

    M

    Thc

    miniil|ln

    pa35

    at for hir

    coaDonelt

    s

    D5

    1a1012007

    i

    R6poti

    0,U01/200t

    Extraclion

    ,Vitnssslng

    3/l ,07

    &signncots

    tmitted

    afrr

    hedcadlirc

    nd

    withour

    nauthorised

    xrasion

    f irne

    will be

    n rtd m.

    Plerse

    mad(

    your

    a$ignmcnt

    fot

    lhe attsntion

    of:

    Kevin

    Gamcr

    Youslrculd

    kc t very lcsr

    what

    ources

    fidonnatiotr

    avc e' ured;

    wbrr

    *"tetiaviofo.nxion

    6-

    thcs ourcs

    s

    quotedt m sIbccle$ty

    Eferncd

    sing

    heHarvard

    RfeEncing)61en.

    Details

    atr obtained

    oE l,emitrg

    anrca)

    Th. asaignment

    must

    be

    handad

    n to the

    City

    clmpu3 Rogislry.

    A signed

    eceipt

    usl e

    obtained

    hen

    he

    assignments

    rasubmK{ed'

    You

    shoutd

    koep

    your

    teceipt

    n a aaf

    plac.

    Youareadvisod

    o

    keop

    our

    o\,rn lectronic

    hatd'

    copyof any

    vork

    ubmittedExensions

    willnot

    bs

    given

    or ost

    iectonic

    ata.

    Make egllar

    acJ(ups

    f

    your

    work

    (r.""."\

    zz

    I

  • 8/10/2019 FMEA FTA Reliability

    13/76

    Co[aborrtive

    De.ign

    (AlsigEnenr

    2

    -

    weight'

    g

    50'/')

    iln Crr.io.it"tio"olttrrrctiotr

    40olo'lndMdu'l

    Rcpo

    60%

    I$ue dat:18[0n

    07

    Ernd-in dde:

    04/01/2108

    Enraction

    witnesring:

    13n2l2007

    *HJ""["il*

    *"

    *0"

    partof lhis

    assignnet[

    equircs

    ou

    o

    iavestiSate

    ow-datacootained

    ithin

    a

    cAD

    jiii*T"ia."6-*iL

    u.

    ._i"".a

    atrd

    urilised

    wilhitr-third

    any

    sosq,sre

    uch

    wordProcssoE.

    ;";;:IffJt

    Ddb"*

    sl$ems

    The

    ndividust

    wort

    roquited

    ot he

    assignmeol

    sbascd

    n a

    wntrn

    repon

    iJc',t"J on

    u.

    moe

    e".t"l

    3D softI

    deBiled

    clow

    Attdbute

    Enr*tion

    fiill""i',ilitJleo

    g(radion

    Trlorial

    vou

    are

    a5I

    psir' rcquired

    o

    desiSn

    I9'r

    o:a

    9ta

    extractios

    aDDlicatioD.

    ou

    ar

    adviscd

    o slecr

    muhrary;6ufie

    appliication

    hiO

    uitlses

    dda

    tb6.you

    at

    amiliar

    :lin"J;;

    il;reiiil]

    *uult"

    *iutio

    ot

    tit*

    "outaintior

    ue assignrnent-

    [1e

    eduret

    n ibarse

    musl

    hH";ifft;;;ril;r-taot *'r cotii""t rl" e*tracteaaaooutoe input nd

    ilised

    na

    word

    Processor.

    ao

    Base

    r SprEadshel

    ppucauon

    hichever

    s apprDpriate

    o

    the&ta

    being

    manipdded

    On

    completion

    f

    your

    4plication

    please osrt

    hal

    vour

    work

    s wiflcsscd

    I 3/12/07)

    ndsigncd

    ff by

    rhe

    ldurer

    n cbatge

    Questiooing

    "bour

    tht

    ptoosi

    -;l'Eke

    place

    t

    hiljunc{ure

    and

    his

    wiu inform

    rdividual

    omdas.

    his

    sction

    f

    thc

    ^,"orn*'-o"'-"'

    *itb rtre

    n'Unission

    f

    a

    oinr

    overvirs'

    ofthe

    A tocAD

    ixEaction

    Proc.ss

    ncluding

    utoCAD

    prou Jth

    AITDISp

    ta

    to

    oo"

    td

    "of,

    -d

    a com$enl,Iv

    expLiniry

    ilffi;;;;--*"n;8h

    bsrc;n

    dre

    Foduaivitv

    of an

    er[c(Fise

    Individ;d

    Rport

    Con.borrtive

    Dc'lgt

    Tool

    Mobeiswlrroo$ rorirsrD"Tll::-Hfl

    JH

    H,m"S"*T,

    #ffi

    i"jm*.

    web+asd

    ocuenls

    With

    rooetrt

    crc8 s

    r

    iJ-fit'ri*iid*

    "roiog'Mobe

    oecign-sotutions-

    d

    tb$ugh

    heir

    Adobe

    Sol*o::

    $b

    Facc

    ihno:/ r'ftTt.adobc.cotr/sorons/tsugscsrd: o dstlerwhoyouai orwhercyou

    wotk

    Adobe

    an

    nuk'

    a

    difrircucc"

    aad

    or

    aunufrctuling

    Adooc

    ugg;

    that

    user

    canisteoaiunc

    le dTlgt

    Td

    manufactutiqc

    ;il;Ttd;i,era-"

    ti-"-;-tfrt""

    Furtirtnore

    rlrough

    rir

    Mobe

    Acrobat

    D

    leb

    pases

    htDJfultrv.adobe

    otr/proOu"w'*t'

    tJ tg8p*

    -among

    other

    ene6u'

    har

    heir

    Acrobat

    D

    softr'are

    allo*6

    the

    desigtlet

    r orgimer

    o:

    .

    Easily

    isrribute

    D desigDs

    ootaidlg

    prod_uclalufacturinJ

    donnation

    PMI)

    such

    sdimensio$'

    iorerinces.

    naaonotations

    o

    you

    extDded

    tT

    uftcturing

    e'ms

    .

    kt voul

    o.tndedlcaE

    uUy

    parnopat

    n e' ail-

    or

    stsbascd-rcvitFs

    fPDFdlcumcds

    The

    -

    illii"?iiiillt-ea.ti

    neaaeienattc

    len

    to

    mart

    cROUp

    >

    GLOBAL

    .

    For

    Thursdav

    /

    Novembryou

    areexpected

    o complete

    ully

    and

    est

    out the

    part

    List

    Exh;tior

    exelcNe.

    In

    order o

    assist

    you

    in developiDg our

    o\rn application

    end o

    tbink

    about

    he

    sort

    or oala

    you

    wrsh

    o

    extact

    you

    are

    aow rcquired

    o

    plan

    out

    aDd

    comDlete

    n

    exDaction

    process

    or

    the followiq

    application:

    A

    sports

    alub has

    a total

    of l2 acres

    of land

    that

    may

    be used

    or

    a variety

    offield

    sportl,

    lvhia

    miSht

    nclud

    sporrs

    uchas

    Football,

    Rugby

    and

    Hockey

    etc.

    you

    are

    required

    o

    plan

    out the

    area

    so hat several

    different

    sports

    can

    be

    cab;ed

    fo;at

    the

    same ime (no

    repetitions

    and

    ry to rDaximile

    he

    useofthe

    field).

    Do not

    worry

    about he-

    ctual

    shape

    of the area

    but

    you

    must,,ot

    cxced

    he

    li aqe,

    *u

    thiot,

    yoo

    may

    need

    o colrvglt

    acres

    o

    yad.s

    or mets

    and

    hen

    use

    he

    official

    recommended

    size

    ofthe

    wrious

    spons

    pitches).

    Once h

    ayout

    ofthe

    areahas

    been

    plamed,

    consider

    what

    nformation

    micht

    bc

    required

    o book

    the facilities

    sayon a

    weekly

    basis

    e.g.

    Narre

    ofperson

    ,"liog

    tt

    "lookin-g:tc1c..:tY9u should welopaminimu- of5 d.isctctei"ce,oiiof*i*t oo

    ror

    eacn

    boohng/tacility.

    () c

    the

    acilities

    have

    been

    irlly

    booked

    out for

    all

    the

    sports

    you

    have

    hcluded

    you

    should

    extat

    the

    data

    n CSF

    ormat

    ad

    include

    t

    in

    a

    Word

    document,

    Print

    this out

    andkeep

    as

    evidence

    hat

    you

    have

    corrpteteJ

    he tast.

    Beyond

    he

    sports

    acilides

    you

    might consider

    additional

    booking

    details

    based

    around

    he club

    housg

    showsn,

    bar,

    ood

    and so

    on.

  • 8/10/2019 FMEA FTA Reliability

    19/76

    Asriermpntderaits

    You ar-requ:red

    o derrp.

    Je\etop.

    grr.

    nd

    docummr

    sotulun

    o rhc

    st..crficdion irLn

    bclo$.Th-s)stemi l tobcd,r \1. :otedi rh j {c . l . rne$.cbpigecJnbecreatrdLsln anvsuiL,bt

    m.thod

    or

    ou.

    chorce

    Tlc

    [\ccl m".jct

    shou]rt

    nchrde

    -s

    l_,

    "r

    ir,"'i"jl"*i,r_

    lj,a:r..i

    taatures

    fE]{cei

    s

    possible:

    .

    macro inldl

    to cofimrnd

    button.

    .

    on-srecn

    elp

    c.B_

    .rcqn

    ipsJ

    .

    so4ing

    d

    4

    .

    filrering

    data.

    .

    usc

    oflf

    funclion.

    .

    use

    fPivol

    Tslt.s,

    . use fVLOOKLD tlnclion.

    llsnd-ln

    d.trlh

    Yout *ch

    paCc

    tl.l

    rcur

    so.ti

    g

    Ex.et

    r)nc7

    storcd

    n

    r]oppy

    lsc

    $.ilh

    rs

    &ccomDinun

    o(um.Dranon

    rc

    o bc

    h.nded

    n ro

    hc sr

    dcnl

    eginr

    bI, he

    d.r\ ro,licnte,i

    n rour'rno,r.,rl

    surdc.

    All $ork

    shotrld

    e

    prcscnred

    h r

    conrprered

    overshccr.'Th;

    tr;-;;;il;.

    ;;;j

    and

    ttrchcd

    o

    yourpapis

    Gemamber

    o kc.p

    a b{k-up

    copy

    of},oLLr

    vork).

    Docu

    mntrilon

    Docurcnrarion

    ust

    be

    word,proc.ssed.

    dtahl.r.

    truclurcd

    e.g.

    ub-bcadirys

    or:

    nlrod(crion

    to

    thc

    prcbleh,

    dcsignof lh.

    sprcadsheer,

    lovelopment

    f

    ttrclnodct.

    tgo;ihm;,,*d.

    ;iil:

    coD(luslon)

    nd

    hrve t collents agc.

    Yor|

    need

    o include

    n

    rorlr

    docunrcntation

    or yo|rr

    ]lcel

    s]stcmi-

    J.

    lnlruJuctroD

    o tlle

    problem

    nd

    -rour

    Llcsjgn

    hr vo,rr

    solurion.

    o ncluJc

    Lridenc

    oI

    puftrn8,

    e.g

    skceher

    drlsn on pipr.

    .1r)d

    tcsi$ of

    r

    rensjblc

    (r.rcrure

    or

    tlre

    sysrctn,

    .g.

    nren

    on

    frrsr

    r'orksh.ct,

    booting

    nform,rtion

    onsecond orksfieet,

    rc. l

    ro

    2

    plgcs

    plus

    slcrches).

    Assilrnmenrr

    (60?i,)

    I

    Dc(riplio'r

    of your

    jerclopmmr

    f

    ]nur

    so,unon.

    e.g.

    algo.ithnls,

    brmulae.

    caturcs

    elc.

    uscd,

    l

    o 2

    prgcs).

    I

    User

    guide,

    ricfdelails

    bur

    softicie

    rbr

    r ne{

    prus

    $cr n

    ots).

    user

    o

    nn

    vour ppticarion.

    1

    page

    I

    Acrudresdrtru e,tJndrheresulrsof lourl

  • 8/10/2019 FMEA FTA Reliability

    20/76

  • 8/10/2019 FMEA FTA Reliability

    21/76

    ?roblem

    Spctficarion

    , l :1, tu,1 ' r . f fa lani

    ,s

    a

  • 8/10/2019 FMEA FTA Reliability

    22/76

    FailureModesandBffects

    Analysis

    FMBA)

    Introduction

    Failure fcomponents

    anoccur or a

    variety f different casons ependingpon he

    product

    and ts application. he

    ist

    of

    failuremodesn any

    pa

    icular

    product

    ouldbe

    quite

    considerable.he raditional ulturc fdesignerss oneofsolvinga failuremodeproblem nce

    it hasoccuffed.

    he

    philosophy

    f design ssurance

    s

    one

    of failure

    prevention

    y analysing

    failuremodes t he nitial decision

    making tages f thedesign

    rocess,

    .e. he Trontend'.

    When ndividual ailuremodos

    avebeendentifiedn a system,

    arious

    echniquesan

    be used

    for thesynthesisf these

    ailuremodesnto a

    procedure

    or systematicnalysis

    nd o

    propose

    solutionso them.These

    echniquesavebeen roadly alled'Hazard

    nalysis'methods nd

    haveoftenbeen mployed

    n

    post-modem

    ituationlt,fter he

    componentr

    product

    as ailed,

    ONE

    procedure

    ontained ithin hisbroad

    andof Hazard nalysiss a

    procedure

    alled

    FMEA

    (Failure

    Mode$

    ndEffectsAna.lysis).

    Hazard analysis

    Definitionof Hazad:

    'A

    setofconditionsn theoperation

    f a

    product

    r system ith the

    potential

    or initiating n

    accident equence.'

    BS

    477813.3.1).

    oresimply:a

    potential

    ource f harm

    Preliminaryhazardanalysis

    This s a broad tudymadc

    n theearlystages fdesign, t consists fbreaLking

    heengineering

    system own

    nto sub-systemsr even o ndividual omponentsnd

    or each, nsweringhe

    following

    questions:

    1. Sub-systemr itemunder onsideration

    2. Modeofoperation.

    3. Hazardouslement

    4.

    Event

    hat dggershehazardouslement

    5. Hazardouscondition.

    6. Event hat riggers

    he

    potential

    ccident

    7. Potential ccident.

    8. Possible ffects f accident

  • 8/10/2019 FMEA FTA Reliability

    23/76

    9.

    Measusaken o contain r

    DrEveot

    ccurnces

    10.Classifrcstionf hazard

    Refer o infonnation

    low or the

    qualitative

    lassificationf hazard.

    Informationor completinghePreliminary azardAnalysis omesrompcnonalcxpcrience,

    interviewswith operating

    qsonnel

    upervisors,

    itelature

    eta.Con|ider he

    ollowing

    example

    of a tic-barbrackctn &hostileenvironment;

    hc aDalysis,ouldbe:

    1.

    Ti-bar rackot

    2. Partof cngine abilising

    sy8tem

    3. Hostilcenvitonnnt

    4.

    Operation

    f engine

    5. Corosion

    6. Corosion

    Educes ross cctiomlalaof bracket

    7. Brackct ails

    8. All

    motionof engincansfelred o mountings

    9.

    Modify matedal nd/or urface

    eatment

    of bracket

    10.Classiflcation

    V.

    the reviewof caretully

    gcpared

    PrcliminaryHazad Checklists

    s

    an

    mpofiant

    echnique

    o

    nsurhatno obviousDoints Ioverlooked.

    _;r_

    'di,i,o

  • 8/10/2019 FMEA FTA Reliability

    24/76

    Delinition of

    FMEA:

    The study f thepotentialailureshatmightoccurn anypartofa system,o determinehe

    probable

    ffects f eachon ajl theother

    pafs

    of thesystem ndon

    probable

    perationaluccess.'

    (BS

    4'778 '1 '7)'.

    The echnique f FMEA

    is

    based

    n a

    quite

    simple

    rinciple

    nd ts aim s to anticipate

    otential

    failures o hat heirsource

    anbeeliminated.

    t

    conrists f a GililEfana-ii"i--aTlE

    -

    mrlfunctioni

    hatcanbe

    producedn thecomponentsf anengineedngystem nd he

    subsequentffects hat hese an

    haveon sub-assemblies,ssembliesnd

    inally

    he

    product.

    A

    complex

    roduct

    an ail

    in

    an

    almostnfinitenumber fways.Therefore,

    t

    seems

    mpossibleo

    determine very

    possible

    ailuremodeof a

    givenproduct.

    However,f the

    product

    s

    S$g E4St94lS$-lgILb4s

    ents he ailure

    modes

    of these

    co4p9191111 considerably

    reduced,his meanshat heFMEA always as o be started t hemostbasic evelof an

    assembly,

    t

    proceeds

    rom here pwards

    n thehierarchy fthe system. MEA

    is

    actua

    y

    called he bottom-up'method.

    o reduceheworkloadt maybe advisableo

    follow and

    examG onliifrela-iiurE6'odes

    ith thehighest

    robability

    f

    occurrence.

    As anexample

    onsiderhe ailures

    which

    can

    ead o anaircraftjet ngine reakdown;heyarc

    almost

    nfinite.However,hemain

    ailuremodesor thecomponentsf theengine uchas

    ts

    fuel system re

    probably

    more imited. f theanalyst onsidershebasic

    parts

    of the

    uel system

    e.g. uel

    pump,

    uel

    pip,

    njection ozzle tc,, he

    possible

    ailuremodesor thissystem re

    evenmore

    educed. y using hisapproach,

    orking romcomponento sub-asseqlly, ndsu -

    q',eaqylg.res -Ul c@-lelt@-

    establish failureanalysisor the,cggt 9qqg 49.

    Thebasic deaunderlying

    he echnique f FMEA

    s

    to discipline

    he luxing houghts nd deas

    whichoccur

    n the mindof thedesigner uring

    hedesign

    rocess,

    o hat n followinga

    methodical

    locedure

    hedesigner

    s forced o follow thesehoughtsn a thorough

    manner.n its

    most igorousorm,an

    FMEA s a summary f theengineerl houghts

    including

    n analysis f

    everyconceivable

    tem hatcan

    go

    wrong,based

    n experiencend

    past

    problems),

    she/she

    designs component

    r system.

    Over

    h9

    years

    he FMEA method

    asbeenmoreandmore efined nd t is now

    virtually

    standard

    ractice

    o

    usea standardisedorm of

    presentation.

    ifferent

    product

    reas .g.

    aerospace,uclear, ndautomobilendustdes ighthavea slightlydifferent mphasisn cefiain

    areas,

    Outline

    The echnique

    f F.M.E.A. s used o assess

    ny

    potential

    hoficomingsn the Design nd

    Manufacturef a component,

    ub-assemblyr finished

    roduct.

    hebroad oncept

    f F.M.E.A.

    is that hedesign nd

    process

    recarefully nalysed nd heir

    potential

    hoficomingsre

    recorded.

    numerical ssessments then

    made

    nd

    hese ssessmentsre hen ankedbr action.

    Whenciuried

    out correctly, n F.M.E.A.enables

    ngineerso look at all aspectsfthe design

    and

    process nd hen o highlight

    where

    osteffective ction anbe aken.

    Theanalysis ill showwhereactions neededo achieveeduced arranty osts, crap osts,

    inspectionosts urd

    W.I.P.costs.t will also

    help n themarketing rea o mprove ales nd

  • 8/10/2019 FMEA FTA Reliability

    25/76

    obtainneworders. heachievementf a

    highdegree

    lsafety

    where

    afety ritical

    products

    re

    involvedwill be helped yF.M.E.A. echniques.

    When To UseF.M.E.A.

    F.M.E.A. anbecarried ut at anystage f a

    products

    evelopment

    rom ts initial

    conceptiono

    its final manufacture.hemostbeneficial

    imes o use he echnique re:

    1. At the concept tage,

    when

    outlinesand specificationsre beingset and when

    'mock

    ups'are eing

    made

    2. As soonas he

    designs laid downbut

    pdor

    to anymanufacturingeingstarted

    3.

    when thedesign asbeen

    roduced

    nd he

    process

    s being aid down

    4. At a stagewhen

    majormodifications re o be carriedout. Again at design nd

    proce$s

    lEratrons

    5. When actions avebeen

    highlighted

    nd corrective ctions avebeen akenan

    F.M,E.A. hould a

    re-assessed.

    Valueof the Technique

    Thevalue fthe techniques that

    t

    ensures

    ll risksare dentified nd hat

    action

    s

    taken.

    he

    fact hata.ll he nformation

    lr recorded,educesigdfrcantly hechance fa risk being

    overlooked.f thedesign$ nd

    processes

    reanalysedoEectly,he echnique as

    great

    alue

    both n the

    manufacturingreas nd n themarketing leas,

    F.M.E.A.

    gives

    a highdegree f assurance

    ndconfidencehat he

    product

    anbe

    produced

    o

    give

    a highdegree fsatisfaction

    o both heemployeesnd

    potential

    ustomers,t will

    generate

    confidence

    n thedesign,manufacture,

    uality

    and eliability

    of a

    product.

    he

    stored

    ocuments

    will

    provide

    eady eferences

    f

    a

    problem

    hould evelop.

    DesignF,M.E.A.

    A

    design

    .M.E.A. hould e carried ut at heearliest

    ossible

    tagett the ife of a

    product.

    t is

    used o ascertainhat he

    product

    will carryout ts function orrectlywhen

    produced.

    o ensure

    that heproduct anbe manufacturedssimplyaspossible ith no avoidable onstraints.g.

    tighter

    oleranceshannecessary.ach

    eaturemust

    be

    analysedor

    potential

    ailure,

    resuming

    that t will be manufacturdo the

    given

    drawings ndspecifications.

    Once hedesign

    s beyondheconcept tage ndadvancedssue rawings reavailable, ach

    dimension

    anbe assessed.hedesign

    .M.E.A. ollows

    analmost hildlike

    simplicity,

    questioning

    he need or the

    size, he oleranceor the

    presence

    f the feature.

    Delinitions and the Standard

    Worksheet

    The

    product

    nd ts drawingnumber hould

    e

    appendedo each heet efore onrmencing

    he

    F.M.E.A.Each olumn hould

    owbe filled out usilg the ollowingdefinitions:

  • 8/10/2019 FMEA FTA Reliability

    26/76

    1 ParuProcess

    equircments indicatesas

    precisely

    as

    possible

    he

    function

    of

    the

    part

    or the

    prccess.

    2. Deviation

    -

    this is the

    potential

    ailure mode,which shouldbe identified as cleady as

    possible

    in the ollowing

    manner:

    y'hat could

    possibly

    go

    wrong?

    How can he

    pafi

    fail to meetspcification?

    What

    woulda customer onsidero be unacceptable,

    egardless

    f engineering

    specifications

    T,?ical

    deviations

    are:-

    o Broken

    o Fatigue

    o Distortion

    o Omitted

    o

    lraking

    o Loose

    o Rough

    o

    Mis-assembled

    3.

    Ef&glIO

    -

    at this stageassume

    hat the ndicateddeviationhasoccuned, hen describe

    what

    the customer

    might notice or experience.Someexamples

    f effectsof failure arc:.

    o Operation mpaired

    o Poor inish

    o Noise

    o Lack of secudty

    o Lack of

    power

    ,

    -

    .o

    IntmittentoDeration

    -.

    Jt4)i.l

    4.

    ggusglsl-

    ist each

    otrtial

    cause f failue whichcanbe assignedo eachdeviation.

    o

    Incorrectmaterial

    o Assemblyelror

    o Overheating

  • 8/10/2019 FMEA FTA Reliability

    27/76

    o

    Tool damaged

    o Partomitted

    o Overstfessed

    5.

    Rq i g

    -

    onceeach f thecategories

    asbeen ompleted ratingcanbe applied.

    ach ating

    is a subjective

    ssessmentf the

    degreeo whicheachofthe above

    tems anaffect he

    part

    or

    process.

    he atings

    re isted.The atings

    hould e agreed y the eamasa wholeand

    appendedo the

    orm at he nitialcondition

    tage.

    The

    mportancef the eam

    makeup becomes pparent t his stage, ince

    nowledge f

    warrantyetums n similar

    products

    or example,

    s a keyrequiremento establish ccurrence.

    The atings rebased ponwhatcouldhappen nd hereforet is unlikely hat ndividual

    enginee$

    ould

    give

    each ategory

    he same alue. t is importantherefore

    hat

    he sameeam

    remainsogether.

    o

    Sglgdq

    -

    estimatehe severity

    f the effectof failure o the customer n

    a scale

    of

    1

    -

    10.Sevedty

    s the actor hat epresentshe se ousnesltf

    the ailure o the

    customer fter t

    halr ccurred.

    o

    QqqplqlE

    -

    this s an

    ndication f the number f itemsor operations

    eededo

    complete

    he tembeing

    analysed,heestimates on a scale f

    |

    - 5.

    o Occurrencethe

    estimate f occurence

    s

    on a base

    f I

    -

    10and s

    udged

    by the

    engineerrom his knowledgehat he fault,a) will occul n the uture ife of the

    product

    r b) hasalready

    ccurred

    o

    914gjqg-

    is an

    estimate f the

    probability,

    hata

    defect aused y the ndicated

    failurewill leave he

    manufacturingreaand each he customer.

    ssuminghat

    the cause f failure

    hashappened,etection

    s

    an

    estimate f the ability of the

    quality

    system

    o

    prevent

    hipment

    nd s made n a scale f 1

    -

    5,

    6. RiskPrioritvNumber R.P.N.)

    theRisk

    P ority Number s a calculation chieved y

    the

    multiplication f the

    values elected

    or

    Occurrence,

    everity, etection nd

    complexity.

    SEVERITY OCCURRENCE

    DETECTION

    COMPLEXITY

    =

    R.P.N.

    Thisvalue an

    henbe used o assess

    hedesign r

    process.

    nce hedesign

    r

    process

    asbeen

    evaluated

    he mprovement

    rocess

    anbe started.

    ctionmustbe aken n thehighR.P.N.

    values, ut where n

    ndividual aluation

    s high, his temshould e considered

    n

    the

    action

    list. Theobjective

    mustbe o minimise

    ) theR.P.N alueand i) each

    ndividual alue.This

    however

    mustbe achievedn a

    cost-effectivc anner

    ith

    every

    gard or safety.

    7.

    CorectiveAction conective

    ctions

    mustbe ogged ndactions. nce heaction

    asbeen

    taken heF.M.E.A.

    hould e re-assessed

    nda newR.P.N. alue

    produced.

    ince

    heaim s

    Continuous

    mprovement'inhe

    whole

    product

    ange, .M.E.Al should e

    continuouslye-

    assessed,

    o achieve s ow an

    R.P.N. alueas

    possible.

    bviously

    dorities

    mustbe established

    with safety ndcosteffectivenesseing oremost onsideration.

  • 8/10/2019 FMEA FTA Reliability

    28/76

    An F.M.E.A.

    hould etermine hatcould:

    o Prevent hc part from operating

    o Cause

    he

    part

    to be unacccptable )

    the Customer

    o Reduce he

    parts

    ite

    o Endanger hc

    cnd applicatlonor user

    Corrective

    Actions

    Thc F.M.E.A. will identily thc

    need orl

    o More testing o pfove designadequacy

    o

    Dimensionuleviews

    o Moredcsign

    work o eliminate hazard

    o Designwofk

    to improvehe 'unctioningf thc

    product

    o

    Highlight heneed br

    spccial arcwherca risk hasbeen dentified nd here s no

    immediatenswcr

    o Specialiscd

    raining

    o

    Thc nccd or a further

    eviewol manufactufingapacity

    ScrEiE

    Eaik

    Efilcl on cndusEr

    f.ilu| rat

    D.t.clion

    dect

    Rrnk c,ilirie

    rs|dring

    1.

    very

    ow sava,ily,lslomor

    ,\ou

    probqhly

    ho unlbla lo Cdacl hull

    2.

    3

    4.

    5.

    E.

    cqusngsome

    lvlodorale

    oveity,hiqhdi

    oi cudofi er dissalblbclin

    7. Fiqhsererily,a ufaoi

    6. sub+t{|em,norconpliance

    vth slsl ulory regUations

    9. Vcryhlgh

    Bveiiy,

    otential

    1 , sqt |y'6ldl.d

    okleh

    ,x

    Femole

    po$blrYor

    lOrt

    the 1r qfoocordng.

    LowFossibillv

    -

    d..iqn

    ol

    praclgs

    inilaf o existing

    iypc

    v{h owirilure

    ate

    ld odcrrto

    possibilily

    -

    des

    gn

    of

    proccss

    milarloe)dding

    1fl0r

    lypeMilh ccEionalcllu$

    L

    2.

    3,

    5.

    6.

    7. l-ligh

    G.tbiliiy-

    dolgo"or

    :

    L

    procss

    im

    lar

    o hos.lhal ha

    ''

    caus

    pfoblem

    in he

    pasl

    L Veryhigh

    assibllity

    -

    1,10

    10. almod

    ceilainlal lEilwe 'ill

    RendB itelihoodhal

    ,.da' 4

    $lll r.ch

    Low kalihood

    hal dclact lLl

    lifrllffll?llffl

    3

    ,

    2.

    5.

    i t rNunbe'(RFl ' l )

    i

    10

    30

    50

    lnn'

    2+

    3 11

    +31

    1.4 1

    _l

  • 8/10/2019 FMEA FTA Reliability

    29/76

    FMECA (Failure Modes and Effects Cridcality Anslysis).

    Definitionof FMECA:

    The study of

    the

    potential

    ailures hat might occur n any

    part

    of a system o determine he

    probable

    effect ofeach on all the other

    parts

    of thc systemand on

    probable

    operational uccess,'

    the esults f whicharo

    ankedn orderofseriousness.l

    BS

    477817.8).

    Theobvious

    method fdisplaying his s to do exactly s t says,.e,

    put

    hem n order, hemost

    sedous t he op

    Anothermethod s to

    plot

    a

    graph

    of

    RPN againstCdticality of Hazarde.g.

    t t tv v

    Conclusion

    Today,

    manycompanies rc inding that an

    FMEA is

    a contractual

    Equircmetrt,

    .g, a

    procedural

    document tating:

    l.

    What components/sub-assemblievassemblievFoductshould be analysed,using

    FMEA?

    2. Who should

    perfom

    it?

    (Status

    evel

    -

    perhaps

    SeniorDesigner).

    3.

    Method of results

    presentation.

    4, What corective action

    hasbeen

    performed?

    Obviouslydesignconfidentiality

    will have o be espected, nd n somecases dy a limited

    amountof information would be ssued o theprospective ustomer.

  • 8/10/2019 FMEA FTA Reliability

    30/76

    Tailoring of FMEA StandardPresentation

    As previously tated, standardorm ofprcsentations used heso ays o show he results f the

    analysis. owever, iffcrcnt

    ndustries ould

    perhaps

    ncludemorc nformation. or example,

    Reliability.

    Definitionof Rcliability:

    The

    probability

    hata componcnt,ystem

    r

    prodLrct

    ill

    pedorm

    without ailure or a specified

    period

    of TME, undcrspecified

    perating onditions.'

    In

    yourpartjculafndustry,

    ou

    couldconsiderncluding omenfbrmation n he eliabilityof

    the

    pa|t

    n

    question

    n heFMEA form.

    Typical nfofmation, hichcouldbe airly confidential,

    could eMTBF Mean imeBetwccn ailures)r FPMH FailureserMill ionHours) fthe

    part.

    TheRPNobtaincd

    rom heFMEA,

    even

    hough henumbers resubiective),oesbeara

    passing

    escmblancc

    o he eliabilityf the

    part

    TangibleBenelits

    o Sollware

    rograms

    fc availableor FMEAS, whichwill reducehe

    (ime

    aken o

    perform

    hcanalysis,

    elativeo hand alculations.

    o

    The

    procedure

    f

    perlbrming

    an

    FMEA

    could opena

    prcviously

    undiscovercd

    window o allowa

    new

    perspective

    o beobtained n

    product

    afety.

    3

    sunrn:mnrmrrr'u-t'

    -

    - -

    0Model)ar&hide(+-

    - - -

    - -

    othf iu | - - - -

    - - - - - - .@

    soh.dur.dt.-

    - - - - -

    - - -

    la

    [7 f iO O

    Suphrjsorn./siqnmr.r

    -.

    .

    FMEAdn.(oddnn)r-

    - - - --

    G

    0

    @

    @

    @

    trb

    3

    I

    - .@,

    @

    ':ft\\\s'"

    3i&\

    I

    a. t

    XX

    *rt

    x.i

  • 8/10/2019 FMEA FTA Reliability

    31/76

    POTENTIAL FAILURE MODES AND EFFECTSANALYSIS RANKING TABLE

    SEVERITY

    Rank Effect on enduser

    OCCI]RRENCE

    Rank Criteria

    Possible

    Failure Ratc

    DETECTION

    Rank

    Criteria

    Possibility of defect

    reaching customer

    Very ow

    severity,

    ustomer ould

    probably

    be

    unable o detect ault.

    I-ow severity,minor aultcausing ome

    customer nnoyirnce

    Moderateseverity,high degreeof customer

    dissatisfaction

    High severity,

    ailure

    of

    sub-system,

    non-compliance ith statutory egulafions

    Very high severity,

    potential

    safety

    related

    problem

    2

    3

    4

    5

    o

    '1

    8

    9

    10

    Remote

    possibility

    of the

    failure occurring

    I-owpossibility- designor process

    similar to existing j /pe with low

    failure rate

    Moderate

    ossibility designor

    process

    imilar to e)dsting l.pe

    with occasional ailues

    Highpossibility design r

    process

    similar to those hat havecaused

    problems

    n the

    past

    Very high

    possibility

    -

    almost

    certainhat ailure

    will

    occur

    l/ 100000

    l/1000

    IIIO

    5

    6

    7

    8

    2

    3

    9

    lo

    Remote ikelihood that defect

    will

    rcach

    ustomer

    I-ow likelihood that defectwill

    rcach ustomer

    Modrale

    ikelihood that defectwill

    reachcustomer

    High likelihood that defectwill

    reachcustomer

    Very high likelihood that defect

    will rcachcustomer

    0- lV o

    lffiVo

    COMPLEXITY

    Rank Numberof components

    l 1-3

    2 4-tO

    3 lr 30

    4 31 -50

    5 5l

    -

    10 0

    Risk Priority Number

    RPI$

    =

    Severityx Occurrence Detection

    x

    Complexity

    PRODUCTFAILURE

    FOR REASONS

    STATED

    IS NEITHER ADMITIED NOR MPLIED

  • 8/10/2019 FMEA FTA Reliability

    32/76

    Fault TreeAnalysis FTA)

    This echnique asbeen

    used y theNationalAeronauticsndSpace dministration

    NASA)

    n

    theirspace

    rogrammes

    ndhasalsobeen sd

    n

    the

    Nuclearndustry. TA is used xtensively

    in the

    ield of reliability, afety,.and k analysis.

    t is

    a

    convenient ethod f representinghe

    logicalconnectionetweenhe

    ailuremodes f a system. he op ofthe tree, he op event, an

    be evaluated

    ualitatively

    nd

    quantitatively

    failure

    atedatawouldbe

    requiredor this

    altemative),

    ith theaid ofa computer

    rogram.

    FtA is defined

    s

    "The

    studyof the

    possible

    equencesf events

    onstitutinghe ailurcof a

    $y$temsing hediagrammaticethod falgorithms."BS4778 17.9.)

    The ilst step s to define he

    systemhat s to be analysed,o

    prevent

    he ree

    rom

    becoming

    oo

    complex. treecan

    only analyse neeventandso a

    numbermay

    be

    neededor one

    product.

    system

    anbedivided nto ts operation

    hases

    n order hateach anbe analysedeparately.g.

    $tart-up,

    un,shut-down. henextstep

    s theselection f the op event,which s theundesirable

    event, .g. ire, explosion, r

    failureof a system, ub-systemr assembly.he ree hendevelops

    by the dentification f the

    ogicalcombination f the ailulemodeshatwould

    esult n the

    occuffencef th9 op

    event.

    Themodes f failurecanhavea

    variety fcauses, uchas hebreakdown f an ndividual

    component,perator rror, he

    ailureof a test

    procedure

    r a maintenance

    rogram.

    he ailure

    modes recombinedn a number f wayswhicharecalledgates'.

    U

    An e,,rii,usrclly

    a fault, .s.tlting

    lron iha co,nbln.tlonl morebasc

    E rd c cohpnlnl lbult v'hich can

    bBesigmd e

    p|obabillly

    t

    ocoirlen ce bascd

    on tlst llsuts

    of

    phlsica

    ol hilulEana

    ysis

    A teult ol

    d8\lopBdtuftfErs

    lo itscaus$

    bac $ollact( ol

    Inlof|natiorl,lrha,r \,|luc n

    A cond[ion.l .v6nt

    -

    on vtr'ich

    h ustoacurn oilar oran nput

    bull

    (cause)

    o Esult

    in an oupr.tl

    iault

    (Etrbc't)

    An .wnl o&61.d to occuf

    AND

    Ertl -

    itu odpnt s\nt ocorrs

    o d

    y

    $hcn all h. Input vlnts .16

    OF

    gate

    -ihe

    outpulavenl

    ocdrls

    v*rcn

    on6

    or nol oll lE Inpute\nts

    Reler.ne k ey o .noth6r

    Pot

    o lh ELuli ilr v'Irfa lha idantiaal

    saqu8nccol Bvents s shov'n

    A

    0

    A

    A

    Some asic

    FaultTreesymbols.

    Havingcompletedhe ree, he

    analyst ill thenevaluatet to discover

    hatspecific ctions

    required nd hen,

    obviously,make he appropriate

    ecommendations.

  • 8/10/2019 FMEA FTA Reliability

    33/76

  • 8/10/2019 FMEA FTA Reliability

    34/76

  • 8/10/2019 FMEA FTA Reliability

    35/76

    of separatedentical ystems

    r meanso separateutomatically,single ydraulic ircuit n

    order o isolate fault n

    pressurea

    s.

    Thesimple aultheeanalysis,

    n Figure , ofthe type

    of

    steering ear

    used

    n

    the

    Arro.o

    Cddit

    showshe

    oute

    o

    failure n a

    qualitative

    anner irect hrough heOR

    gates.

    igure shows

    fault

    reeanalysis

    fa conventionalour-ram teering

    ear

    with six failuremodeseading

    throughheOR

    gates.

    igure6 shows

    fault

    reeanalysis f thesame)?e of steering-gecr

    designedn accordanceith the

    new egulations,nd ittedwith separatend ndependent

    ower

    actuating ystems, nd

    shows he ailuremodeshroughheOR

    gates

    educedo two.

    The eliult fthe

    grounding

    f theAmocoCadiuwasa series lcomplex nternationalaw suits

    whichwereconsolidatednto a single ourt

    action. udge rankMccarr

    of the

    Eastern ivision

    of theNorthemCircuit,Courtof

    lllinois ssued I I l-page

    opinion.He$aid, nteralia,thdl

    Amocowasentitled o damagesgainst stilleros,heSpanish hipyard hichbuilt heA,roco

    Cudi{, o theextent

    hat ts own iabilitywascont buted o by thenegligencend aultof the

    shipbuilderl

    Thejudge oncluded

    hatAmoco nternational il Company

    AIOC),

    heoperator, egligently

    performed

    ts

    duty

    o ensurehat heAmocoCodiz n

    general

    nd ts steering

    ear

    n

    particular

    were

    Jeaworthy.

    dequotely ainlrined nd

    n

    proper

    epair,

    He noted hatAIOC hegligently

    erformed

    ts duty o ensurehat he clevt

    of

    theAmoco

    Cadiz.

    was

    properly

    rained', nd ailed n its duty o ensurehat hedesign ndconstructionfthe

    Amoco

    Cadiz

    was

    broperly

    arried ut

    so

    as

    o result n

    a seaworthy

    gssel'. e

    said

    AIOC was

    negligentn operatingheAmocoCadizwithouta redundantteering ystem, r anyothermeans

    ofcontrolling he udder,

    n theevent fthe completeailureofthe hydraulic teering ystem.

    In anivingat

    hisdecision udgeMccarr outlined hehistoryandopelatlorLf theAmocoCadiz,

    Thesendicatedhere

    were

    problems

    ith its steering

    ear

    rom hestart,whichwercnot

    adequatelyomprehended

    r repaired.n addition heOil Company id not ollow he

    maintenancenstructionsor the

    steering

    ar,

    which

    ultimately

    ausedhe

    disaster.

    JudgeMccarr listed

    everal

    reas

    hercAIOC thiled o maintain

    hesteering

    ear

    f

    theAmrc.)

    Cadiz

    properly.The

    ompany

    id not act o ensurehat he ilterson he steering

    ear

    were

    clea[edaccording

    o the nstructionmanual;t did not act o ensurehat heoil in thesteering-

    gearwaschanged;t did not alrangeo have amples f thehydraulicluid analysed;t did not

    requirehe

    ship'.steering-gearystemo be

    purged

    o remove ir.

    In

    addition

    e aulted hecompanyor accepting

    he ship rom

    heSpanish

    hipyard

    ith

    acknowledgedetbctsn its

    steering

    ear.

    n

    pafiicular

    heshipwasdelivered ith cast-iron

    steedng-gearambushings.

    t anangedo havebronze ushingsnstalled n ts own vessels nd

    placed

    dditional

    ushings n board heArrocoCadiz. hescwerenot nstalled.

    Thejudgenoted hatAmocoCadiz's

    teerj,ng

    ear

    n the ast ourmonths fits life was osing7

    to 12litresofhydraulic

    luid a day.Thiswas

    greatly

    n excess f whatwouldoccurwith a

    properlymaintainedystem'. he eport aid,This excessiveonsumption asknown o AIOC

    which n theexercise f ordinary kill and

    prudence,

    hould ave ecognisedt

    assymptomatic

    of aprogressiveegradationfthe system'seliability.'

  • 8/10/2019 FMEA FTA Reliability

    36/76

    With both

    steedng

    gearpumps

    securedho

    Amoco

    Cadiz and

    ur sister-ships xperienced s

    much as 15 degrees f ruddermovementwh.ile n

    port.

    This fact was well known amongAIOC

    engineers nd should

    have signalleda seriousmalfunctionof the two-sidcd

    estrain

    system

    of the

    Amoco Cadiz slering

    mechanism,'The nexplained

    uddermovement

    of

    theAmoco

    Ca.diz

    was

    not

    propedy

    nvestigatedand was not corrected.

    AIOC failed

    to

    insfuct the Amoco Cadizcrew

    in

    emergency

    teering-gear rills and

    procedures

    o b followed in the eventof a steering-gear

    breakdown,

    Comrnunlcrtlon-,

    SimpleFault

    TreeAnalysis howinghe oute o failureof an

    Amoco

    Cadiz

    '?es steering

    ea

    {-'-,\

    Lorr ol sl..ilg

    .loct hllc

    Sic6 nq

  • 8/10/2019 FMEA FTA Reliability

    37/76

  • 8/10/2019 FMEA FTA Reliability

    38/76

    nodop ot nd n mgrr

    The igureshows completeault rr analysis f a baringwith thundsirableop event

    batatrophicbealing ailur'

  • 8/10/2019 FMEA FTA Reliability

    39/76

    ET3008Collaborative

    esign

    ;1

    ^

    rl"u h-^

    ' lou'

    ProJ'^' ' t

    1=,1-'^1

    t-o

    lh

    v\ou

    -5

    /

    J

    J

    ,..,

    J

    ia c,t.\e: (.Reliabititv vo_er

    '

    ( t i '

  • 8/10/2019 FMEA FTA Reliability

    40/76

    ET3008Collaborative

    esign

    1.0

    200

    300

    Timen hou6d nc e$ sla,le

    Noticehow heReliability

    rogressively

    blls,

    ellingus

    whatwe

    already

    now,

    hat he

    onger

    we expect nythingo

    last,

    he

    more ikely t is to fail duing that ime.

    Failure Rate

    Supposehatat he

    nstantwhen

    =

    200hours,we areable o determinehat he

    parts

    are

    ailing

    at 3

    per

    hour.Since 00 arestill

    working,we couldexpresshe uteat which heyare ailingas

    follows:

    0e

    nSa aneous

    Nl|nb6rhilinEp.rour in.bnli

    ]Tur]r-EeTT'flSliiqa-liFTffi 'r

    .0005per

    our

    This nstantaneous

    ailure ate s

    given

    hesymbol , Thereforehe nstantaneousailure

    ate

    at

    the nstant

    is writtenz(t).Thismay,at

    irst sight, eem ather

    onfusing

    o express n

    "instantaneous"

    ailure ate n number

    f failures

    er

    HOUR.This s necessaryecausen an

    infinitelysmallamount f time

    .e.an nstant,here sjust no imeavailableof anythingo

    happen

    we

    can

    now define he Failure

    Rate

    as he

    probability

    f failure n unit timeof an tem,which s

    still workingsatisfactorily.y "stillworkingsatisfactorily, e mean hatwe shallNOT count

    failures

    whichhaveoccurred efore he

    nstant

    f

    time n whichwe are nterested.his s why n

    our

    calculation

    hedenominator

    s 600,NOT 1000, ecause e did not count he400which

    failed

    pdor

    o the nstant

    when he ime

    =

    200hours.We canshowhow heFailureRate aries

    with Timeon a

    graph

    .g.

    -6tT

    ModuleLeader:G Oakes

  • 8/10/2019 FMEA FTA Reliability

    41/76

    ET3008Collaborative

    Design

    Usatuv\oi(lnqltb

    Edly

    polord

    O-A/

    A-B)b-e

    Cr.^.

    R(t)

    -

    "' '

    whcr.r

    R(t)

    l

    no.- ,.----

    B

    A"d"

    w".t|.

    l.\@i

    -

    R^1a,{^?

    ey-\ut1-r --'26

    Thnen EulE na8Bdde Ed

    Typicalbath-tub

    urveofFailureRateagainst ime

    It is

    often

    hecase hat he nstantaneousailureRat s constalt ,e. ine s horizontal,

    arallel

    o

    X-axisiz(t) s usually hen

    g.iven

    he symbol

    ambda.Mathematically,

    t canbe shown hat or a

    constantailure ate .e. holizontaline

    n

    bath-tub

    urve.

    RrLirbilityal iror t.

    Constrnt ailure

    atc.

    Exomple:

    A device asa constantailure ateof

    I

    every

    10000 ours,

    approximalely year).

    What

    s its

    Reliability n anoperating

    riod

    of

    1000 ours?

    Solution:

    Therefore,

    Constantailure ate=

    f : -J--rxro.

    10000

    '" ' "

    R(')

    ' ' - 'r

    )t

    t

    ' R0OO0) t-rrrc{xroo

    R(1OOO)

    -

    3-or

    .

    R0000)

    -

    0.9048

    If therc were 2000 tems n a test,how many ailures would be expectedn 1000hours?

    Module Irader: G Oakes

  • 8/10/2019 FMEA FTA Reliability

    42/76

    ET3008CollaborativeDesign

    Numbersuryiving the est

    Number of failuEs

    = Reliability number n est

    =

    0.9 x 2000

    =.tr*

    =

    number t start number urviving

    =

    2000

    1800

    = 200

    Notc: hc cciprocalf I iscell.d hrMEANTIMEBETWXENAILURES

    dTBF)

    SYSTEMReltrb

    lty for more hanotr omponnt.

    SERIES ellabtltty

    Overall

    eliability 0.9x 0.9

    =

    0.81

    .c.

    kss than ither.

    Generally, verallReliability

    =

    RAx RBx Rc x RD RE ..,..etc,

    PARALLEL Retablllty

    Overall

    Reliability

    =1-(1-Rr( l -RB)

    =l-( l -0.9)(1

    -

    0.9)

    Module ader: G Oakes

  • 8/10/2019 FMEA FTA Reliability

    43/76

    ET3008Collaborative esign

    =1-(0.rx0.1)

    = 0.99 .e.GREATER haneither.

    Generally, verallReliability

    =

    I

    -

    ( l

    -

    ReXl

    -

    RsXl Rc) ...etc.

    Rellability acceptance ests

    Therearc wo main ypes f

    Reliability ests:

    In theory, ests

    reanalogouso sampling

    nspection

    fincomingbatches f

    material.

    1, Takearandom ample.

    2. Test or a

    pre-set

    imeunder

    a

    given

    setof conditions.

    3.

    Batchor samplewill be accepted

    f

    at

    the

    endof the

    pra-set

    ime, he

    number

    f

    failures

    observed oes ot exceedhe

    numbar llowed

    y the

    sampling

    lan.

    Nota:Testmaybe stoppedf thenumber

    f failures xceedshe

    pre-set

    imit

    before

    he allocated

    timehaselapsed.

    Acceptance

    cstsarcconcemed ith demonstratinghat he

    Reliability

    fthe

    items s

    satisfactory

    for some

    urpose.

    n

    general

    heydo

    not

    provide

    noughnformationo

    give

    anyadequate

    estimate f theactualReliability r MTBF,becausehe est imesarcusually oo short.

    n^

    Refiabilitymegsuremenb:

    tS

    lhe

    .^1t .

    \

    \6.

    hct-et-y'

    4'd.lb"cz

    "l

    N 5q6@,

    a-.J

    ts

    olten.

    a,kft,,e4

    +6

    thz

    -41fu1

    .We

    o+

    tk"

    &,,.