Introduction to ergonomics and human factors.pdf
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About This Presentation
Introduction to Ergonomics for product design.
Slide Content
Introduction to Ergonomics
(ID 3203)
Prof. MohitLal
Department of Industrial Design
NIT Rourkela
(ID 3203)
Prof. MohitLal
Department of Industrial Design
NIT Rourkela
Lecture 1
Datalogging,datacollection,datareductionanddataanalysistechniques.Grosshumananatomy,
anthropometry,biomechanics,musclestrengthandexertionpotentialofdifferentlimbs,workcapacity,
environmentaleffects.Exercisesforevaluationofposturalformsandworkspaces.Environmental
conditionsincludingtemperature,illumination,noiseandvibration.Perceptionandinformation
processing,designofdisplays,handcontrols,typographyandreadability,layoutandcomposition.
Exercisesinevaluationofhumanresponsetoproductinterface.Productsafetyandproductsliability.
Studentseminarsoncriticalergonomicalstudyofanexistingproduct/service.Exerciseinform
designforergonomicoptimality.
Courseoutcomes:
ThecourseisdesignedtohelpstudentstoachievethefollowingoutcomesAwarenessonimpactofhuman
anatomy,Anthropometry,Biomechanics,musclestrengthinworkenvironment,etc.Basicknowledgeon
humanfactorsindesignandengineering
Markingsystem
TermProject,Assignments,ClassTest1&Class
Test2–20(lastweekofAugust&Ocober)
MidSem–30
EndSem–50
Lectures:
Monday–04:20–05:10
Tuesday-04:20–05:10
Thursday-04:20–05:10
Datalogging,datacollection,datareductionanddataanalysistechniques.Grosshumananatomy,
anthropometry,biomechanics,musclestrengthandexertionpotentialofdifferentlimbs,workcapacity,
environmentaleffects.Exercisesforevaluationofposturalformsandworkspaces.Environmental
conditionsincludingtemperature,illumination,noiseandvibration.Perceptionandinformation
processing,designofdisplays,handcontrols,typographyandreadability,layoutandcomposition.
Exercisesinevaluationofhumanresponsetoproductinterface.Productsafetyandproductsliability.
Studentseminarsoncriticalergonomicalstudyofanexistingproduct/service.Exerciseinform
designforergonomicoptimality.
Courseoutcomes:
ThecourseisdesignedtohelpstudentstoachievethefollowingoutcomesAwarenessonimpactofhuman
anatomy,Anthropometry,Biomechanics,musclestrengthinworkenvironment,etc.Basicknowledgeon
humanfactorsindesignandengineering
Markingsystem
TermProject,Assignments,ClassTest1&Class
Test2–20(lastweekofAugust&Ocober)
MidSem–30
EndSem–50
Lectures:
Monday–04:20–05:10
Tuesday-04:20–05:10
Thursday-04:20–05:10
Lecture 1
NPTEL Lectures by
1.Prof.D. Chakrabarti, IIT Guwahati
2.Prof.Shantanu Bhattacharya, IIT Kanpur
3.Prof.InderdeepSingh, IIT Roorkee
Other Sources such as
1.Google Scholar
2.Research Articles
3.Internet Sources
NPTEL Lectures by
1.Prof.D. Chakrabarti, IIT Guwahati
2.Prof.Shantanu Bhattacharya, IIT Kanpur
3.Prof.InderdeepSingh, IIT Roorkee
Other Sources such as
1.Google Scholar
2.Research Articles
3.Internet Sources
Lecture 1
So,ergonomicsisabouttakingcareofuserdifficultiesorinotherwordsanalyzingthefactors
responsiblefordecreasingthesystemperformanceandworkonthoseaspects,therebymaking
systemcompletelyefficient
Lecture 1
responsiblefordecreasingthesystemperformanceandworkonthoseaspects,therebymaking
systemcompletelyefficient
Lecture 1
Ergonomicsisthestudyoftheinteractionbetweenpeopleandmachinesandthefactorsthat
affecttheinteraction.Itspurposeistoimprovetheperformanceofsystemsbyimproving
humanmachineinteraction.Thiscanbedonebydesigningabetterinterfaceinthework
environment,inthetaskorintheorganisationofworkthatdegradehuman–machine
performance.
Thename‘ergonomics’comesfromtheGreekwords‘ergon’,whichmeanswork
and‘nomos’whichmeanslaw.
Lecture 2
affecttheinteraction.Itspurposeistoimprovetheperformanceofsystemsbyimproving
humanmachineinteraction.Thiscanbedonebydesigningabetterinterfaceinthework
environment,inthetaskorintheorganisationofworkthatdegradehuman–machine
performance.
Thename‘ergonomics’comesfromtheGreekwords‘ergon’,whichmeanswork
and‘nomos’whichmeanslaw.
Lecture 2
Whatisergonomics??
Thescientificdisciplineconcernedwithunderstandingof
interactionsamonghumansandotherelementsofasystem
andtheprofessionthatappliestheory,principles,methods
anddatatodesigninordertooptimizehumanwell-being
andoverallsystemperformance.
Lecture 2
Hence,Ergonomiststudyhumancapabilitiesinrelationshiptoworkdemand.
Thescientificdisciplineconcernedwithunderstandingof
interactionsamonghumansandotherelementsofasystem
andtheprofessionthatappliestheory,principles,methods
anddatatodesigninordertooptimizehumanwell-being
andoverallsystemperformance.
Lecture 2
Hence,Ergonomiststudyhumancapabilitiesinrelationshiptoworkdemand.
Systemscanbeimprovedby
Designingtheuser-interfacetomakeitmorecompatiblewiththetaskandtheuser.Thismakesit
easiertouseandmoreresistanttoerrorsthatpeopleareknowntomake
Changingtheworkenvironmenttomakeitsaferandmoreappropriateforthetask
Changingthetasktomakeitmorecompatiblewithusercharacteristics
Changingthewayworkisorganisedtoaccommodatepeople’spsychological,andsocialneeds
Lecture 2
Designingtheuser-interfacetomakeitmorecompatiblewiththetaskandtheuser.Thismakesit
easiertouseandmoreresistanttoerrorsthatpeopleareknowntomake
Changingtheworkenvironmenttomakeitsaferandmoreappropriateforthetask
Changingthetasktomakeitmorecompatiblewithusercharacteristics
Changingthewayworkisorganisedtoaccommodatepeople’spsychological,andsocialneeds
Lecture 2
Problemsandcorrespondingknowledgearisingfromtheintroductionofcomputerinthe
workplace
Lecture 2
Problems
Workpostureandkeying--------------------
Sizeofscreencharacters,contrastetc------
Environmentalfactors-------------------------
Problemsolvingatwork----------------------
Designofnewsystem--------------------------
Knowledgerequiredtosolveproblems
Biomechanics
Visionperception
Noiseandenvironmentalstress
Cognitiveengineering
Systemdesign
workplace
Lecture 2
Problems
Workpostureandkeying--------------------
Sizeofscreencharacters,contrastetc------
Environmentalfactors-------------------------
Problemsolvingatwork----------------------
Designofnewsystem--------------------------
Knowledgerequiredtosolveproblems
Biomechanics
Visionperception
Noiseandenvironmentalstress
Cognitiveengineering
Systemdesign
Theimplementationofergonomicsinsystemdesignshouldmakethesystemwork
betterbyeliminatingaspectsofsystemfunctioningthatareundesirable,uncontrolledorunaccounted
for,suchas
Inefficiency–whenworkereffortproducessub-optimaloutput
Fatigue–inbadlydesignedjobspeopletireunnecessarily
Accidents,injuriesanderrors–duetobadlydesignedinterfacesand/orexcess
stresseithermentalorphysical
Userdifficulties–duetoinappropriatecombinationsofsubtasksmakingthe
dialogue/interactioncumbersomeandunnatural
Lecture 2
betterbyeliminatingaspectsofsystemfunctioningthatareundesirable,uncontrolledorunaccounted
for,suchas
Inefficiency–whenworkereffortproducessub-optimaloutput
Fatigue–inbadlydesignedjobspeopletireunnecessarily
Accidents,injuriesanderrors–duetobadlydesignedinterfacesand/orexcess
stresseithermentalorphysical
Userdifficulties–duetoinappropriatecombinationsofsubtasksmakingthe
dialogue/interactioncumbersomeandunnatural
Lecture 2
AccordingtotheInternationalErgonomicsAssociation,therearethreebroaddomainsof
ergonomics:
Physical ergonomics
Cognitive ergonomics
Organizational ergonomics
Physicalergonomicsisconcernedwithhumananatomical,anthropometric,physiologicaland
biomechanicalcharacteristicsastheyrelatetophysicalactivity.(Relevanttopicsinclude
workingpostures,materialshandling,repetitivemovements,workrelatedmusculoskeletal
disorders,workplacelayout,safetyandhealth.)
Lecture 3
ergonomics:
Physical ergonomics
Cognitive ergonomics
Organizational ergonomics
Physicalergonomicsisconcernedwithhumananatomical,anthropometric,physiologicaland
biomechanicalcharacteristicsastheyrelatetophysicalactivity.(Relevanttopicsinclude
workingpostures,materialshandling,repetitivemovements,workrelatedmusculoskeletal
disorders,workplacelayout,safetyandhealth.)
Lecture 3
Lecture 3Anthropometry physiology, biomechanics and anatomy
Lecture 3
CognitiveErgonomics:“Cognitiveergonomicsisconcernedwithmentalprocesses,suchas
perception,memory,andreasoning,astheyaffectinteractionsamonghumansandother
elementsofasystem.”(Relevanttopicsincludementalworkload,decision-making,skilled
performance,human-computerinteraction,humanreliability,workstressandtrainingasthese
mayrelatetohuman-systemdesign.)
Organizationalergonomicsisconcernedwiththeoptimizationofsociotechnicalsystems,
includingtheirorganizationalstructures,policies,andprocesses.(Relevanttopicsinclude
communication,crewresourcemanagement,workdesign,designofworkingtimes,teamwork,
communityergonomics,cooperativework,newworkparadigms,virtualorganizations,and
qualitymanagement.)
Lecture 3
perception,memory,andreasoning,astheyaffectinteractionsamonghumansandother
elementsofasystem.”(Relevanttopicsincludementalworkload,decision-making,skilled
performance,human-computerinteraction,humanreliability,workstressandtrainingasthese
mayrelatetohuman-systemdesign.)
Organizationalergonomicsisconcernedwiththeoptimizationofsociotechnicalsystems,
includingtheirorganizationalstructures,policies,andprocesses.(Relevanttopicsinclude
communication,crewresourcemanagement,workdesign,designofworkingtimes,teamwork,
communityergonomics,cooperativework,newworkparadigms,virtualorganizations,and
qualitymanagement.)
Lecture 3
Thefocusofergonomics
Thefocusofergonomicsisontheinteractionbetweenthepersonandthemachineandthedesignofthe
interfacebetweenthetwo.Everytimeweuseatooloramachineweinteractwithitviaaninterface(ahandle,a
steeringwheel,acomputerkeyboardandmouse,etc.).Wegetfeedbackviaaninterface(thedashboard
instrumentationinacar,thecomputerscreen,etc.)Thewaythisinterfaceisdesigneddetermineshoweasilyand
safelywecanusethemachine.
Whenfacedwithproductivityproblems,engineersmightcallforbettermachines,
personnelmanagementmightcallforbetter-trainedpeople.Ergonomistscallfora
betterinterfaceandbetterinteractionbetweentheuserandthemachine–bettertask
design.
Lecture 4
Thefocusofergonomicsisontheinteractionbetweenthepersonandthemachineandthedesignofthe
interfacebetweenthetwo.Everytimeweuseatooloramachineweinteractwithitviaaninterface(ahandle,a
steeringwheel,acomputerkeyboardandmouse,etc.).Wegetfeedbackviaaninterface(thedashboard
instrumentationinacar,thecomputerscreen,etc.)Thewaythisinterfaceisdesigneddetermineshoweasilyand
safelywecanusethemachine.
Whenfacedwithproductivityproblems,engineersmightcallforbettermachines,
personnelmanagementmightcallforbetter-trainedpeople.Ergonomistscallfora
betterinterfaceandbetterinteractionbetweentheuserandthemachine–bettertask
design.
Lecture 4
Abasicworksystem
Eveninasimplesystemconsistingofoneperson,onemachineandanenvironment,sixdirectional
interactionsarepossible(H>M,H>E,M>H,M>E,E>H,E>M)andfouroftheseinvolvethe
person.Eachofthecomponentsofaparticularworksystemmayinteracteitherdirectlyorindirectly
withtheothers.Forexample,themachinemaychangethestateoftheenvironment(byemittingnoise
orheat)andthismayaffecttheuser.
Lecture 4
Eveninasimplesystemconsistingofoneperson,onemachineandanenvironment,sixdirectional
interactionsarepossible(H>M,H>E,M>H,M>E,E>H,E>M)andfouroftheseinvolvethe
person.Eachofthecomponentsofaparticularworksystemmayinteracteitherdirectlyorindirectly
withtheothers.Forexample,themachinemaychangethestateoftheenvironment(byemittingnoise
orheat)andthismayaffecttheuser.
Lecture 4
Interactions
H>M:Thebasiccontrolactionsperformedbythehumanonthemachine.Applicationoflarge
forces,‘finetuning’ofcontrols,stockingrawmaterials,maintenance,etc.
H>E:Effectsofthehumanonthelocalenvironnent.Humanémitheat,noise,carbondioxide,etc.
M>H:Feedbackanddisplayofinformation.Machinemayexertforcesonthehumandueto
vibration,acceleration,etc.Machinesurfacesmaybeexcessivelyhotorcoldandathreattothehealth
ofthehuman.
M>E:Machinemayalterworkingenvironmentbyemittingnoise,heat,noxiousgases.
E>H:Theenvironment,inturn,mayinfluencethehuman’sabilitytointeractwiththemachineorto
remainpartoftheworksystem(owingtosmoke,noise,heat,etc.).
E>M:Theenvironmentmayaffectthefunctioningofthemachine.Itmaycauseoverheatingor
freezingofcomponents.
Lecture 4
H>M:Thebasiccontrolactionsperformedbythehumanonthemachine.Applicationoflarge
forces,‘finetuning’ofcontrols,stockingrawmaterials,maintenance,etc.
H>E:Effectsofthehumanonthelocalenvironnent.Humanémitheat,noise,carbondioxide,etc.
M>H:Feedbackanddisplayofinformation.Machinemayexertforcesonthehumandueto
vibration,acceleration,etc.Machinesurfacesmaybeexcessivelyhotorcoldandathreattothehealth
ofthehuman.
M>E:Machinemayalterworkingenvironmentbyemittingnoise,heat,noxiousgases.
E>H:Theenvironment,inturn,mayinfluencethehuman’sabilitytointeractwiththemachineorto
remainpartoftheworksystem(owingtosmoke,noise,heat,etc.).
E>M:Theenvironmentmayaffectthefunctioningofthemachine.Itmaycauseoverheatingor
freezingofcomponents.
Lecture 4
ValueofErgonomicsToday
Manypeoplesufferbecausetheirconditionsatworkandhomeareincompatiblewiththeir
needs,abilitiesandlimitations.Thissituationaffectstheirsafetyandwelfare,aswellas,thatof
organizationsandsocieties.
Hightechnologycanmakeourlivesmoreefficientandexciting.However,fascinationwith
technologyandoverlyambitiousbusinessexpectationscancauseustooverlookhumanfactors
risks.Neglectingtheseriskscanhaveseriouseffectsonmanufacturers,suppliersandservice
enterprises.
Therefore,ergonomicsandhumanfactorswillbemoreimportantinthemodernerathanwhen
itwasfirstintroducedinthenineteenthcentury.Inergonomics,absenteeism,injury,poorquality
andhighlevelsofhumanerrorareseenassystemproblemsratherthan‘peopleproblems’and
theirsolutionisseentolieindesigningabettersystemofworkratherthaninbetter‘man
management’orincentives,by‘motivating’workers.
Lecture 5
Manypeoplesufferbecausetheirconditionsatworkandhomeareincompatiblewiththeir
needs,abilitiesandlimitations.Thissituationaffectstheirsafetyandwelfare,aswellas,thatof
organizationsandsocieties.
Hightechnologycanmakeourlivesmoreefficientandexciting.However,fascinationwith
technologyandoverlyambitiousbusinessexpectationscancauseustooverlookhumanfactors
risks.Neglectingtheseriskscanhaveseriouseffectsonmanufacturers,suppliersandservice
enterprises.
Therefore,ergonomicsandhumanfactorswillbemoreimportantinthemodernerathanwhen
itwasfirstintroducedinthenineteenthcentury.Inergonomics,absenteeism,injury,poorquality
andhighlevelsofhumanerrorareseenassystemproblemsratherthan‘peopleproblems’and
theirsolutionisseentolieindesigningabettersystemofworkratherthaninbetter‘man
management’orincentives,by‘motivating’workers.
Lecture 5
Typesofsystems:(1).ManualSystem(2).MechanicalSystem(3)
Man–machinesystems
Man-machinesystemisacombinationofoneormorehumanbeinginteractingwithone
ormorephysicalcomponenttobringoutsomedesiredoutputformgiveninput.
Man-machinesystemconsistsofanytypeofphysicalobject,device,equipment,facilityand
activitiesperformedbyman.Thedesignissuesmaybethelocationofdisplays,effectsof
lighting,noiselevel,vibrationlevel,effectsontheperceptionandcognition.Issueregarding
workspaceenvelop,skilllevels,training,howmuchfatigueaparticularpersoninthat
particularsystemisfacing,motivationalfactorsandmanyotherfactors.
Lecture 5
AutomatedSystem
Man–machinesystems
Man-machinesystemisacombinationofoneormorehumanbeinginteractingwithone
ormorephysicalcomponenttobringoutsomedesiredoutputformgiveninput.
Man-machinesystemconsistsofanytypeofphysicalobject,device,equipment,facilityand
activitiesperformedbyman.Thedesignissuesmaybethelocationofdisplays,effectsof
lighting,noiselevel,vibrationlevel,effectsontheperceptionandcognition.Issueregarding
workspaceenvelop,skilllevels,training,howmuchfatigueaparticularpersoninthat
particularsystemisfacing,motivationalfactorsandmanyotherfactors.
Lecture 5
AutomatedSystem
Lecture 5
Humancomponents
Thehumanbodyispartofthephysicalworldandobeysthesamephysicallawsasother
animateandinanimateobjects.Thegoalofergonomicsatthislevelistooptimisethe
interactionbetweenthebodyanditsphysicalsurroundings.Thismeansensuringthat
physicalspacerequirementsaremet(usingdataonhuman‘anthropometry’)andthatinternal
andexternalforcesactingonthebodyarenotharmful.
Humancomponents
Thehumanbodyispartofthephysicalworldandobeysthesamephysicallawsasother
animateandinanimateobjects.Thegoalofergonomicsatthislevelistooptimisethe
interactionbetweenthebodyanditsphysicalsurroundings.Thismeansensuringthat
physicalspacerequirementsaremet(usingdataonhuman‘anthropometry’)andthatinternal
andexternalforcesactingonthebodyarenotharmful.
Lecture 5
Senses
Thesensesarethemeansbywhichwearemadeawareofoursurroundings.Humanbeings
areoftensaidtohavefivesenses–sight,hearing,touch,tasteandsmell.Theexistenceand
natureofa‘sixthsense’remainsdebatable.Visionandhearingarethemostrelevantto
ergonomics,althoughsmellisimportantindetectingleaks,fires,andsoon.
Senses
Thesensesarethemeansbywhichwearemadeawareofoursurroundings.Humanbeings
areoftensaidtohavefivesenses–sight,hearing,touch,tasteandsmell.Theexistenceand
natureofa‘sixthsense’remainsdebatable.Visionandhearingarethemostrelevantto
ergonomics,althoughsmellisimportantindetectingleaks,fires,andsoon.
Lecture 5
Central processes
Inordertocarryoutworkactivities,werequireenergyandinformation.Physiological
processesprovideenergytotheworkingmuscles.Thebraincanberegardedasaninformation
processingcentre,thatcontainslow-levelprogramstocontrolthebasicsensorymotorwork
activitiesandhigher-levelcognitiveprocessesthatmakepossibletheplanning,decision
makingandproblemsolvingactivitiesofwork.
The effectors
Thethreeprimaryeffectorsarethehands,thefeetandthevoice.Generally,themusculoskeletalsystem
andbodyweightcanberegardedaseffectors–nopurposefulphysicalactivityofthelimbscanbe
carriedoutwithoutmaintenanceofthepostureofthebodyandstabilisationofthejoints.
Central processes
Inordertocarryoutworkactivities,werequireenergyandinformation.Physiological
processesprovideenergytotheworkingmuscles.Thebraincanberegardedasaninformation
processingcentre,thatcontainslow-levelprogramstocontrolthebasicsensorymotorwork
activitiesandhigher-levelcognitiveprocessesthatmakepossibletheplanning,decision
makingandproblemsolvingactivitiesofwork.
The effectors
Thethreeprimaryeffectorsarethehands,thefeetandthevoice.Generally,themusculoskeletalsystem
andbodyweightcanberegardedaseffectors–nopurposefulphysicalactivityofthelimbscanbe
carriedoutwithoutmaintenanceofthepostureofthebodyandstabilisationofthejoints.
Lecture 6
Machinecomponents
A‘machine’canbeanyman-madedevicethataugmentsworkcapacity.Thetypicalhuman–
machinesystemofergonomicsisillustratedbythecaranddriver.Recentdevelopmentsin
informationtechnologyhaveshiftedmuchoftheattentionofergonomicstoinformation
systemsinwhichtheworksystemisabstractandhasnouniquespatiallocation.Apieceof
softwareonacomputernetworkisanexampleofsuchamachine.Thelocalenvironmentmay
bethenetworkitselfandmanyusers,indifferentlocations,mayinteractwiththemachineat
thesametime.
Controls
Humaninteractionwithmachinesdependsontheprovisionofsuitablecontrols,whichcanbe
actedonbytheeffectors.Withsimpletechnology,themachinecomponentitselfhavethe
control.
Machinecomponents
A‘machine’canbeanyman-madedevicethataugmentsworkcapacity.Thetypicalhuman–
machinesystemofergonomicsisillustratedbythecaranddriver.Recentdevelopmentsin
informationtechnologyhaveshiftedmuchoftheattentionofergonomicstoinformation
systemsinwhichtheworksystemisabstractandhasnouniquespatiallocation.Apieceof
softwareonacomputernetworkisanexampleofsuchamachine.Thelocalenvironmentmay
bethenetworkitselfandmanyusers,indifferentlocations,mayinteractwiththemachineat
thesametime.
Controls
Humaninteractionwithmachinesdependsontheprovisionofsuitablecontrols,whichcanbe
actedonbytheeffectors.Withsimpletechnology,themachinecomponentitselfhavethe
control.
Lecture 6
Displays
Insimpleworksystems,thedisplayisoftenjusttheactionofthemachineonitslocalenvironment.
Withincreasingtechnologicalsophistication,thedistancebetweenthecontrolledprocessandthehuman
componentisincreasedandartificialdisplayshavebeendesigned.
Visualdisplay:Itisthemostcommonmeansofprovidinginformation.
Auditorydisplay:Auditorydisplaysarefrequentlyusedforalerting,warnings,andalarms-situationsin
whichtheinformationoccursrandomlyandrequiresimmediateattention.
Kinaesthesia:Itisrelatedwithsensationofposition,movement,velocityandaccelerationandforcegenerated
byvariousmembersofthebody.
Cutaneoussenses:Itisrelatedwithsensationoftemperature,touchandpainetc.
Chemicalsenses:Itconcernswithtaste&smell.
Displays
Insimpleworksystems,thedisplayisoftenjusttheactionofthemachineonitslocalenvironment.
Withincreasingtechnologicalsophistication,thedistancebetweenthecontrolledprocessandthehuman
componentisincreasedandartificialdisplayshavebeendesigned.
Visualdisplay:Itisthemostcommonmeansofprovidinginformation.
Auditorydisplay:Auditorydisplaysarefrequentlyusedforalerting,warnings,andalarms-situationsin
whichtheinformationoccursrandomlyandrequiresimmediateattention.
Kinaesthesia:Itisrelatedwithsensationofposition,movement,velocityandaccelerationandforcegenerated
byvariousmembersofthebody.
Cutaneoussenses:Itisrelatedwithsensationoftemperature,touchandpainetc.
Chemicalsenses:Itconcernswithtaste&smell.
Lecture 6
Theimmediateenvironment
Thisreferstotheplaceandthecircumstancesinwhichworkiscarriedoutandconsistsofthephysical
workspace,thephysicalenvironmentandthesocialandtechnicalconstraintsunderwhichtheworkis
done.
Workspace
Theworkspaceisthethree-dimensionalspaceinwhichworkiscarriedout.Insimpleworksystems,
theworkspacemaybejusttheplaceinwhichworkisbeingcarriedoutatanypointintimeaswemove
fromonelocationtoanother.
Thephysicalenvironment
Manyaspectsofthephysicalenvironmentcanaffectworkers.Ergonomistsaremostinterestedinthose
thathaveaninfluenceonthewaythehumanandmachinecomponentsinteract.Noise,vibration,
lightingandclimateareofmostconcerntotheergonomist.
Theimmediateenvironment
Thisreferstotheplaceandthecircumstancesinwhichworkiscarriedoutandconsistsofthephysical
workspace,thephysicalenvironmentandthesocialandtechnicalconstraintsunderwhichtheworkis
done.
Workspace
Theworkspaceisthethree-dimensionalspaceinwhichworkiscarriedout.Insimpleworksystems,
theworkspacemaybejusttheplaceinwhichworkisbeingcarriedoutatanypointintimeaswemove
fromonelocationtoanother.
Thephysicalenvironment
Manyaspectsofthephysicalenvironmentcanaffectworkers.Ergonomistsaremostinterestedinthose
thathaveaninfluenceonthewaythehumanandmachinecomponentsinteract.Noise,vibration,
lightingandclimateareofmostconcerntotheergonomist.
Lecture 6
WorkEnvironment:“Whetherworkisphysicalormentalitisperformedinanenvironment.
Bymakingthephysicalcomponentsoftheworkascomfortableandunderstandingaspossible,
betterjobsatisfactionandgreaterproductivityareencouraged.
Visualenvironment:PhysicsofLight,
lightingsystem:400-700nmwavelength
Visibilityandvisualperformance
Typesoflight:DirectandIndirect
Auditoryenvironment:Effectofnoise
Permissiblenoise:frequencyandpitch
Noisecontrol:Distractionanddeviation
Climatecontrol:Thermoregulations
Heatstressandcoldstress
Lecture 4
Bymakingthephysicalcomponentsoftheworkascomfortableandunderstandingaspossible,
betterjobsatisfactionandgreaterproductivityareencouraged.
Visualenvironment:PhysicsofLight,
lightingsystem:400-700nmwavelength
Visibilityandvisualperformance
Typesoflight:DirectandIndirect
Auditoryenvironment:Effectofnoise
Permissiblenoise:frequencyandpitch
Noisecontrol:Distractionanddeviation
Climatecontrol:Thermoregulations
Heatstressandcoldstress
Lecture 4
Lecture 4
Lecture 4
WeseethecoloroflightbeingREFLECTEDfromanobject.
e.g.Ablueobjectreflectsbluelightandabsorbsallothers.
Ablackobjectabsorbsallcolorsoflightanddoesn’treflectany.
Awhiteobjectreflectsalllightandabsorbsnone.
Objectscreatecolorbysubtractingorabsorbingcertainwavelengthsofcolorwhilereflecting
otherwavelengthsbacktotheviewer.
The three primary colors of light are:
All colors we see are
made from these three
colors being reflected
in different combinations
and amounts.
WeseethecoloroflightbeingREFLECTEDfromanobject.
e.g.Ablueobjectreflectsbluelightandabsorbsallothers.
Ablackobjectabsorbsallcolorsoflightanddoesn’treflectany.
Awhiteobjectreflectsalllightandabsorbsnone.
Objectscreatecolorbysubtractingorabsorbingcertainwavelengthsofcolorwhilereflecting
otherwavelengthsbacktotheviewer.
The three primary colors of light are:
All colors we see are
made from these three
colors being reflected
in different combinations
and amounts.
Lecture 4
Three secondary colors of light are made by combining two primary colors in equal amounts:
red+blue=magenta
blue+green=cyan
red+green=yellow
red+green+bluelight=whitelight
yellow,cyanandmagenta=black
Two types of reflection are:
regular:Whenanobjectsurfaceissmooth,and
youseeanimage.Example:aplane(flat)mirror
•diffuse:Whenaroughsurfacescatterslightinmanydirections,andnoimageappears.
Example:paperisroughenoughtoscatterlightsothereisnoimage
Three secondary colors of light are made by combining two primary colors in equal amounts:
red+blue=magenta
blue+green=cyan
red+green=yellow
red+green+bluelight=whitelight
yellow,cyanandmagenta=black
Two types of reflection are:
regular:Whenanobjectsurfaceissmooth,and
youseeanimage.Example:aplane(flat)mirror
•diffuse:Whenaroughsurfacescatterslightinmanydirections,andnoimageappears.
Example:paperisroughenoughtoscatterlightsothereisnoimage
Lecture 4
Properties of light
1.Light travels in a straight line
2.Light travels much faster than sound
3.We see things because they reflects light into our eyes
4.Shadows are formed when light is blocked by an object
Properties of light
1.Light travels in a straight line
2.Light travels much faster than sound
3.We see things because they reflects light into our eyes
4.Shadows are formed when light is blocked by an object
L
R
2
A
R
(radian)
(steradian) 2(1cos)
half plane angle
Case : 1 Case : 22
2 4
R
2
A
R
(radian)
(steradian) 2(1cos)
half plane angle
Case : 1 Case : 22
2 4
Inverse square law
Thislawstatesthat‘theilluminationofasurfaceisinverselyproportionaltothesquareofdistancebetweenthe
surfaceandapointsource’. 1
2
A
d
For area A1
For area A2
For area A31
2
A
II
d
1
1 22
1
1IAflux I
E
areadAd
2 22
2
(2)
II
E
dd
3 22
3
(3)
II
E
dd
Illuminancedecreasesasthedistancefromthelightsourceincreases
Thislawstatesthat‘theilluminationofasurfaceisinverselyproportionaltothesquareofdistancebetweenthe
surfaceandapointsource’. 1
2
A
d
For area A1
For area A2
For area A31
2
A
II
d
1
1 22
1
1IAflux I
E
areadAd
2 22
2
(2)
II
E
dd
3 22
3
(3)
II
E
dd
Illuminancedecreasesasthedistancefromthelightsourceincreases
Lambert's cosine law
Thislawstatesthat‘illumination,Eatanypointonasurfaceisdirectlyproportionaltothecosineoftheangle
betweenthenormalatthatpointandthelineofflux’.1 2
cos
I
E
d
Thislawstatesthat‘illumination,Eatanypointonasurfaceisdirectlyproportionaltothecosineoftheangle
betweenthenormalatthatpointandthelineofflux’.1 2
cos
I
E
d
Que.1.Theluminousintensityofasourceis600candelaisplacedinthemiddleofa10×6×2mroom.Calculatethe
illumination:
1.Ateachcorneroftheroom.
2.Atthemiddleofthe6-mwall.
Que.2.Thecandlepowerofasourceis200candelainalldirectionsbelowthelamp.Themountingheightofthe
lampis6m.
Findtheillumination:
1.Justbelowthelamp.
2.3mhorizontallyawayfromthelampontheground.
3.Thetotalluminousfluxinanareaof1.5-mdiameteraroundthelampontheground
Que.3.Twosourcesofcandlepowerorluminousintensity200candelaand250candelaaremountedat8and10m,
respectively.Thehorizontaldistancebetweenthelamppostsis40m,calculatetheilluminationinthemiddleofthe
posts.
illumination:
1.Ateachcorneroftheroom.
2.Atthemiddleofthe6-mwall.
Que.2.Thecandlepowerofasourceis200candelainalldirectionsbelowthelamp.Themountingheightofthe
lampis6m.
Findtheillumination:
1.Justbelowthelamp.
2.3mhorizontallyawayfromthelampontheground.
3.Thetotalluminousfluxinanareaof1.5-mdiameteraroundthelampontheground
Que.3.Twosourcesofcandlepowerorluminousintensity200candelaand250candelaaremountedat8and10m,
respectively.Thehorizontaldistancebetweenthelamppostsis40m,calculatetheilluminationinthemiddleofthe
posts.
ObjectivesoftheErgonomics:
Humanrequirementsarethesystemrequirements,ratherthansecondaryconsiderations
andcanbestatedingeneraltermsasrequirementsfor–
1.Equipmentthatisusableandsafe.
2.Tasksthatarecompatiblewithpeople’sexpectations,limitationsandtraining.
3.Anenvironmentthatiscomfortableandappropriateforthetask.
4.Asystemofworkorganisationthatrecognisespeople’ssocialandeconomicneeds.
Humanrequirementsarethesystemrequirements,ratherthansecondaryconsiderations
andcanbestatedingeneraltermsasrequirementsfor–
1.Equipmentthatisusableandsafe.
2.Tasksthatarecompatiblewithpeople’sexpectations,limitationsandtraining.
3.Anenvironmentthatiscomfortableandappropriateforthetask.
4.Asystemofworkorganisationthatrecognisespeople’ssocialandeconomicneeds.
Ergonomicsanditsareaofapplicationintheworksystem
Oneoftheproblemsfacingtheergonomistbothinthedesignofnewworksystemsandintheevaluation
ofexistingonesistoensurethatallaspectsareconsideredinasystematicway.Thehuman–machine
approachenableskeyareastobeidentifiedirrespectiveoftheparticularsystemsothatergonomicscan
beappliedconsistentlyindifferentsystems.
1.Thefirststepistodescribetheworksystemanditsboundaries.Thisenablesthecontentandscopeof
theapplicationofergonomicstobespecified.
2.Next,thehumanandmachinecomponentsandthelocalenvironmentaredefinedanddescribedin
termsoftheirmaincomponentsasdepicted.
3.Followingthis,theinteractionsbetweenthevariouscomponentscanbeanalysedtoidentifythepoints
ofapplicationofbasicknowledgetothedesign/evaluation.
Oneoftheproblemsfacingtheergonomistbothinthedesignofnewworksystemsandintheevaluation
ofexistingonesistoensurethatallaspectsareconsideredinasystematicway.Thehuman–machine
approachenableskeyareastobeidentifiedirrespectiveoftheparticularsystemsothatergonomicscan
beappliedconsistentlyindifferentsystems.
1.Thefirststepistodescribetheworksystemanditsboundaries.Thisenablesthecontentandscopeof
theapplicationofergonomicstobespecified.
2.Next,thehumanandmachinecomponentsandthelocalenvironmentaredefinedanddescribedin
termsoftheirmaincomponentsasdepicted.
3.Followingthis,theinteractionsbetweenthevariouscomponentscanbeanalysedtoidentifythepoints
ofapplicationofbasicknowledgetothedesign/evaluation.
Ergonomicsanditsareaofapplicationintheworksystem
Ergonomicsanditsareaofapplicationintheworksystem
FMJVsFJM
Anumberofgeneraltrendscanbeidentifiedinthehistoricalreview.
First,organisationsattemptedtoincreasetheirproductivitybyintroducingnewmethodsandmachines.
Intheeraofpureengineeringthisworkedbecausegreatimprovementsinmachinedesignwerepossible
(manyexistingprocesseshadnotbeenmechanisedatalluntilthen).
Secondly,toincreaseproductivity,organisationstriedtooptimisethedesignoftaskstominimise
apparentlyunproductiveeffort.
Attemptstofitthemantothejob‟(FMJ)werebasedontheideathatproductivityorefficiencycouldbe
improvedbyselectingworkerswiththerightaptitudesforaparticularjob.Thisapproachformsoneof
therootsofmodernoccupationalpsychology.Itisbasedontheassumptionthatimportantaptitudesfor
anyparticularjobreallydoexistandthattheycanbeidentifiedandobjectivelymeasured.Thisis
certainlytrueinthesenseofselectingpeoplewithformalqualificationsorskillstofillparticularposts
andthereisplentyofevidencethatitiscost-effective.
Anumberofgeneraltrendscanbeidentifiedinthehistoricalreview.
First,organisationsattemptedtoincreasetheirproductivitybyintroducingnewmethodsandmachines.
Intheeraofpureengineeringthisworkedbecausegreatimprovementsinmachinedesignwerepossible
(manyexistingprocesseshadnotbeenmechanisedatalluntilthen).
Secondly,toincreaseproductivity,organisationstriedtooptimisethedesignoftaskstominimise
apparentlyunproductiveeffort.
Attemptstofitthemantothejob‟(FMJ)werebasedontheideathatproductivityorefficiencycouldbe
improvedbyselectingworkerswiththerightaptitudesforaparticularjob.Thisapproachformsoneof
therootsofmodernoccupationalpsychology.Itisbasedontheassumptionthatimportantaptitudesfor
anyparticularjobreallydoexistandthattheycanbeidentifiedandobjectivelymeasured.Thisis
certainlytrueinthesenseofselectingpeoplewithformalqualificationsorskillstofillparticularposts
andthereisplentyofevidencethatitiscost-effective.
Itisalsotrueforsomejobse.g.,firemen,lifesaversandthoseworkinginthearmedservicesare
restrictedtoindividualswithcertainspecificaptitudesand/orphysicalcharacteristics.Historically,
anthropometricselectioncriteriaweremadeuseof.However,owingtochangesinlabourlegislationand
theincreasedemphasisonequalopportunities,staticanthropometriccriteriahavegivenwayto
functionaltests.Insteadofselectingonthebasisofsizeorchestcircumference,recruitmentdependson
theapplicants’abilitytocarryoutsomegenericorjob-criticaltaskunderdefinedconditionsandtoa
pre-setstandard.
Analternativeapproach,whichistheguidingphilosophyofergonomics,isknownas“fittingthejobto
theman‟(FJM).Muchoftheearlyhumanengineeringandworkspacedesignattemptedtodesigntasksto
suitthecharacteristicsoftheworker.TheunderlyingassumptionsoftheFJMapproacharethatasuitable
setofworkercharacteristicscanbespecifiedaroundwhichthejobcanbedesignedandthatcanbedone
foranyjob.Alargepartofthesubjectisdevotedtodescribingthesecharacteristicsattheanatomical,
physiologicalandpsychologicallevelsandexplainingtheirdesignimplications.
restrictedtoindividualswithcertainspecificaptitudesand/orphysicalcharacteristics.Historically,
anthropometricselectioncriteriaweremadeuseof.However,owingtochangesinlabourlegislationand
theincreasedemphasisonequalopportunities,staticanthropometriccriteriahavegivenwayto
functionaltests.Insteadofselectingonthebasisofsizeorchestcircumference,recruitmentdependson
theapplicants’abilitytocarryoutsomegenericorjob-criticaltaskunderdefinedconditionsandtoa
pre-setstandard.
Analternativeapproach,whichistheguidingphilosophyofergonomics,isknownas“fittingthejobto
theman‟(FJM).Muchoftheearlyhumanengineeringandworkspacedesignattemptedtodesigntasksto
suitthecharacteristicsoftheworker.TheunderlyingassumptionsoftheFJMapproacharethatasuitable
setofworkercharacteristicscanbespecifiedaroundwhichthejobcanbedesignedandthatcanbedone
foranyjob.Alargepartofthesubjectisdevotedtodescribingthesecharacteristicsattheanatomical,
physiologicalandpsychologicallevelsandexplainingtheirdesignimplications.
Atwork,ergonomicsisappliedtothedesignoftheworkplaceandtasks.Itisoftenreferredtoas
occupationalergonomicswithintheOHScommunity.Assuchitaimstopromotehealth,
efficiencyandwellbeinginemployeesbydesigningforsafe,satisfyingandproductivework.
Positiveperformancefactorssuchasworkercomfort,wellbeing,Efficiency,Productivityareall
consideredindetermininghowtoachieveanacceptableresult.Goodergonomicsinthe
workplaceshouldimproveproductivityandmoraleanddecreaseinjuries,sickleave,staff
turnoverandabsenteeism.
Elementsinoccupationalergonomics:
Theworker:Employeeshavearangeofcharacteristicsthatneed
tobeconsideredincludingphysicalandmentalcapacities;experienceandskills;education
andtraining;age;gender;health.
occupationalergonomicswithintheOHScommunity.Assuchitaimstopromotehealth,
efficiencyandwellbeinginemployeesbydesigningforsafe,satisfyingandproductivework.
Positiveperformancefactorssuchasworkercomfort,wellbeing,Efficiency,Productivityareall
consideredindetermininghowtoachieveanacceptableresult.Goodergonomicsinthe
workplaceshouldimproveproductivityandmoraleanddecreaseinjuries,sickleave,staff
turnoverandabsenteeism.
Elementsinoccupationalergonomics:
Theworker:Employeeshavearangeofcharacteristicsthatneed
tobeconsideredincludingphysicalandmentalcapacities;experienceandskills;education
andtraining;age;gender;health.
Job/taskdesign–Whattheemployeeisrequiredtodoandwhattheyactuallydo.Itincludesjob
content;workdemands;restrictionsandtimerequirementssuchasdeadlines;individual’scontrolover
workloadincludingdecisionlatitude;workingwithotheremployees;andresponsibilitiesofthejob.
Workenvironment–Thebuildings,workareasandspaces;lighting,noise,thethermalenvironment.
Equipmentdesign–Thehardwareoftheworkplace.Itisthepartofergonomicsthateverybody
recognizesandincludeselectronicandmobileequipment,protectiveclothing,furnitureandtools.
Workorganization–Itincludespatternsofwork;peaksandtroughsinworkload,shiftwork;
consultation;inefficienciesororganizationaldifficulties;restandworkbreaks;teamwork;howthe
workisorganizedandwhy;theworkplaceculture;aswellasthebroadereconomicandsocial
influences.
content;workdemands;restrictionsandtimerequirementssuchasdeadlines;individual’scontrolover
workloadincludingdecisionlatitude;workingwithotheremployees;andresponsibilitiesofthejob.
Workenvironment–Thebuildings,workareasandspaces;lighting,noise,thethermalenvironment.
Equipmentdesign–Thehardwareoftheworkplace.Itisthepartofergonomicsthateverybody
recognizesandincludeselectronicandmobileequipment,protectiveclothing,furnitureandtools.
Workorganization–Itincludespatternsofwork;peaksandtroughsinworkload,shiftwork;
consultation;inefficienciesororganizationaldifficulties;restandworkbreaks;teamwork;howthe
workisorganizedandwhy;theworkplaceculture;aswellasthebroadereconomicandsocial
influences.
Humanfactorsandergonomics:
Humanfactorsandergonomicshavealwayshadmuchincommon,buttheirdevelopmenthasmoved
alongsomewhatdifferentlines.
•Humanfactorsputsmuchemphasisontheintegrationofthehumanconsiderationsintothetotal
systemdesignprocess.Ithasachievedremarkablesuccessinthedesignoflargesystemsintheaerospace
industry.
•Ergonomicsissometimesmorepiecemeal(unsystematicpartialmeasurestakenoveraperiodoftime)
andhastraditionallybeenmoretiedtoitsbasicsciencesortoaparticulartopicorapplicationarea.
•IntheUSA,theHumanFactorsSocietychangeditsnametotheHumanFactorsandErgonomicsSociety
(HFES).
•BothhumanfactorsandergonomicstaketheFJMapproachandstatethatjobsshouldbemade
appropriateforpeopleratherthantheotherwayaroundi.e.,FMJ.
Humanfactorsandergonomicshavealwayshadmuchincommon,buttheirdevelopmenthasmoved
alongsomewhatdifferentlines.
•Humanfactorsputsmuchemphasisontheintegrationofthehumanconsiderationsintothetotal
systemdesignprocess.Ithasachievedremarkablesuccessinthedesignoflargesystemsintheaerospace
industry.
•Ergonomicsissometimesmorepiecemeal(unsystematicpartialmeasurestakenoveraperiodoftime)
andhastraditionallybeenmoretiedtoitsbasicsciencesortoaparticulartopicorapplicationarea.
•IntheUSA,theHumanFactorsSocietychangeditsnametotheHumanFactorsandErgonomicsSociety
(HFES).
•BothhumanfactorsandergonomicstaketheFJMapproachandstatethatjobsshouldbemade
appropriateforpeopleratherthantheotherwayaroundi.e.,FMJ.
Attemptsto“HumaniseWork”
Generalfeaturesofagoodjob:(Psychologically)
Optimumworkloading
Minimumroleambiguities
Minimumroleconflict
Supportfromcolleaguesandmanagement
Socialcontent/need
1960–1980largescaleprogrammeinEuropean
Highqualityjobbychangingworkorganisation
Casestudy:Volvomotors:ConventionalproductionlinemethodVsunitproductionmethod
(objective:newwayofassemblytohavemorestable,motivatedandproductiveworkforce)
Generalfeaturesofagoodjob:(Psychologically)
Optimumworkloading
Minimumroleambiguities
Minimumroleconflict
Supportfromcolleaguesandmanagement
Socialcontent/need
1960–1980largescaleprogrammeinEuropean
Highqualityjobbychangingworkorganisation
Casestudy:Volvomotors:ConventionalproductionlinemethodVsunitproductionmethod
(objective:newwayofassemblytohavemorestable,motivatedandproductiveworkforce)
AccordingtoBernoux(1994)therequirementsforeffectiveparticipationare:
(employee groups sampled: managers, professionals, clerks, skilled workers, semiskilled and unskilled
worker)
•Employeeshavetoacknowledgetheneedforparticipation.
•Employeeshavetotrustthattheirparticipationwillnothavenegativeeffectsandthattheywillhave
somecontroloverthefinaldecisions.
•Employeeshavetoperceivethatchangesarebeingintroducedinalegitimateway.
•Employeeshavetobelievethatchangeisbeingimplementedcorrectly.
•Employeeshavetobegivenarealroletoplayintheintroductionandtestingofnewwaysofworking.
Autonomyisapropertyofhigher-statusindividuals.Lower-statusindividualsalmostexcludedfrom
participationindecisionsaboutproductionintheirorganisations.
(employee groups sampled: managers, professionals, clerks, skilled workers, semiskilled and unskilled
worker)
•Employeeshavetoacknowledgetheneedforparticipation.
•Employeeshavetotrustthattheirparticipationwillnothavenegativeeffectsandthattheywillhave
somecontroloverthefinaldecisions.
•Employeeshavetoperceivethatchangesarebeingintroducedinalegitimateway.
•Employeeshavetobelievethatchangeisbeingimplementedcorrectly.
•Employeeshavetobegivenarealroletoplayintheintroductionandtestingofnewwaysofworking.
Autonomyisapropertyofhigher-statusindividuals.Lower-statusindividualsalmostexcludedfrom
participationindecisionsaboutproductionintheirorganisations.
Contributionofmodernergonomicsinsystemdesignandmanagement
Modernergonomicscontributestothedesignandevaluationofworksystemsandproducts.Unlikein
earliertimeswhenanengineerdesignedawholemachineorproduct,designisateameffortnowadays.
Theergonomistusuallyhasanimportantroletoplaybothattheconceptualphaseandindetaileddesign
aswellasinprototypingandtheevaluationofexistingproductsandfacilities.Modernergonomics
contributesinanumberofwaystothedesignoftheworksystem.Theseactivitiesshouldbeseenasan
integralpartofthedesignandmanagementofsystemsratherthan‘optionalextras’.
1.Standardformatfordescribinghuman–machinesystems
2.Identificationandclassificationofdesignissues
3.Taskandhuman–machineinteractionanalysis
4.Specificationofsystemdesign
5.Identificationandanalysisofcoretrends
6.Generationandimplementationofnewconcepts
7.Evaluationofsocio-technicalimplications
Modernergonomicscontributestothedesignandevaluationofworksystemsandproducts.Unlikein
earliertimeswhenanengineerdesignedawholemachineorproduct,designisateameffortnowadays.
Theergonomistusuallyhasanimportantroletoplaybothattheconceptualphaseandindetaileddesign
aswellasinprototypingandtheevaluationofexistingproductsandfacilities.Modernergonomics
contributesinanumberofwaystothedesignoftheworksystem.Theseactivitiesshouldbeseenasan
integralpartofthedesignandmanagementofsystemsratherthan‘optionalextras’.
1.Standardformatfordescribinghuman–machinesystems
2.Identificationandclassificationofdesignissues
3.Taskandhuman–machineinteractionanalysis
4.Specificationofsystemdesign
5.Identificationandanalysisofcoretrends
6.Generationandimplementationofnewconcepts
7.Evaluationofsocio-technicalimplications
Modernergonomics
1.Standardformatfordescribinghuman–machinesystems
•Thetwomostimportantcomponentinhuman-machinemodeltodescribeare:themachine/technology
andtheuser/operator.
•Machines/technologiesarenormallywell-describedandplentyofinformationareavailableintheform
ofmanualsandtextbooks.Whereaslessdetailandlessformalinformationaboutpeople/operator/user.
Designeroftenneedstomakeassumptionsaboutpeopleinawaythattheywouldneverdoabout
machines.
•Userdescriptionscanbephysical,intermsofdimensionsandabilitiesandincludingphysiological
factorssuchasageandfitness.Psychologicaldescriptionsincludedetailsofskills,knowledge,experience
andmotivationandmayincludedetailedconsiderationssuchaspreferredwaysofworking,etc.
1.Standardformatfordescribinghuman–machinesystems
•Thetwomostimportantcomponentinhuman-machinemodeltodescribeare:themachine/technology
andtheuser/operator.
•Machines/technologiesarenormallywell-describedandplentyofinformationareavailableintheform
ofmanualsandtextbooks.Whereaslessdetailandlessformalinformationaboutpeople/operator/user.
Designeroftenneedstomakeassumptionsaboutpeopleinawaythattheywouldneverdoabout
machines.
•Userdescriptionscanbephysical,intermsofdimensionsandabilitiesandincludingphysiological
factorssuchasageandfitness.Psychologicaldescriptionsincludedetailsofskills,knowledge,experience
andmotivationandmayincludedetailedconsiderationssuchaspreferredwaysofworking,etc.
2.Identificationandclassificationofdesignissues
Amajorroleofergonomicsistoidentifydesignissuesthataffectpeopleandtoclassifytheminorderto
renderthemforfurtheranalysisusingappropriateknowledge.
•Allworksystemsarespecific,yetmanypublisheddesignguidelinesaregeneral.
•Properinterpretationofergonomicsissuesandtheirhumanimplicationsisacrucialstepinthedesign
orredesignprocess.
•Effectivepreventionandmanagementmustconsiderpsycho-socialaswellasphysicalfactorsinto
account.
•Systemmalfunctionsthatinvolvehumansmustthereforebeanalysedincontext,whichrequiresthatthe
focusoftheanalysisbeshiftedfromthehumantothehuman–machinesystem.
3.Taskandhuman–machineinteractionanalysis
Simpleflowdiagramscanbeusedto‘choreograph’human–machineinteractionand,ateachstage,the
appropriatenessandsuitabilityofthedesigncanbeassessed.
Amajorroleofergonomicsistoidentifydesignissuesthataffectpeopleandtoclassifytheminorderto
renderthemforfurtheranalysisusingappropriateknowledge.
•Allworksystemsarespecific,yetmanypublisheddesignguidelinesaregeneral.
•Properinterpretationofergonomicsissuesandtheirhumanimplicationsisacrucialstepinthedesign
orredesignprocess.
•Effectivepreventionandmanagementmustconsiderpsycho-socialaswellasphysicalfactorsinto
account.
•Systemmalfunctionsthatinvolvehumansmustthereforebeanalysedincontext,whichrequiresthatthe
focusoftheanalysisbeshiftedfromthehumantothehuman–machinesystem.
3.Taskandhuman–machineinteractionanalysis
Simpleflowdiagramscanbeusedto‘choreograph’human–machineinteractionand,ateachstage,the
appropriatenessandsuitabilityofthedesigncanbeassessed.
4.Specificationofsystemdesign
Aftermanyyears,researchinergonomicsanditsrelateddisciplineshasyieldedstandardsandguidelines
fortightercontrolofworkingconditions.TheInternationalOrganizationforStandardization(ISO)in
Geneva,Switzerlandpublishedanergonomicsstandards.
•Standardsspecify‘howwedothings’andareusuallyadoptedbyagreement,oftenbetweendifferent
countries.Theydonothavethesameforceasregulationsbutarenormallymorespecificthanguidelines
andcontainmoretechnicalinformation.
•Ergonomistsindesignteamsoftenfindthattheycancommunicatetheirideasmoreeffectivelywhen
theyexpressthemwithreferencetostandards.Ergonomistsareoftenmosteffectivewhentheycangive
focused,quantitativespecificationtoengineersanddesigners.
Aftermanyyears,researchinergonomicsanditsrelateddisciplineshasyieldedstandardsandguidelines
fortightercontrolofworkingconditions.TheInternationalOrganizationforStandardization(ISO)in
Geneva,Switzerlandpublishedanergonomicsstandards.
•Standardsspecify‘howwedothings’andareusuallyadoptedbyagreement,oftenbetweendifferent
countries.Theydonothavethesameforceasregulationsbutarenormallymorespecificthanguidelines
andcontainmoretechnicalinformation.
•Ergonomistsindesignteamsoftenfindthattheycancommunicatetheirideasmoreeffectivelywhen
theyexpressthemwithreferencetostandards.Ergonomistsareoftenmosteffectivewhentheycangive
focused,quantitativespecificationtoengineersanddesigners.
5.Identificationandanalysisofcoretrends
Animportantroleforergonomicsistoactasaninterfacebetweenbasichumanandbiologicalsciences
anddevelopmentsinorganisationalneeds.Theergonomistisfrequentlyoneofthefewmembersofthe
designteamwithformaltrainingintheseareas.
•Ergonomicshasgeneratedmanydesignguidelinesandrecommendations,whicharefrequentlymade
availabletoengineersanddesigners.Anergonomistusesbackgroundknowledgeofhumansciencesto
interpretgeneralguidelinessothattheyareappropriatetotheparticularsystem.
•Forexample,designmanualsoftengivethedimensionsofworkstationsirrespectiveoftheparticular
industry.Becauseergonomistsknowstherationaleforagivenguidelineorspecification,theycandecide
whetheritneedstobemodified.
Animportantroleforergonomicsistoactasaninterfacebetweenbasichumanandbiologicalsciences
anddevelopmentsinorganisationalneeds.Theergonomistisfrequentlyoneofthefewmembersofthe
designteamwithformaltrainingintheseareas.
•Ergonomicshasgeneratedmanydesignguidelinesandrecommendations,whicharefrequentlymade
availabletoengineersanddesigners.Anergonomistusesbackgroundknowledgeofhumansciencesto
interpretgeneralguidelinessothattheyareappropriatetotheparticularsystem.
•Forexample,designmanualsoftengivethedimensionsofworkstationsirrespectiveoftheparticular
industry.Becauseergonomistsknowstherationaleforagivenguidelineorspecification,theycandecide
whetheritneedstobemodified.
6.Generationandimplementationofnewconcepts
Theergonomisthasanimportantroletoplayattheconceptgenerationstagetoanticipatewhatwillbe
thedemandsofthenewsystemandhowwilltheyaffectoperators?
•Theergonomistmustanalysethereasonsforcurrentorproposeddesignsandsuggestimprovements
andalternativeconcepts.
•Itisnecessarytodevelopasensitivitytothecost–benefitimplicationsandpracticalitiesofnewdesign
ideas.
•Thecategorychosenforarecommendationdependsontheneedforchange,asperceivedbythe
ergonomist,andtheimplementationcostsintermsofmoney,time,expertise,impactonday-to-day
running,etc.
Theergonomisthasanimportantroletoplayattheconceptgenerationstagetoanticipatewhatwillbe
thedemandsofthenewsystemandhowwilltheyaffectoperators?
•Theergonomistmustanalysethereasonsforcurrentorproposeddesignsandsuggestimprovements
andalternativeconcepts.
•Itisnecessarytodevelopasensitivitytothecost–benefitimplicationsandpracticalitiesofnewdesign
ideas.
•Thecategorychosenforarecommendationdependsontheneedforchange,asperceivedbythe
ergonomist,andtheimplementationcostsintermsofmoney,time,expertise,impactonday-to-day
running,etc.
Waysofprioritizingrecommendationsare-
1.Implementrecommendationimmediately(e.g.thereisseriousdesignflawthreateningemployeehealth
orsystemreliabilityorcontraveninglegislation).
2.Implementrecommendationsoon(e.g.thecurrentwayofworkingisunsatisfactorybutthereisno
immediatedanger).
3.Implementwhenequipmentisshutdown(e.g.ifstoppagesareexpensiveandthereisnoimmediate
danger,waituntilthesystemisshutdownforregularmaintenanceorrepairandthenimplementthe
idea).
4.Implementwhencost–benefitisacceptable(e.g.whenthefinancialsituationimproves,when
implementationcostsarelower).
5. Implement when equipment is built or purchased (e.g. phase-in new products or items on a
replacement basis as old ones are discarded).
1.Implementrecommendationimmediately(e.g.thereisseriousdesignflawthreateningemployeehealth
orsystemreliabilityorcontraveninglegislation).
2.Implementrecommendationsoon(e.g.thecurrentwayofworkingisunsatisfactorybutthereisno
immediatedanger).
3.Implementwhenequipmentisshutdown(e.g.ifstoppagesareexpensiveandthereisnoimmediate
danger,waituntilthesystemisshutdownforregularmaintenanceorrepairandthenimplementthe
idea).
4.Implementwhencost–benefitisacceptable(e.g.whenthefinancialsituationimproves,when
implementationcostsarelower).
5. Implement when equipment is built or purchased (e.g. phase-in new products or items on a
replacement basis as old ones are discarded).
7.Evaluationofsocio-technicalimplications
Thedesignofnewsystemsandtheredesignofexistingonescanhaveseriousimplicationsforthe
organizationalclimate.
•Technologicalandorganizationalchangescanhaveprofoundeffectsontheworkinglivesofindividuals
anditispartoftheergonomist’sfunctiontodeterminewhattheseeffectsmightbeandtoanticipate
futureproblems.
Thedesignofnewsystemsandtheredesignofexistingonescanhaveseriousimplicationsforthe
organizationalclimate.
•Technologicalandorganizationalchangescanhaveprofoundeffectsontheworkinglivesofindividuals
anditispartoftheergonomist’sfunctiontodeterminewhattheseeffectsmightbeandtoanticipate
futureproblems.
Designtoday:Howdesigninfluencesourlifeandwhatmaybenecessarytothink?
Thislikenessagainstcost;ifitmatcheswithour
requirementandouraspirationandifitiscompatibleto
ourbodysize,ourbehavior,ourphysiologicaltolerance
limit
Usability,reusabilityandconvenience
Pleasurevalue,
bodymatch
Purpose,intention
The cost, efficiency, persons comfort, feeling and the context
Thislikenessagainstcost;ifitmatcheswithour
requirementandouraspirationandifitiscompatibleto
ourbodysize,ourbehavior,ourphysiologicaltolerance
limit
Usability,reusabilityandconvenience
Pleasurevalue,
bodymatch
Purpose,intention
The cost, efficiency, persons comfort, feeling and the context
Human Aspects
(compatibility, affordability and
sustainability)
Design today
Design is a continuous problem solving process
with conversion of ideas into reality, keeping in
mind the user’s characteristics, limitations, art and
aesthetics, materials and process and new
technology.
DesignisanInnovative,Practicaland
Reproducible,solution/processtosatisfyhuman
need.
A good design aids human functional need (usability) as well as pleasure value (pleasurability).
(compatibility, affordability and
sustainability)
Design today
Design is a continuous problem solving process
with conversion of ideas into reality, keeping in
mind the user’s characteristics, limitations, art and
aesthetics, materials and process and new
technology.
DesignisanInnovative,Practicaland
Reproducible,solution/processtosatisfyhuman
need.
A good design aids human functional need (usability) as well as pleasure value (pleasurability).
Scientificmanagementandworkstudy
Scientificmanagement,developedbyF.W.TaylorandWorkstudydevelopedbyFrankBunker
GilbrethandLillianMollerGilbreth.Around20
th
century(Victorianera)
Boththemethodsweredevelopedbasedontherealizationthatproductivitycouldbeimproved
byredesigningthewayworkwasdoneandnotjustbyusingbettermachines.
1.Factoryownerssupplypremises,powerandrawmaterials,etc.andhireforemento
organizethework.
2.Managementisconcernedonlywithoutputandhasonlyaglobalaim‘productivity’.
3.Incentivesareprovidedforemployeestosuggestimprovementsinthework.
Taylorrealizedthatthereweremanydrawbackstothis‘incentiveandinitiative’styleof
management.Nobodywasdirectlyresponsibleforproductivityandthesystemwasopentothe
corruptionandexploitationofworkers(harassmentoffemales).
Scientificmanagement,developedbyF.W.TaylorandWorkstudydevelopedbyFrankBunker
GilbrethandLillianMollerGilbreth.Around20
th
century(Victorianera)
Boththemethodsweredevelopedbasedontherealizationthatproductivitycouldbeimproved
byredesigningthewayworkwasdoneandnotjustbyusingbettermachines.
1.Factoryownerssupplypremises,powerandrawmaterials,etc.andhireforemento
organizethework.
2.Managementisconcernedonlywithoutputandhasonlyaglobalaim‘productivity’.
3.Incentivesareprovidedforemployeestosuggestimprovementsinthework.
Taylorrealizedthatthereweremanydrawbackstothis‘incentiveandinitiative’styleof
management.Nobodywasdirectlyresponsibleforproductivityandthesystemwasopentothe
corruptionandexploitationofworkers(harassmentoffemales).
Scientificmanagementandworkstudy
Tayloremphasisedthateveryjob,nomatterhowsmall,isworthyofstudyandworkfor
improvement.Furthermore,heemphasisedthatitismanagement’sresponsibilitytoseethat
theworkisdoneintheinterestsofmaximisingreturnsforthefinancialbenefitofthecompany,
shareholdersandemployees.
Believes:Thetasksneedtobebrokendownintotheirsimplestpossibleformand,withthe
introductionofanappropriatebonusscheme,itisassumedthatworkerswouldmaximisetheir
output.
Criticism:Thesocialaspectsofworkandsatisfactionwereignored.Anassumptionthatall
partiesinanindustrycananddohavethesameinterests.Itisassumedthatallwillcooperate
tomaximisetheireconomicreturns.
Tayloremphasisedthateveryjob,nomatterhowsmall,isworthyofstudyandworkfor
improvement.Furthermore,heemphasisedthatitismanagement’sresponsibilitytoseethat
theworkisdoneintheinterestsofmaximisingreturnsforthefinancialbenefitofthecompany,
shareholdersandemployees.
Believes:Thetasksneedtobebrokendownintotheirsimplestpossibleformand,withthe
introductionofanappropriatebonusscheme,itisassumedthatworkerswouldmaximisetheir
output.
Criticism:Thesocialaspectsofworkandsatisfactionwereignored.Anassumptionthatall
partiesinanindustrycananddohavethesameinterests.Itisassumedthatallwillcooperate
tomaximisetheireconomicreturns.
AdvantagesofTaylormanagementtheory
1.Itallowedgreaterflexibilityinallocatingoperatorstoeasilylearntasks.
2.Fewerskilledworkerswereneeded.
3.Skillshortageswereavoidedandtrainingcostsandwagescouldbemoreeasilycontained.
4.Theintroductionofpacedworkenabledproductionschedulestobemorerigorously
quantified.Betterpredictionsofoutputcouldbemade.
5.Ifeveryoneworkedatthesamepace,theresultwasalwaysafinishedproduct.
1.Itallowedgreaterflexibilityinallocatingoperatorstoeasilylearntasks.
2.Fewerskilledworkerswereneeded.
3.Skillshortageswereavoidedandtrainingcostsandwagescouldbemoreeasilycontained.
4.Theintroductionofpacedworkenabledproductionschedulestobemorerigorously
quantified.Betterpredictionsofoutputcouldbemade.
5.Ifeveryoneworkedatthesamepace,theresultwasalwaysafinishedproduct.
Scientificmanagementandworkstudy
WorkstudydevelopedbyFrankBunkerGilbrethandLillianMollerGilbreth,American
industrialpsychologists.Theydevelopedmethodsforanalysingandevaluatingthewaytasks
shouldbeperformed.
1.Ataskshouldbebrokendowninto‘elements(thebasicmovementsandproceduresrequired
toperformit)’.
2.Inefficientorredundantmovementsshouldbeeliminated.
3.Redesigningandreconfiguringtheremainingelementstoenhanceproductivity.
Therblig
Therbligsare18kindsofelementalmotionsusedinthestudyofmotioneconomyinthe
workplace.Aworkplacetaskisanalysedbyrecordingeachofthetherbligunitsforaprocess,
withtheresultsusedforoptimizationofmanuallaborbyeliminatingunneededmovements.
WorkstudydevelopedbyFrankBunkerGilbrethandLillianMollerGilbreth,American
industrialpsychologists.Theydevelopedmethodsforanalysingandevaluatingthewaytasks
shouldbeperformed.
1.Ataskshouldbebrokendowninto‘elements(thebasicmovementsandproceduresrequired
toperformit)’.
2.Inefficientorredundantmovementsshouldbeeliminated.
3.Redesigningandreconfiguringtheremainingelementstoenhanceproductivity.
Therblig
Therbligsare18kindsofelementalmotionsusedinthestudyofmotioneconomyinthe
workplace.Aworkplacetaskisanalysedbyrecordingeachofthetherbligunitsforaprocess,
withtheresultsusedforoptimizationofmanuallaborbyeliminatingunneededmovements.
Basic motion elements (Therbligs)
Workstudyconcernswiththeimprovementintheproductivity.Itisasystematicwayofexamining
themethodsforcarryingoutsomespecificactivitybydividingtheworkintosimplertasks.Workstudy
helpstovisualizewhatisgoingonwithinacertaindomainofwholeproductionunit.
Productivityiscrucialtothewelfareofindustrialfirmaswellasfortheeconomicprogressofthe
country.Highproductivityreferstodoingtheworkinashortestpossibletimewithleastexpenditureon
inputswithoutsacrificingqualityandwithminimumwastageofresources.
Productivityisthequantitativerelationbetweenwhatweproduceandweuseasaresourcetoproduce
them,i.e.,
Productivityreferstotheefficiencyoftheproductionsystem.
Itisanindicatortohowwellthefactors(4M’s)ofproduction(Machines,Materials,Methods,and
Manpower)areutilised.
themethodsforcarryingoutsomespecificactivitybydividingtheworkintosimplertasks.Workstudy
helpstovisualizewhatisgoingonwithinacertaindomainofwholeproductionunit.
Productivityiscrucialtothewelfareofindustrialfirmaswellasfortheeconomicprogressofthe
country.Highproductivityreferstodoingtheworkinashortestpossibletimewithleastexpenditureon
inputswithoutsacrificingqualityandwithminimumwastageofresources.
Productivityisthequantitativerelationbetweenwhatweproduceandweuseasaresourcetoproduce
them,i.e.,
Productivityreferstotheefficiencyoftheproductionsystem.
Itisanindicatortohowwellthefactors(4M’s)ofproduction(Machines,Materials,Methods,and
Manpower)areutilised.
Amajorproblemwithproductivityisthatitmeansmanythingstomanypeople.
EconomistsdetermineitfromGrossProduct(GP)
Managersviewitascostcuttingandspeeduptheprocess
Engineersthinkofitintermsofmoreoutputperhourfrommachine
Differencebetweenproductionandproductivity:
Productionofanycommodityorserviceisthevolumeofoutputirrespectiveofthequantityorqualityof
resourcesemployedtoachievethelevelofoutput.
Onceweaddthetermefficiencywithwhichtheresourcesareusedwecallitproductivity.Meansthe
inputremainsthesameandtheproductionoutputincreasesthanthereisimprovementinproductivity.
EconomistsdetermineitfromGrossProduct(GP)
Managersviewitascostcuttingandspeeduptheprocess
Engineersthinkofitintermsofmoreoutputperhourfrommachine
Differencebetweenproductionandproductivity:
Productionofanycommodityorserviceisthevolumeofoutputirrespectiveofthequantityorqualityof
resourcesemployedtoachievethelevelofoutput.
Onceweaddthetermefficiencywithwhichtheresourcesareusedwecallitproductivity.Meansthe
inputremainsthesameandtheproductionoutputincreasesthanthereisimprovementinproductivity.
1.Controllable(Internal)Factors
a.Design
b.Inputmaterial
c.Technologicaldevelopments(innovations)
d.Plantlayout
e.Methodsandmaterials(handlingtechniques)
f.Managementtechniques
2.Uncontrollable(External)Factors
a.Capitalavailability
b.Naturalresources(water,power)andtheirmobility
c.Taxation,lawsandrestrictionsimposedbyGovernment
d.Competitioninthemarket
e.Political,socialandeconomiccondition
Productivity Improvement Techniques
CAD, CAM, CIM
a.Design
b.Inputmaterial
c.Technologicaldevelopments(innovations)
d.Plantlayout
e.Methodsandmaterials(handlingtechniques)
f.Managementtechniques
2.Uncontrollable(External)Factors
a.Capitalavailability
b.Naturalresources(water,power)andtheirmobility
c.Taxation,lawsandrestrictionsimposedbyGovernment
d.Competitioninthemarket
e.Political,socialandeconomiccondition
Productivity Improvement Techniques
CAD, CAM, CIM
TotalProductivityMeasure(TPM):Itisbasedonalltheinputs.
PartialProductivityMeasure(PPM):Itisbasedonindividualinputs(4M’s).
Que.1.Acompanyproduces160kgofplasticmouldedpartsofacceptablequalitybyconsuming200kgofraw
materialsforaparticularperiod.Forthenextperiod,theoutputisdoubled(320kg)byconsuming420kgofraw
materialandforathirdperiod,theoutputisincreasedto400kgbyconsuming400kgofrawmaterial.Estimate
theincrease/decreaseinproductivity.
PartialProductivityMeasure(PPM):Itisbasedonindividualinputs(4M’s).
Que.1.Acompanyproduces160kgofplasticmouldedpartsofacceptablequalitybyconsuming200kgofraw
materialsforaparticularperiod.Forthenextperiod,theoutputisdoubled(320kg)byconsuming420kgofraw
materialandforathirdperiod,theoutputisincreasedto400kgbyconsuming400kgofrawmaterial.Estimate
theincrease/decreaseinproductivity.
Workstudyisameansofenhancingtheproductionefficiency(productivity)ofthefirmbyeliminating
wasteandunnecessaryoperations.
Itisatechniquetoidentifynon-valueaddingoperationsbyinvestigationofallthefactorsaffectingthe
job.
Work study
classification
Method study
Motion study
Work measurement
Time study
Higher productivity
(Production efficiency)
wasteandunnecessaryoperations.
Itisatechniquetoidentifynon-valueaddingoperationsbyinvestigationofallthefactorsaffectingthe
job.
Work study
classification
Method study
Motion study
Work measurement
Time study
Higher productivity
(Production efficiency)
Methodstudyisthesystematicrecordingofexistingwayofdoingthetaskforthedevelopmentofmoreeffective
taskwithreducedcost.
Methodstudyinvolvesthebreakdownofanoperationorprocedureintoitscomponentelementsandtheir
systematicanalysis.Incarryingoutthemethodstudy,therightattitudeofmindisimportant.
Themethodstudymanshouldhavethefollowingcharacteristics:
1.Thedesireanddeterminationtoproduceresults.
2.Abilitytoachieveresults.
3.Anunderstandingofthehumanfactorsinvolved.
Theimprovementinefficiencyisachieved:
1.Byimprovinglayoutanddesigningofworkplace.
2.Byimprovingtheworkprocedures.
3.Byeffectiveutilisationofmen,machinesandmaterials.
4.Byimprovingdesignorspecificationofthefinalproduct.
taskwithreducedcost.
Methodstudyinvolvesthebreakdownofanoperationorprocedureintoitscomponentelementsandtheir
systematicanalysis.Incarryingoutthemethodstudy,therightattitudeofmindisimportant.
Themethodstudymanshouldhavethefollowingcharacteristics:
1.Thedesireanddeterminationtoproduceresults.
2.Abilitytoachieveresults.
3.Anunderstandingofthehumanfactorsinvolved.
Theimprovementinefficiencyisachieved:
1.Byimprovinglayoutanddesigningofworkplace.
2.Byimprovingtheworkprocedures.
3.Byeffectiveutilisationofmen,machinesandmaterials.
4.Byimprovingdesignorspecificationofthefinalproduct.
ObjectivesofMethodStudy:
1.Toimprovetheprocesses,proceduresandproduction
2.Toeliminatewastageoftimeandlabour
3.Topreventfatigueandbreakthemonotonyofrepetitivework
4.Tofindthebestwayofdoingjob
5.Toimprovethedesignofworkplacelayout
6.Toreducewasteandscrapandimprovequality
TechniquesofMethodStudy:
1.Onlineprocesschart
2.Flowprocesschart
3.Stringdiagram
4.Multi-activitychart
5.Simultaneousmotion(SIMO)cyclechart->Micromotionstudy
1.Toimprovetheprocesses,proceduresandproduction
2.Toeliminatewastageoftimeandlabour
3.Topreventfatigueandbreakthemonotonyofrepetitivework
4.Tofindthebestwayofdoingjob
5.Toimprovethedesignofworkplacelayout
6.Toreducewasteandscrapandimprovequality
TechniquesofMethodStudy:
1.Onlineprocesschart
2.Flowprocesschart
3.Stringdiagram
4.Multi-activitychart
5.Simultaneousmotion(SIMO)cyclechart->Micromotionstudy
MicromotionStudy:
ItisrepresentedbyTherbligsnotations.Eachhumanactivitycanbedividedorsplitintosmall
movements.Thepurposeofsuchstudyistofindforanoperatoronebestpatternofmovementwhich
involveslessefforts,timeandfatiguetoaccomplishatask.Thisstudyisbestsuitedforthoseoperations
whichareshortincycleandarerepeatednumberoftimes.
Motionusedinfillinginkinafountainpen
S. No. Name of motion Symbol/abbreviationDescription of motion
1 Search S Look forthe pen
2 Transport Empty TE Approach/reach to the pen
3 Grasp G Pickupthe pen for use
4 Transport Loaded TL Move the pen to the ink pot
5 Position P Set the pen in the position
6 Transport loaded TL Fill the ink
7 Release load RL Put the pen onthe stand
8 TransportEmpty TE Return the hand in original position
ItisrepresentedbyTherbligsnotations.Eachhumanactivitycanbedividedorsplitintosmall
movements.Thepurposeofsuchstudyistofindforanoperatoronebestpatternofmovementwhich
involveslessefforts,timeandfatiguetoaccomplishatask.Thisstudyisbestsuitedforthoseoperations
whichareshortincycleandarerepeatednumberoftimes.
Motionusedinfillinginkinafountainpen
S. No. Name of motion Symbol/abbreviationDescription of motion
1 Search S Look forthe pen
2 Transport Empty TE Approach/reach to the pen
3 Grasp G Pickupthe pen for use
4 Transport Loaded TL Move the pen to the ink pot
5 Position P Set the pen in the position
6 Transport loaded TL Fill the ink
7 Release load RL Put the pen onthe stand
8 TransportEmpty TE Return the hand in original position
Motionandtimestudyistheanalysisofthemethods,materials,tools,equipmentusedorgoingtobeused
toperformanactivity.Thepurposeoftheseanalysesare:
1.Tofindthemosteconomicalwayofdoingthework
2.Tostandardizethemethods,materials,toolsandequipment
3.Todeterminethetimerequiredbyaqualifiedpersonworkingatnormalpace
4.Toassistintrainingtheworkerinthenewmethod
Timestudy:Timestudyisaworkmeasurementtechniqueandisusedtodeterminethetimerequiredby
aqualifiedandwelltrainedpersonworkingatnormalpacetodoaspecifictaskatadefinedlevelof
performance.Thetimecalculatedisknownas“standardtime”/RPA
R->performanceratingfactor
P->predeterminedmotiontime
A->averagetime A Constant, for same jobR
toperformanactivity.Thepurposeoftheseanalysesare:
1.Tofindthemosteconomicalwayofdoingthework
2.Tostandardizethemethods,materials,toolsandequipment
3.Todeterminethetimerequiredbyaqualifiedpersonworkingatnormalpace
4.Toassistintrainingtheworkerinthenewmethod
Timestudy:Timestudyisaworkmeasurementtechniqueandisusedtodeterminethetimerequiredby
aqualifiedandwelltrainedpersonworkingatnormalpacetodoaspecifictaskatadefinedlevelof
performance.Thetimecalculatedisknownas“standardtime”/RPA
R->performanceratingfactor
P->predeterminedmotiontime
A->averagetime A Constant, for same jobR
Rating factor (%)
Normal time = Observed time
100
Allowance (%)
Allowance = Normal time
100
Standard Time = Normal time + Allowance Allowances:Allowancesaretheadditionaltimeallowedtoperformtheworkandareabovethenormal
time.OrItisanamountoftimeaddedtonormaltimetoprovideforpersonaldelays,unavoidabledelays,
fatiguedelays,etc.
Normal time = Observed time
100
Allowance (%)
Allowance = Normal time
100
Standard Time = Normal time + Allowance Allowances:Allowancesaretheadditionaltimeallowedtoperformtheworkandareabovethenormal
time.OrItisanamountoftimeaddedtonormaltimetoprovideforpersonaldelays,unavoidabledelays,
fatiguedelays,etc.
1.Inaworkstudyexperiment,itisobservedthataworkercompletesajobinanaveragetimeof15
minuteswiththeperformanceratingof120%.Findouttheaveragetimerequiredforanotherwork
havingperformancerating80%tocompletethesamejob.
2.Theobservedtimeforanelementis2.4minutes.Thepaceratingis90%andthesumofallsecondary
adjustmentamountsto40%.Findoutthestandardtime?
3.Observedtimeofanactivityis0.5minutes.Ratingfactoris125%andallowancesis15%ofNormal
time.Calculatestandardtime.
4.OT=0.75minutes,RelaxationAllowance=10%ofnormaltime,DelayAllowance=2%ofnormaltime,
RF=110%,CalculateST?
minuteswiththeperformanceratingof120%.Findouttheaveragetimerequiredforanotherwork
havingperformancerating80%tocompletethesamejob.
2.Theobservedtimeforanelementis2.4minutes.Thepaceratingis90%andthesumofallsecondary
adjustmentamountsto40%.Findoutthestandardtime?
3.Observedtimeofanactivityis0.5minutes.Ratingfactoris125%andallowancesis15%ofNormal
time.Calculatestandardtime.
4.OT=0.75minutes,RelaxationAllowance=10%ofnormaltime,DelayAllowance=2%ofnormaltime,
RF=110%,CalculateST?
Arepetitivestraininjuryisdamagetomuscles,tendonsornervescausedbyrepetitivemotionsandconstantuse
oftheseparts.Itisalsocalledrepetitivestressinjuries.
Repetitivestraininjury(RSI)isatermsometimesusedforpaincausedbyrepeatedmovementofpartofthe
body.Itoftengetsbetteronitsown,buttherearethingsyoucandotohelpspeedupyourrecovery.
Repetitivestraininjury(RSI)affectsmanypartsofthebody,butitmostoftenaffectsthe(upperlimbs):
Shoulders,Elbows,ForearmsandWrists,HandsandFingers
Thesymptomsusuallystartgraduallyandcaninclude:
•Pain,whichmayfeellikeburning,achingorthrobbing
•Stiffnessandweakness
•Tinglingornumbness
•Musclecramps
•Swelling
oftheseparts.Itisalsocalledrepetitivestressinjuries.
Repetitivestraininjury(RSI)isatermsometimesusedforpaincausedbyrepeatedmovementofpartofthe
body.Itoftengetsbetteronitsown,buttherearethingsyoucandotohelpspeedupyourrecovery.
Repetitivestraininjury(RSI)affectsmanypartsofthebody,butitmostoftenaffectsthe(upperlimbs):
Shoulders,Elbows,ForearmsandWrists,HandsandFingers
Thesymptomsusuallystartgraduallyandcaninclude:
•Pain,whichmayfeellikeburning,achingorthrobbing
•Stiffnessandweakness
•Tinglingornumbness
•Musclecramps
•Swelling
Causesofrepetitivestraininjury(RSI)
Repetitivestraininjury(RSI)iscausedbyrepeateduseofabodypart,suchasyourshoulder,elbow,forearm,
wristorhand.
YoumayexperienceRSIif:
•Dorepetitiveactivitieslikehairdressing,decorating,typingakeyboard,usingcomputermouseorworking
onanassemblylineforlongerperiodoftime
•Playsportslikegolfortennisthatinvolvelotsofrepetitivemovements
•Havepoorposturewhensittingorstandingatwork
•Usehand-heldpowertoolsregularly
RepetitiveorstrenuousworkdoesnotalwayscauseRSI.Manypeopledothesamejobforyearswithout
havingaproblem.
Paininapartofthebodylikethearmisoftencausedbyacombinationofthings,includingaging.
Repetitivestraininjury(RSI)iscausedbyrepeateduseofabodypart,suchasyourshoulder,elbow,forearm,
wristorhand.
YoumayexperienceRSIif:
•Dorepetitiveactivitieslikehairdressing,decorating,typingakeyboard,usingcomputermouseorworking
onanassemblylineforlongerperiodoftime
•Playsportslikegolfortennisthatinvolvelotsofrepetitivemovements
•Havepoorposturewhensittingorstandingatwork
•Usehand-heldpowertoolsregularly
RepetitiveorstrenuousworkdoesnotalwayscauseRSI.Manypeopledothesamejobforyearswithout
havingaproblem.
Paininapartofthebodylikethearmisoftencausedbyacombinationofthings,includingaging.
What are the risk factors?
Repetitive exertions
Posture stresses
Contact stresses
Static exertions
Forceful exertions
Area likely to
experience RSI
Muscle:Mayoccurfromchronicoverusewithrestsymptomsresolveinadayortwo
Tendon:Attachmuscletobone,Withoverusethetendonmaybecomedamagedandnotoperateproperly.
Ligament:Connectbonetobone-suchasvertebrae-andcanbedamagedifimproperliftingtechniqueis
usedorotherbackproblemsmayoccur
Nerve:Oftenoccursduetocompressionsuchaselbowsrestingonhardsurfacesorsleepingonyourarms
Results of RSIs:
Pain, ranging from mild to severe, tenderness, swelling, stiffness, tingling or numbness
weakness, sensitivity to cold or heat
Repetitive exertions
Posture stresses
Contact stresses
Static exertions
Forceful exertions
Area likely to
experience RSI
Muscle:Mayoccurfromchronicoverusewithrestsymptomsresolveinadayortwo
Tendon:Attachmuscletobone,Withoverusethetendonmaybecomedamagedandnotoperateproperly.
Ligament:Connectbonetobone-suchasvertebrae-andcanbedamagedifimproperliftingtechniqueis
usedorotherbackproblemsmayoccur
Nerve:Oftenoccursduetocompressionsuchaselbowsrestingonhardsurfacesorsleepingonyourarms
Results of RSIs:
Pain, ranging from mild to severe, tenderness, swelling, stiffness, tingling or numbness
weakness, sensitivity to cold or heat
Initself,repetitionisnotveryrisky,butwhencombinedwithotherriskfactors
suchashighforceandpoorposture,repetitiontakesonincreasedsignificance
Includesactivitiessuchas:
Assemblylinework
Typing
Manualmaterialshandling
Laboratoryprocedures
Etc.
suchashighforceandpoorposture,repetitiontakesonincreasedsignificance
Includesactivitiessuchas:
Assemblylinework
Typing
Manualmaterialshandling
Laboratoryprocedures
Etc.
Ifyouexperienceposturestresses,habitmodificationandnewequipmentarethings
toconsider
Includesthingslike:
Awkwardwristbending
Stooping
Holdingthephonebetweenshoulderandearetc.
TaskstressandPosturalstress
toconsider
Includesthingslike:
Awkwardwristbending
Stooping
Holdingthephonebetweenshoulderandearetc.
TaskstressandPosturalstress
Contact Stresses
Typicallyinvolvesupperextremitiesandahardsurface
Example:Typingor“mousing”onasquareedgetable-theundersideofthearmisatriskofacompression
injurywherethearmmakescontactwiththe“sharp”edgeofthedesk
Considerpurchasingwristrestsforyourkeyboardandmouse-pad
Typicallyinvolvesupperextremitiesandahardsurface
Example:Typingor“mousing”onasquareedgetable-theundersideofthearmisatriskofacompression
injurywherethearmmakescontactwiththe“sharp”edgeofthedesk
Considerpurchasingwristrestsforyourkeyboardandmouse-pad
Static Exertions
Areductioninbloodflowcantakeatollonoursofttissues
Examples:standingforlongperiodsoftimemaycausepoolingofbloodinthelegs,whilekeyingatypistmay
findsomemusclesintheforearmthatexperienceconstantloading(contraction),etc.
Besuretotakebreaksandmoveorstretchallofyourmusclestogetbloodflowmovingfaster.
VibrationandcoldweathercanalsoimpedecirculationandleadtoorworsenRSI’s
Considertakingbreakswhenusingthingslikepneumatictoolsandwearwarmclothingifyouworkinacooler
environment
Areductioninbloodflowcantakeatollonoursofttissues
Examples:standingforlongperiodsoftimemaycausepoolingofbloodinthelegs,whilekeyingatypistmay
findsomemusclesintheforearmthatexperienceconstantloading(contraction),etc.
Besuretotakebreaksandmoveorstretchallofyourmusclestogetbloodflowmovingfaster.
VibrationandcoldweathercanalsoimpedecirculationandleadtoorworsenRSI’s
Considertakingbreakswhenusingthingslikepneumatictoolsandwearwarmclothingifyouworkinacooler
environment
Forceful Exertions
Therepetitivestressinjuryduetoforceincreasesasotherriskfactorscomeintoplay
RSI’stypicallytakemonthsoryearstodevelopandmonthsoryearstoresolve.
Whenmovingheavyobjects-especiallywithpoorphysicalconditioningandimpropertechnique-tissuedamage
canoccurimmediately
It’simportanttoplanouthigh-demandtasksandtomakegradualincreasesinstrengthtrainingroutines
Therepetitivestressinjuryduetoforceincreasesasotherriskfactorscomeintoplay
RSI’stypicallytakemonthsoryearstodevelopandmonthsoryearstoresolve.
Whenmovingheavyobjects-especiallywithpoorphysicalconditioningandimpropertechnique-tissuedamage
canoccurimmediately
It’simportanttoplanouthigh-demandtasksandtomakegradualincreasesinstrengthtrainingroutines
Acute Injury Risk Factor
Acute (Critical/Serious) back injury may occur due to:
Slips, trips, falls
Auto accidents
Sedentary lifestyle (with occasional lifting)
Heavy and/or awkward loads
Improper lifting technique
Acute (Critical/Serious) back injury may occur due to:
Slips, trips, falls
Auto accidents
Sedentary lifestyle (with occasional lifting)
Heavy and/or awkward loads
Improper lifting technique
ChronicInjuryRiskFactor
Chronicbackinjurymayresultfrom:
Poorpostureand/orimproperliftingtechniquecombinedwithrepetitivelifting
Genetics
Overallphysicalfitness
Chronicbackinjurymayresultfrom:
Poorpostureand/orimproperliftingtechniquecombinedwithrepetitivelifting
Genetics
Overallphysicalfitness
How is RSI diagnosed?
Magneticresonanceimaging(MRI)toassessinternalstructureinthehumanbody,includingthe
organs,bones,musclesandbloodvessels.tissuedamage.
Anelectromyography(EMG)measuresmuscleresponseorelectricalactivityinresponsetoa
nerve'sstimulation.
RSI treatment:
The initial treatment for RSI symptoms is conservative. This may include:
RICE, which stands for rest, ice, compression, and elevation
Non-steroidal anti-inflammatory drugs (NSAIDs), both oral and topical
Steroid injections
Exercises, which may be prescribed as part of a physical therapy treatment plan
Stress reduction and relaxation training
Wrapping the area or securing it with a splint to protect and rest the muscles and tendons
Magneticresonanceimaging(MRI)toassessinternalstructureinthehumanbody,includingthe
organs,bones,musclesandbloodvessels.tissuedamage.
Anelectromyography(EMG)measuresmuscleresponseorelectricalactivityinresponsetoa
nerve'sstimulation.
RSI treatment:
The initial treatment for RSI symptoms is conservative. This may include:
RICE, which stands for rest, ice, compression, and elevation
Non-steroidal anti-inflammatory drugs (NSAIDs), both oral and topical
Steroid injections
Exercises, which may be prescribed as part of a physical therapy treatment plan
Stress reduction and relaxation training
Wrapping the area or securing it with a splint to protect and rest the muscles and tendons
Advantages/benefitsoftheRICEmethod:
Rest:Immobilizationpreventsfurtherinjuryandgivesthebodytimetorecover.
Ice:Coldreducespainbynumbingtheaffectedarea.
Compression:Pressurekeepsswellingundercontrol.
Elevation:Keepingtheinjuredbodypartabovetheheartreducesswellingandtheassociated
painanddiscomfort.
It is most useful for mild to moderate injuries. Doctors usually recommend the RICE method for:
•sprains
•strains
•other soft tissue injuries
Rest:Immobilizationpreventsfurtherinjuryandgivesthebodytimetorecover.
Ice:Coldreducespainbynumbingtheaffectedarea.
Compression:Pressurekeepsswellingundercontrol.
Elevation:Keepingtheinjuredbodypartabovetheheartreducesswellingandtheassociated
painanddiscomfort.
It is most useful for mild to moderate injuries. Doctors usually recommend the RICE method for:
•sprains
•strains
•other soft tissue injuries
RiskReduction-ChronicInjury
Maintaininganeutralspinalpostureisimportantwhenseatedaswellasduringliftingtasks
Ifsittingwithoutbacksupport:
Rotatethehipsforwarduntilaneutralpositionisachieved
Ifusingthebackrest:
Sitbackinthechairtoallowthebackresttohelpmaintainaneutral
postureandreducemuscleloading
Maintaininganeutralspinalpostureisimportantwhenseatedaswellasduringliftingtasks
Ifsittingwithoutbacksupport:
Rotatethehipsforwarduntilaneutralpositionisachieved
Ifusingthebackrest:
Sitbackinthechairtoallowthebackresttohelpmaintainaneutral
postureandreducemuscleloading
RiskReduction–Engineering/Design
Youcandesignasaferliftingenvironmentby:
Avoidingveryhighandverylowobjectplacement
Reducingobjectweightandsize
Providinghandles
Eliminatingtheneedfortwistingmotions
Eliminatingbendingandstoopedpostures
Providingmechanicalassistance
Youcandesignasaferliftingenvironmentby:
Avoidingveryhighandverylowobjectplacement
Reducingobjectweightandsize
Providinghandles
Eliminatingtheneedfortwistingmotions
Eliminatingbendingandstoopedpostures
Providingmechanicalassistance
RiskReduction–LiftingTips
When lifting, you can substantially reduce your risk of back injury and pain by:
Keeping the object close to you
Bending your knees
Maintaining your lumbar curve (bend knees and stick buttocks out)
Not twisting or bending sideways
Avoiding rapid, jerky movements
Asking for assistance with heavy and/or bulky loads
When lifting, you can substantially reduce your risk of back injury and pain by:
Keeping the object close to you
Bending your knees
Maintaining your lumbar curve (bend knees and stick buttocks out)
Not twisting or bending sideways
Avoiding rapid, jerky movements
Asking for assistance with heavy and/or bulky loads
RiskReduction–AtHome
Be sure to maintain neutral spinal posture when stooped
Forexample,whenshaving,brushingteeth,bathingchildren,repairingcars,shoveling,etc.
Planningliftsandgettingassistanceormechanicalhelpwheneverpossibleisalsoagoodriskreduction
strategy
Be sure to maintain neutral spinal posture when stooped
Forexample,whenshaving,brushingteeth,bathingchildren,repairingcars,shoveling,etc.
Planningliftsandgettingassistanceormechanicalhelpwheneverpossibleisalsoagoodriskreduction
strategy
Stretchingandexerciseareoftenrecommendedforbackpain,however,someoftheseactivitiesmayaggravate
someconditions
Somediscomfortisconsideredacceptableduringtheactivity,butshouldnotpersistwhentheactivityis
discontinued
StretchingandExercise
someconditions
Somediscomfortisconsideredacceptableduringtheactivity,butshouldnotpersistwhentheactivityis
discontinued
StretchingandExercise
Correct&IncorrectTechniques
PracticeWellnessatWorkandHome!
Exercise
Nutrition
Relaxation
Body
Mind
Spirit
Exercise
Nutrition
Relaxation
Body
Mind
Spirit
MOVE
STRETCH
PracticeWellnessatWorkandHome!
STRETCH
PracticeWellnessatWorkandHome!
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