Accident-Incident Investigation Technique guideline

Most accident investigations follow a research technique called the scientific method. This method involves gathering and analyzing facts, and developing ... AboutWordPressWordPress.orgDocumentationSupportFeedbackLogInRegisterSearch Skiptocontent HomeHSESafetyAccident-IncidentInvestigationTechniqueguideline ThousandsofaccidentsoccurthroughouttheWorldeveryday.Thefailureofpeople,equipment,supplies,orsurroundingstobehaveorreactasexpectedcausemostoftheaccidents.Accidentinvestigationsdeterminehowandwhythesefailuresoccur.Byusingtheinformationgainedthroughaninvestigation,asimilarorperhapsmoredisastrousaccidentmaybeprevented.Conductaccidentinvestigationswithaccidentpreventioninmind.InvestigationsareNOTtoplaceblame. Takeaway:Asuccessfulaccidentinvestigationdeterminesnotonlywhathappened,butalsofindshowandwhytheaccidentoccurred. Anaccidentisanyunplannedeventthatresultsinpersonalinjuryorinpropertydamage.Whenapersonalinjuryrequireslittleornotreatment,itisminor.Ifitresultsinafatalityorinapermanenttotal,permanentpartial,ortemporarytotal(lost-time)disability,itisserious.Similarly,propertydamagemaybeminororserious.Investigateallaccidentsregardlessoftheextentofinjuryordamage.Accidentsarepartofabroadgroupofeventsthatadverselyaffectthecompletionofatask.Theseeventsareincidents.Forsimplicity,theproceduresdiscussedinlatersectionsreferonlytoaccidents.Theyare,however,alsoapplicabletoincidents.Thisdiscussionintroducesthereadertobasicaccidentinvestigationproceduresanddescribesaccidentanalysistechniques. ACCIDENTPREVENTION Accidentsareusuallycomplex.Anaccidentmayhave10ormoreeventsthatcancause.Adetailedanalysisofanaccidentwillnormallyrevealthreecauselevels:basic,indirect,anddirect.Atthelowestlevel,anaccidentresultsonlywhenapersonorobjectreceivesanamountofenergyorhazardousmaterialthatcannotbeabsorbedsafely.ThisenergyorhazardousmaterialistheDIRECTCAUSEoftheaccident.Thedirectcauseisusuallytheresultofoneormoreunsafeactsorunsafeconditions,orboth.UnsafeactsandconditionsareINDIRECTCAUSESorsymptoms.Inturn,indirectcausesareusuallytraceabletopoormanagementpoliciesanddecisions,ortopersonalorenvironmentalfactors.ThesearetheBASICCAUSES. Inspiteoftheircomplexity,mostaccidentsarepreventablebyeliminatingoneormorecauses.Accidentinvestigationsdeterminenotonlywhathappened,butalsohowandwhy.Theinformationgainedfromtheseinvestigationscanpreventtherecurrenceofsimilarorperhapsmoredisastrousaccidents.Accidentinvestigatorsareinterestedineacheventaswellasinthesequenceofeventsthatledtoanaccident.Theaccidenttypeisalsoimportanttotheinvestigator.Therecurrenceofaccidentsofaparticulartypeorthosewithcommoncausesshowsareasneedingspecialaccidentpreventionemphasis. INVESTIGATIVEPROCEDURES Theactualproceduresusedinaparticularinvestigationdependonthenatureandresultsoftheaccident.Theagencyhavingjurisdictionoverthelocationdeterminestheadministrativeprocedures.Ingeneral,responsibleofficialswillappointanindividualtobeinchargeoftheinvestigation.Theinvestigatorusesmostofthefollowingsteps: 1.Definethescopeoftheinvestigation. 2.Selecttheinvestigators.Assignspecifictaskstoeach(preferablyinwriting). 3.Presentapreliminarybriefingtotheinvestigatingteam,including: a.Descriptionoftheaccident,withdamageestimates. b.Normaloperatingprocedures. c.Maps(localandgeneral). d.Locationoftheaccidentsite.e.Listofwitnesses. f.Eventsthatprecededtheaccident. 4.Visittheaccidentsitetogetupdatedinformation. 5.Inspecttheaccidentsite. a.Securethearea.Donotdisturbthesceneunlessahazardexists. b.Preparethenecessarysketchesandphotographs.Labeleachcarefullyandkeepaccuraterecords. 6.Intervieweachvictimandwitness.Alsointerviewthosewhowerepresentbeforetheaccidentandthosewhoarrivedatthesiteshortlyaftertheaccident.Keepaccuraterecordsofeachinterview.Useataperecorderifdesiredandifapproved. 7.Determine a.Whatwasnotnormalbeforetheaccident. b.Wheretheabnormalityoccurred. c.Whenitwasfirstnoted.d.Howitoccurred. 8.Analyzethedataobtainedinstep7.Repeatanyofthepriorsteps,ifnecessary. 9.Determine a.Whytheaccidentoccurred. b.Alikelysequenceofeventsandprobablecauses(direct,indirect,basic).c.Alternativesequences. 10.Checkeachsequenceagainstthedatafromstep7. 11.Determinethemostlikelysequenceofeventsandthemostprobablecauses. 12.Conductapost-investigationbriefing. 13.Prepareasummaryreport,includingtherecommendedactionstopreventarecurrence.Distributethereportaccordingtoapplicationinstructions. Aninvestigationisnotcompleteuntilalldataareanalyzedandafinalreportiscompleted.Inpractice,theinvestigativework,dataanalysis,andreportpreparationproceedsimultaneouslyovermuchofthetimespentontheinvestigation. (learnmore:near-miss-incidents-overview) FACT-FINDING Gatherevidencefrommanysourcesduringaninvestigation.Getinformationfromwitnessesandreportsaswellasbyobservation.Interviewwitnessesassoonaspossibleafteranaccident.Inspecttheaccidentsitebeforeanychangesoccur. Makephotographsandsketchesoftheaccidentscene.Recordallpertinentdataonmaps.Getcopiesofallreports.Documentscontainingnormaloperatingprocedures,flowdiagrams,maintenancecharts,orreportsofdifficultiesorabnormalitiesareparticularlyuseful.Keepcompleteandaccuratenotesinaboundnotebook.Recordpre-accidentconditions,theaccidentsequence,andpost-accidentconditions.Inaddition,documentthelocationofvictims,witnesses,machinery,energysources,andhazardousmaterials.Insomeinvestigations,aparticularphysicalorchemicallaw,principle,orpropertymayexplainasequenceofevents.Includelawsinthenotestakenduringtheinvestigationorinthelateranalysisofdata.Inaddition,gatherdataduringtheinvestigationthatmaylenditselftoananalysisbytheselaws,principles,orproperties.Anappendixinthefinalreportcanincludeanextendeddiscussion. INTERVIEWS Ingeneral,experiencedpersonnelshouldconductinterviews.Ifpossible,theteamassignedtothistaskshouldincludeanindividualwithalegalbackground.Inconductinginterviews,theteamshould: 1.Appointaspeakerforthegroup. 2.Getpreliminarystatementsassoonaspossiblefromallwitnesses. 3.Locatethepositionofeachwitnessonamasterchart(includingthedirectionofview). 4.Arrangeforaconvenienttimeandplacetotalktoeachwitness. 5.Explainthepurposeoftheinvestigation(accidentprevention)andputeachwitnessatease. 6.Listen,leteachwitnessspeakfreely,andbecourteousandconsiderate.7.Takenoteswithoutdistractingthewitness.Useataperecorderonlywiththeconsentofthewitness. 8.Usesketchesanddiagramstohelpthewitness. 9.Emphasizeareasofdirectobservation.Labelhearsayaccordingly.310.Besincereanddonotarguewiththewitness. 11.Recordtheexactwordsusedbythewitnesstodescribeeachobservation.Donot“putwordsintoawitness’mouth.” 12.Wordeachquestioncarefullyandbesurethewitnessunderstands. 13.Identifythequalificationsofeachwitness(name,address,occupation,yearsofexperience,etc.). 14.Supplyeachwitnesswithacopyofhisorherstatements.Signedstatementsaredesirable.Afterinterviewingallwitnesses,theteamshouldanalyzeeachwitness’sstatement.Theymaywishtore-interviewoneormorewitnessestoconfirmorclarifykeypoints. Whiletheremaybeinconsistenciesinwitnesses’statements,investigatorsshouldassembletheavailabletestimonyintoalogicalorder.Analyzethisinformationalongwithdatafromtheaccidentsite.Notallpeoplereactinthesamemannertoaparticularstimulus.Forexample,awitnesswithincloseproximitytotheaccidentmayhaveanentirelydifferentstoryfromonewhosawitatadistance.Somewitnessesmayalsochangetheirstoriesaftertheyhavediscusseditwithothers.Thereasonforthechangemaybeadditionalclues. Awitnesswhohashadatraumaticexperiencemaynotbeabletorecallthedetailsoftheaccident.Awitnesswhohasavestedinterestintheresultsoftheinvestigationmayofferbiasedtestimony.Finally,eyesight,hearing,reactiontime,andthegeneralconditionofeachwitnessmayaffecthisorherpowersofobservation.Awitnessmayomitentiresequencesbecauseofafailuretoobservethemorbecausetheirimportancewasnotrealized. PROBLEM-SOLVINGTECHNIQUES Accidentsrepresentproblemsthatmustbesolvedthroughinvestigations.Severalformalproceduressolveproblemsofanydegreeofcomplexity.Thissectionconsiderstheseproblems-solvingprocedures. TheScientificMethod Thescientificmethodformsthebasisofnearlyallproblem-solvingtechniques.Itisusedforconductingresearch.Initssimplestform,itinvolvesthefollowingsequence:makingobservations,developinghypotheses,andtestingthehypotheses.Evenasimpleresearchprojectmayinvolvemanyobservations.Aresearcherrecordsallobservationsimmediately. Agoodinvestigatormustdothesamething.Wherepossible,theobservationsshouldinvolvequantitativemeasurements.Quantitativedataareoftenimportantinlaterdevelopmentandtestingofthehypotheses.Suchmeasurementsmayrequiretheuseofmanyinstrumentsinthefieldaswellasinthelaboratory.Whenmakingobservations,theinvestigatordevelopsoneormorehypothesesthatexplaintheobservations.Thehypothesismayexplainonlyafewoftheobservationsoritmaytrytoexplainallofthem. Atthisstage,thehypothesisismerelyapreliminaryidea.Evenifrejectedlater,theinvestigatorhasagoaltowardwhichtoproceed.Testthehypothesisagainsttheoriginalobservations.Aseriesofcontrolledexperimentsareoftenusefulinperformingthisevaluation.Ifthehypothesisexplainsalloftheobservations,testingmaybeasimpleprocess.Ifnot,eithermakeadditionalobservations,changethehypothesis,ordevelopadditionalhypotheses. Aswithscientificresearch,themostdifficultpartofanyinvestigationistheformulationofworthwhilehypotheses.Usethefollowingthreeprinciplestosimplifythisstep: 1.Theprincipleofagreement. Aninvestigatorusesthisprincipletofindonefactorthatassociateswitheachobservation. 2.Theprincipleofdifferences. Thisprincipleisbasedontheideathatvariationsinobservationsaredueonlytodifferencesinoneormorefactors. 3.Theprincipleofconcomitantvariation. Thisprincipleisthemostimportantbecauseitcombinestheideasofbothoftheprecedingprinciples.Inusingthisprinciple,theinvestigatorisinterestedinthefactorsthatarecommonaswellasthosethataredifferentintheobservations.Inusingthescientificmethod,theinvestigatormustbecarefultoeliminatepersonalbias.Theinvestigatormustbewillingtoconsiderarangeofalternatives.Finally,heorshemustrecognizethataccidentsoftenresultfromthechanceoccurrenceoffactorsthataretoonumeroustoevaluatefully. ChangeAnalysisAsitsnameimplies,thistechniqueemphasizeschange.Tosolveaproblem,aninvestigatormustlookfordeviationsfromthenorm.Aswiththescientificmethod,changeanalysisalsofollowsalogicalsequence.Itisbasedontheprincipleofdifferencesdescribedinthediscussionofthescientificmethod.Considerallproblemsresultingfromsomeunanticipatedchange.Makeananalysisofthechangetodetermineitscauses.Usethefollowingstepsinthismethod: 1.Definetheproblem(Whathappened?). 2.Establishthenorm(Whatshouldhavehappened?). 3.Identify,locate,anddescribethechange(What,where,when,towhatextent). 4.Specifywhatwasandwhatwasnotaffected. 5.Identifythedistinctivefeaturesofthechange. 6.Listthepossiblecauses. 7.Selectthemostlikelycauses. SequenceDiagramsGanttchartsaresequencediagrams.Usethemforschedulinginvestigativeprocedures.Theycanalsoaidinthedevelopmentofthemostprobablesequenceofeventsthatledtotheaccident.Suchachartisespeciallyusefulindepictingeventsthatoccurredsimultaneously. GrossHazardAnalysisPerformagrosshazardanalysis(GHA)togetaroughassessmentoftherisksinvolvedinperformingatask.Itis“gross”becauseitrequiresfurtherstudy.Itisparticularlyusefulintheearlystagesofanaccidentinvestigationindevelopinghypotheses.AGHAwillusuallytaketheformofalogicdiagramortable.Ineithercase,itwillcontainabriefdescriptionoftheproblemoraccidentandalistofthesituationsthatcanleadtotheproblem.Insomecases,theanalysisgoesastepfurthertodeterminehowtheproblemcouldoccur.AGHAdiagramortablethusshowsataglancethepotentialcausesofanaccident.OneofthefollowinganalysistechniquescanthenexpanduponaGHA. JobSafetyAnalysisJobsafetyanalysis(JSA)ispartofmanyexistingaccidentpreventionprograms.Ingeneral,JSAbreaksajobintobasicsteps,andidentifiesthehazardsassociatedwitheachstep.TheJSAalsoprescribescontrolsforeachhazard.AJSAisachartlistingthesesteps,hazards,andcontrols.ReviewtheJSAduringtheinvestigationifaJSAhasbeenconductedforthejobinvolvedinanaccident.PerformaJSAifoneisnotavailable.PerformaJSAasapartoftheinvestigationtodeterminetheeventsandconditionsthatledtotheaccident. FailureModeandEffectAnalysisFailuremodeandeffectanalysis(FMEA)determineswherefailuresoccurred.Considerallitemsusedinthetaskinvolvedintheaccident.Theseitemsincludepeople,equipment,machineparts,materials,etc.Intheusualprocedure,FMEAlistseachitemonachart.Thechartliststhemannerormodeinwhicheachitemcanfailanddeterminestheeffectsofeachfailure.Includedintheanalysisaretheeffectsonotheritemsandonoveralltaskperformance.Inaddition,makeevaluationsabouttherisksassociatedwitheachfailure.Thatis,projectthechanceofeachfailureandtheseverityofitseffects.Determinethemostlikelyfailuresthatledtotheaccident.Thisisdonebycomparingtheseprojectedeffectsandriskswithactualaccidentresults. FaultTreeAnalysisFaulttreeanalysis(FTA)isalogicdiagram.Itshowsallthepotentialcausesofanaccidentorotherundesiredevents.Theundesiredeventisatthetopofa“tree.”Reasoningbackwardfromthisevent,determinethecircumstancesthatcanleadtotheproblem.Thesecircumstancesarethenbrokendownintotheeventsthatcanleadtothem,andsoon.Continuetheprocessuntiltheidentificationofalleventscanproducetheundesiredevent.Usealogictreetodescribeeachoftheseeventsandthemannerinwhichtheycombine.Thisinformationdeterminesthemostprobablesequenceofeventsthatledtotheaccident. REPORTOFINVESTIGATIONAsnotedearlier,anaccidentinvestigationisnotcompleteuntilareportispreparedandsubmittedtoproperauthorities.Specialreportformsareavailableinmanycases.Otherinstancesmayrequireamoreextendedreport.Suchreportsareoftenveryelaborateandmayincludeacoverpage,atitlepage,anabstract,atableofcontents,acommentaryornarrativeportion,adiscussionofprobablecauses,andasectiononconclusionsandrecommendations.Thefollowingoutlinehasbeenfoundespeciallyusefulindevelopingtheinformationtobeincludedintheformalreport: 1.BackgroundInformation a.Whereandwhentheaccidentoccurred b.Whoandwhatwereinvolved c.Operatingpersonnelandotherwitnesses 2.AccountoftheAccident(Whathappened?) a.Thesequenceofevents b.Extentofdamage c.Accidenttype d.Agencyorsource(ofenergyorhazardousmaterial) 3.Discussion(AnalysisoftheAccident–HOW;WHY) a.Directcauses(energysources;hazardousmaterials) b.Indirectcauses(unsafeactsandconditions) c.Basiccauses(managementpolicies;personalorenvironmentalfactors) 4.Recommendations(topreventarecurrence)forimmediateandlong-rangeactiontoremedy: a.Basiccauses b.Indirectcauses c.Directcauses(suchasreducedquantitiesorprotectiveequipmentorstructures) (learnmore:incident-report-form) SUMMARY ThousandsofaccidentsoccurdailythroughouttheWorld.Theseresultfromafailureofpeople,equipment,supplies,orsurroundingstobehaveasexpected.Asuccessfulaccidentinvestigationdeterminesnotonlywhathappened,butalsofindshowandwhytheaccidentoccurred.Investigationsareanefforttopreventasimilarorperhapsmoredisastroussequenceofevents.Mostaccidentinvestigationsfollowaresearchtechniquecalledthescientificmethod.Thismethodinvolvesgatheringandanalyzingfacts,anddevelopinghypothesestoexplainthesefacts.Eachhypothesismustbetestedagainstthefacts,andthemostprobableexplanationoftheaccidentneedstobeselected.Anyoneofseveralproblem-solvingtechniquesbasedonthisapproachmaybeused.Aninvestigationisnotcompletehowever,untilcompletionofafinalreport.Responsibleofficialscanthenusetheresultinginformationandrecommendationstopreventfutureaccidents. Tags:accidentinvestigationFailureModeandEffectAnalysisFaultTreeanalysisincdientincidentAnalysisincidentinvestigationJHANear-MissReportofInvestigationSequenceDigram ContinueReading PreviousWhatAreElectrolytesandWhyTheyMatterforOn-the-JobHydrationNextRegularSafetyMeetings6WaysKeepEmployeesSafeandDecreaseIncidents MoreStories 6minread Downloads E-Books HSE Oil&Gas Processsafety&Instrumentation Safety E-Books:EssentialPracticesforCreating,Strengthening,andSustainingProcessSafetyCulture 2daysago KhaledIsmail 6minread Construction HSE Safety ChainsawSafety 4daysago KhaledIsmail 7minread Construction HSE Safety AccidentInvestigationSafetyTrainingProgram 6daysago KhaledIsmail LeaveaReplyYoumustbeloggedintopostacomment. 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