Accident Investigation

CHAPTER11 p.;

Cause and Effect Analysis

The cause and effect analysis is a structured approach to determine the causes and effects of events, which lead to the accident. There are many types of cause and effect analysis used in accident investigations, and this book will focus on the Apollo method (cause and effect process) and the Ishikawa Fishbone analysis ( developed by Kaoru Ishikawa) that the best way to view the causes and effects was to draw it out like a fish skeleton, with the problem at the head of the fish and the bones representing the causes. Another view of a cause and effect analysis is the "5 Whys" or "Questions to the Void." The 5 Whys approach is to analyze the event to five levels (give or take a couple) until it is clear that the root cause is found.

The cause and effect approach is a structured approach, and examining the Apollo Method is based on (1) defining the problem; (2) developing a causal understanding of why the problem occurred (cause and effect chart); (3) identifying solutions; and ( 4) implementing and monitoring effectiveness of the best solutions (Gano 2007). For accident investigations, the problem has been identified, so for this approach, the only part discussed will be the cause and effect approach and the cause and effect chart.

117

P11rt Ill: Anab•timl Trchniquu

11 8

Cause and Effect Approach

The cause and effect analysis is best performed as a charc . events and causal factors analysis or tree analysis. The k s1Illilar to h

. . ey to the t e effect analysts 1s che thought process of developing the effe caus, •nd and repeating that sequence. The process is the sam h cts of cau

. . e w ether . ses Apollo Cause and Effect, Ishikawa F1shbone, or the 5 Wh using the ·th h ·d d ys analy · approach is to start WI t e aca ent an analyze until • sis. 'l-1 1t reache th 'n,

factors . The approoch to this an alysis can be perfo d s e caus,i rme on c software (Apollo 2011 ) or done on a sheet of paper h . 0 rnputer

. , w lteboard using adhesive nores. The benefit of a thorough cau , or bi· . . se and effe . keep analyzing unnl all causal fac tors are found includin ct IS to

h · th · . g any sysr . causes, althoug many runes . e 1nvesugato r will stop at th enuc causes. e superficial

The approach to these three cause and effect analyses . . are very Similar

Exlubit 11.1 displays the charnng structure for the three approaches. ·

The Apollo Method is a software-based m ethod that leads th • . e tnvesngator

through the approach with an effect followed by at least two causes. Each effect is "'caused by" a conditional cause and an action cause. According ro the Apollo method, "every time we ask 'why,' we should find at leasr ru-o causes and for each of these causes we should find at least two more causes resulting in four causes, and so on" (Gano 2008). Normally the chan is developed from left to right.

The fishbone diagram has been used for many years in business and as a quality rool for manufacturing. The diagram resembles the skeleton of a fish and focuses on the causes rather than the symptoms of a problem. The problem statement is the head of the fish along the fish's backbone. The ne..u step is the brainstorming or in case of an accident investigation, the facrs and analysis are analyzed to structure the big bones of the fish that are connected to the backbone (Ishikawa 1968). What areas of the acciden< investigation are the major types of causes? Some investigators _use the same major big bones such as people, policies, procedures, eqwpmem, and measurement, materials, and/ or environme nt. Others change each

Chapter 11: Cause and Effect Anafysis

es of causes for the accident, such as lockout the relevant typ . h Thi

" """n ID . . procedure and management overstg t. s wa5•- dure uammg, ' . h .,gou• proc~ 'm different and more specific to the accident; owever, -,kes each agra_ ti ier to start the process. Most fish bone diagrams 1...- , is a lit e eas . k ,)le firS t wa) d ent on the right of the page and will actually wor

.th the hea or ev h th fi h' ,..,. wt 1 f . however it really doesn't matter whic way e s s bacJ.,,ar<ls w the e t, • d · poinung.

he< 15

. thod of solving a problem or finding the causes of 5 Whys IS a me . • The t dly asking-at least five tunes-why the problem, ·dent by repea e

an ,co .d t occurred and then why that cause occurred to explore . oracoen . . h

esenr, d effect relationship and discover the causal factors (Haig t the cause an . f th h thi .

X'h,ile this is not a precise techruque as many o e ot ers, s IS an 2008). ·ct · · · h the effective technique if the investigator or acct ent mvest:1gatton ~earn as . th faces and analyses of the accident. This is not a technique you use m-<lepbemnning of the investigation, but only after investigating and gaining ,i ihe ,,.---- . · al much of the information and knowledge of the accident. As any analyoc ,echnique, you must know the information before starting the analyS1s. While this technique is used by many individuals and many comparues around the world, it is also highly misused and the correct causal factors and corrective actions are not found, which doesn't correct the real root cause. One of the failures in this technique is by companies forcing a "root cause analysis" technique to be used by untrained investigators, thinking !hey are analyzing the accident better by using a technique. Although this seems to be a simple technique to learn and use, to be effective it requires !he same training, knowledge, and structure as any of the other analytical rrchniques, and as always, practice makes perfect. There is no magic in the number five, but the theory is that you must keeping asking why until you gtl 10 the root of the problem. This technique is very effective if used by a <earn 10 brainstorm and work through the analysis together. The problem "accident is placed at the top and is best used on adhesive notes. The why is repeated until the causal factors are found. This technique is also used ~o discover systemic causes at the bottom as well. Normally this •echruque Starts at the top and works down; however, it can also be used left 10 right.

l'"rt Ill· . A 11aly1fr,,/ T , . 8CfJl1Jq11e.s

120

Fishbone Diagram

~eople J ~ _l!kof ~~ures

1~--~ // Equipment ] [ Policies J SWhys

Event

Why?

Why? Bad Housekeeping

Chapter 11: Ca11st and Ejftd Ana!Jsis

cause and Effect Process

· to deterrnine the effect (event, accident, problem). In an · ·· Thi . .

1n' . ·gacion the effect is the ace1dent, UlJury, or damage. s 1s •dent lflvesu , . '"' f' er that effect is then analyzed by asking: •'Why?"; •'What was this

,hefirSte ,e ' , • · ., b ,, ... or ''\VhY did this happen?' to get to the next level. This 1s then ted until the causal factors are found. One of the issues with any causal

c,,11SCU } · ' ::~ analysis is knowing when to stop. If there is lack of investigating or 1:n,wledge of the facts and analysis of the accident, then these techniques ,ill not lead to the causal factors but will stop short and lead to symptoms of problems instead. Tbere are many types of problems that can occur with the cause and effect analysis, as listed in Exhibit 11.2.

Exhibit 11.2 ;:::: PROBLEMS WITH,.c;AUSE Afilf EFFECT

• Stopping too soon (stopping at th supert1c1al causes) e

• The need to place blame

• Not having enou h of the accident o;st~~owledge (facts) analysis too soon ,ng the

• Not looking at all issues (management pol' supervision, t/aini~cy' human factors des~g• ' n, etc.)

Exarnpl S Tu, e cenario example scenarj

]

P<norrnin o has alread b • •by in g a cause and y een analyzed b ll"1 . rnosr accide . effect chart sh y some of th

)~cal techr,j nt investiga . ould be f . l e other techni ques to find th Uons there is b' airy straightfo ques

e causal facto a tg benefit of _rward. This rs. If using the 5 ~sing multiple

ys techni que,

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Parl II/: Analytital I,,bniqueJ

122

the accident would be laid out similar to the tree analy · . s15 and WouJd shape. For purposes of usrng the technique, let's do take that

a couple of . . of the 5 Whys. The top event would be the individual fallin ueranons \Vhy did the individual fall off the ladder> Exhibit l l 3 di off th• ladder. th 5 Wh h . w n.. . thi . sp ays the s••-e ys tee ruque. w uen usrng s technique, you will h ~, of many iterations to get all of the causal factors . ave to per/onn

Exhibit 11.3

Event Falling off ladder

.0. Why? Ladder hit

by forklift

.0. Why? Failure to

barricade aisle

Summary

There are three types of cause and effect analysis: Apollo Method, fishbone diagram, and the 5 Whys. Each of these techniques is a structured approachw stan with the accident and analyze it until it reaches the causal factors. While there are problems with this technique, if it is used by experienced trruned ~ ve5rigators, these techniques are very effective at reaching causal factors, mcluding systemic causes.

*

Chapter 11: Couse a11d Ejftrl A11olysis

REVIEW QUESTIONS d effect analysis?

es of cause an . , ethe three !'/P and effect analysts .

1.wttatar . three types of cause he differences tn the

iWhatare t ctured approach? J. wt,at is the Apallo method stru . fusing a cause and effect analysis

blems orfatlures o 4 W,,ataresome of the pro

. such as the 5 Whys? . does the investigator d ffect what questions

5. When analyzing a cause an e '

continually ask? A llo method and the I the example scenario with the po 6. Continue to ana yze

fishbo ne diagram.

CHAPTER12 I ••r

Specialized and Computerized Techniques

So far this book has discussed five major types of analytical techniques: events and causal factors analysis, change analysis, barrier analysis, tree analysis, and cause and effect analysis. Many other specialized analytical techniques can be used in accident investigations, and each has a role in certain situations. (NOTE: 1n some types of accidents, these specialized techniques may yield so much information and so many possible causes that the investigator cannot deal with them. The process becomes too confusing and frustrating. The mvestigator must learn to use the appropriate technique for each type of accident)

Some of the newest analytical techniques for accident investigation involve ~-~oo d . all . . mputers an software. Some programs s!Illply ow investigators to portray a ·a · ·d cc, ents graphically, but others actually help to analyze acc1 ents.

h " . d . e tee ruques range from computerized trees to fully an!Illate accident re . construction programs.

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Part lll: At1u!) t1l"al Trrhm<J,m

126

Specialized Techniques

Time Loss Analysis

Time loss_ analysis ,~•as developed for the National Tran Board. It 1s a graphical analysis tool that investigators casportation Sifett ro ~nderstand, de~'elop, an~ evaluate interventions and em: use proacti\"e:\;. ~coons, ~nd r~acav~ly co give credit to good emergenc , re tgency responst 1mervent10ns 1n accident situations. ) sponse effons or

Time loss analysis helps the investigator to evaluate how the _ . em~ncy response or loss control actions affected the loss cau llnung of ac~dent and to analyze _the losses that occurred as the events lea . sed hr the acadeot progressed. It 1s useful in determining how 1 up to the oss control mterv . changed (or could have changed) the amount of loss a d h . . enao~

n owumeincrcasea ~r decre~sed lo~ses ~r costs. It provides a way to analyze the interventions l.Il an acadent s1 ruat1on and determine how they changed the course of the accident sequence (SSDC 1987) .

To use this technique, investigators follow these seeps:

Discover and analyze all interventions that took place leading up to and during the accident.

Determine whether these interventions increased, decreased, or had no effect on the outcome (the accident sequence). Forexample,ini car crash with an injury, what is the effect o f the vehicle having anti-lock brakes? D o the brakes allow the car to sto p any sooner or in a shorter distance? What about airbags? What about crumple zones?

Assign a time value to each intervention. The time value can be an acrw.l number or a relative positio n on the chart. For example, the brakes stan

to act as soon as the driver senses danger and applies them. The anti-Jock brake mechanism activates when the wheels begin to lock. The air b~ activate at the moment of impact. The crumple zones crumple after che

. . h damage to che initial impact as the car continues to m ove, increasmg t e car but distributing energy away from the passengers.

2!'.iiW S

. f-,,ed and Computen'z.rd Tedmiqurs Chapter 12: p,na1,

k d in dollars or units of The loss axis is usually mar e b er of people injured ,

e the loss- d d or gas leaked, num ' p,.,i112.t ount of water £loo e •• (iJll f . hides damaged). . c the simple car crash

I# o ,e al •sts chart ior . n1,l!ll . wires a time loss an ) . fall three intervenoo ns- £.tlubit 12.1 l~ lowest amount ofloss occurs t ed. Even if all three

b(<labO'·e. e . and crumple zones-are us d th amount . k br.ikes, :ur bags, if they are not use ' e

,h(·lflo-lOC ill be some damage; however, ¢ therew

i,'t , ,ill be much greater. oi\oSSW

Analysis 11uman Factors al . and a human factors or ri f h an factors an ysts, 1'1..- ire man}' methods o um al ' The basis of human factors .. ~- h uld erform the an l ses. . ..oonomics expert s o p chin / w· orunent interaction and to detemune .,- . tify human/ ma e en f ~'Sisis to1den : h d an effect on the accident. There is som e type o ~ticther the intw.cnon a f cident The key is to determine the

involvement in all aspects o an ac . . ~= involvement and the human capabilities to perform the task. Exhibit 12.1

(

+

TIME LOSS ANALYSIS

TO - Driver senses danger

I _______ T 1 -Driver applies brakes \ I T 2 -Anti-lock brakes deploy T 3 - Airbags deploy I, T 4 -Crumple zones crumple t \~~ Natural : : : : , course of

: \ \ \ \ \ accident 9 : \ : Courseof

\ : ; \ l ~i~~d=l~t : \ interventions

-~ ineffect To T, T2 T3 T4

TIME

128

To ~ nduct n human/ machine / environment analysis c.,-pc:.n tollm.vs these steps: of an accid

•n~ th Analyze ho·w the human interacted with th '

e rnachin environment, etc. e, eqUiPrnen Llst the bad interactions in the accident t, - - sequence l mter.1cao ns that do not favor the capabilities of the h · hese are th capabilities include physical interactions (stre h umf! a~ body. I-I1.1rn '

. . . . ngt , ex,bi]j an m~a~ n, eyesight, ~eann~, men~al tnteractions (knowled e ~• ra~ge of tr.11n1Ilg), and emononal mteracnons (morale mon· . g • lrltelligence

, vanon, attitud • Other types of human factors analysis analyze anthropome . e). rk h · I cl · d · · try, btomechani ,vo - p ysio ogy, s ecnon an traU11ng of personnel, job tasks and w ts,

In this of analysis, the focus i~ on the work environme~t that orkloads. bad beha"',or. The safety professional tries to eliminat th b Produces . . eeadbeh · instead of focusing on human error (Oakley and Smith 2000). avior

Integrated Accident Event Matrix

An integrated accident event matrb. includes a list of all individuals who were at the scene of an accident and a time-based chart that shows their interactions (DOE 1999). This matrix allows an investigator to analyze what each individual was doing at the time of the accident. Although the chan can include any amount of time before the accident, it usually only covers the ten co twenty minutes before the accident occurred. This type of matrix is helpful for many types of accident investigations and is very simple to perform. It is a low-tech method of accident reconstruction.

To perform an integrated accid ent event matrix, the investigator follows these steps:

List all of the individuals who may hav e been involved in the accident in the left column of the matrix.

. d · h ' activities under Mark the next columns with umes, an write eac person s ed the appropriate time. Exhibit 12.2 illustrates an example of an integrat accident event matrix. ft shows that there was no interaction ben~een the

. U d at the p1pefiner pipefitter and the mechanic and that the supervisor ye e . to get the job done as soon as possible, interrupting him. Creaong an

Chapter 12: SperialiZJd and Co111puterized Tedmiqtm

. . a simple technique that can be used to ed accident event macnx is

ji11ef1' . ns between people. dis(O"er wceracno

odes and Effects Analysis . failure M al . . sually used as a proacave safety tool d effects an ys1s ts u ,,_:1,,re rnodes an . al al how failures can affect systems. The r,.,i- - r rofesston s an yze . . d . .,, help safe[) P d actively for accident invesogaaons an 1s ,., also be use re .d ttChnique can I if the accident was caused by a system failure. In acc1 ent rs~ y.usefu all failure modes should be analyzed to determine whether J11rtsogat1ons,

Exhibit 12.2 C: INTEGRATED ACCIDENT EVENT MATRIX Note: This technique is very helpful in fata l acciden~s

or other situations where some viewpoints are not available.

PEOPLE 10:01 10:02 10:03 10:04

Usf all people Record what whocouldgive each worker infomlotion was doing at aboutinter- each time in ocrionsand the sequence. lttlp toanalyze whatoc:curred otthetimeof rht ocddent.

Pipefitter Walked to job Turned to talk Went to Walked to site with super- electrical box equipment;

visor and turned on found breaker mechanic in

pain Supervisor Talked with Yelled at Finished Finished

vendor pipefitter paperwork for paperwork pipefitter

Mechanic Worked on Worked on Talked on Received equipment equipment cell phone electrical - shock

Part TT!: A 11a!Jtiral Terh11iq11es

132

Other Specialized Techniques

Expert Techniques

Some techniques that can be useful in accident investiga,-; . uOnare b by e.,--pe.rts. E.,;:amples include: est Perfottned

Sofa,,ar, ha-:z.ard ana!Jrsis. Helps investigators to analyze f so tware fail find causal fuctors in computer systems. llres '-nd

Common Cal/St faihm ana!Jsis. Used to find system failures th . . . at led to accide

• Sneak amal ana!Jn.s. Looks at sneaks (failures) in a s nts. ystem or circuit.

Failure Analysis and Structural Analysis

Failure analysis and structural analysis can be used for aca·d · . ent mvesuga · ro determine types of failures and structural flaws that led t . llons o an acadent.

Sdentific Modeling

]Vlany types of modeling can be used to describe possible accident scenarios or ro sample data to reconstruct scenarios. These types of analysis are performed by experts who understand data collection and analysis processes. Most of these types of analysis are performed in a laboratory setting.

Acddent Reconstruction

Accident reconstructions may be simulated or computer-generated. To reconstruct an accident, the investigator finds out how each step in the accident sequence occurred. Once this sequence is determined, the reconstruction will help ro analyze the effects or potential effects of the each event in the sequence.

Computerized Techniques

Graphical Programs . . Mi soft VisioTM and

lnvesogators can use graphical programs such as cro h alytical h rts grap an CorelDRAWTM ro create events and causal factors c a ' d effects

d ture cause an trees, draw barrier analysis summary charts, an strUC

Chapter 12: Specialized a11d Computerized Tech11iq11es

s such as Microsoft PowerPoint™ and Corel ration program . . , .. ....ens-Presen d t draw simple charts and analyocal trees. While ill'5'- rM can be use o . . . .

sent:1cions . all di play the results of the accident mvesogaaon, p~ ms graphic y s . . tJ,<SC progt" all analyze the invesogaaon.

d not actu Y tb<Y o

. al Programs ,\Jlalyuc t ized programs however, can help accident b ed of compu er , . A new re . blem solving, investigation, and analysis. These programs

·"'tors with pro . . b al ~res0o·· nl find causal facrors and correcave acoons, ut so to be used not o y to c,J\ al ses into written reports. - ~m y . .

rograms have been designed for accident analysis, Many custom p . 1 . U .

d 1 factors charting and analysis, and tree ana ys1s. smg - m= . .. 1· am does not take the place of mvesogaong, ana yzmg, ,computer progr . . . thi ki however. Four accident invesogaoon and problem solvmg ,nd n ng,

programs are: , REASON® Root Cause Analysis by Decision Systems, Inc.

, Apollo Root Cause Analysis and RealityCharting™ by Apollo Associated Services

, TapRooT® System with SnapCharT® Software and Root Cause Tree® Software by System Improvements, Inc.

' RootCause LEADER™ Software by ABS Consulting, Inc.

The following short descriptions of the capabilities of each program were obtained from the companies' web sites. Web site addresses are listed in the bibliography at the end of the book.

REASON® Root Cause Analysis

The latest version of this root cause analysis software from Decision Systems, Inc. is called REASON@ 7.2. REASON® believes root cause analysis should be a validated and consistent process that discovers the root cause of a Ptoblem so th b · - f h at usiness pracoces can be used to prevent recurrence o t e ('

0 _blem. One of the key features of REASON® is that it gives the user a

thrailroad track to get you to the correct root cause." In other words, it gives e user th l

e too s to find the failure. The program leads the user to ask the

133

Parl III: A 11t1()'hcal Terlmiqu,s

134

right questions, and thus arrive at the e d . n pomt ( an e.,perc sys tem software tha t guides yo root cause) "t> . u to uncov · ,,ea your operaoons problems, enable you to er the r00 50n is . manage and t cau acoon plans and communicates the lesson learned track Your c ses of activities" (Decision Systems Inc. 2011) from Y0 ur probl orrective ernso[ ·

111.is software is used not only for accide · . V!ng . nt mvest::tgations of problem so!V1.ng or process improvement. A vali . , but for an

c.... ti · · . dat::ton ste . Y type son ,vare; us gives consistency to the root ca al . Pis built in d

use an ys1s pro to the oes nor attempt to funnel the user into a sel cess. REAsoN

. . ect number of root ca r t Other unportant funcnons are a correctiv . Uses. . . e act::ton datab

correcove acoons and a searchable query for hin ase that track searc g previ s issues, root causes, and corrective actions. The ftw ous accidents so are also h ' report editor. This program can be used for both . as a powerful . . . . reacove and .

s1tuanons and combrnes rntegrated root cause anal . _proacuve . ys1s, corrective ac .

tracking, and lessons learned. (Decision Systems Inc. 20l l) Uon

Apollo Root Cause Analysis

When Apollo Associated Services first started out it introduc d . . ' e an approach to basic problem solvrng that also works well for accident investigation. A llo has developed a very effective training program and cause-and-effect pr!:ss. The cause-and-effect process can be performed either on a computer or on paper. The process and a particular method of analysis is Apollo's real product. As the computer has grown to be a more important tool in accident investigation, Apollo has developed a variety of computerized charting programs. The newest is RealityCharting™.

RealityCharting™ is a graphical program that facilitates the cause-and· effect charting process. One of its features is the ability to drag and drop causes to any location on the chart. The software also provides:

• embedded Apollo Root Cause Analysis methodology

• detailed problem definition helps you understand sigiuficance

• graphic representation of interrelated causes and causal paths

• effective solution generation

• comprehensive reporting features

-I S

. ,. ed and Co/Jlputerized Techniques Chapter t 2: pee1a,1z

. nal user through the rules of the ,,,,ides the new or occas10 Jetion of a RealityChart (Apollo

0ndoW b- th rn roward comp if!I' d leads e ,\ ~tz ethod llfl ,,,,uo m . s 2011)-~, . red service -~-o0a . .

o0'f® . two computerized accident invesngat1on f1pB T®Systern consists of T e® These products are

Roo d R ot Cause re · d ,i,, fap SnapChar'f® an o . dhesive notes to chart events an

grams, t over using a h d pro irnprovernen . al gram that draws c arts an Jefini1ely an Char'f® is a graphic pro . li

., factors. Snap .fi . The result is a presentation-qua ty ~us~ modi 1cat1ons. d h . ,.,ms and allows easy . h I investigators understan w at

,lii5•- Ch 'f® diagram e ps "The Snap ar d h ,, (Systems Improvement ch•rt- 1 . what happene to ot ers. happened and exp am J 2011) ff nc. ot Cause Tree® software picks up where SnapCharT® leaves o • 'In~:~® detemunes what happened, and Root Cause Tree® finds root

lnap ard develops corrective actions. 111.is software features a Root Cause ~m C Tree®diccionary and a Corrective Action Helper® module. The Root ause Tre~includes a Human Performance Troubleshooting Guide that helps investigators ask the right questions to solve human performance problems. A built-in reporting feature and integrated databases ensure that corrective ,ctions are tracked (Systems Improvement Inc. 2011 ).

RaotCause LEADER™ Software RootCause LEADER™ allows accident investigators to investigate and track my l}pe of incident, event, or nushap. It can also perform data trending and ana!ys15, generate report forms, and include a detailed background/ description for each causal fact d >-rL: ftw . . . . or an root cause. , ms so are can 1dent1fy root causes of madents events · d • . . .

b . • , acc1 ents, near nusses, reliability problems, quality impacts,

or Ustness losses.

RootCause LEADER™ h . . . usino R C as five key features: identifying consequences -.,, OOt ause Ma TM hin '

recornrn d . P ' attac g photo files and other documents, tracking en auons and tr d. Th Roo1ca M ' en ing. e consequence categories and ABS's use apTM ar £ £

investigator identi e eatures or customizing the database and helping the fy root causes (ABS Consulting Inc. 2011 ) .

135

Part [] I: A nalytical T echnique,

136

Many specialized and . . cornputeriz d

Summary

accident 1nvestigatio I e anaJyticaJ h . n. n Order to technj

tee 111que, it rnust be c receive th que, <an b per,orrned in th e IIlost inf e •std rnust be perforrned on[ b e correq . . orlllati fo

1 . y y an expe ,, S!tuatton ,, on fro u sed for accident analysis b . rt. <>1any syste~ . "'any re,, .. ~• . . , ut cauaon h ... safety "'ll'!lrti gamed 1s useful. These anaJys . s 0 uJd be used t ana.Jys,

8 , , _

th es rnay identify O ensu, ..,. be at rnay not be practical for th .d . an overwhel-, e that th, ,. al . e ace, ent tn . "'ung "'ll an ys1s and problem-so[v;~g p vesttgati 00

_.,, . u, rograrns b •nenew to tnvestigators. are ecorning i . c

1. What does time loss analysis try to analyze?

2. Which techniques must be performed b

ncreastngl , . l rn,Po"'n,

y an expert? 3. What does a failure modes and effects analysis look for?

4. What is the difference between a design criteria analysisand h c angeanalysisl

5. How can computerized techniques be helpful in accident investigations?

Part IV < z

e

PREVENTING ACCIDENTS

D · d hich is the ultimate f, how to prevent future ace, ents, w . art: :;~:~::cnting accident investigations. Determining the accident purpo d the causal factors prepares the accident investigator to deterrrune stljUence an · · hould corrective actions that will prevent similar accidents. Correcuve acuons s be initiated, documented, and followed up (audited) to ensure that they are perfonning as intended.

Writing an accident report or filling out an accident form is not simply an exercise in paperwork. The report should document that the facts and analysis are correct, the accident sequence has been determined, and corrective actions have been developed to avoid recurrence of the accident.

Learning from accidents is one of the important aspects for conducting an accident investigation. Communicating the lessons learned, preventing systemic problems, and improving the safety programs are key components of learning from the accident. No accident should be repeated.

Objectives for Part IV:

U nd

er st

and the purpose of corrective actions and be able to develop effecuve corrective actions and recommendations for accidents. Understand th I · hi

. e re auons ps among facts, analysis causes and correcu·ve , ,