Root Cause Analysis

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Root Cause Analysis

F

Fo

o

r

Beginners

by

byJames J. Rooney and Lee James J. Rooney and Lee N. Vanden HeuvelN. Vanden Heuvel

oot cause analysis (RCA) is a process oot cause analysis (RCA) is a process designed for use in investigating and designed for use in investigating and cate-gorizing the root causes of events with gorizing the root causes of events with safe-ty, health, environmental, qualisafe-ty, reliability and ty, health, environmental, quality, reliability and production impacts. The term “event” is used to production impacts. The term “event” is used to

generically identify occurrences that produce or generically identify occurrences that produce or have the potential to

have the potential to produce these types of conse-produce these types of conse-quences.

quences.

Simply stated, RCA is a tool designed to help Simply stated, RCA is a tool designed to help identify not only

identify not onlywhatwhatandandhowhowan event occurred,an event occurred, but also

but alsowhywhyit happened. Only when investiga-it happened. Only when investiga-tors are able to determine why an event

tors are able to determine why an event or failureor failure occurred will they be able to

occurred will they be able to specify workablespecify workable corrective measures that prevent future events of corrective measures that prevent future events of the type observed.

the type observed.

Understanding why an event occurred is the Understanding why an event occurred is the key to developing effective recommendations. key to developing effective recommendations. Imagine an occurrence during which an Imagine an occurrence during which an opera-tor is instructed to close valve A; instead, the tor is instructed to close valve A; instead, the operator closes valve B. The typical operator closes valve B. The typical investiga-tion would probably conclude operator error tion would probably conclude operator error was the cause.

was the cause.

This is an accurate description of what This is an accurate description of what hap-pened and how it haphap-pened. However, if the pened and how it happened. However, if the ana-lysts stop here, they have not probed deeply lysts stop here, they have not probed deeply enough to understand the reasons for the mistake. enough to understand the reasons for the mistake. Therefore, they do not know what to do to Therefore, they do not know what to do to pre-vent it from occurring again.

vent it from occurring again.

In the case of the operator who turned the In the case of the operator who turned the wrong valve, we are likely to see wrong valve, we are likely to see recommenda-tions such as retrain the operator on the tions such as retrain the operator on the proce-dure, remind all operators to be alert when dure, remind all operators to be alert when

R

In 50 Words

Or Less

•

• Root cRoot cause aause analysis nalysis helps helps identifidentify whaty what, how, how and why something happened, thus preventing and why something happened, thus preventing recurrence.

recurrence. •

• Root Root causes causes are uare underlyinderlying, ang, are reare reasonabsonablyly identifiable, can be controlled by management identifiable, can be controlled by management and allow for generation of recommendations. and allow for generation of recommendations. •

• The The procesprocess invos involves dlves data cata collectiollection, con, causeause charting, root cause identification and charting, root cause identification and recom-mendation generation and implementation. mendation generation and implementation.

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manipulating valves or emphasize to all personnel manipulating valves or emphasize to all personnel that careful attention to the job should be that careful attention to the job should be main-tained at all times. Such recommendations do little tained at all times. Such recommendations do little to prevent future occurrences.

to prevent future occurrences.

Generally, mistakes do not just happen but can Generally, mistakes do not just happen but can be traced to some well-defined causes. In the case be traced to some well-defined causes. In the case of the valve error, we might ask, “Was the of the valve error, we might ask, “Was the proce-dure confusing? Were the valves clearly labeled? dure confusing? Were the valves clearly labeled? Was the operator familiar with this particular Was the operator familiar with this particular task?”

task?”

The answers to these and other questions will The answers to these and other questions will help determine why the error took

help determine why the error took place andplace and what the organization can do to prevent what the organization can do to prevent

recur-rence. In the case of the valve error, example rence. In the case of the valve error, example recommendation

recommendations might s might include revising theinclude revising the procedure or performing procedure validation to procedure or performing procedure validation to ensure refere

ensure references to valves nces to valves match the valve match the valve labelslabels found in the field.

found in the field.

Identifying root causes is the key

Identifying root causes is the key to preventingto preventing similar recurrences. An added benefit of an effective similar recurrences. An added benefit of an effective RCA is that, over time, the root causes identified RCA is that, over time, the root causes identified across the population of occurrences can be used to across the population of occurrences can be used to target major opportunities for improvement.

target major opportunities for improvement. If, for example, a significant number

If, for example, a significant number of analysesof analyses point to procurement inadequacies, t

point to procurement inadequacies, then resourceshen resources can be focused on

can be focused on improvement of this managementimprovement of this management system. Tr

system. Trending of root cending of root causes allows developmentauses allows development of systematic improvements and assessment of the of systematic improvements and assessment of the impact of corrective programs.

impact of corrective programs.

Definition

Although there is substantial debate on the Although there is substantial debate on the defi-nition of root cause, we use t

nition of root cause, we use the following:he following: 1.

1. Root caRoot causes uses are are specific specific underlyunderlying ing causes.causes.

2.

2. Root caRoot causes auses are thre those thaose that can t can reasoreasonably nably bebe identified.

identified. 3.

3. Root caRoot causes auses are thre those maose managemenagement has nt has controlcontrol to fix.

to fix. 4.

4. Root cauRoot causes arses are those e those for whfor which efich effective rfective rec- ec-ommendations for preventing recurrences can ommendations for preventing recurrences can be generated.

be generated. Root causes are

Root causes are underlying causes.underlying causes.The investi-The investi-gator’s goal should be to identify specific gator’s goal should be to identify specific underly-ing causes. The more specific the investigator can ing causes. The more specific the investigator can be about why an event

be about why an event occurred, the easier it willoccurred, the easier it will be to arrive at

be to arrive at recommendarecommendations that will preventtions that will prevent recurrence.

recurrence.

Root causes are those that can reasonably be Root causes are those that can reasonably be identified.

identified.Occurrence investigationOccurrence investigations must s must be costbe cost beneficial. It is not practical to

beneficial. It is not practical to keep valuable man-keep valuable man-power occupied indefinitely searching for the root power occupied indefinitely searching for the root causes of occurrences. Structured RCA helps causes of occurrences. Structured RCA helps ana- ana-lysts get the most out of the time

lysts get the most out of the time they have invest-they have invest-ed in the investigation.

ed in the investigation. Root causes are

Root causes are those over which managementthose over which management has control.

has control.Analysts should avoid using generalAnalysts should avoid using general cause classifications such as operator error, cause classifications such as operator error, equip-ment failure or external factor. Such causes are not ment failure or external factor. Such causes are not specific enough to allow management to make specific enough to allow management to make effective changes. Management needs to know effective changes. Management needs to know exactly why a failure occurred before action can be exactly why a failure occurred before action can be taken to prevent recurrence.

taken to prevent recurrence.

We must also identify a root cause that We must also identify a root cause that manage-ment can

ment can influence. Identifying “severe weather”influence. Identifying “severe weather” as the root cause of

as the root cause of parts not being delivered onparts not being delivered on time to customers is

time to customers is not appropriate. Severe weath-not appropriate. Severe weath-er is not controlled by management.

er is not controlled by management.

Root causes are those for which effective Root causes are those for which effective recom-mendations can be generated.

mendations can be generated. RecommendationsRecommendations should directly address the root causes identified should directly address the root causes identified during the investigation. If the analysts arrive at during the investigation. If the analysts arrive at vague recommendations such as, “Improve vague recommendations such as, “Improve adher-ence to written policies and procedures,” then ence to written policies and procedures,” then they probably have not found a basic and specific they probably have not found a basic and specific enough cause and need to expend more effort in the enough cause and need to expend more effort in the analysis process.

analysis process.

Four Major Steps

The RCA is a

The RCA is a four-step process involvinfour-step process involving the fol-g the fol-lowing:

lowing: 1.

1. DaData ta colcollelectictionon.. 2.

2. CauCausal sal factfactor or chachartinrting.g.

QUALITY BASICS

Identifying “severe weather”

as the root cause of parts not

being delivered on time to

customers is not appropriate.

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Aluminum Aluminum melts, melts, forming forming hole in pan hole in pan burner burner shorts out shorts out Grease ignites Grease ignites when it when it contacts contacts burner burner Fire starts Fire starts on the on the stove stove Mary meets Mary meets with Jane with Jane Arcing heats Arcing heats bottom of bottom of aluminum aluminum pan pan Mary leaves Mary leaves the frying the frying chicken chicken unattended unattended Jane rings Jane rings the doorbell the doorbell Jane comes Jane comes

to the door

Mary Mary begins begins frying frying chicken chicken Mary Mary uses an uses an aluminum aluminum pan pan CF CF CF CF Mary Mary Pan Pan Jane Jane Jane, Mary Jane, Mary Mary Mary Pan Pan Pan Pan Conclusion Conclusion Mary Mary Mary Mary 10 minutes 10 minutes Fire Fire generates generates smoke smoke Assumed Assumed Mary runs Mary runs into the into the kitchen kitchen Mary Mary Smoke Smoke detector detector alarms alarms Jane, Mary Jane, Mary About 5:10 pm About 5:10 pm Fire extinguisher Fire extinguisher is not is not charged charged Mary Mary Fire extinguisher Fire extinguisher does not does not operate when operate when

Mary tries to use it

Mary Mary Mary pulls Mary pulls the plug the plug on the fire on the fire extinguisher extinguisher Mary Mary Mary sees Mary sees the fire the fire on the stove on the stove Mary Mary Mary tries Mary tries to use to use the fire the fire extinguisher extinguisher Mary Mary CF CF How How much oil is much oil is used? How used? How much chicken? much chicken? Chicken, Chicken, pan, oil pan, oil What What exactly exactly

did she see?

Mary Mary Had it Had it been been previously used? previously used? Inspection tag Inspection tag Had it Had it not been not been originally charged? originally charged? Fire Fire extinguisher extinguisher Had it Had it leaked? leaked? Fire extinguisher, Fire extinguisher, floor floor Does Mary Does Mary know how know how

to use a fire

extinguisher? extinguisher? Mary Mary Is "plug" Is "plug" the same the same as pin? as pin? Mary Mary CF

CF = = Causal Causal factorfactor

5:00 pm 5:00 pm

Figure 1 continued on next page Figure 1 continued on next page

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3.

3. Root Root causcause ide identientificaficationtion.. 4.

4. RecommendRecommendation ation generageneration tion and and implemenimplementa- ta-tion.

tion.

Step one—data collection.

Step one—data collection. The first step in theThe first step in the analysis is to gather data. Without complete analysis is to gather data. Without complete infor-mation and an understanding of the event, the mation and an understanding of the event, the causal factors and root causes associated with the causal factors and root causes associated with the event cannot be identified. The majority of time event cannot be identified. The majority of time spent analyzing an event is spent in gathering spent analyzing an event is spent in gathering data.

data.

Step two—Causal factor charting.

Step two—Causal factor charting.Causal factorCausal factor charting provides a structure for investigators to charting provides a structure for investigators to orga-nize and analyze the information gathered during nize and analyze the information gathered during the investigation and identify gaps and deficiencies the investigation and identify gaps and deficiencies in knowledge as the investigation progresses. The in knowledge as the investigation progresses. The causal factor chart is simply a sequence diagram causal factor chart is simply a sequence diagram with logic tests that describes the events leading up with logic tests that describes the events leading up to an occurrence, plus the conditions surrounding to an occurrence, plus the conditions surrounding these events (see Figure 1, p. 47).

these events (see Figure 1, p. 47). Preparation of the causal factor

Preparation of the causal factor chart shouldchart should begin as soon as investigators start to collect begin as soon as investigators start to collect infor-

infor-mation about the occurrence. They begin with a mation about the occurrence. They begin with a skeleton chart that is

skeleton chart that is modified as more relevantmodified as more relevant facts are uncovered. The causal factor

facts are uncovered. The causal factor chart shouldchart should

drive the data collection process by identifying drive the data collection process by identifying data needs.

data needs.

Data collection continues until the investigators Data collection continues until the investigators are satisfied with the thoroughness of the chart are satisfied with the thoroughness of the chart (and hence are satisfied with the thoroughness of (and hence are satisfied with the thoroughness of the investigation). When the entire occurrence has the investigation). When the entire occurrence has been charted out, the investigators are in a good been charted out, the investigators are in a good position to identify the major contributors to the position to identify the major contributors to the incident, called causal factors. Causal factors are incident, called causal factors. Causal factors are those contributors (human errors and component those contributors (human errors and component failures) that, if eliminated, would have either failures) that, if eliminated, would have either pre-vented the occurrence or reduced its severity. vented the occurrence or reduced its severity.

In many traditional analyses, the most visible In many traditional analyses, the most visible causal factor is given all the attention. Rarely, causal factor is given all the attention. Rarely, how-ever, is there just one causal factor; events are ever, is there just one causal factor; events are usu-ally the result of a

ally the result of a combination of contributors.combination of contributors. When only one obvious

When only one obvious causal factor is addressed,causal factor is addressed, the list of recommendations will likely not be the list of recommendations will likely not be com-plete. Consequently, the occurrence may repeat plete. Consequently, the occurrence may repeat itself because the organization did not learn all that itself because the organization did not learn all that it could from the event.

it could from the event.

Step three—root cause identification.

Step three—root cause identification. After allAfter all the causal factors have been identified, the the causal factors have been identified, the investi-gators begin root cause

gators begin root cause identification. This stepidentification. This step

QUALITY BASICS

Part two Part two Fire spreads Fire spreads throughout throughout the kitchen the kitchen Kitchen, Mary Kitchen, Mary Mary throws Mary throws water on water on the fire the fire Mary Mary

Mary calls the

fire department fire department Mary, FD Mary, FD Fire department Fire department arrives arrives Observation Observation Fire department Fire department

puts out fire

FD, observation FD, observation Kitchen Kitchen destroyed destroyed by fire by fire Other losses Other losses

from smoke and

water damage? water damage? Time? Time? Time? Time? Time? Time? CF CF Fire was a Fire was a grease fire grease fire Mary, pan Mary, pan Did she do Did she do anything else? anything else? Mary Mary Was Mary Was Mary trying to do this? trying to do this? Mary Mary

Did she know

this was wrong?

Lack of practice Lack of practice fighting fires? fighting fires? Mary Mary What is What is

Jane doing during

this time? this time? Mary, Jane Mary, Jane How long How long

did it take for the

FD to arrive? FD to arrive? FD FD dispatcher dispatcher Did the FD Did the FD

use the correct

techniques?

FD FD

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about why particular causal factors exist or about why particular causal factors exist or occurred. The identification of root causes occurred. The identification of root causes helpshelps the investigator determine the reasons the the investigator determine the reasons the eventevent occurred so the problems surrounding the occurred so the problems surrounding the occur-rence can be addressed.

rence can be addressed.

Step four—recommendation generation and Step four—recommendation generation and implementation.

implementation.The next step is tThe next step is the generation ofhe generation of recommendati

recommendations. Following identification of ons. Following identification of thethe root causes for a particular causal factor, achievable root causes for a particular causal factor, achievable recommendations for preventing its recurrence are recommendations for preventing its recurrence are then generated.

then generated.

The root cause analyst is often not responsible The root cause analyst is often not responsible for the implementation of

for the implementation of recommendarecommendations gener-tions gener-ated by the analysis. However, if the ated by the analysis. However, if the recommenda-tions are not implemented, the effort expended in tions are not implemented, the effort expended in performing the analysis is wasted. In

performing the analysis is wasted. In addition, theaddition, the events that triggered the analysis should be events that triggered the analysis should be expect-ed to recur. Organizations neexpect-ed to ensure that ed to recur. Organizations need to ensure that rec-ommendations are tracked to completion.

ommendations are tracked to completion.

Presentation of Results

Root cause summary tables (see Table 1, p. 52) Root cause summary tables (see Table 1, p. 52) can organize the information compiled during data can organize the information compiled during data analysis, root cause identification and analysis, root cause identification and recommen-dation generation. Each column represents a major dation generation. Each column represents a major aspect of the RCA

aspect of the RCA process.process. •

• In the firsIn the first column, a t column, a generageneral descriptl description of theion of the causal factor is presented along with sufficient causal factor is presented along with sufficient background information for the reader to be background information for the reader to be able to understand the need to address this able to understand the need to address this causal factor.

causal factor. •

• The secoThe second columnd column shown shows the Pas the Path or Path or Pathsths through the Root Cause Map associated with through the Root Cause Map associated with the causal factor.

the causal factor. •

• The thirThe third column prd column presents resents recommendecommendationsations to address each of the root causes identified. to address each of the root causes identified. Use of this three-column format aids the Use of this three-column format aids the investi-gator in ensuring root causes and gator in ensuring root causes and recommenda-tions are developed for each causal factor. tions are developed for each causal factor.

The end result of an RCA

The end result of an RCA investigation is gener-investigation is gener-ally an investigation report. The format of the ally an investigation report. The format of the report is usually well defined by the administrative report is usually well defined by the administrative documents governing the

documents governing the particular reporting sys-particular reporting

sys-The following example is

The following example is nontechnical, allowingnontechnical, allowing the reader to focus on the analysis process and not the reader to focus on the analysis process and not the technical aspects of the situation. The

the technical aspects of the situation. The followingfollowing narrative is the account of the

narrative is the account of the event according toevent according to Mary:

Mary:

It was 5 p.m. I was frying chicken. My friend

Jane stopped by on her way home from the

doc-tor, and she was very upset. I invited her into

tor, and she was very upset. I invited her into

the living room so we could talk. After

the living room so we could talk. After about 10about 10

minutes, the smoke detector near the kitchen

came on. I ran into the kitchen and found a fire

on the stove. I reached for the fire extinguisher

and pulled the plug. Nothing happened. The

fire extinguisher was not charged. In

despera-tion, I threw water on the fire. The fire spread

tion, I threw water on the fire. The fire spread

throughout the kitchen. I called the fire

depart-ment, but the kitchen was destroyed. The fire

ment, but the kitchen was destroyed. The fire

department arrived in time to save the rest of

the house.

Data gathering began as soon as possible after Data gathering began as soon as possible after the event to

the event to prevent loss or alteration of the data.prevent loss or alteration of the data. The RCA team toured the area as soon as the fire The RCA team toured the area as soon as the fire

department declared it safe. Because data department declared it safe. Because data fromfrom people are the most fragile, Mary, Jane and the people are the most fragile, Mary, Jane and the fire-fighters were interviewed immediately after the fighters were interviewed immediately after the fire. Photographs were taken to record physical fire. Photographs were taken to record physical and position data.

and position data.

The analysts then developed the causal factor The analysts then developed the causal factor chart (see Figure 1, p. 47) to

chart (see Figure 1, p. 47) to clearly define theclearly define the sequence of events that led

sequence of events that led to the fire. The causalto the fire. The causal factor chart begins with the event; Mary begins factor chart begins with the event; Mary begins fry-ing chicken at 5 p.m.

ing chicken at 5 p.m. As the chart develops fromAs the chart develops from

In many traditional analyses,

the most visible causal factor

is given all the attention.

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QUALITY BASICS

Root Cause Map

FIGURE 2 FIGURE 2 Section one Section one 1 1 2 2

Start here with each causal factor. Start here with each causal factor. ₁₁

6 6 Equipment Equipment reliability program reliability program problem problem ₇₇ Installation/ Installation/ fabrication fabrication 8 8 Equipment Equipment misuse misuse 2 2 Equipment difficulty Equipment difficulty Corrective maintenance Corrective maintenance LTA LTA •

• Troubleshooting/Troubleshooting/correctivecorrective action LTA

action LTA •

• Repair impleRepair implementationmentation LTA LTA Preventive maintenance Preventive maintenance LTA LTA •

• Frequency Frequency LTALTA •

• Scope LTAScope LTA •

• Activity implActivity implementationementation LTA LTA Predictive maintenance Predictive maintenance LTA LTA •

• Detection Detection LTALTA •

• Monitoring Monitoring LTALTA • Troubleshooting/ • Troubleshooting/

corrective action LTA corrective action LTA •

• Activity implActivity implementationementation LTA LTA 29 29 32 32 36 36 30 30 31 31 33 33 34 34 35 35 37 37 38 38 39 39 40 40 Proactive maintenance Proactive maintenance LTA LTA •

• Event specifiEvent specificationcation LTA

LTA •

• Monitoring Monitoring LTALTA •

• Activity implActivity implementationementation LTA

LTA

Failure finding maintenance Failure finding maintenance LTA

LTA •

• Scope LTAScope LTA • Troubleshooting/ • Troubleshooting/

corrective action LTA corrective action LTA •

• Repair impleRepair implementationmentation Routine equipment Routine equipment rounds LTA rounds LTA •

• Activity implActivity implementationementation LTA LTA 41 41 42 42 43 43 44 44 45 45 47 47 48 48 49 49 50 50 52 52 53 53 54 54 46 46 51 51 Equipment Equipment reliabilitreliabilityy program implementation program implementation LTA LTA ₂₈₂₈ Procedures Procedures 111 111 No program No program Program LTA Program LTA • Analysis/design • Analysis/design procedure LTA procedure LTA •

• InappropriatInappropriate typee type of maintenance of maintenance assigned assigned •

• Risk acceptRisk acceptanceance criteria LTA criteria LTA • • Allocation Allocation ofof resources LTA resources LTA 22 22 23 23 24 24 25 25 26 26 27 27 Equipment reliability Equipment reliability program design program design less than adequate (LTA) less than adequate (LTA) ₂₁₂₁

16 16 Design input Design input LTA LTA Design output Design output LTA LTA 1717 Design input/ Design input/ output output 15 15 Equipment Equipment design records design records LTA LTA Equipment Equipment operating/ operating/ maintenance maintenance history LTA history LTA 19 19 20 20 Equipment Equipment records records 18 18 Administrative/ Administrative/ management management systems systems ₅₅₅₅

Note: Node numbers correspond to matching page in Appendix A Note: Node numbers correspond to matching page in Appendix A of theof the Root Cause Analysis Handbook.

Root Cause Analysis Handbook.

Customer Customer interface/ interface/ services services • Customer • Customer requirements requirements not identified not identified •

• Customer Customer needsneeds not addressed not addressed • Implementation • Implementation LTA LTA 106 106 108 108 109 109 110 110 Document and Document and configuration configuration control control •

• Change notChange not identified identified •

• Verification Verification of design/of design/ field changes LTA field changes LTA (no PSSR*) (no PSSR*) • Documentation • Documentation content not kept content not kept up to date up to date •

• Control of oControl of officialfficial documents LTA documents LTA 100 100 102 102 103 103 104 104 105 105 Procurement Procurement control control • Purchasing • Purchasing specifications LTA specifications LTA •

• Control of Control of changeschanges to procurement to procurement

specifications LTA specifications LTA •

• Material Material acceptanceacceptance requirements LTA requirements LTA • Material inspections • Material inspections LTA LTA •

• Contractor seContractor selectionlection LTA LTA 93 93 95 95 96 96 97 97 98 98 99 99 Product/material Product/material control control •

• Handling Handling LTALTA •

• Storage Storage LTALTA • Packaging/ • Packaging/ shipping LTA shipping LTA •

• Unauthorized mUnauthorized materialaterial substitution substitution •

• Product acceProduct acceptanceptance criteria LTA criteria LTA •

• Product iProduct inspectionsnspections LTA LTA 85 85 87 87 88 88 89 89 90 90 91 91 92 92 Safety/hazard/ Safety/hazard/ risk review risk review •

• Review LTA Review LTA oror not performed not performed •

• Recommendations Recommendations notnot yet implemented yet implemented • Risk acceptance • Risk acceptance criteria LTA criteria LTA • Review procedure • Review procedure LTA LTA 72 72 74 74 75 75 76 76 77 77 Standards, Standards, policies or policies or administrative administrative controls (SPACs) controls (SPACs) LTA LTA • No SPACs • No SPACs •

• Not strNot strictict enough enough • Confusing, • Confusing, contradictory or contradictory or incomplete incomplete •

• Technical errTechnical erroror • Responsibility • Responsibility for item/activity for item/activity not adequately not adequately defined defined •

• Planning, scheduPlanning, schedulingling or tracking of work or tracking of work activities LTA activities LTA • Rewards/incentives • Rewards/incentives LTA LTA •

• Employee screeniEmployee screening/ng/ hiring LTA hiring LTA 57 57 59 59 60 60 61 61 62 62 63 63 64 64 65 65 66 66

SPACs not used SPACs not used • Communication of • Communication of

SPACs LTA SPACs LTA •

• Recently chaRecently changednged •

• Enforcement Enforcement LTALTA

67 67 69 69 70 70 7 711 Problem Problem identification identification control control •

• Problem reporProblem reportingting LTA LTA • Problem analysis • Problem analysis LTA LTA •

• Audits LTAAudits LTA •

• Corrective actCorrective actionion LTA

LTA •

• Corrective actCorrective actions notions not yet implemented yet implemented 78 78 80 80 81 81 82 82 83 83 84 84 Not used Not used •

• Not availabNot available orle or inconvenient to inconvenient to obtain obtain •

• Procedure difProcedure difficultficult to use

to use •

• Use not requiUse not requiredred but should be but should be •

• No procedure No procedure forfor task task 112 112 113 113 114 114 115 115 116 116 Misleading/confusing Misleading/confusing •

• Format confusing Format confusing oror LTA

LTA •

• More than one More than one actionaction per step

per step •

• No checkoff No checkoff spacespace provided but should be provided but should be •

• Inadequate checklInadequate checklistist •

• Graphics LTAGraphics LTA •

• Ambiguous or confAmbiguous or confusingusing instructions/ instructions/ requirements requirements • Data/computations • Data/computations wrong/incomplete wrong/incomplete •

• Insufficient Insufficient or excessiveor excessive references

references •

• IdentificatiIdentification of revisedon of revised steps LTA

steps LTA •

• Level of detail Level of detail LTALTA • Dif

• Difficult to ficult to identifyidentify

118 118 117 117 120 120 121 121 122 122 123 123 124 124 125 125 126 126 127 127 128 128 129 129 Wrong/incomplete Wrong/incomplete •

• Typographical Typographical errorerror •

• Sequence wrSequence wrongong •

• Facts wroFacts wrong/ng/ requirements not requirements not correct correct •

• Wrong revisiWrong revision oron or expired procedure expired procedure revision used revision used • Inconsistency • Inconsistency between between requirements requirements •

• Incomplete/sitIncomplete/situationuation not covered not covered •

• Overlap or Overlap or gapsgaps between between procedures procedures 130 130 131 131 132 132 133 133 134 134 135 135 136 136 137 137 5 5 Equipment Equipment design problem design problem

Figure 2 continued on next page Figure 2 continued on next page

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9 9 Company Company employee employee 10 10 Contract Contract employee employee ₁₁₁₁ Natural Natural phenomena phenomena 12 12 Sabotage/ Sabotage/ horseplay horseplay 13 13 External External events events 14 14 Other Other Training Training 163 163 Human factors Human factors engineering engineering 138 138 Communications Communications 192 192 No training No training • Decisi • Decision on notnot

to train to train • Training • Training requirements not requirements not identified identified 164 164 165 165 166 166 Training records Training records system LTA system LTA • Traini

• Training ng recordsrecords incorrect incorrect • Traini

• Training ng recordsrecords not up to date not up to date 167 167 168 168 169 169 Training LTA Training LTA • Job/task analysis • Job/task analysis LTA LTA • Progr

• Program am design/design/ objectives LTA objectives LTA • Lesson content • Lesson content LTA LTA • On-the-job • On-the-job training LTA training LTA • Qualification • Qualification testing LTA testing LTA • Continuing • Continuing training LTA training LTA • Training • Training resources LTA resources LTA • Abnormal events/ • Abnormal events/ emergency emergency training LTA training LTA 170 170 171 171 172 172 174 174 175 175 176 176 177 177 178 178 179 179 Immediate Immediate supervision supervision 180 180 Preparation Preparation • No preparation • No preparation •

• Job plan Job plan LTALTA •

• Instructions to Instructions to workersworkers LTA

LTA • Walkt

• Walkthrough LTAhrough LTA • Schedul • Scheduling LTAing LTA • Worker selection/ • Worker selection/ assignment LTA assignment LTA Supervision during Supervision during work work • Super

• Supervision LTAvision LTA • Improper performance • Improper performance not corrected not corrected • Teamwork LTA • Teamwork LTA 181 181 182 182 188 188 183 183 184 184 185 185 186 186 187 187 189 189 190 190 191 191 Personal Personal performance performance 208 208 Problem Problem detection LTA detection LTA *Sensory/perceptual *Sensory/perceptual capabilities LTA capabilities LTA *Reasoning *Reasoning capabilities LTA capabilities LTA *Motor/physical *Motor/physical capabilities LTA capabilities LTA *Attitude/attention *Attitude/attention LTA LTA *Rest/sleep LTA *Rest/sleep LTA (fatigue) (fatigue) *Personal/medication *Personal/medication problems problems 209 209 210 210 211 211 212 212 213 213 214 214 215 215 No communication or No communication or not timely not timely •

• Method unavailable orMethod unavailable or LTA

LTA • Communicat

• Communication betweenion between work groups LTA work groups LTA • Communicat

• Communication betweenion between shifts and management shifts and management LTA

LTA • Communicat • Communication withion with

contractors LTA contractors LTA • Communicat • Communication withion with

customers LTA customers LTA 194 194 195 195 196 196 197 197 198 198 199 199 Misunderstood Misunderstood communication communication • Standard • Standard terminology not terminology not used used • Verification/ • Verification/

repeat back not repeat back not used used • Long message • Long message 200 200 201 201 202 202 203 203 Wrong Wrong instructions instructions 204204

Job turnover LTA Job turnover LTA • Communication • Communication within shifts LTA within shifts LTA • Communication • Communication between shifts between shifts LTA LTA 205 205 206 206 207 207 Workplace layout Workplace layout • Controls/displays • Controls/displays LTA LTA • Control/display • Control/display integration/ integration/ arrangement LTA arrangement LTA • • Location ofLocation of controls/displays controls/displays LTA LTA • Confl

• Conflicting icting layoutslayouts • Equipment • Equipment location LTA location LTA • • Labeling ofLabeling of equipment or equipment or locations LTA locations LTA 140 140 141 141 143 143 144 144 145 145 146 146 147 147 Work environment Work environment • Housekeepi • Housekeeping ng LTALTA •

• Tools LTATools LTA • Protectiv

• Protective e clothing/clothing/ equipment LTA equipment LTA • Ambient • Ambient conditions LTA conditions LTA • Ot

• Other her environmentalenvironmental stresses excessive stresses excessive 148 148 149 149 150 150 151 151 152 152 154 154 Workload Workload • Excessive control • Excessive control action action requirements requirements • Unrealistic • Unrealistic monitoring monitoring requirements requirements • Knowl

• Knowledge edge basedbased decision decision required required • Excessive • Excessive calculation or calculation or data manipulation data manipulation required required 155 155 156 156 157 157 158 158 159 159 Intolerant Intolerant system system • Erro • Errors rs notnot

detectable detectable • Erro • Errors rs notnot

correctable correctable 160 160 162 162 161 161 2 2

*Note:

*Note:These nodes are for descriptiveThese nodes are for descriptive purposes only.

purposes only. Shape Description Shape Description

Primary difficulty source Primary difficulty source Problem category Problem category Root cause category Root cause category Near root cause Near root cause Root cause Root cause *PSSR

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QUALITY BASICS

Root Cause Summary Table

TABLE 1 TABLE 1

Event description:

Event description:Kitchen is destroyed by fire and damaged by smoke and water.Kitchen is destroyed by fire and damaged by smoke and water. Event #:Event #:2003-12003-1

Description: Description:

Mary leaves the frying chicken unattended.

•

• Personnel Personnel difficulty.difficulty.

•

• AdministrativeAdministrative/manageme/management systems.nt systems.

•

• Standards, policiStandards, policies or administrativees or administrative

controls (SPACs) less than

controls (SPACs) less than adequate (LTA).adequate (LTA).

• No SPACs.

•

• Implement a policy that hot oil Implement a policy that hot oil is never leftis never left

unattended on the stove.

•

• Determine wheDetermine whether policies shouther policies should beld be

developed for other types of hazards in the

facility to ensure they are not left unattended.

•

• Modify the risk assessmModify the risk assessment process orent process or

procedure development process to address

requirements for personnel attendance

during process

during process operations.operations. P Paatthhs Ts Thhrroouuggh Rh Roooot Ct Caauusse Me Maapp RReeccoommmmeennddaattiioonnss Causal factor # Causal factor # 11 Description: Description:

Electric burner element fails (shorts out).

•

• Equipment Equipment difficulty.difficulty.

•

• Equipment reliaEquipment reliability program probbility program problem.lem.

•

• Equipment reliaEquipment reliability program desigbility program design LTA.n LTA.

• No program.

•

• Replace all burners Replace all burners on stove.on stove.

•

• Develop a Develop a preventive maintenance strategypreventive maintenance strategy

to periodically replace the burner elements.

•

• Consider alternaConsider alternative methods for pretive methods for preparingparing

chicken that may involve fewer

chicken that may involve fewer hazards,hazards,

such as baking the chicken or purchasing

the finished product from a

the finished product from a supplier.supplier.

Fire extinguisher does not operate when

Mary tries to use it.

•

• Equipment proactive Equipment proactive maintenance LTA.maintenance LTA.

•

• Activity implemActivity implementation LTentation LTA.A.

•

• AdministrativeAdministrative/manageme/management systems.nt systems.

•

• Problem identificProblem identification and contation and control LTA.rol LTA.

•

• Refill the fire eRefill the fire extinguisher.xtinguisher.

•

• Inspect otheInspect other fire extinguishers in ther fire extinguishers in the

facility to ensure they are full.

•

• Have incident reports describing the use Have incident reports describing the use ofof

fire protection equipment routed to

maintenan

maintenance to trigger ce to trigger refilling of the refilling of the firefire

extinguishers.

•

• Add this fire extinguAdd this fire extinguisher to the audit list.isher to the audit list.

•

• Verify that all fire extingVerify that all fire extinguishers are on theuishers are on the

quarterly fire extinguisher audit list.

•

• Have all maintenance work Have all maintenance work requests thatrequests that

involve fire protection equipment routed to

the safety engineer so the quarterly

checklists can be modified as

checklists can be modified as required.required.

Mary throws water on fire.

•

• Personnel Personnel difficulty.difficulty.

•

• Company eCompany employee.mployee.

• Training.

• Training LTA.

•

• Abnormal events/Abnormal events/emergency traininemergency training LTA.g LTA.

•

• Provide practicaProvide practical (hands-on) trainl (hands-on) traininging

on the use of

on the use of fire extinguishers. Classroomfire extinguishers. Classroom

training may be insufficient to

training may be insufficient to adequatelyadequately

learn this skill.

•

• Review other skill based aReview other skill based activities toctivities to

ensure appropriate level of hands-on training

is provided.

•

• Review the Review the training development processtraining development process

to ensure adequate guidance is provided for

determining the proper training setting (for

example,classr

example,classroom, lab, simulator, on oom, lab, simulator, on the jobthe job

training, computer based

training, computer based training).training).

Paths Through Root Cause Map is a

Paths Through Root Cause Map is a trademark of ABSG Consulting.trademark of ABSG Consulting.

P Paatthhs Ts Thhrroouuggh Rh Roooot Ct Caauusse Me Maapp RReeccoommmmeennddaattiioonnss Causal factor # Causal factor # 22 P Paatthhs Ts Thhrroouuggh Rh Roooot Ct Caauusse Me Maapp RReeccoommmmeennddaattiioonnss Causal factor # Causal factor # 33 P Paatthhs Ts Thhrroouuggh Rh Roooot Ct Caauusse Me Maapp RReeccoommmmeennddaattiioonnss Causal factor # Causal factor # 44

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is developed from right to left (backwards). is developed from right to left (backwards).

Development always starts at the end because that Development always starts at the end because that is always a known fact. Logic and time tests are is always a known fact. Logic and time tests are used to build the chart back to the beginning of used to build the chart back to the beginning of the event. Numerous questions are usually the event. Numerous questions are usually gener-ated that identify additional necessary data. ated that identify additional necessary data.

After the causal factor chart was complete After the causal factor chart was complete (addi-tional data were gathered to answer the questions tional data were gathered to answer the questions shown in Figure 1), the analysts identified the shown in Figure 1), the analysts identified the fac- fac-tors that influenced the course of events. There are tors that influenced the course of events. There are four causal factors for t

four causal factors for this event (see Table 1).his event (see Table 1). Elimination of these causal factors

Elimination of these causal factors would havewould have either prevented the occurrence or reduced its either prevented the occurrence or reduced its sever- sever-ity. Note the recommendations in Table 1 are written ity. Note the recommendations in Table 1 are written as if Mary’s

as if Mary’s house were an industrial facility.house were an industrial facility. Notice that causal factor two may

Notice that causal factor two may be unexpect-be unexpect-ed. It wasn’t overheating of the oil

ed. It wasn’t overheating of the oil or splattering ofor splattering of the oil that ignited the

the oil that ignited the fire. If the wrong causal fac-fire. If the wrong causal fac-tor is

tor is identified, the wrong corrective actions willidentified, the wrong corrective actions will be developed.

be developed.

The application of the technique identified that The application of the technique identified that the electric burner element failed by shorting out. the electric burner element failed by shorting out. The short melted

The short melted Mary’s aluminum pan, releasingMary’s aluminum pan, releasing the oil onto the hot burner, starting the fire.

the oil onto the hot burner, starting the fire. The analyst must be willing to probe the The analyst must be willing to probe the datadata first to determine

first to determinewhatwhathappened during the occur-happened during the occur-rence, second to describe

rence, second to describe howhowit happened, andit happened, and third to understand

third to understandwhywhy..

B I B L I O G R A P H Y

Accident/Inci

Accident/Incident dent Investigation ManualInvestigation Manual, second edition,, second edition, DOE/SSDC 76-45/27, Department of Energy. DOE/SSDC 76-45/27, Department of Energy. Events and Causal Factors Charting

Events and Causal Factors Charting, DOE/SSDC , DOE/SSDC 76-45/14,76-45/14, Department of Energy, 1985.

Department of Energy, 1985. Ferry, Ted S.,

Ferry, Ted S., Modern Accident Investigation and Analysis Modern Accident Investigation and Analysis, sec-, sec-ond edition, John Wiley and Sons, 1988.

ond edition, John Wiley and Sons, 1988. Guidelines for Investigating Chemical

Guidelines for Investigating Chemical Process IncidentsProcess Incidents,, American Institute of Chemical Engineers, Center for American Institute of Chemical Engineers, Center for Chemical Process Safety, 1992.

Chemical Process Safety, 1992.

Occupational Safety and Health Administration Accident Occupational Safety and Health Administration Accident

Investigation Course, Office of Training and Education, 1993. Investigation Course, Office of Training and Education, 1993.

sion five, DPST-87-209, E.I. duPont de

sion five, DPST-87-209, E.I. duPont de Nemours, Savan-Nemours, Savan-nah River Laboratory, 1986.

nah River Laboratory, 1986.

JAMES J. ROONEY

JAMES J. ROONEYis a senior risk is a senior risk and reliability engineerand reliability engineer

with ABSG C

with ABSG Consulting Inc.’onsulting Inc.’s Risk Cs Risk Consulting Division inonsulting Division in

Knoxville, TN. He earned a master

Knoxville, TN. He earned a master’s degre’s degree in nuclear engi-e in nuclear

engi-neering from the University of

neering from the University of TTennessee. Rooney is a ennessee. Rooney is a FellowFellow

of ASQ and

of ASQ and an ASQ certified quality an ASQ certified quality auditorauditor, quality audi-, quality

audi-tor-hazard analysis and critical control points, quality

tor-hazard analysis and critical control points, quality

engi-neer

neer, quality , quality improvement associate, quality manager andimprovement associate, quality manager and

reliability engineer.

LEE N. VANDEN HEUVEL

LEE N. VANDEN HEUVELis a senior risk and reliabilityis a senior risk and reliability

engineer with ABSG C

engineer with ABSG Consulting Inc.’onsulting Inc.’s Risk Cs Risk Consultingonsulting

Division in Knoxville, TN. He earned a

Division in Knoxville, TN. He earned a master’s degree inmaster’s degree in

nuclear engineering from the University of Wisconsin.

Vanden Heuvel co-authored the

Vanden Heuvel co-authored the Root Cause AnalysisRoot Cause Analysis

Handbook: A Guide to Effective Incident

Investiga-tion

tion, co-developed the, co-developed the RootCause LeaderRootCause Leadersoftware and wassoftware and was

a co-author of the

a co-author of the Center for Chemical Process Safety’sCenter for Chemical Process Safety’s

Guidelines for Investigating Chemical Process

Incidents

Incidents. He develops and teaches courses on the subject.. He develops and teaches courses on the subject.

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