HUMAN FACTORS

HFACS – Who Would Have

Thought?

Scott A. Shappell, Ph.D.

HUMAN FACTORS

Necessity is the Mother of Invention

HUMAN FACTORS

Inputs

Accident & Injury

OrganizationalInfluences

SupervisoryFactors

Preconditionsfor

Unsafe Acts

Unsafe

Acts

Failed orAbsent Defenses

Swiss Cheese Model of Human Error

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Modest Beginnings

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Unsafe Acts

Routine Exceptional

ViolationsErrors

DecisionErrors

Skill-basedErrors

PerceptualErrors

Preconditionsfor Unsafe Acts

CommunicationCoordination

Planning

Fitness forDuty

Personal/Interpersonal

Factors

Condition ofOperators

AdverseMental States

AdversePhysiological

States

Physical/Mental

Limitations

PhysicalEnvironment

TechnologicalEnvironment

EnvironmentalFactors

Supervision

SupervisoryViolations

InadequateSupervision

PlannedInappropriate

Activities

Failed toCorrectProblem

OrganizationalInfluences

ResourceManagement

OrganizationalClimate

OperationalProcess

HUMAN FACTORS

Aviation

Military (Shappell & Wiegmann, 2004; Li et al., 2004; Li & Harris, 2006;

Guar,2005; Li & Harris, 2007; Gibb & Olsen, 2008; Pagan & de Voogt, 2008;

Paletz, 2009; Belland et al.,, 2010)

Commercial (Wiegmann & Shappell, 2001; Shappell et al., 2007; Li &

Harris, 2006; Li et al., 2008; Majumdar er al.,2009; Harris & Lee, 2011)

General Aviation (Wiegmann et al., 2005; Lenne et al., 2008; Dambier &

Hinkelbein, 2006; Guar, 2005; Lenné, et al., 2008; Li, Harris, & Yu, 2008 )

Unmanned Aerial Vehicles (Thompson, 2005; Tvaryanas,

Thompson, & Constable, 2006)

Aviation Maintenance (Krulak, 2004; Boquet et al., 2004; Rashid et

al., 2010)

Air Traffic Control (Scarborough, et al, 2005; Olsen & Shorrock, 2010)

Non-Aviation

Combat Operations (Jennings, 2008)

Construction (Garrett & Teizer, 2009)

Forensics (Wertheim, 2010)

Mining (Patterson et al., 2010)

Railway (Reinnach & Vaile, 2009; Baysari et al., 2008; Baysari et al., 2009)

Maritime (Winters & Valaitis, 2005; Celik & Cebi, 2009; Xi et al., 2009; Schröder-Hinrichs et al., 2011)

Medical (ElBardissi et al., 2007; Portalur, et al.., 2010)

Petrochemical (Koo et al., 2009)

Nuclear Power (Kim et al., 2008)

Expansion of HFACS

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General Aviation

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Skill-based

Errors

Perceptual

Errors

Decision

Errors

ViolationsPe

rce

nta

ge

of A

ccid

en

ts

YearPercentages do not add up to 100%

General Aviation: Overall

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ERROR CATEGORY OVERALL SEMINAL

Frequency (%)

Fatal Non-fatal Total

Frequency (%)

Fatal Non-fatal Total

Directional Control 20 (0.50) 2018 (15.2) 2038 (11.8) 9 (0.57) 1326 (17.5) 1335 (14.6)

Airspeed 713 (17.9) 1127 (8.5) 1840 (10.6) 302 (19.2) 605 (8.0) 907 (9.9)

Stall/Spin 592 (14.9) 753 (5.7) 1345 (7.8) 84 (5.3) 144 (1.9) 228 (2.5)

Aircraft Control 654 (16.5) 665 (5.0) 1319 (7.6) 311 (19.8) 429 (5.7) 740 (8.1)

Compensation for winds 23 (0.6) 1046 (6.2) 1069 (6.2) 12 (0.8 859 (11.4) 871 (9.5)

General Aviation: Fine Grained Analysis(Skill-Based Errors)

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Number of

Cases Unsafe Act

Precondition

for Unsafe Act

Unsafe

Supervision

Organizational

Influence

Data Set n n (%) n (%) n (%) n (%)Chinese Military

Aviation325 325 (100%) 265 (81.54%) 159 (48.92%) 110 (33.85%)

Chinese Civil

Aviation35 35 (100%) 31 (88.57%) 28 (80.00%) 26 (74.29%)

Critical Cases 161 161 (100%) 73 (45.34%) 7 (4.35%) 12 (7.45%)

Entertainment 173 173 (100%) 107 (61.85%) 16 (9.25%) 2 (1.16%)

Food Services 328 328 (100%) 265 (80.79%) 123 (37.5%) 7 (2.13%)

Maintenance - Field 392 392 (100%) 161 (41.07%) 7 (1.79%) 14 (3.57%)

Maintenance - Site 87 87 (100%) 50 (57.47%) 9 (10.34%) 2 (2.30%)

Middle East Aviation 31 31 (100%) 20 (64.52%) 5 (16.13%) 4 (12.90%)

Mining - Australian 475 475 (100%) 380 (80.00%) 163 (34.32%) 43 (9.05%)

Mining - US 242 242 (100%) 216 (89.26%) 205 (84.71%) 128 (52.89%)

Remotely Piloted

Aircraft Operations48 48 (100%) 43 (89.58%) 22 (45.83%) 38 (79.17%)

US Commercial

Aviation - FAR 121143 143 (100%) 80 (55.94%) 14 (9.79%) 10 (6.99%)

US Commercial

Aviation - FAR 135779 779 (100%) 556 (71.37%) 26 (3.34%) 25 (3.21%)

US General Aviation -

FAR 13361 61 (100%) 26 (42.62%) 2 (3.28%) 0 (0.00%)

US General Aviation -

FAR 137761 761 (100%) 392 (51.51%) 2 (0.26%) 2 (0.26%)

US General Aviation -

FAR 9112516 12516 (100%) 7426 (59.33%) 477 (3.81%) 23 (0.18%)

US Gyroplane

Aviation158 158 (100%) 103 (65.19%) 4 (2.53%) 0 (0.00%)

-- 48.61% 1.91% 0.40%

-- 58.13% 7.95% 4.96%

-- 67.65% 14.00% 9.53%

HFACS Tier

Lower Confidence IntervalMean

Upper Confidence Interval

Benchmarking

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Benchmarking

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Benchmarking

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Benchmarking

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Associations Between Categories

Red – Data not included

Yellow – Data sampled

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Associations Between Categories

Solid blue line – Significant Chi-Square, Odds Ratio,

and Lower Relative Risk

Dashed blue line – Significant Chi-Square and Odds

Ratio

Dashed orange line – Significant Chi-Square

HUMAN FACTORS

Solid blue line – Significant Chi-Square, Odds Ratio,

and Lower Relative Risk

Dashed blue line – Significant Chi-Square and Odds

Ratio

Dashed orange line – Significant Chi-Square

Associations – Tier Jumping

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Comparison with other Studies

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Future Directions

Offshore Oil Drilling• Gulf of Mexico

Forensic Science• Latent Fingerprint Analyses

• Questioned Document Analyses

Medicine• Sentinel Events

• Cardiovascular OR

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Questions?