Human Factors Analysis and Classification System (HFACS).pptx

Human Factors Analysis and Classification System (HFACS).pptx

1. Human Factors Analysis and Classification System (HFACS) MSA 604

2. Human Factors Analysis and Classification System (HFACS) HFACS (developed by Shappell & Wiegmann , 1997) considers all human error components involved and the relationships among them Addresses human error at all levels of the system Originally developed for US military but now used diversely, including outside of aviation Based on Reason’s (1990) model of an accident chain rather than single event Philosophy of accident/mishap analysis that focuses on the system rather than the individual HFACS Guiding Principles Aviation is similar in nature to other complex, productive systems Human errors are inevitable within such a system Blaming an error on the pilot is like blaming a mechanical failure on the aircraft An accident, no matter how minor, is a failure of the entire system Accident investigation and error prevention go hand-in-hand

3. Breakdown of a Productive System: HFACS Incorporated into Swiss Cheese Model (Reason, 1990) The Swiss Cheese Model on the left shows how an accident can be traced back to several other causal factors in the environment (note: there can be as many or few layers of this model as necessary to fully depict the chain of events) While an organization (initial “slice of cheese”) can have policies and procedures for safe operations at various levels, an accident occurs when there is a breach (“hole in the cheese”) that does not prevent the unsafe act (e.g., lack of policy, bad decision-making by CEO, lack of funding to support safe behaviors) Failures to prevent the unsafe act at subsequent layers (e.g., supervision) allow unsafe conditions to propagate down the chain of events until an accident occurs at the lowest level (unsafe acts) Therefore, while an individual might be blamed for an accident, that accident can sometimes be traced back to previous layers in the system, and sometimes as far back as the organization itself HFACs shares a similar hierarchical structure as the Swiss Cheese Model, but adds more detail in terms of possible factors at each level (see next slides). The four HFACS levels (organizational factors, unsafe supervision, preconditions, and unsafe acts) can each correspond to a layer of “cheese” in the Swiss Cheese Model as you see on the left. Swiss Cheese model adapted from Reason (1990); HFACS adapted from Shappell & Wiegmann (1997) Latent Conditions Latent Conditions Active and Latent Conditions Failed or Absent Defenses Organizational Factors Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts Active Conditions Accident & Injury

4. Adapted from Alton, J. (2008) The HFACS system Errors ACTS Errors Perception Errors Skill-Based Errors Judgment and Decision-Making Errors Violations Inadequate Supervision Planned Inappropriate Operations Failed to Correct Known Problem Supervisory Violations SUPERVISION Resource/Acquisition Management Organizational Climate Organizational Process ORGANIZATIONAL INFLUENCES Condition of Individuals Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors PRECONDITIONS Perceptual Factors Physical/ Mental Limitations Adverse Physiological States HFACS Structure Lowest level: Acts – factors describing the individual(s) behaviors that directly caused the accident However, Acts can be influenced be various Preconditions Supervision factors can lead to the Preconditions Highest level: Organizational Influences – factors directly controlled by the company or organization that can lead to poor Supervision factors Note that there can be more than one relevant factor at each of the four HFACS levels

5. Using HFACS to analyze an accident The following slides decompose each facet of the HFACS model on each of the four levels As you review an accident case, start with identifying each of the reasons why the individual(s) involved committed each of the acts. Note that there may be more than one reason (e.g., if errors were committed, there could be both skill- and perception-based errors; there could also be violations committed in addition to errors) Then try to identify preconditions that led to each of the acts. There may be more than one precondition for each act. Next, identify supervision factors that can be linked to each precondition. Again, there may be more than one supervision factor per precondition. Finally, try to identify organizational influences that can be linked to each supervision factor. Again, there could be more than one organizational influence upon each supervision factor.

6. ACTS Violations Errors Misperception Errors Judgment and Decision Errors Skill-Based Errors Unsafe Acts Unsafe Acts First (lowest) HFACS level: ACTS (direct cause of the accident) ACTS can correspond to the lowest level of the Swiss Cheese Model, since they lead directly to the accident Errors (not committed on purpose) and violations (willfully committed on purpose) are two types of Acts Three subcategories of errors (described in more detail on following slides): Judgment/decision Skill-based Misperception

7. DECISION ERRORS Risk Assessment – During Operation Improper Prioritization of Tasks Necessary Action – Rushed Necessary Action – Delayed Caution/Warning – Ignored Wrong choice of action ACTS Violations Errors Misperception Errors Judgment and Decision Errors Skill-Based Errors Unsafe Acts

8. SKILL-BASED ERRORS ACTS Violations Errors Misperception Errors Judgment and Decision Errors Skill-Based Errors Inadvertent Operation Checklist Error Procedural Error Overcontrol/Undercontrol Breakdown in Visual Scan Inadequate Anti-G Straining Maneuver Unsafe Acts

9. MISPERCEPTION ERRORS (due to) Misjudge Distance, Altitude, Airspeed Spatial Disorientation Visual Illusions ACTS Violations Errors Misperception Errors Judgment and Decision Errors Skill-Based Errors Unsafe Acts

10. ACTS Violations Errors Misperception Errors Judgment and Decision Errors Skill-Based Errors Unsafe Acts VIOLATIONS (Willful disregard for rules and instructions!) Violation – Work-around Violation – Routine/Widespread Violation – Extreme Remember that the difference between an error and a violation is that an error is an unsafe act that was beyond the control of the individual or was committed unknowingly (“by accident”). However, a violation is an unsafe act that the individual committed on purpose , knowing that it was the wrong thing to do.

11. Condition of Individuals Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors Perceptual Factors Physical/ Mental Limitations Adverse Physiological States Cognitive Factors Preconditions for Unsafe Acts Unsafe Acts PRECONDITIONS Second HFACS level: PRECONDITIONS (lead to the unsafe acts) Preconditions can correspond to the second-lowest level of the Swiss Cheese Model, since they lead directly to the unsafe acts Three main categories of preconditions, each with multiple sub-categories: Environmental factors Conditions of the individual(s) who committed the unsafe act(s) Personnel factors

12. Condition of Individuals Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors PRECONDITIONS Perceptual Factors Physical/ Mental Limitations Adverse Physiological States PHYSICAL ENVIRONMENT Icing/fog/etc. on Windows Meteorological Conditions Dust/smoke/ e tc . in Workspace Brownout/Whiteout Thermal Stress: Cold/Hot Maneuvering Forces Inflight Noise Interference Preconditions for Unsafe Acts Unsafe Acts

13. Cognitive Factors Psycho-Behavioral Factors Perceptual Factors Physical/ Mental Limitations Adverse Physiological States Technological Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Environmental Factors PRECONDITIONS TECHNOLOGICAL ENVIRONMENT Seating and Restraints Instrument and Sensory Feedback Visibility Restrictions Controls and Switches Automation Personal Equipment Interference Communications - Equipment Physical Environment Condition of Individuals Preconditions for Unsafe Acts Unsafe Acts

14. Cognitive Factors Technological Environment Physical Environment Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors PRECONDITIONS Adverse Physiological States Physical/ Mental Limitations Perceptual Factors COORD/COMM/PLAN Crew/Team Leadership, CRM Cross-Monitoring Performance Task Delegation Rank/Position Authority Gradient Communicating Critical Info Standard/Proper Terminology Mission Planning/Briefing Miscommunication Condition of Individuals Self-Imposed Stress Preconditions for Unsafe Acts Unsafe Acts

15. Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors PRECONDITIONS Adverse Physiological States Physical/ Mental Limitations Perceptual Factors SELF-IMPOSED STRESS Alcohol Physical Fitness Drugs/Supplements/Self Medication Nutrition Inadequate Rest Unreported Disqualifying Medical Condition Condition of Individuals Preconditions for Unsafe Acts Unsafe Acts

16. COGNITIVE FACTORS Inattention Channelized or Tunneled Attention Cognitive Task Oversaturation Confusion Negative Transfer Distraction Geographic Disorientation (Lost) Checklist Interference Condition of Individuals Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors PRECONDITIONS Perceptual Factors Physical/ Mental Limitations Adverse Physiological States Preconditions for Unsafe Acts Unsafe Acts

17. PSYCHO-BEHAVIORAL Personality Style Preexisting Personality Disorder Preexisting Psychological Disorder Emotional State Overconfidence, Overly Aggressive Complacency Get-Home-Itis/Get-There-It is (pressure to arrive at destination as planned) Condition of Individuals Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors Perceptual Factors Physical/ Mental Limitations Adverse Physiological States Preconditions for Unsafe Acts Unsafe Acts PRECONDITIONS

18. ADVERSE PHYSIOLOGICAL Effects of G Forces (G-LOC, etc.) Physical Fatigue (Overexertion) Fatigue – Physiological/Mental Hypoxia Motion Sickness Circadian Rhythm Desynchrony Preexisting Physical Illness/Injury Prescribed Medications for Injury/Illness Condition of Individuals Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Environmental Factors PRECONDITIONS Perceptual Factors Physical/ Mental Limitations Adverse Physiological States Psycho-Behavioral Factors Preconditions for Unsafe Acts Unsafe Acts

19. Condition of Individuals Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors PRECONDITIONS Perceptual Factors Physical/ Mental Limitations Adverse Physiological States PHYSICAL/MENTAL LIMITS Learning Ability/Rate Memory Ability/Lapses Anthropometric/Biomechanical Limits Motor Skill/Coordination or Timing Deficiency Technical/Procedural Knowledge Preconditions for Unsafe Acts Unsafe Acts

20. Condition of Individuals Cognitive Factors Technological Environment Physical Environment Self-Imposed Stress Coordination/ Communication/ Planning Factors Personnel Factors Psycho-Behavioral Factors Environmental Factors PRECONDITIONS Perceptual Factors Adverse Physiological States PERCEPTUAL FACTORS Illusions: Kinesthetic/Vestibular/Visual Misperception of Operational Conditions Misinterpreted/Misread Instrument Expectancy Auditory Cues Spatial Disorientation Temporal Distortion Physical/ Mental Limitations Preconditions for Unsafe Acts Unsafe Acts

21. Inadequate Supervision Planned Inappropriate Operations Failed to Correct Known Problem Supervisory Violations SUPERVISION Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts Third HFACS level: SUPERVISION (leads to the preconditions) Supervision factors can correspond to a third level of the Swiss Cheese Model, since they lead directly to the preconditions for unsafe acts These four supervision factors refer to the improper acts committed by the supervisors and/or managers of the individual(s) involved in the unsafe acts.

22. Inadequate Supervision Planned Inappropriate Operations Failed to Correct Known Problem Supervisory Violations SUPERVISION INADEQUATE SUPERVISION Leadership/Supervision/Oversight Inadequate Supervision – Modeling Local Training Issues/Programs Supervision – Policy Supervision – Personality Conflict Supervision – Lack of Feedback Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts

23. PLANNED INAPPROPRIATE OPERATIONS Ordered/Led Mission Beyond Capability Crew/Team/Flight Makeup/Composition Limited Recent Experience Limited Total Experience Proficiency Authorized Unnecessary Hazard Inadequate Supervision Planned Inappropriate Operations Failed to Correct Known Problem Supervisory Violations SUPERVISION Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts

24. FAILED TO CORRECT A KNOWN PROBLEM Personnel Management Operations Management Inadequate Supervision Planned Inappropriate Operations Failed to Correct Known Problem Supervisory Violations SUPERVISION Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts

25. SUPERVISORY VIOLATIONS Supervision – Discipline Enforcement Supervision – Unwritten Policy Directed Violation Assigned Unqualified Individuals Inadequate Supervision Planned Inappropriate Operations Failed to Correct Known Problem Supervisory Violations SUPERVISION Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts

26. Organizational Influences Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts Organizational Climate Resource/Acquisition Management Organizational Process ORGANIZATIONAL INFLUENCES RESOURCE/ACQUISITION MANAGEMENT Air Traffic Control Resources Airfield Resources Operator Support Acquisition Policies/Design Processes Attrition Policies Accession/Selection Policies Personnel Resources Information Resources/Support Financial Resources/Support Fourth HFACS level: ORGANIZATIONAL INFLUENCES (leads to the supervision factors) Organizational factors can correspond to a fourth level of the Swiss Cheese Model, since they lead directly to unsafe supervision factors These three organizational influences are the highest level of factors and refer to decisions, behaviors, and processes at the highest levels of the company or group; they the actions and decisions made by the highest level of management, CEOs, and possibly even the industry itself. Unsafe or improper practices at this level filter down to the lower levels (supervisors and then preconditions and eventually the individuals).

27. Organizational Climate ORGANIZATIONAL INFLUENCES ORGANIZATIONAL INFLUENCES Organizational Climate ORGANIZATIONAL CLIMATE Unit/Organizational Values/Culture Evaluation/Promotion/Upgrade Perceptions of Equipment Unit Mission/Aircraft Change Unit Deactivation Organizational Structure Resource/Acquisition Management Organizational Process Organizational Influences Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts

28. Organizational Climate Operational Process ORGANIZATIONAL INFLUENCES ORGANIZATIONAL INFLUENCES Organizational Process ORGANIZATIONAL PROCESS Operations Tempo/Workload Program and Policy Risk Assessment Procedural Guidance/Publications Organizational Training Issues/Programs Doctrine Program Oversight/Program Management Resource/Acquisition Management Organizational Influences Unsafe Supervision Preconditions for Unsafe Acts Unsafe Acts

29. HFACS Example An H-60 helicopter enters out-of-control flight after loss of tail-rotor effectiveness. Aircraft becomes uncontrollable resulting in a hard landing and rollover. Engineering investigation reveals improperly installed tail-rotor mechanism pin. Act: Procedure performed incorrectly (AE103). Tail rotor cotter pin not correctly installed. Preconditions: Warning systems (PE202). Lack of written warning for improperly installed pin. Supervisory: Inadequate oversight (SI001). Quality assurance (QA) missed improper pin placement. Organizational: Informational resources (OR008). Lack of diagram showing pin placement in relation to all other holes. Flawed Doctrine (OP005). Army had solved the problem several years before. Information not made part of Navy maintenance. DoD HFACS Coding

30. HFACS Exercise (for Weekly Presentation 6) Use the HFACS to decompose the Downeast Flight 46 accident which occurred May 30, 1979. Identify as many of the factors (and subfactors) as possible on each of the four levels of the HFACS model. This is a complex accident, so you should be able to identify many such factors and trace them up the chain of the organization. The video for the Downeast Flight 46 accident starts at 21:23 (ends at 36:36) on the following link: https://www.youtube.com/watch?v=Btr_vMH5tEw For this assignment, you can submit either a PowerPoint (presentation) or Word file.

31. Source: Naval Safety Center School of Aviation Safety HFACS-ME is a version of the HFACS with a focus on maintenance