Human Error

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Human Error

• Brian Harkins

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Error

• Definition An action that unintentionally
  departs from an expected behavior
• People do not operate in a vacuum, where they
  can decide and act all-powerfully. To err or not
  to err is not a choice. Instead, peoples work
  is subject to and constrained by multiple
  factors.
• --Sidney Dekker

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Violation

• Deliberate, intentional acts to evade a known
  policy or procedure requirement for personal
  advantage usually adopted for fun, comfort,
  expedience, or convenience
• Violation is a motivational issue

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Error Or Violation?

• People do not make mistakes intentionally.
• Error is behavior, without malice of forethought.
• Violation involves the deliberate deviation from
  expected behavior.
• Errors are for the most part unintentional.
  It is very hard for management to control what
  people did not intend to do in the first place.
• Dr. James Reason

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Can we punish errors away?

• You did not intend to make that mistake and did
  not understand the consequences, so I am going to
  punish you so the next time you dont intend to
  do something, you wont do it

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Strategic Approach

• The strategic approach to improving human
  performance embraces two primary changes
• Anticipate, prevent, catch, and recover from
  active errors at the job site.
• Identify and eliminate latent organizational
  weakness that provoke human error and degrade
  defenses against error and the consequences of
  error.
• Reduce errors Manage defenses No Events
• Re Md ?E

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• Events are not so much the result of error-prone
  workers as they are the outcome of error-prone
  tasks and error-prone work environments, which
  are controlled by the Organization.
• James Reason, Managing the Risks of
  Organizational Accidents
• ---------------------------------------
• A review of 35 events in nuclear power plants
  that had the potential to do core damage
  identified 270 errors of which 81 were latent
  and 19 were active errors.
• Nuclear Regulatory Commission, NUREG/CR-6753,
  March 2002

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Job-Site Conditions
The link between organization and the job-site
Source Dean Ripley. Performance Improvement
Pathfinders, Models for Organizational Learning.
1997, p54.
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JENGA
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Terminology

• Active Errors Error that results in immediate
  unfavorable result to the plant or personnel.
• Latent Errors Errors that result in hidden
  organization related weaknesses or equipment
  flaws that lie dormant.
• Latent Organizational Weaknesses Hidden
  deficiencies in management control processes or
  values creating workplace conditions that provoke
  error.
• Error Precursors Unfavorable conditions at the
  work site that increase the probability of errors

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Common Traps of Human Nature

• Stress
• Mental Strain Avoidance
• Inaccurate Mental Models
• Limited Working Memory
• Limited Attention Resources
• Mind-Set

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Common Traps of Human Nature

• Difficulty Seeing Ones Own Error
• Limited Perspective
• Susceptibility to Emotional/Social Factors
• Motivated toward Goal Accomplishment
• Fatigue

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Unsafe Attitudes

• Risk Perception Human beings are poor judges of
  risk. People are less afraid of risks or
  situations
• They feel they have control
• Risk provides wanted benefits
• Know about and live with the hazard
• Risks are routine - not new or novel
• Risks come from people or organizations they
  trust
• Unaware of the hazard(s)

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Hazardous Attitudes

• Pride - Dont insult my intelligence.
• Heroic - Ill get it done, hook or by crook.
• Invulnerable - That cant happen to me.
• Fatalistic - Whats the use?
• Bald Tire I have 60K miles and havent had
  a flat yet.
• Summit Fever - Were almost done.
• Pollyanna - Nothing bad will happen.

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Uneasiness and Intolerance

• People should possess a keen sense of uneasiness
  toward any activity
• Uneasiness prompts a person to expect success
  but anticipate failure.
• Strategic foundation for improving performance
  Personnel recognizing error-likely situations and
  degraded or missing defenses.

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Error-likely - Is this a setup?
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Error-likely Situation
An error aboutto happen due toerror precursors
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Error Precursors Short List
Task Demands
Individual Capabilities
Work Environment
Human Nature
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Formosa Plastic Plant Explosion Fire Video

• What are the Error Precursors that you see?
• What was the Active Error?
• What was the Passive Errors?
• What was the Human Error?

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Human Information Processing
Thinking
Sensing
Acting
When people err, there is typically a fault with
one or more of the stages of information
processing, not with one's motivation.
Source Wickens, 1992
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Performance Modes
Source James Reason. Managing the Risks of
Organizational Accidents, 1998.
1/2
15 of errors
KB
1/1,000
Inaccurate Mental Picture
60 of errors
RB
Misinterpretation
1/10,000
25 of Errors
SB
88 - 90 of our time!! ---
Inattention
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Skill Based (SB) Performance

• Very familiar situations executed from memory
  without significant conscious thought or with
  little attention.
• Test - can the person carry on a conversation
  while performing the task.
• Error mode - Inattention. Primarily execution
  errors, involving slips and lapses in attention
  or concentration. Errors involve inadvertent
  slips and unintentional omissions triggered by
  simple human variability or by not recognizing
  changes in task requirements, system response, or
  plant conditions related to the task.
• Error Rate - less than 1 in 10,000.
• 90 of a persons daily activities are spent in
  the skill-based performance mode.
• 25 of all errors.

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Rule Based (RB) Performance

• Based on the selection of stored rules derived
  from one's experience or from a procedure it
  follows an IF (symptom X), THEN (situation Y)
  logic.
• Test Is the worker using IF (symptom X), THEN
  (situation Y) logic either using a procedure or
  by conscious mental thought.
• Error mode is misinterpretation. Errors involve
  deviating from an approved procedure, applying
  the wrong response to a work situation, or
  applying the correct procedure to the wrong
  situation.
• Error Rate - 1 in 1,000.
• Roughly 60 of all errors.

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Knowledge Based (KB) Performance

• The person relies on his or her understanding and
  knowledge of the system (mental model), the
  system's present state, and the scientific
  principles and fundamental theory related to the
  system to develop an appropriate response.
• Test Is this a unfamiliar situation (no skill
  or rule recognizable by the individual).
• Error mode is an inaccurate mental model of the
  system, process, or situation. Knowledge-based
  activities require diagnosis and problem-solving.
  Decision-making is erroneous if problem-solving
  is based on inaccurate information.
• Error Rate - 1 in 2.
• 15 of all errors.

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Error Precursors Effect on Performance Modes

• Some error precursors are particularly powerful,
  depending on the performance mode of the
  individual performing the action. For instance
• Skill-based performance strongly influenced by
  distractions, simultaneous tasks, and fatigue
• Rule-based performance - strongly influenced by
  mindset confusing displays, and confusing
  procedures
• Knowledge-based performance - strongly influenced
  by assumptions, first-time performance of the
  task, time pressure, lack of knowledge, and
  inexperience

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Helicopter Landing Video

• What were the performance modes of the pilot?

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Error Prevention at the Jobsite

• Machines Equipment can be designed to catch
  errors
• Other People Co-workers and Supervisors are
  resources to help prevent or catch errors
• Individuals The individual can catch his or her
  own error before it results in an event.

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PROACTIVE MENTAL FRAMEWORK
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Proactive Mental Framework - Plan

• TWIN Analysis Reducing error precursors

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Proactive Mental Framework - Prepare

• SAFER Dialogue
• Summarize Critical Steps
• Anticipate Error Traps
• Foresee Potential Consequences
• Evaluate Defenses
• Review Experience
• Task Preview Before During Pre-job

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Critical Process Step Concept
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Critical Steps

• Draining Waste Water from Reactor Vessel at
  Formosa Plastics
• Ensure hazardous gasses have been purged from the
  reactor.
• Open the manway door.
• Power wash residue from walls.
• Open the bottom valve and drain valve and drain
  flush water to the floor drains.
• Close bottom valve and drain valve.
• Notify the Poly Operator that the reactor is
  ready for a new batch.
• Warning
• Worker could be exposed to hazardous gasses if
  reactor has not been purged before the manway
  door is opened.
• Do not over ride the bottom valve interlock
  without Shift Supervisor approval.

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Guidance for Level of Pre-job Briefing
Task
Simple or Repetitive
SAFER Dialogue
Preplanned Prejob Briefing Forms
 
 
 
Complex or Infrequent
Generic Prejob Briefing Checklist
Infrequently Performed Testor Evolution
 
 
 
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Pre-job Brief Should Cover

• Task (Scope, Sequence Critical Steps)
• Expected Plant Responses
• Responsibility of each individual
• Specific method(s) of communications
• Radiological and environmental concerns
• Operating experiences and lesson learned
• List of job hazards, special precautions and
  appropriate PPE
• Appropriate procedures, drawings, and other
  references
• Identification of energy source controls
• Input, questions and concerns from those in
  attendance 

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Five Key Pre-Job Questions

• Have we done this job before? (Identify problems
  and operating experience)
• What are the critical steps? (Irrecoverable
  actions)
• What mistakes might be made? (Error likely
  situations)
• What is the worst thing that can happen? (to the
  workers, plant or equipment) What kind of
  defenses should be considered? (what defenses are
  in place, are they adequate, how we know and what
  will we do if a defense fails)

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Things to Avoid During Pre-job Briefs

• Generalities no discussion of specific error
  traps
• No adaptation of error-prevention tools
• Monologue by one person
• Principal participants not present for briefing
• Supervisor responsible for conducting multiple
  pre-job briefings at the same time
• No consideration of the scope of the task or when
  the original task becomes a new task
• No planning for the conduct of the pre-job
  briefing
• Using a checklist of over 270 items to cover
  during a pre-job briefing, especially low-risk
  activities
• Conducted in a distracting location

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Proactive Mental Framework - Perform
Error-Prevention Tools

• Self-checking
• Peer-checking
• Three-way communication
• Procedure Use and Adherence
• Stop when Unsure
• Interruption/Backup

• Questioning Attitude
• Place keeping
• Stop Think Act Review (STAR)
• Concurrent verification
• Independent verification
• Stating Intentions Before Acting
• Flagging

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Proactive Mental Framework Pursue Excellence

• Post-job Critique
• Management System Feedback
• LEARN
• Look Critically,
• Engage to Improve,
• Avoid Recurrence,
• Report Honestly,
• Nurture Learning in Others

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Post-Job Critique

• Purpose Organizational Improvement
• Quick and easy
• Production and Prevention
• Management Acknowledgement
• Follow-through

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Top 10 Error Traps

• Time pressure
• Distracting environment
• High workload
• First time evolution
• First working day after days off
• One-half hour after wake-up or meal
• Vague or incorrect guidance
• Over-confidence
• Imprecise communications
• Work stress

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Team Errors

• Halo Effect Blind trust in specific individuals
  because of their experience or position in the
  organization
• Pilot / Co-pilot Subordinate person reluctant
  to challenge senior person
• Free Riding One person leads while others loaf
• Groupthink Reluctance to share contradictory
  information because it might break harmony
• Risky Shift Tendency to gamble more as a group
  because accountability is diffused

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Antidotes to Team Errors

• Train on team errors and their causes
• Practice questioning attitude/situation awareness
• Designate a devils advocate
• Maintain independence in thought from other
  members
• Challenge actions and decisions of others

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Antidotes to Team Errors

• Call time outs to help the team achieve a
  shared understanding of plant or product status
• Perform a thorough and independent task preview