1. Human Error and Calculated Risks
Stephen Harris
Amcham HSE Conference – Guyana 17/7/19

2. Definition of calculated risk
A hazard or chance of failure whose degree of probability has been reckoned or estimated before some undertaking is entered upon
An undertaking or the actual or possible product of an undertaking whose chance of failure has been previously estimated
Why u r in business in the first place
Merriam-Webster

3. Definition of calculated risk
A chance that is taken after a careful estimation of the possible outcomes. People use this expression when the possible gain is worth more than what will be lost if the action fails.
People highlighted…..we depend on people at all levels to deliversafely
Business Dictionary

4. Risk management process
Step 1: Identify the hazards.
Step 2: Decide who might be harmed and how.
Step 3: Evaluate the risks and decide on precautions.
Step 4: Record your findings and implement them.
Step 5: Review your assessment and update if necessary.
Leading into PHA…..after u decide to move forward…..the risk now is to continue in business……one significant safety event could wipe you out

5. Process Hazard Analysis (PSM)
A process hazard analysis (PHA), or evaluation, is one of the most important elements of the process safety management program. A PHA is an organized and systematic effort to identify and analyze the significance of potential hazards associated with the processing or handling of highly hazardous chemicals.
Prelim pha
Check list…what if
Hazop – scenarios that impact people n envir as well operatability
Process hazard review – alternative to hazop
Fault tree analysis

6. Human Factors Defined
“Environmental, organizational and job factors and human and individual characteristics which influence behaviour at work in a way which can affect health and safety”
HSE

7. Physical Factors vs Human Factors
Past legislation focused primarily on the physical elements of safety rather than the human element
Whilst this strategy has improved the physical work environment, they have not always eliminated workplace accidents.
Changes in the physical environment must include the human factors.
Human factors have to do with integrating in the workplace the relationships between people, processes and equipment.

8. It Is Estimated That Human Error Accounts For At Least 80% Of Accidents
Safe Place Strategy
Safe Person Strategy
No. of fatal Accidents/annum
Physical Guards
Safe Systems
Personal Factors
1945
1985
2005
HSE

9. Human Factors – Focus Facilities and Equipment People Systems
Equipment design, control systems, human computer interface, labeling etc.
People
Training, environmental factors, communications, manual handling, workloads etc.
Systems
Culture, procedures, MOC, risk analysis, SWP, PTW etc.

10. Accident, industry and date Human contribution and other causes
Consequences
Human contribution and other causes
Space Shuttle Challenger
Aerospace
1986
An explosion shortly after lift-off killed all seven astronauts on board.
An O-ring seal on one of the solid rocket boosters' splits after take-off releasing a jet of ignited fuel. Inadequate response to internal warnings about the faulty seal design. Decision taken to go for launch in very cold temperature despite faulty seal. Decision-making result of conflicting scheduling/safety goals, mindset, and effects of fatigue.
Piper Alpha
Offshore
1988
167 workers died in the North Sea after a major explosion and fire on an offshore platform.
Formal inquiry found several technical and organisational failures. Maintenance error that eventually led to the leak was the result of inexperience, poor maintenance procedures and poor learning by the organization. There was a breakdown in communications and the permit-to-work system at shift changeover and safety procedures were not practiced sufficiently.
Union Carbide Bhopal, India
Chemical processing
1984
The plant released a cloud of toxic methyl isocynate. Death toll was 2500 and over one quarter of the city’s population was affected by the gas
The leak was caused by a discharge of water into a storage tank. This was the result of a combination of operator error, poor maintenance, failed safety systems and poor safety management.

11. Conclusion
Human Error Was often one of the main explanations given for the cause of these accidents/disasters. However, examination of all the facts suggests that several things such as:
Poor design,
Poor maintenance,
Equipment failures,
Organizational failings and human fallibility usually combined to produce the end result.

12. Elements which influences Human Behavior
Personal Factors – Includes training, selection, motivation, risk perception, safety attitudes, skill, memory
Organizational Factors – Includes Mgt commitment, control, co-operation, communication, culture, policies
Job Factors - Includes job content, workload, design of human-machine interfaces, procedures, workplace environment.

13. In order to address human factors in workplace, peoples’ capabilities and limitations must first be understood.

14. Classification of Human Error
Human Failure
Errors
Not deliberate
Skill based errors
Slips of action
Actions not as planned
 Steps in wrong order
 Too soon
 Too strong
 Too weak
 Up rather than down
Lapses
Memory
 Forget to carry out action
 Lose place in task
 Example forget to turn something on
Mistakes
Doing the wrong thing believing it to be right
Rule based
 Remember rules of familiar procedure
 Apply wrong rule
 Apply rules to wrong situation
Knowledge based
 Unfamiliar circumstance
 Apply knowledge
 E.g. mechanic
Violations
Deliberate
Routine
 Normal way of work
Situational
 Job pressure
 Time
 Rule not safe at time
 Incorrect equipment
Exceptional
 Emergency situations
 Something goes wrong
 Not carry out safely decisions taken, normally due to time won’t allow

15. Key Messages
Everyone can make errors no matter how well trained and motivated they are.
Through a failure a person can directly cause an accident.
People do not set out to make errors deliberately.
People are often ‘set up to fail’ by the way our brain processes information, by our training, through the design of equipment and procedures and even through the culture of the organization we work for.

16. Key Messages
People can make disastrous decisions even when they are aware of the risks.
We can also misinterpret a situation and act inappropriately and as a result lead to the escalation of an incident.
Paying attention to individual attitudes and motivations, design features of the job and the organization will help to reduce violations.
The challenge is to develop error-tolerant systems and to prevent errors from occurring.

17. Key Messages
Failures arising from people other than those directly involved in operational or maintenance activities are important. Managers’ and designers’ failures may lie hidden until they are triggered at some time in the future.
There are two main types of human failure: errors and violations. Controls will be more effective if the types are identified and addressed separately.
Reducing human error involves far more than taking disciplinary action against an individual. There are a range of measures which are more effective controls including design of the job and equipment, procedures and training.

18. Summary
Significant Improvement achieved in Health and Safety with the introduction of machine guarding and Safety Systems.
Regulations in the past focused mainly on Physical Factors.
Workplace incidents continues despite these improvements.
Recent thrust on Human factors for further reductions includes focusing on the interrelationship between equipment , people and systems.

19. Summary
Understanding why human makes mistakes is a key element in preventing Human errors.
Personal, Organizational and Job factors are the main contributors to safety performances.
Human Factors integrates the key elements necessary for further reducing workplace incidents.
Sources
HSE publications
CCPS publications

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