Addressing Human Error
Leonard G. Middleton
Asset Management Solutions
www.asset-management-solutions.com
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Agenda
• Urban Legend?
• A Brief History of Human Error
• Why People Do Things Wrong
• Improving the Odds
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Urban Legend?
• In early 1980’s a business consultant makes a presentation on addressing human error…
• "I think we can all agree that we can go for 30 seconds without making a mistake. And if we can go 30 seconds without making a mistake, we can go a minute without making a mistake. And if we can go a minute without making a mistake, we can go two minutes… 3
Urban Legend?
• At the end of the presentation the consultant asked whether anyone had any questions.
• Someone raised their hand, and asked…
• "I'm just curious, were you born stupid, or is this something you've been studying?"
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Urban Legend?
• Who is right?
• Is addressing human error as simple as hiring the right people who are conscious and can focus on ensuring the job is done right?
• Or is it much more than that?
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A Brief History of Human Error
• First instance of human error would have preceded the invention of written language.
• One of the early failures would have been likely related to tools and their construction.
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A Brief History of Human Error
• Function of an early simple one piece tool, the wood club.
– To increase the kinetic energy developed by the arm muscles, and transfer it to an object.
• Consequences of failure could be severe, even fatal.
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A Brief History of Human Error
• What could cause a wood club fail?
– Not strong enough. - Too thick
– Too long for accuracy - Too short
– Too flexible - Difficult to grip / hold
– Too heavy - Too light
– Too soft - Poorly balanced…
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A Brief History of Human Error
• Can make a higher performance club and make it more complex by tying a rock onto a stick, however the causes of failures can quickly increase…
– Materials used to fabricate.
– Assembly method and technique.
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A Brief History of Human Error
• Fast forward a few millennia, and the most complex tools that are regularly built, operated and maintained are found to fail too frequently.
• Results in the 1978 Knowlan and Heap study on failures of civilian aircraft.
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A Brief History of Human Error
• One critical finding of study is the infant mortality failure pattern is most common failure pattern.
• Factors and causes include:
– Complex systems
– Defective parts and materials
– Human error11
Why People Do Things Wrong
• Anthropometric factors relate to ergonomic issues.
• Given different body characteristics, it may be difficult, or impossible to perform certain tasks.
– Strength, size, reach, etc.
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Why People Do Things Wrong
• Human sensory factors relate to ease and ability to sense what is happening around individuals and make decisions based upon what is happening.
• Operating environment impacts ability to sense.
– Poor visibility, high ambient noise, strong odours, high vibration, etc.
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Why People Do Things Wrong
• Physiological factors relate to environmental stress that can reduce performance.
• Extreme environment situations can increase stress, causing fatigue and increase errors.
– Temperature extremes, high humidity, etc.
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Why People Do Things Wrong
• Psychological factors are divided between unintended and intended actions.
• Unintended actions are skill based errors related to distraction or preoccupation.
– Slip causing something normally done well, to be done incorrectly.
– Lapse causing a key step in sequence to be missed.
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Why People Do Things Wrong
• Intended actions can result in mistakes or violations.
• Rule based mistake
– Misapplication of a “good rule” where context is not appropriate to the rule.
– Or application of a “bad rule” that is not generally appropriate, but typically used in context.
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Why People Do Things Wrong
• Knowledge based mistake
– Inappropriate response to a situation new to the individual.
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Why People Do Things Wrong
• Violation results when knowingly and deliberately commits an error.
– Routine violation
– Exceptional violation
– Sabotage
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Improving the Odds
• Human error has been around a long time, it may not be possible to eliminate, but there are things can be done to improve the odds.
• Reliability is a result of: how suitable are the assets to their intended use; how well are they installed; how well they are operated; and how well they are maintained.
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Improving the Odds
• Design efforts can focus upon effectively reducing the probability of failures, and reducing the consequences of failures.
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Improving the Odds
• Design focus respecting “Murphy’s Law”, to reduce probability.
• Design philosophy of “making it easy to do it right, and hard to do it wrong”.
– No guarantees, just improves the odds.
• Address different physical characteristics of those performing work, and impact of the work environment. 21
Improving the Odds
• Design focus to address consequences.
• Reduce system dependencies to limit the extent of consequences.
• Evaluate compromise of adding protective systems, versus added complexity (increased probability of failure), cost, and increased maintenance requirements.
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Improving the Odds
• Use a cross functional effort in MOC process (Management of Change) to reduce potential of design changes resulting in problems not obvious to individual making the changes.
• Train all involved in MOC process to ensure they fully understand their responsibilities.
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Improving the Odds
• Focus hiring and training efforts to ensure those assigned work are competent to perform the assigned tasks.
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Improving the Odds
• Develop SOPs (Standard Operating Procedures) to provide instructions for common procedures, especially those done infrequently.
– Start up, shutdown, emergency procedures, etc.
• Ensure all required individuals are trained on procedures, and procedure documents available for their use. 25
Improving the Odds
• Develop job plans for maintenance work, especially for complex jobs, and where the failure consequences of doing the work wrong are severe.
• Given current demographics, may likely be hiring new employees, and can greatly reduce their probability of doing things wrong.
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Improving the Odds
• Violations will need to be addressed through HR policies and procedures.
• How many of your human error failures are related to violations?
– If the number is significant, there may be significant organizational issues that need to be resolved.
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References and Useful Links1. “Reliability-Centered Maintenance” by John
Moubray
2. Wikipedia http://en.wikipedia.org , see human reliability, man made disasters, human error, KISS Principle, Murphy’s Law, etc.
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Leonard G. Middleton
Asset Management Solutionswww.asset-management-solutions.com
Questions?
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Leonard G. Middleton
Asset Management Solutionswww.asset-management-solutions.com
Thank You!
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