Human Failure. Overview. People are never 100% reliable. Andy Brazier. Types of human failure Slips Mistakes Violations

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1 Human Failure Andy Brazier Tel: (+44) Mob: (+44) Overview Types of human failure Slips Mistakes Violations Causes of human failure Things to be aware of 2 People are never 100% reliable Our failures are predictable They are not always preventable Understanding human failure allows us to manage the risks by: Reducing consequences Improving mitigation Reducing likelihood. 3

2 How many errors? Human factors is impotent when your asessing tge risks in your organization 4 Simple errors Competent and experienced people Minor lack of precision or attention to detail Training won t help or telling people to be more careful Procedures won t be read Need to design systems so that they are Arranged in a logical way Labelled clearly Can be used without thinking. 5 6

3 More complex errors Making the wrong decisions or choices People don t understand how the system works Presented with confusing or misleading information Training can help Procedures can help in some circumstances Letting people concentrate Minimise fatigue and distractions. 7 Made in China 8 Violations Deliberate deviations from rules & procedures Most are motivated by trying to get the job done Like errors, they are caused Difference between policies and practices Impractical recommended practices Inappropriate priorities Lack of understanding of hazards and risks Lack of feedback Group or peer pressure Frustration Feeling that it doesn t matter. 9

4 Taking short cuts 10 People are fallible People are good at Detecting small signals & perceiving patterns Improvising and using procedures flexibly Recalling historical information when needed Exercising judgement They are not so good at Paying attention for a long time Being precise in physical tasks Analysing lots of data Doing things exactly the same each time. 11 People are different They have different: Physical abilities Mental aptitudes Experience But they all: Make errors Violate rules and procedures There is no evidence that individuals are error or accident prone 12

5 Types of human failure Human Failure Unintended action Slips Lapses Mistakes Attention failures Memory failures Rule-based Knowledge based Routine Intended action Violations Exceptional Situational Sabotage 13 Types of error Slips and lapses occur in very familiar tasks We need to be aware of these types of errors and try to design equipment and tasks to avoid or reduce their occurrence Mistakes are a more complex type of human error where we do the wrong thing believing it to be right The failure involves our mental processes which control how we plan, assess information, make intention and judge consequences 14 Understanding Human Behaviour Skill-Based Automated routines with little conscious attention Automatic Rule-Based IF symptom X THEN cause is Y IF the cause is Y THEN do Z Knowledge-Based No routines or rules available for handling situation Conscious 15

6 Violations Violations are any deliberate deviations from rules, procedures, instructions and regulations Most violations are motivated by a desire to carry out the job despite prevailing constraints, goals and expectations 16 Causes of violations Difference between policies and practices Impractical recommended practices In appropriate priorities Lack of understanding hazards and risks Lack of feedback Group or peer pressure Frustration Feeling that it doesn t matter. 17 Something to beware of Any of these sound familiar? Forgetting to take your change Forgetting to take your receipt Leaving headlights on when getting out of the car Leaving the gas on when finished cooking Leaving the original in the photocopier Forgetting the attachment on an All examples of where there is an extra step after the main task is complete. 18

7 Checking errors It is easy to over-rely on checking as a way of protecting against human failures However People are not very good at identifying faults especially if failures occur infrequently Not every error or violation can be identified by a check Also, people doing the task can become less vigilant if they know their work will be checked To be of any value, checks must be completely independent of the task 19 Maintenance error Maintenance relies on good communication between groups Intrusive activities Introduction of latent failures Resetting safety devices after the task Lack of plant or hazard knowledge contractors Failure to carry out maintenance or inspections. 20 Group exercise Identify examples of the following Errors you have made outside of work Errors that have occurred at work Violations you have made outside of work Violations that have occurred at work Explain why they may have occurred. 21

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