IOSH Human Factors in Safety 4

Question 1

What is the 'Swiss Cheese Model' and how does it relate to human factors?

Accepted Answer

James Reason's model showing how accidents result from the alignment of failures (holes) across multiple defensive layers, with human factors influencing each layer

Answer

Reason's Swiss Cheese Model shows that organisations have multiple layers of defence against accidents. Each layer has weaknesses (holes) — from organisational culture and management decisions down to individual errors. An accident occurs when holes in multiple layers align, allowing a hazard to pass through all defences.

Question 2

How can task design reduce human error?

Accepted Answer

By simplifying procedures, reducing cognitive demands, providing clear feedback, standardising processes, and matching tasks to human capabilities

Answer

Good task design reduces error by: simplifying procedures (reducing unnecessary steps), standardising processes, providing clear and immediate feedback, designing tasks that match human capabilities and limitations, reducing reliance on memory, and building in checks and verification at critical points.

Question 3

What is 'perception of risk' and why does it matter?

Accepted Answer

How people subjectively assess the level of risk, which can differ significantly from the objective risk level and influence their behaviour

Answer

Risk perception is how individuals subjectively judge the level of risk. It can differ significantly from objective risk assessments due to: familiarity (familiar risks seem less dangerous), personal experience, perceived control, dread factors, and media influence. When perception is wrong, behaviour may be inappropriately safe or unsafe.

Question 4

What is 'normalisation of deviance'?

Accepted Answer

The gradual process by which unacceptable practices or standards become acceptable over time as people get used to them

Answer

Normalisation of deviance (coined by Diane Vaughan studying the Challenger disaster) is when shortcuts, rule violations, or degraded standards gradually become accepted as normal because 'nothing bad has happened'. Over time, the boundary of acceptable practice shifts until a serious incident occurs.

Question 5

How does worker wellbeing influence safety performance?

Accepted Answer

Physical and mental wellbeing directly affect concentration, decision-making, physical capability, risk perception, and engagement with safety practices

Answer

Worker wellbeing directly influences safety through: concentration and alertness, quality of decision-making, physical capability and coordination, willingness to follow procedures, engagement with safety practices, reporting behaviour, and team dynamics. Poor wellbeing (stress, fatigue, illness) impairs all of these.

IOSH Managing Safely Practice Test

IOSH Managing Safely Practice Test

IOSH Human Factors in Safety 4