In simple terms
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Health and safety
9990 Organisational — workplace accidents, stress-related illness, and safety culture.
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Heinrich's Domino Theory suggests a simple, linear cause-and-effect chain for accidents.
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Reason's Swiss Cheese Model provides a systems framework, viewing accidents as a result of multiple, interacting failures.
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Latent failures are hidden weaknesses in an organisation's defences (e.g., poor design, inadequate training).
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Active failures are the unsafe acts committed by front-line personnel (e.g., slips, mistakes).
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At a glance — side by side
Compare key properties side by side — ideal for exam contrasts.
Comparison of Person and Systems Approaches to Accident Causation
| Feature | Person Approach | Systems Approach |
|---|---|---|
| Focus of Blame | The individual operator (front-line worker). | The organisation and its management systems. |
| Main Causal Factor | Human error (e.g., forgetfulness, inattention, negligence). | System failures and latent conditions (e.g., poor design, inadequate training, communication breakdown). |
| View of Human Error | A cause of failure; something to be eliminated. | A symptom of deeper trouble in the system; an effect, not a cause. |
| Primary Countermeasure | Discipline, retraining the individual, posters/slogans. | Redesigning the system, improving procedures, enhancing training and communication. |
| Analogy | A 'bad apple' that must be removed from the barrel. | The alignment of 'holes' in multiple slices of Swiss cheese. |
Focus of Blame
Person Approach
Systems Approach
Main Causal Factor
Person Approach
Systems Approach
View of Human Error
Person Approach
Systems Approach
Primary Countermeasure
Person Approach
Systems Approach
Analogy
Person Approach
Systems Approach
Full topic notes
Formal explanation with the rigour you need for the exam.
Theories of Accident Causation: From Dominoes to Swiss Cheese
Understanding why accidents happen is fundamental to preventing them. Early theories, like Heinrich's (1931) 'Domino Theory', proposed a linear sequence of events: social environment and ancestry lead to individual faults, which cause unsafe acts, culminating in accidents and injuries. Removing one 'domino', such as an unsafe act, could prevent the injury. However, this model is criticised for oversimplifying complex events and focusing on individual blame. A more contemporary and influential model is James Reason's (1990) 'Swiss Cheese Model'. This systems approach analogises organisational defences (like procedures, training, and equipment) to slices of Swiss cheese. Each slice has holes (latent failures or weaknesses) which are constantly shifting. An accident occurs when the holes in multiple slices momentarily align, allowing a hazard to pass through and cause a loss.
Heinrich's Domino Theory suggests a simple, linear cause-and-effect chain for accidents.
Reason's Swiss Cheese Model provides a systems framework, viewing accidents as a result of multiple, interacting failures.
Latent failures are hidden weaknesses in an organisation's defences (e.g., poor design, inadequate training).
Active failures are the unsafe acts committed by front-line personnel (e.g., slips, mistakes).
Human Error and the 'Person Approach'
The 'person approach' focuses on the errors and violations of individuals as the primary cause of accidents. It is rooted in the idea of 'accident proneness'—the controversial notion that certain people have stable personality traits or psychological characteristics that predispose them to having accidents. This perspective often leads to a culture of blame, where countermeasures involve naming, shaming, and retraining the individuals involved. While human error is a factor in most incidents, modern safety science views it as a symptom, not the cause. Relying solely on the person approach is problematic because it fails to address underlying systemic issues and can discourage employees from reporting near-misses for fear of punishment, thereby hiding valuable safety information from the organisation.
The person approach attributes accidents to individual failings like carelessness, negligence, or violations.
It is associated with the concept of 'accident proneness', which has limited empirical support.
Countermeasures often involve disciplinary action, posters, and targeting individuals.
A major criticism is that it leads to a blame culture and fails to address root causes.
Workplace Stress and Stress-Related Illness
Health and safety extends beyond physical accidents to encompass psychological well-being. Workplace stress is a significant cause of illness, absenteeism, and reduced productivity. It arises when the demands of a job exceed an employee's resources or ability to cope. Key models help explain this. For example, Karasek's (1979) Job Demands-Control model posits that the most stressful jobs involve high demands (e.g., heavy workload) coupled with low control (e.g., little autonomy). Chronic exposure to such stress can lead to serious health outcomes, including cardiovascular disease, musculoskeletal disorders, anxiety, depression, and burnout. Organisational interventions, such as job redesign, flexible working, and employee support programmes, are crucial for mitigating these risks and promoting a healthier workforce.
Workplace stress is a major contributor to both physical and psychological illness.
Karasek's model identifies high demands and low control as a toxic combination for employee health.
Consequences of chronic stress include burnout, anxiety, and increased risk of heart disease.
Organisational-level interventions are more effective than purely individual coping strategies.
Developing a Proactive Safety Culture
A positive 'safety culture' is the most effective long-term strategy for ensuring workplace health and safety. It refers to the shared values, beliefs, and norms that influence how safety is managed in an organisation. It is 'the way we do things around here' regarding safety. A strong safety culture is not merely about having rules; it is about creating an environment where safety is a top priority for everyone, from senior management to front-line workers. Key components include visible leadership commitment, open communication where errors can be reported without fear of blame, employee involvement in safety decisions, and a shared belief that accidents are preventable. Organisations can measure their safety culture using tools like safety climate questionnaires and work proactively to improve it through training and systemic changes.
Safety culture is the collective set of attitudes and behaviours regarding safety in an organisation.
It moves beyond mere compliance with rules to a shared commitment to safety.
Key elements include leadership, communication, employee involvement, and a learning orientation.
A positive safety culture is proactive and preventative, rather than reactive and blaming.
In exam questions, be prepared to contrast the 'person' and 'systems' approaches to accidents. Use Reason's Swiss Cheese Model to explain the systems approach and critique the limitations of blaming individuals (the person approach). Use specific examples, such as the Three Mile Island or Chernobyl disasters, to illustrate how latent failures contributed to catastrophe.
Worked examples
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A nurse administers the wrong drug dose during a double shift on a understaffed ward. The hospital had cut training budgets and managers discouraged incident reports. Analyse using Reason's model and work-stress theory.
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Swiss cheese — aligned holes: (1) Latent: Understaffing, cut training, culture discouraging reports; (2) Active: Nurse slip under fatigue from double shift (4.4.2 circadian/stress); (3) Defences failed: labelling, checking protocols, staffing ratios.
A factory recorded 600 near-miss incidents, 30 minor first-aid injuries, and 1 serious lost-time injury over the past year. The average cost of a minor injury is £500, and a serious injury costs the company £50,000. Using Heinrich's Accident Ratio (1-30-600), calculate the potential annual cost saving if a new safety program costing £25,000 is implemented and successfully reduces near-misses by 50%.
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Step 1: Verify the baseline against Heinrich's Ratio. The plant's data (1 serious injury, 30 minor injuries, 600 near-misses) perfectly matches the 1-30-600 ratio. This suggests the model is applicable.
How it all connects
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Glossary
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Quick check
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Revision flashcards
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Reason's Swiss cheese model?
Accidents occur when holes in multiple defence layers (training, equipment, supervision, culture) align at one moment.
Key takeaways
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- ✓
Heinrich's Domino Theory suggests a simple, linear cause-and-effect chain for accidents.
- ✓
Reason's Swiss Cheese Model provides a systems framework, viewing accidents as a result of multiple, interacting failures.
- ✓
Latent failures are hidden weaknesses in an organisation's defences (e.g., poor design, inadequate training).
- ✓
Active failures are the unsafe acts committed by front-line personnel (e.g., slips, mistakes).
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