In the Swiss cheese model, what do the 'holes' represent?

In the Swiss cheese model, what do the 'holes' represent?

• A. Layers of defense.
• B. Strong safety nets.
• C. Errors or weaknesses.
• D. Regulatory compliance.

Answer: (C)

The holes in the Swiss cheese model are gaps where defenses fail—mistakes or weaknesses that exist in each layer of protection. Each defensive layer has potential flaws, whether from design, processes, or human performance. When these gaps line up across multiple layers, a hazard can pass through all defenses and cause harm. So the holes symbolize errors or weaknesses, not the defenses themselves or regulatory requirements. This idea helps explain why incidents can happen even with several safeguards: no single layer is perfect, but redundancy and diversity in defenses reduce the overall risk.

The holes in the Swiss cheese model are gaps where defenses fail—mistakes or weaknesses that exist in each layer of protection. Each defensive layer has potential flaws, whether from design, processes, or human performance. When these gaps line up across multiple layers, a hazard can pass through all defenses and cause harm. So the holes symbolize errors or weaknesses, not the defenses themselves or regulatory requirements. This idea helps explain why incidents can happen even with several safeguards: no single layer is perfect, but redundancy and diversity in defenses reduce the overall risk.