The Swiss cheese model demonstrates that errors occur when latent gaps align across multiple defenses.

• A. True
• B. False
• C. Not relevant
• D. It's a budgeting model

Answer: (A)

The Swiss cheese model focuses on how accidents arise when holes in multiple layers of defense line up. In any complex system, each defense (policy, procedure, double-checks, alerts, training) has potential gaps—latent conditions or active mistakes. Most of the time, these gaps don’t align, and the error is caught or stopped. When the holes across several defenses align, a trajectory of error can pass through all layers and reach the patient, causing harm. This is why the idea is that errors occur due to the alignment of latent gaps across defenses, not just a single slip.

So the statement is true. For example, a wrong medication can happen if labeling is unclear, there’s a miscommunication during handoff, and a missing double-check fails—each is a hole that, if aligned, allows harm to occur. The model also guides safety improvements by adding defenses, reducing gaps, or making holes more likely to be detected before reaching the patient.