Siouxsie Wiles & Toby Morris: Covid-19 and the Swiss cheese system:

Twenty years ago, James Reason, a professor of psychology at the University of Manchester in the UK, published a paper in the British Medical Journal in which he described what he called the “Swiss cheese model of system accidents”. Reason was trying to move people’s thinking from treating mistakes as individual errors by “bad” people to a systems approach that accepts that humans are fallible and mistakes are to be expected. Rather than blaming individuals for failure, we should try to understand how and why the failure happened to prevent it from happening again.

But what has Swiss cheese got to do with all this?

The idea behind the systems approach is to build in layers of barriers and safeguards. In an ideal world, each of these defensive layers would be impenetrable. But in the real world, they aren’t. So Reason likened each layer to a slice of Swiss cheese – it has holes in it. To be fair to the Swiss, they have lots of different cheeses, many of which don’t have holes, so it’s probably more accurate to call Reason’s model the “Emmental Model”.