Swiss Cheese for COVID-19

Ryan Quiring
2 min readNov 9, 2020


Photo by Edward Jenner from Pexels

As the pandemic rages on, infections continue to increase, governments continue to struggle with appropriate steps, and people grow tired of being inundated with news and articles about the disease. We are still mindful that we don’t want an outbreak within our workforce.

An outbreak within a company’s workforce could halt its operations for weeks with workers staying home, leaving management scrambling to deliver bad news to clients about slipping timelines, taking care of media, or attempting to locate temporary workers.

With this in mind, it is essential to remember that risk mitigation doesn’t happen in one step, reducing all risk to zero. We need multiple layers of both prevention and mitigation tactics. These layers should be independent of each other, and each provides a small level of risk reduction.

Layering these risk reduction methods, known as the swiss cheese model, enables us to multiply the risk reduction factors to reduce potential risk to a tolerable level.

For example, if you were to implement the following four layers of risk reduction, you could reduce your risk of an outbreak by 10,000x

  1. Social distancing measures
  2. Wear masks when working nearby
  3. Monitor self-assessments/questionnaires
  4. Increased workforce training for work during the pandemic

The power of diverse, independent layers of protection becomes apparent when we look at each of these protection layers individually. Implementing them separately is not overbearing or complicated, and only doing one won’t be effective. But all of them together build a foundation of risk reduction that can’t be beat.

The risk reduction calculation goes as follows. For each procedural layer of protection, we apply the industry-standard level of risk reduction factor (RRF), 10. An RRF of 10 means that one in ten times this procedure is acted upon; it will likely fail. Bring in the next layer of protection with another RRF of 10. The likelihood of both layers of protection failing is not 1/10 times 1/10, or an RRF of 100.

When we continue with this math for each independent layer we come down to 10 x 10 x 10 x 10 = 10,000. This means that all layers of risk reduction will fail one in ten thousand times. And that is a robust system that will ultimately protect your workforce from an outbreak.



Ryan Quiring

Passionate about solving one of the largest problems that still exist today — workplace safety. CEO & Founder SafetyTek.