What is the Swiss Cheese Model?

We always take precautions and maintain proper safety procedures during working, but accidents do inevitably happen. But many questions related to these accidents may come to our mind like why do accidents happen? From where do they originate? What measures can be taken to stop them? These types of questions are answered by the Sweet cheese accident causation model.

The Sweet Cheese Model of accident causation is an ideal model that is implemented in risk management and analysis in the section like engineering, healthcare, a foundation for layered security, safety of the aviation, computer security and defense. The model was invented by James T. Reason and Dante Orlandella who were the professors of the University of Manchester. This cheese model is also known as the “Cumulative act effect”. In the book by James T. Reason named Human Error, he has described several disasters like space shuttle accidents of the Challenger. He suggested an integrated theory of accident causation that is known as the Swiss Cheese Model.

Swiss Cheese Model

What actually is the Swiss cheese Model?

The Swiss cheese model is a theoretical assumption that is used in risk management, risk analysis, and risk prevention before any accident. Any component of an organization is considered as a cheese slice of this model. Management, resource allocation, efficient safety program, operational support all are considered as a part of the cheese slice.

If there are any flaws or deficiencies in the cheese slices of an agency or organization, then there will be a hole in those slices. If there is a line up of the holes within each slice of an enterprise, it leads to the creation of one big hole instead of small ones, thus causing an accident. Big holes are formed due to the ignorance of one weakness into another.

Main concepts of the Swiss Cheese Model

The Swiss cheese model of James Reason has led to the following insights via in-depth research and the nature of the accidents. The key concepts of the model are:

  • Accidents happen due to confluence of one or more than one factors
  • The accidental factors can vary from organizational errors to unsafe acts of an individual
  • Most of the accidents are caused due to latent errors that are lying dormant and are waiting to be activated by several errors
  • To avoid accidents and to save humans from any operational errors, it is essential to install highly maintained and the latest systems to mitigate manual errors.

Latent and Active Errors in the Swiss cheese Model

According to a report by the US National Library of Medicine, most of the unpleasant disasters occur due to amalgamation of the latent and active errors. Let us see these two aspects in detail.

Active Errors

Active Errors or failures are the unprotected acts that are committed by mankind. An example of active failure is an employee who decides not to follow the safety measures during cleaning debris that are flammable from a working machine. But according to the theory of the Swiss Cheese Model, active errors are not the eventual source of the accidents. There are other factors also play their part in the mishap.

Latent Errors

Latent Errors or conditions are the type of failures that are built into systems, procedures, machines, or buildings by the builders, management, writers and designers. These types of conditions are inactive and are waiting to be set off by the active failures. An example of a latent error condition is an inoperable faulty fire alarm system. If an active condition happens, then latent errors lead to a disastrous accident.

The Basic Structure of the Swiss cheese Model

The basic structure of the Swiss cheese model consists of a hierarchical position in an organization to well suit the complex process of the production system. The structures are as follows.


Decision-makers include managers at a high level who set some goals or manages the strategies to enhance the safety and productivity system performance.

Line Management

Departmental managers or HODs mainly occupy this position to implement the goals and strategies of the decision-makers within the sales and training areas of the operations.


Preconditions are the different types of operational qualities possessed by the machines, people, and the working environment. This includes trustworthy instruments, organizational culture, and motivated workforces.

Productive activities 

Productive activities refer to the presentations at the operational levels.


Defenses include safeguards and other protection measures that negatively handle foreseeable outcomes and shielding such outcomes, and defending the machines and the workforces.

Applications of the Swiss cheese Model

The Swiss cheese model is applicable in different areas of healthcare. For example a latent error due to similar packaging of two different medicines that are kept side by side in a pharmacy. Such an error would be a contributing factor in the management of the incorrect drug to a patient. This type of accident has led to the comprehension that medial failures can be the consequences of system flaws and not character flaws like greed, malice, laziness or ignorance.

Swiss cheese model is also incorporated into the fire fighting engineering systems to decrease the number of human errors by introducing additional layers of safety into the system. This technique is known as Crew Resource Management. Moreover, the Swiss cheese model is also included in the multifaceted aspects of the data breaches in the healthcare industries.

According to the Swiss cheese model, accidents occur due to windows of negative opportunities or weaknesses. These weaknesses are open in all levels of the production system, allowing a chain of events starting at the higher levels of the structure and moving down. This will ultimately result in a major accident if the faults or errors are stopped at any point. To find the exact location of the holes, organizations should shift their focus on each level of the production and should further increase the defensive layers of the company. The Swiss cheese model can also be applied to interpret negative errors and outcomes in any field.