Swiss Cheese model
Encyclopedia
Models of accident causation are used for the risk analysis
and risk management
of human systems. Since the 1990s they have gained widespread acceptance and use in healthcare, in the aviation safety
industry, and in emergency service organizations. Many of them focus on so-called the cumulative act effects.
The model includes, in the causal sequence of human failures that leads to an accident or an error, both active failures and latent failures. The former concept of active failures encompasses the unsafe acts that can be directly linked to an accident, such as (in the case of aircraft accidents) pilot error
s. The latter concept of latent failures is particularly useful in the process of aircraft accident investigation, since it encourages the study of contributory factors in the system that may have lain dormant for a long time (days, weeks, or months) until they finally contributed to the accident. Latent failures span the first three levels of failure in Reason's model. Preconditions for unsafe acts include fatigued air crew or improper communications practices. Unsafe supervision encompasses such things as, for example, two inexperienced pilots being paired together and sent on a flight into known adverse weather at night. Organizational influences encompass such things as reduction in expenditure on pilot training in times of financial austerity.
The same analyses and models apply in the field of healthcare, and many researchers have provided descriptive summaries, anecdotes, and analyses of Reason's work in the field. For example, a latent failure could be the similar packaging of two different prescription drugs that are then stored close to each other in a pharmacy. Such a failure would be a contributory factor in the administration of the wrong drug to a patient. Such research has led to the realization that medical error
can be the result of "system flaws, not character flaws", and that individual greed, ignorance, malice, or laziness are not the only causes of error.
Risk analysis (engineering)
Risk analysis is the science of risks and their probability and evaluation.Probabilistic risk assessment is one analysis strategy usually employed in science and engineering.-Risk analysis and the risk workshop:...
and risk management
Risk management
Risk management is the identification, assessment, and prioritization of risks followed by coordinated and economical application of resources to minimize, monitor, and control the probability and/or impact of unfortunate events or to maximize the realization of opportunities...
of human systems. Since the 1990s they have gained widespread acceptance and use in healthcare, in the aviation safety
Air safety
Air safety is a term encompassing the theory, investigation and categorization of flight failures, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.-United...
industry, and in emergency service organizations. Many of them focus on so-called the cumulative act effects.
James Reason
James Reason hypothesizes that most accidents can be traced to one or more of four levels of failure: Organizational influences, unsafe supervision, preconditions for unsafe acts, and the unsafe acts themselves. In this model, an organization's defences against failure are modelled as a series of barriers, with individual weaknesses in individual parts of the system, and are continually varying in size and position. The system as a whole produces failures when all individual barrier weaknesses align, permitting "a trajectory of accident opportunity", so that a hazard passes through all of the holes in all of the defenses, leading to a failure.The model includes, in the causal sequence of human failures that leads to an accident or an error, both active failures and latent failures. The former concept of active failures encompasses the unsafe acts that can be directly linked to an accident, such as (in the case of aircraft accidents) pilot error
Pilot error
Pilot error is a term used to describe the cause of an accident involving an airworthy aircraft where the pilot is considered to be principally or partially responsible...
s. The latter concept of latent failures is particularly useful in the process of aircraft accident investigation, since it encourages the study of contributory factors in the system that may have lain dormant for a long time (days, weeks, or months) until they finally contributed to the accident. Latent failures span the first three levels of failure in Reason's model. Preconditions for unsafe acts include fatigued air crew or improper communications practices. Unsafe supervision encompasses such things as, for example, two inexperienced pilots being paired together and sent on a flight into known adverse weather at night. Organizational influences encompass such things as reduction in expenditure on pilot training in times of financial austerity.
The same analyses and models apply in the field of healthcare, and many researchers have provided descriptive summaries, anecdotes, and analyses of Reason's work in the field. For example, a latent failure could be the similar packaging of two different prescription drugs that are then stored close to each other in a pharmacy. Such a failure would be a contributory factor in the administration of the wrong drug to a patient. Such research has led to the realization that medical error
Medical error
A medical error may be defined as a preventable adverse effect of care, whether or not it is evident or harmful to the patient. This might include an inaccurate or incomplete diagnosis or treatment of a disease, injury, syndrome, behavior, infection, or other ailment.-Definitions:As a general...
can be the result of "system flaws, not character flaws", and that individual greed, ignorance, malice, or laziness are not the only causes of error.
See also
- Healthcare error proliferation modelHealthcare error proliferation modelThe Healthcare Error Proliferation Model is an adaptation of James Reason’s Swiss Cheese Model designed to illustrate the complexity inherent in the contemporary healthcare delivery system and the attribution of human error within these systems. The Healthcare Error Proliferation Model explains...
- Latent human errorLatent human errorA Latent human error is a human error which is likely to be made due to systems or routines that are formed in such a way that humans are disposed to making these errors...
- Root cause analysisRoot cause analysisRoot cause analysis is a class of problem solving methods aimed at identifying the root causes of problems or events.Root Cause Analysis is any structured approach to identifying the factors that resulted in the nature, the magnitude, the location, and the timing of the harmful outcomes of one...
- Swiss cheese modelSwiss cheese modelThe Swiss cheese model is a organizational model, proposed by James Reason of the University of Manchester and Dante Orlandella, used to analyze the causes of systematic failures or accidents, commonly used in the fields of aviation, engineering and healthcare...
- System accidentSystem AccidentA system accident is an "unanticipated interaction of multiple failures" in a complex system. This complexity can either be technological or organizational, and often is both....
- Systems engineeringSystems engineeringSystems engineering is an interdisciplinary field of engineering that focuses on how complex engineering projects should be designed and managed over the life cycle of the project. Issues such as logistics, the coordination of different teams, and automatic control of machinery become more...