Error metaphor

The Person Versus System Approach in Viewing Errors

James Reason (2000) described two approaches to viewing and managing human errors – the person and the system. The person approaches errors as a result of deficient mental processing or lack of morals. This may include a lack of attention to detail or motivation, forgetfulness, or general careless behavior. Errors are typically managed with discipline, reeducation, or shaming as a way to correct the behavior. The system approach looks at errors occurring as a result of ineffective or poorly designed systems and accounts for human error to be expected. The solution involves building better systems or processes to mitigate future errors. This article describes the person versus system approach in viewing errors, and error classification, and details the Swiss Cheese model of accident causation in organizations. It is the first in a 2-part series differentiating the different types of error and breaking down the associated behaviors. 

Person versus Systems Approach 

“Human error is an inevitable, unpredictable, and unintentional failure in the way we perceive, think, or behave. It is not a behavioral choice- we do NOT choose to make errors, but we are fallible” (ISMP, 2020, p. 2) 

When breaking down the causes of errors, two categories emerge- endogenous and exogenous causes. Endogenous errors occur simply as a result of being human, and factors such as anxiety, stress, and fatigue increase the risk of these types of errors occurring. Management systems that focus on the person approach direct solutions at fixing human behavior- i.e. the need to do a better job paying attention to detail or being in the moment, with countermeasures including disciplinary action, re-education, blaming, creating another policy/procedure or adding more steps to current ones (Reason, 2000).  

Human-based system errors, also known as exogenous, occur when something in the environment/system contributes to the error. This includes things such as dim lighting, distractions, inadequate staffing, and technology that doesn’t work properly or has functional design flaws (ISMP, 2020). Proponents of the systems approach dig down into the details to determine why the event occurred, specifically looking for error traps in the environment or processes/protocols that are not realistic or just plain not working. (Reason, 2000). 

In addition, “Countermeasures are based on the assumption that though we cannot change the human condition, we can change the conditions under which humans work” (Reason, 2000, p. 768).  Solutions are aimed at developing better systems that are error-proof or error resistant. This may involve standardization, simplification, use of forcing functions, and technology. 

Error Classification

In addition to understanding the causes of human errors, it’s important to understand the classifications under which errors fall. The two big buckets include a failure to appropriately carry out actions leading to errors, and a failure to appropriately plan leading to errors. See the table below for more details. 

The Person Versus System Approach in Viewing Errors

(ISMP, 2020)

The Swiss Cheese Model

A framework for analyzing errors and patient safety events from a systems approach, known as the Swiss Cheese Model, was developed by James Reason. In complex systems, there are naturally built-in layers of defense designed to prevent harm. In healthcare, this includes things such as policies, procedures, checklists, bar code medication administration, independent double checks, and alarms. These layers are depicted as pieces of swiss cheese. 

Why Swiss cheese and not American? Well, the layers have weak points, analogous to the holes in swiss cheese. Holes can represent pressure to transfer or discharge patients, inadequate staffing, a steep power gradient, or unsafe acts due to slips or lapses. In the real world environment, these holes are continuously shifting location, closing, and opening. Patient harm occurs when all the holes in the swiss cheese lineup, representing errors that go through all the weak points in the layers of defense and reach the patient (Wachter, 2008). The system’s approach is aimed at building up these layers of defense to make the holes smaller or disappear altogether, thus reducing the risk of patient harm. 

How Do We Do Better? 

Building a just culture that takes into account both the human side and the system side. From a human perspective, an assessment of individual behavior is made in an effort to understand the intentions that led to the behavior causing the error. There is accountability for actions when necessary.  This may be viewed as a modified person approach. In addition, an assessment of systems opportunities that may have led to the error occurring is also made, followed by system improvements to build in better layers of defense resulting in smaller or nonexistent weak points. 

*If this article interests you, you may also enjoy my book titled: Obstetric and Neonatal Quality and Safety (C-ONQS) Study Guide: A Practical Resource for Perinatal Nurses, available on amazon: Amazon_obneonatalstudyguide



Institute for Safe Medication Practices (ISMP) (2022, April 07). Criminalization of Human Error and a Guilty Verdict: A Travesty of Justice that Threatens Patient Safety. Retrieved from

Institute for Safe Medication Practices (ISMP) (2019, January 17). Safety Enhancements Every Hospital Must Consider in Wake of Another Tragic Neuromuscular Blocker Event.  Retrieved from

Reason, J. (2000). Human error: models and management. British Medical Journal, 320, 768-70. 

Wachter, R. M. (2008). Understanding patient safety. McGraw Hill.

Copyright by Jeanette Zocco MSN, RNC-OB, C-EFM, C-ONQS

2 thoughts on “The Person Versus System Approach in Viewing Errors”

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top