Human Factors in Accidents

Human factors, sometimes described as ergonomics, involve the interaction of people with systems and objects. The study of human factors seeks to explore how products and systems can be made more compatible with the skill and capacity of the people who use them. Ideally, this will lead to the development of processes that improve performance and reduce accidents.

For accidents, human factors describe how actions or omissions attributable to a person contributed to the accident. Those human factors may relate not only to the person operating a system or equipment, but also to other workers or persons who were involved in the accident.


The study of human factors may be used to improve systems and products, and to reduce the likelihood of future accidents and injuries despite human interaction and involvement.

Study of Human Factors

While it is true that human factors play a role in most accidents, it is not the case that all accidents are caused by humans, nor that system developers or manufacturers should be excused from their role in contributing to an accident. Instead, the goal is to apply scientific knowledge of human behavior and psychology in order to develop systems and products that allow for optimal performance and reduced probability of an accident or injury.

The purpose of studying human factors is not to affix blame on people. The study of human factors is not meant to shift responsibility for accidents from those who develop or manufacture systems and products to the end user, or to blame avoidable accidents on people. The ideal is to identify how all of the elements of a workplace or other situation interact, and to use that information to both properly identify the causes of accidents and to reduce the likelihood of future accidents.

An expert in human factors will examine the full circumstances of an accident and attempt to determine the extent to which the accident was caused by human actions, the surrounding environment and context, and by interaction between the two.

Human Factors and Accident Causation

The contribution of human factors to an accident does not of itself mean that a person involved in the accident was careless, negligent or irresponsible. Sometimes an accident will occur despite a person's best efforts, and the study and application of human factors. The study and application of human factors may help improve a system, increase compliance and reduce error, so as to reduce accidents even when people are doing their best work. By looking at the decision-making of a person during events leading up to an accident, it becomes possible to develop systems that reduce the likelihood of a similar, future outcome. That information may be applied to try to avoid similar accidents in the future.

Examples of Human Factors

Human factors that may contribute to an accident include:

  • Attention: Distraction, the failure to pay attention, or the failure to maintain attention.
  • Competence: The level of experience, skill or competence on the part of a person involved in an accident.
  • Judgment: Lapses of judgment, resulting from anything from poor training to fatigue or intoxication.
  • Health: A person's state of health and mind, including age-related factors, strength, fatigue, and stress level, may contribute to an accident.
  • Memory: Lapses of memory may affect performance at any time.
  • Perception: Factors affecting human perception and response time may contribute to an accident.
  • Personality: The personal characteristics of an individual may contribute to an accident, including their temperament and attitude such as cautiousness, arrogance or overconfidence.
  • Risk perception: The degree to which the individual perceives and responds to risk.

Human Interaction

When human factors are studied with the goal of reducing workplace accidents, the study involves not only examining the people within the workplace, but the workplace itself. This is, after all, a study of human interaction with objects and systems.

  • The design, configuration and layout of a building, workplace or work station may affect employee performance and rates of error, and at times the effect will be significant.
  • Such factors as noise, lighting, temperature, vibration, and air quality may affect human performance.
  • The presence and placement of instructions, warning signs and labels may affect the chance of an accident or injury.

Similarly, the design of equipment and machinery may significantly affect how humans interact with those items. Factors the may affect ease of use and error rate include the design and placement of displays and controls, the user interface, warning systems, feedback provided to the user, and other factors affecting ease of use.

Reducing the Impact of Human Factors

Measures that may reduce the number of industrial accidents caused or worsened by human factors include:

  • Feedback: Providing direct feedback, whether generated by the system or by a supervisor, to help ensure compliance with systems and product safety.
  • Inspection: Conducting inspections and audits to ensure that systems and products are functioning as intended, and for early detection of possible problems.
  • Supervision: Adequately supervising, monitoring and correcting workers.
  • Training: Providing better education and training, including ongoing training, and helping workers develop their skills.
Copyright © 2018 Aaron Larson, All rights reserved. No portion of this article may be reproduced without the express written permission of the copyright holder. If you use a quotation, excerpt or paraphrase of this article, except as otherwise authorized in writing by the author of the article you must cite this article as a source for your work and include a link back to the original article from any online materials that incorporate or are derived from the content of this article.

This article was last reviewed or amended on Apr 16, 2018.