Ferrell’s Human Factors Theory

Ferrell’s Human Factors Theory:

Dr. Russell Ferrell, Professor of Human Factors at the University of Arizona give this theory of accident causation as shown in diagram below:

Ferrell’s Human Factors Theory

This theory states that accidents are the result of a casual chain (as in multiple causation theory), one or more of the causes being human error, which is in turn caused by three situations – overload, incompatibility and improper activities. Factors affecting these three situations are as follows:

  1. Overload (A mismatch of capacity, load and a state) due to-


(a) Load Task (Physical information processing)
Environment (Light, noise, distraction, stressors that require active coping)
Internal (Worry, emotional stress)
Situational (Ambiguity of goals or criteria, danger)
(b) Capacity Natural endowment, physical condition, state of mind, training, drugs, pollutants, pressure, fatigue, stressors that impair ability to respond
(c) State Motivational level and arousal level

 

  1. Incompatibility (incorrect response or mismatch) due to –
(a) Stimulus Response Due to control – display
(b) Stimulus Stimulus Due to inconsistent display types
(c) Response Response Due to inconsistent control types or locations
(d) Work station Size, force, reach, feel

 

  1. Improper Activities due to-
  • The worker did not know how to do it.
  • He deliberately took risk due to
  • Low perceived probability of accident
  • Low perceived cost of accident

Since this is basically human factor model greater emphasis is placed on the first two causes of human error, overload and incompatibility.

Saurabh Ranjan is Founder of rlshumancare.com. I have dedicated & committed to publishing some innovative content and useful topics regarding Health, Safety & Environment, which will help and awareness to people for daily life. Also trying to continually improve my content for better awareness and suit to dedicated people.

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