[1] Reliability of humans can be affected by many factors such as age, physical health, mental state, attitude, emotions, personal propensity for certain mistakes, and cognitive biases.
Human reliability is important to the resilience of socio-technical systems, and has implications for fields like manufacturing, medicine and nuclear power.
[7][8] Erik Hollnagel has developed this line of thought in his work on the Contextual Control Model (COCOM)[9] and the Cognitive Reliability and Error Analysis Method (CREAM).
This model of control mode transition consists of a number of factors, including the human operator's estimate of the outcome of the action (success or failure), the time remaining to accomplish the action (adequate or inadequate), and the number of simultaneous goals of the human operator at that time.
[11][12] It is based on James Reason's Swiss cheese model of human error in complex systems.
"Unsafe acts" are performed by the human operator "on the front line" (e.g., the pilot, the air traffic controller, or the driver).