To err is human understanding and managing the drivers of human error

To Err is Human: Understanding and Managing the Drivers of Human Error

By Emily Wood

Many high-risk industries have carefully studied thousands of near miss, accident, and incident reports, finding most were very similar. Investigations found the same causes of error influenced people to make mistakes, and if they changed the date, location and employee names, the same accidents and incidents were seen again and again. This blog speaks to five of the most common preconditions for human error (in no particular order) and identifies some countermeasures various industries have identified to combat such error.

The American Institute of Stress found 83% of US workers suffer from work-related stress and US businesses lose $300 billion each year as a direct result of workplace stress.

Stress and Fatigue

The National Institute for Occupational Safety and Health defines job stress as harmful physical and emotional responses that occur when the requirements of the job do not match the capabilities, resources, or needs of the worker.[1] There are two types of stress we must be aware of:

  • Acute stress arises from real-time demands (personal emergency, immense time pressures)
  • Chronic stress arises from long-term demands (family problems, finances, or poor working conditions).

Fatigue is a natural physiological reaction and is defined by ICAO as a physiological state of reduced mental or physical performance capability resulting from sleep loss, extended wakefulness, circadian phase, and/or workload that can impair a person’s alertness and ability to perform safety related operational duties.[1] As people become fatigued, as is also seen when stressful situations are experienced, one’s ability to concentrate, remember and make decisions decreases. Studies found employees who average less than 5hrs of sleep are 265% more likely to be involved in a safety incident than those who sleep more than 7hrs a night.[2]

Possible Countermeasures

Sleep and stress go hand in hand. A stressed-out mind can keep one up late into the night, and a lack of sleep can raise stress levels. As stress and fatigue are two of the biggest threats to safety, methods to combat both have been successfully implemented across a multitude of industries. Some countermeasures include:

  • Improved Knowledge Sharing: pre-flight briefings, annual trainings and clearly communicated bulletins when procedural changes are made, within the aviation industry, stress is minimized by ensuring employees feel confident in their abilities and have the knowledge required to complete a safe flight. 
  • Fatigue Risk Management Systems (FRMS): data-driven means of monitoring and managing fatigue-related risk, based on scientific principles to ensure staff are working at an optimal level of alertness.

Production Pressure

If leadership values production, such that emphasis is placed upon meeting work demands, schedule or budget rather than working safely, production pressure occurs. Pressure can be created directly or indirectly from a company’s leadership, but also from clients, colleagues, and oneself. Research found health care expenditures at high-pressure companies are nearly 50% greater than at other organizations.[1]

Possible Countermeasures

In 2019, the American Institute of Stress found 94% of employees shared they experience production pressure at work. 23% responded they feel they experience high levels of production pressure.

The key to achieving a balance between safety and production pressure is to ensure all communication and action from employees across all levels of an organization show an ongoing commitment to safety, even when speaking up and raising safety concerns may result in financial loss or unexpected delays. The aviation industry has been able to successfully create and maintain a delicate balance between productivity and safety. Employees understand safety cannot be compromised and missteps have had devastating consequences. Workers are encouraged to raise concerns no matter their role and are provided with the tools and resources they need to make informed safety decisions. Tools include:

  • Minimum Equipment Lists: enable the flight crew to determine whether a flight may be commenced, continued or immediately stopped should an instrument, equipment or system become inoperative.  
  • Quick Reference Handbooks: support various roles and help ensure all required actions are performed without omission and in an orderly manner. Normal and abnormal operating procedures are listed and if any step is not or cannot be completed, solutions to manage the situation are provided.

Distractions and Complacency 

If activities are thought of as easy and safe, vigilance decreases, and important signals are missed. Factors that should prevent accidents-experience, training, and expertise, all lead to distracted and complacent behavior. Distractions draw attention away from the task which a person is completing. Some distractions are unavoidable, such as loud noises and day-to-day problems that require immediate solving. Other distractions can be avoided or delayed, such as messages from home or management decisions concerning non-immediate work. Studies have found around 21% of people are actively engaged in the work they are completing, the remaining 79% of the time, are distracted or going through the motions without much thought.[1]

Complacency can be defined as self-satisfaction, and/or a sense of security in one’s own abilities, which is often accompanied by an unawareness of actual dangers or deficiencies. According to the NSC, complacency is responsible for 442 deaths across the US each day.[2] When people get used to things being done the same way, hazards are often forgotten, and the risks associated with the tasks being performed are underestimated.

Possible Countermeasures

A 2015 Study in France found 8 of 18 simulated procedures when distracted, resulted in major surgical error. When there were no operating room distractions or interruptions, only 1 of 18 simulated procedures was complicated by error.

To reduce errors from distractions, complete tasks before responding to distraction. If the task cannot be completed, identifying the last completed step acts as a reminder to whoever is finishing the work and it is recommended they start at least three steps back from the reminder, to ensure no steps are missed. Additionally, when workers are engaged in critical tasks, creating do not disturb areas can minimize distractions. Introduced in 1981 by the FAA, the sterile cockpit rule was implemented after a series of accidents were caused by flight crew distraction. During critical phases of flight, only activities required for the safe operation of an aircraft could now be carried out. Learning from the success of this rule, the health care industry implemented similar policy.[1]

While too much pressure creates stress, too little results in complacency. When carrying out routine tasks, it is important to maintain a certain level of stress to minimize complacency. There should be an expectation fault will always be found to create an optimum level of stress. Complacency can be further minimized by mixing teams, completing work in different locations, or switching work roles/tasks when possible.

Crew Communication

According to ICAO, between 1976 and 2000, more than 1,100 passengers and crew lost their lives in accidents where a lack of communication played a contributory role.  

Many times, people speak but are not heard, messages are not fully understood, or employees choose not to speak up for fear of repercussion or the belief their voice does not matter. However, safety and communication go hand in hand; you cannot have a successful safety program with poor communication.

Possible Countermeasures

Communication across a multitude of industries has been greatly improved through the use of Crew Resource Management (CRM), beginning with the aviation industry in 1979. While CRM alone is not adequate to mitigate communication failure in complex processes, employees are taught to use resources effectively, ask for help when needed and communicate to reduce confusion. An additional technique to improve communication is the usage of three-way communication. Three-way communication helps ensure the correct transfer of safety information in dangerous situations and is composed of the following steps:

  • Informer provides receiver with information and waits for a response. Informer verifies receiver understood and if not, returns to step one. Work does not start until understanding is confirmed.

Knowledge and Professional Orientation

Research has found six common themes that are seen in organizations that have successful learning and safety cultures:

·       Open Communication

·       Employee Empowerment

·       Organizational Collaboration

·       Alignment of Espoused and Enacted Priorities

·       Internal Systematic Alignment

·       Management Prioritization of Safety

A clear connection is seen between organizational learning and safe work environments. Regulations often outline the trainings and qualifications needed for employees to have a foundation of knowledge before they begin work, but continual learning through on-the-job training is vital to operationalize new knowledge and best-practises.

Learning from one another, both in formal and informal settings, and understanding the role each employee has in improving safety increases one’s professional orientation. Defined as the knowledge and belief one has about their role in the ownership of safety, organizational change, and the betterment of the lives of those around them, professional orientation is the drive which motivates employees to act as they believe taking action is their responsibility and no one else’s.

Increasing Knowledge and Professional Orientation

Many industries look to the aviation industry to increase the skills and knowledge their employees need to understand their professional orientation. The aviation industry collectively emphasizes a shared commitment to safety and employees are actively involved in driving change. Management has complete trust in their employees when it comes to speaking up about concerns to ensure the safe arrival of their flights. Flight crews are trained to have a deep professional orientation that drives ownership and accountability over the safety of their colleagues and passengers.

To ensure flight crews are always up to date on their knowledge and are comfortable speaking up no matter what crew they are a part of, all pilots and flight attendants must complete:

  • Annual Recurrent Training-focuses on the technical knowledge and the cognitive and interpersonal skills required to successfully complete a safe flight. These trainings must be passed before employees are permitted to return to work and if an employee has been off, the training is mandated.


We, as humans, have our own unique limitations. Employees at all organizational levels must understand the risks associated with their own limitations and the limitations of those around them and work to develop countermeasures to reduce the possibility human errors lead to accidents and incidents. Employees are the most valuable resource of all organizations and studies show employee well-being is a key factor in determining an organization’s long-term success. Accepting humans have limitations and will error when the above preconditions exist has driven improvements in many high-risk industries.

At Propulo, we can help you apply Human Performance principles to your existing safety systems.


[4] https://hbr.rg/2015/12/proof-that-positive-work-cultures-are-more-productive
[6] https://www.nscorg/nsc-membership/injury-facts

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