“We must accept human error as inevitable – and design around that fact.”  — Donald Berwick

The idea of human error and its contribution to industrial incidents has been the center of debate in recent years.  If you’ve been part of more than one incident investigation, you’ve probably experienced an incident being attributed to human error.  As technology advances and becomes more reliable, it becomes easier to assume that the error was not with the technology, but with the human responsible for operating the technology.  As a result, there is often a preconceived bias that incidents are, at least in some part, the result of human error.

The problem with that assumption is that the investigation ends when human error has been established as a direct cause.  If we look deeper into what caused the error, however, we have an opportunity improve human performance reliability – and, therefore, decrease the likelihood of incidents.

Human Performance Reliability

In industry, human performance reliability refers to the reliability of humans to correctly (and safely) perform actions as they interface with the processes in which they work.  In other words, the likelihood that human error will not occur.  Human performance reliability can be affected by many factors.  Factors outside the control of the employer include age, state of mind, physical health, attitude, etc.  However, there are factors that affect human performance reliability that can be controlled, or at least improved or influenced, by employers and it’s important to set employees up for success, especially when safety depends on it.

Situational Awareness

In psychology, we learn that there are two types of thinking – fast and slow.  Fast thinking is unconscious, emotional and instinctive.  It results in fast judgement.  We operate in fast thinking when we do things like drive, brush our teeth or (depending on how long we’ve been at our job) even when we work.  It happens when our tasks are routine – when we rely more on muscle memory than actual thought.

Slow thinking is conscious, deliberate and mostly rational.  We use slow thinking to make big decisions or take on tasks that require our concentration.  We use both fast and slow thinking when we process information daily, but we tend to avoid slow thinking when we can because it is more work for our brain.  If we operated in slow thinking all day long, we’d be exhausted.  The problem with fast thinking at work is that the “fast brain” reacts without thinking.  It’s response to routine tasks can lead to missed steps and incomplete work if the circumstances are not identical day in and day out.

The term “situational awareness” is often used when an employee misses something important during their course of work that leads to incident.  An employee lacking situational awareness is operating in fast thinking.  When an employee repeats the same steps time after time, the act becomes habitual and their slow thinking shuts off.  Since the goal of fast thinking is to process visual information and deliver feedback as quickly as possible, the result is a generalized sketch of a situation.  Their brain isn’t allowing them to stop and process detailed information anymore. So they miss cues, which can lead to errors and incidents.

Human performance reliability requires the conscious cognition of slow thinking.  This means the challenge of the employer is to reexamine systems, processes and procedures to encourage intentional actions.  Simply telling people to be situationally aware doesn’t teach them how.  Instead, fostering situational awareness requires designing work environments and processes with the human brain in mind.

Procedural Ambiguity

In my previous job, like most other jobs, we had written procedures.  Every time an error occurred the first question was always “Did you follow the procedure?”  The answer was almost always yes, but the procedures were unclear, inconsistent and nearly always missing steps.  This resulted in inconsistent, and often incorrect, work.

One way to lessen the likelihood of human error is to ensure that procedures are thorough, well written, and easily understood. When the performance of crucial operations relies on past experience or memory, the door is opened for human error. To decrease human error, procedures must align with the way the human brain works.  They must be clear and concise.

Brains often fire quickly (fast thinking), based on immediate responses to visual stimuli.  This means that it is imperative to eliminate confusing instructions, poor design and other opportunities for miscues in procedures.  There should not be room for guessing, assumptions or interpretation.  Clear, detailed and unambiguous procedures leave less room for human error to occur, resulting in an increase in human performance reliability.


Have you ever been so tired that you can’t focus?  We’ve all been there at some point. Whether it be at work, school or home, lack of sleep affects day-to-day activities.  Cognitive fatigue from sleep deprivation can be dangerous in any aspect of our life, but it can be especially dangerous at work – specifically when working in an industrial setting.  Of course, fatigue results from loss of sleep, but it can also result from prolonged mental activity or long periods of stress or anxiety. Fatigue is especially prevalent in those working shift work, night shifts, rotating shifts, or overtime.

When someone is tired, their brains don’t process information or communicate with the rest of their body as effectively.  The more fatigued one is, the more slowly the neurons in their brain fire.  This leads to a reduction in ability, in the recall of details, in our ability to respond to changes in surroundings or information provided, and in increased forgetfulness, and errors in judgment.  In summary, an increase in fatigue often means an increase in incidents, leading many employers in implement a Fatigue Risk Management System, or FRMS.

If an organization doesn’t have the time or resources for an FRMS, there are other ways to limit the amount of fatigue employees face.  While an employee’s activities outside of work are hard to control, they can be assisted while at work by managing factors that can increase the feelings of fatigue: high temperatures, high noise levels, dim lighting or poor visibility, or work tasks that are long, repetitive, paced, difficult, boring, or monotonous.  Keeping tabs on overtime and extra shifts also help to manage worker fatigue risks and increase performance reliability.

Employer Responsibility

It’s common to blame human error on the employee that committed the error – especially if it resulted in incident.  However, regardless of the error, it’s also the responsibility of the employer to ask themselves why it occurred.  Are your workers “checked out?”  Were the procedures too ambiguous?  Are you aware of your employees’ fatigue level?  There are almost always ways to improve.  Employees have a responsibility to come to work prepared, but employers have responsibilities, too. Reliability from an employee demands an opportunity to be reliable.

Change the Cultural Message

The safety culture in an organization starts with the leaders.  They create cultures by sending messages that define success – setting the tone for how their employees work.  When messages are messages of urgency,

  • “Get it done”
  • “Finish quickly”
  • “Accomplish more, faster,”

it puts pressure on employees. Fast thinking takes over, employees wear down more quickly, and error occurs.

Instead of sending messages of urgency, organizational leaders can change the corporate culture by sending messages that encourage slow thinking:

  • “Take your time”
  • “Think it through”
  • “Focus on doing the job right”

These messages build a safer culture of more accurate, well-considered execution and a “get it right the first time” reliability.

Human error is never going away.  We are human, after all.  However, employers who are willing to invest the time and resources have an opportunity to improve human performance reliability. The more you invest in your employees, the more you’ll get back and the safer your organization will be.