How Working Nights Can Affect Your Employees

Fatigue-related accidents are considerably more common at night -- drivers are 50 times more likely to fall asleep at 2 am than at 10 am -- and absenteeism nearly doubles in work places with fatigue issues

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Due to the reduced or impaired alertness caused by fatigue, the inevitable net result is increased human error, and reduced ability to work safely and productively. Numerous scientific studies and extensive field experience confirm that workers with higher relative fatigue index are more likely to experience sleepiness, nodding-off, and making mistakes while working, as well as nodding-off or fighting sleep while commuting to and from work.

Fatigue also affects mood. In 2002 the National Sleep Foundation found that people who do not get enough sleep are more likely to get impatient or agitated, and they have difficulty getting along with others. Increased irritability and stress negatively influences personal, work, and family relationships, resulting in inadequate/ineffective communications, and correlating with increased absenteeism and turnover as well as reduced morale and poorer labor relations. In fact, industrial surveys reveal that absenteeism rates are nearly double in facilities with severe fatigue problems, as compared to facilities where fatigue is not a problem.

Fatigue Levels

The consequences of fatigue also impact a company's operating efficiency and costs. Fatigue results in reduced productivity and customer service quality, reduced operating reliability and decreased operating profit, increased health and wellness costs, and higher overall costs, risks, and liabilities. Industrial survey data further indicates that Workers' Compensation costs per employee per year were almost five times higher in facilities with severe fatigue problems, compared to facilities where fatigue was not a problem.

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Virtually every industry suggests that 80-90% of all their accidents and incidents are human error related. Equipment, maintenance, and human costs pose enormous risks, so safety is indeed a "condition of employment." Yet mental errors, personal injuries, and property and casualty damages are not infrequent occurrences.

While some of these incidents can certainly be attributable to inexperience or behavior, the vast majority are more typically physiological in nature. Adjustment to night work, shift rotations, and/or overtime create health, safety, and performance problems for operators. By every measure, performance decreases at the beginning of early morning shifts, during the post-lunch hours, and during overnight shifts…particularly during the pre-dawn hours.

Research has found that the number of fatigue-related accidents is considerably higher at night than during daytime. In fact, a study found that drivers are 50 times more likely to fall asleep at 2:00 a.m. than at 10:00 a.m. No matter how well trained, skilled, motivated, or experienced, operators are frequently compromised by fatigue. Behavior becomes erratic and deviant…not willfully but because of our physiological nature.

As a result, incidents are often misdiagnosed as being due to behavioral problems, when they are actually physiological in nature. Thus, understanding human physiology is key to successfully identifying, and managing the inherent problems of working the night shift and fatigue-related human error.

The resultant costs of fatigue are far greater than just those of safety, although the $2 billion already spent on cleaning up the Texas City Refinery mess should be enough justification to proactively address this issue. While there were certainly technical and equipment failures involved in this unfortunate incident, the U.S. Chemical Safety Board in 2007 also cited fatigue due to understaffing and excessive overtime/consecutive shifts as a causal factor.

Fatigue also correlates with higher maintenance costs, lost productivity, increased turnover, absenteeism, and presenteeism, higher health and wellness costs, reduced customer service quality, higher operating risks and liabilities, and, ultimately, reduction in overall operating profit.

In his book, The Twenty-four Hour Society: Understanding Human Limits in a World That Never Stops, Martin Moore-Ede established the following conservative estimate of the global costs of fatigue:


We can certainly argue and debate over the magnitude of this cost estimate, but even if Moore-Ede is only partially right, the cost of fatigue is still enormous. The good news is that it clearly represents recoverable opportunity, and a whole new avenue for improving operator safety and performance that has been largely overlooked for the better part of the last century. Moreover, with today's ability to measure and quantify the costs of fatigue, it is now possible to build a compelling business case and ROI proposition to justify a proactive Fatigue Risk Management System (FRMS).

Installing an Effective Fatigue Risk Management System

So how as a company, or as operating managers, can we objectively, systematically, and measurably eliminate fatigue from our operations, thereby reducing our costs, risks and liabilities. And is it really possible to increase operational efficiency... while at the same time improving employee health, safety and quality of life to create a win-win proposition?

Perhaps this sounds far-fetched, but it's already being done. With the current knowledge and experience base that exists today, dramatic improvements are being achieved in the way people live and work, to the betterment of both the employees and the business.

The first, and most important step, is to recognize the cause and the huge costs of fatigue, and make a corporate commitment to eliminate them. Too many companies are losing money and risking the safety of their employees by not recognizing the importance and the urgency of fatigue management.

This is evident by the fact that over 90% of shiftworkers receive no training on how to manage their schedules and shiftwork lifestyles. We see many shiftworkers who are well trained and skilled at their jobs, but who have never been taught how to deal with fatigue, better manage their sleep or adapt to the inherent physical and social challenges of shiftwork.

As a consequence, they develop bad habits and/or become victims of common shiftwork pitfalls that compromise their ability to perform to their fullest capabilities. This is just one of the many reasons that, according to a 2003 study, shiftworking employees conservatively cost companies $8,600 per person per year in excess costs over and above their daytime counterparts.

Once company management has made a corporate commitment to reduce fatigue and optimize the productivity and safety of their workforce, they need to develop a comprehensive, science-based, fatigue risk management plan. To be successful this plan must at the very least:

  • Educate your managers, supervisors and others to achieve consensus and stakeholder support within the company
  • Provide training for employees to empower them to take more control over reducing their personal levels of fatigue, as well as better coping with night work (especially with new hires)
  • Reinforce the training and personal commitment to behavioral lifestyle change by providing educational support publications and practical night work information to operators on a regular basis
  • Educate/train supervisors on how to identify and intervene with tired operators
  • Re-evaluate work schedules and overtime policies and practices to ensure they are not causing excessive fatigue
  • Optimize staffing and crewing levels to maintain manageable overtime levels
  • Evaluate the indoor and outdoor work environment for potential modifications that could reduce fatigue (e.g. more mentally stimulating control rooms, etc.)
  • Evaluate work tasks and activities for opportunities to make them less boring and monotonous
  • Re-evaluate operating policies and procedures that may no longer be valid, in light of our human physiology, and that may actually be counterproductive
  • On a regular basis, screen and treat sleep disorders that are prevalent among night workers, and provide education on managing sleep
  • Incorporate fatigue analytics/human error analysis into reporting systems to monitor and track results by collecting and reporting fatigue-related data
  • Incorporate fitness-for-duty impairment screening programs
  • Keep abreast of new R&D initiatives to continually advance state-of-the-art
  • Establish a continuous improvement process that is not merely today's priority, but rather a permanent core operating value of the company


As responsible managers and operators, we strive to keep our equipment well-oiled and well-maintained. We ensure that it is operated in full accordance with the manufacturers design specifications, in terms of temperatures, pressures, flow rates etc. To do otherwise would ensure premature failure, costly downtime, high maintenance, and lost productivity/capacity. So it would seem to make sense to keep what we all tout as our "most important asset" - our people - equally well maintained and operated.

Yet, ironically, our people often are being asked to operate outside their “design specs” every day to support our continuous production requirements. The net result, as you might surmise, has been premature failure (in terms of sickness and injury), costly downtime (in terms of absenteeism and presenteeism), high maintenance (in terms of health and wellness costs), and lost productivity due to human error.

Continuing to neglect our most important asset will perpetuate this cycle of high cost and catastrophic risk. It is time to understand that these costs, risks and liabilities no longer have to be accepted and financed as part of doing business.

With today's knowledge base, technology, and available fatigue/shiftwork interventions, they can be converted into a new source of operating profit and reliability that we never knew or believed existed. Moreover, they can be systematically addressed through a collaborative, human involvement process between labor and management to achieve substantial win-win benefits.

Information for this article, including much of the research results, is provided by Circadian and is available on its website, Reach Circadian at 781-439-6300 or [email protected].