April 2019

Fatigue risk in your operations – real or rubbish?

  • By Brett Haskins, Global Consulting Manager and Todd Dawson, Fatigue Practice Manager, Caterpillar Inc

Is fatigue just a buzz word in occupational health and safety or is it a real phenomenon that is creating safety and organisational risks?

Operator fatigue is responsible for significant injuries and losses across many key industry segments. It is one of the most overlooked influences in understanding human error and accident causation. Fatigue is often looked at as a contributing factor with no real solution, rather than a primary causal factor that can be prevented. Within mining operations, fatigue is a leading contributor in 60-70 per cent of human error incidents (Caterpillar Inc, 2008) and surveys of shift workers across all industries demonstrate that nearly half of the population nods off while working at least once per week. 

Fatigue is also an overlooked source of excess cost due to reduced productivity and increased incidents. In the absence of appropriate management systems, the challenges of operator fatigue will only be exacerbated by the combination of an aging workforce and ever-increasing demands to achieve higher production at lower costs. 

Many shift workers are well-trained and skilled at their jobs but have never been taught how to deal with fatigue, better manage their sleep or adapt to the inherent physical and social challenges of shift work. They develop bad habits or become victims of common shift work pitfalls that compromise their ability to perform to their fullest capabilities. This is just one of the many reasons that shift working employees conservatively cost companies $8600 per person per annum in excess costs over and above their daytime counterparts (Kerin and Carbone, 2003). 

Over the past five years, a broad international consensus has emerged across many 24/7 industries that the optimal way to manage and reduce employee fatigue risk is through a systematic process called a fatigue risk management system (FRMS). In response to these fatigue-related challenges, Caterpillar has developed a comprehensive fatigue and distraction solution, which includes machine hardware, software and training and consulting services. The development of this marks the first time that a single organisation has been able to offer all aspects of an FRMS along with supporting safety services consulting and products. 

What is fatigue?

Fatigue is the state of being tired, weary or sleepy and is both a physical and mental impairment affecting one’s alertness, attentiveness and mental and physical performance. It most often results from inadequate sleep, prolonged physical or mental work or extended periods of stress and anxiety. But fatigue can also result from various lifestyle factors or medical, psychological or physiological conditions. 

Businesses often look at fatigue as a result of poor personal choices like poor fitness, excessive nightlife or a substance abuse problem. Others may view it as a result of poor character traits like laziness or apathy; however, the most common causes of worker fatigue are far from choices made by individuals and much more associated with their psychology and physiology. To quote Sirois (2009):

‘…from a management perspective, fatigue is often perceived to be a behavioural problem, caused more by personal irresponsibility rather than by other factors and certainly not by our operating policies and procedures.’  

We all experience fatigue on a regular basis as part of our innate physiology. But other factors can increase or exacerbate our level of fatigue. Often these factors are based on the decisions we make about the priority we give to sleep or choices we make about diet, exercise and health. 

Some causes of fatigue in the resources sector include: 

  • Poor shift schedules that lead to highly fatigued operators. 
  • Understaffed and overworked operators with insufficient opportunities for rest.
  • Operator activity being monotonous and using little cognitive and physical interaction. Factors such as a darkened cab, vibration and warm inside temperatures create a fatigue-inducing environment.
  • Employees not managing their off-shift time to get sufficient rest.
  • Employers not doing a good job of risk-assessing their own operators and operations, because they don’t know what to look for or how to measure the risk.
  • Employers not providing employees with sufficient training on shift work and how to respond to symptoms during their shift.
  • Employers not knowing how to talk about fatigue because they don’t fully understand what it is.

The effects of fatigue on a typical person include having slower reaction times, reduced motor skills and decreased coordination. When people are fatigued, there is a loss of environmental awareness, impairment of cognitive/logical reasoning skills, poor judgment and diminished ability to communicate and/or process information (Sirois, 2009). 

There are many factors that affect the level and impact of a person’s fatigue. They include natural phenomena such as circadian rhythms, physiological and psychological factors, and work, environmental, social and medical issues. 

Disruptions in our circadian rhythms come from people being awake when they should be sleeping and vice versa. This can have a greater affect when people frequently change their sleep/wake cycles and misalign their daily alertness cycles with work requirements. 

As adults, people generally experience our strongest drive to sleep during the ‘window of circadian low’ between 1:00 am and 6:00 am, and in the afternoon between 1:00 pm and 3:00 pm. The National Sleep Foundation indicates that the sleepiness people experience during these circadian dips will be less intense if they have had sufficient sleep, and more intense when they are sleep deprived (National Sleep Foundation, 2015). These cycles make people more susceptible to fatigue related issues if they do not recognise their existence and plan for their affects. 

It is easy to understand that not getting the appropriate amount of sleep, for whatever reason, can cause fatigue. It is known that the inability to get normal hours of sleep or the proper quality of sleep can also increase the effect of the circadian rhythms. The National Sleep Foundation (2002) 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. This translates to inadequate or ineffective communications, increased absenteeism and turnover as well as reduced morale and poorer labour relations (National Sleep Foundation, 2002). 

‘The effects of fatigue on workers may not only cost lost productivity, but also produce hidden costs in worker injuries and decreased morale.’

In the workplace, people often accept the misconception that, like our process equipment, an employee’s work capacity is a lineal function. But 80 hours of work by an employee does not yield 80 hours of productive output. It actually nets 50-55 hours depending on the level of employee interaction with the process. Further, the national average for productivity generated by overtime work is only 32 per cent – as opposed to the 50 per cent premium paid for overtime (Nevison, 2001; Dembe et al, 2005). 

The effects of fatigue on workers may not only cost lost productivity at a premium price, but also produce hidden costs in worker injuries and decreased morale. 

Consequences of fatigue

The impairments caused by fatigue limit mental and physical performance, alertness and attentiveness. These limitations often result in human error. Numerous scientific studies, and extensive field experience, confirm that shift-workers with higher relative fatigue 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. 

Four separate studies that focused on the effects of fatigue during extended shifts reported that the ninth to 12th hours of work were associated with feelings of decreased alertness and increased fatigue, lower cognitive function, declines in vigilance on task measures and increased injuries (NIOSH, 2004). 

In particular, the impact of fatigue on worker safety is staggering. The US Chemical Safety Board (2007) cited fatigue due to understaffing, excessive overtime and consecutive shifts as a causal factor (among others) in the 2005 Texas City Refinery explosion that killed 15 people and injured an additional 170. The costs associated with the clean-up of this disaster exceeded US$2 billion (Chemical Safety and Hazard Investigation Board (US), 2007). Two studies reported that overtime was associated with higher on-the-job injury rates in construction workers or health care workers (NIOSH, 2004). 

The price of fatigue is paid not only by the employer, but by the worker as well.

A case study in a large open pit mine showed that the hidden costs of fatigue related incidents were significantly higher than the direct costs. In other words, the direct costs (equipment damage, injuries etc) were far outweighed by the indirect costs such as time for investigation, lost production, repair time, medical costs and so on. 

The price of fatigue is paid not only by the employer, but by the worker as well. The National Institute for Occupational Safety and Health (NIOSH) and the Centres for Disease Control (CDC) reviewed 22 studies addressing general health effects.

Of these 22 studies, 16 revealed that overtime was associated with poorer perceived general health, increased injury rates, more illnesses or increased mortality. Overtime was associated with unhealthy weight gain in two studies, increased alcohol use in two of three studies, increased smoking in one of two studies and poorer neuropsychological test performance in another (NIOSH, 2004). 

Often people address the symptoms of fatigue with the use of energy drinks, caffeine and other stimulants, the use and abuse of which can also have a serious impact on personal health. 

Caterpillar’s solution

The adverse effects of fatigue on personal safety and health and the profitability of employers are clear. To objectively, systematically and measurably eliminate the consequences of fatigue from operations, employers must look at the development of an effective fatigue risk management system (FRMS). 

The biggest hurdle employers face in the development of such a system is a cultural one. Most effective solutions are not commonly used or accepted in the workplace. They include lifestyle training, napping, improved personal health habits (wellness), work process improvements, scheduling adjustments and new emerging technologies. 

The recent general acceptance of an FRMS as the standard for managing and mitigating employee fatigue risk represents a significant maturation in the understanding of and response to this risk. There is much work to be done in moving from a dependence on the old and familiar prescriptive hours of service rules to a process that requires active management but also provides more flexibility. To accomplish this, organisations that implement an FRMS must ensure that the system is firmly embedded in the health and safety management systems of the company and that it is rigorously maintained, carefully monitored and continuously improved upon. This process should all be part of the continuous improvement cycle of managing the risk profile of any organisation’s management system. Provided it is properly designed, implemented and managed, an FRMS offers a major step towards reduction in health and safety risks in 24/7 operations. 

For Caterpillar, the ability to accurately see, mitigate and manage fatigue represented a clear opportunity: build a technology-enabled solution that would equip any organisation with the vision, visibility and insight to quantify their issues regarding operator performance. Using their own proven cultural transformation methodologies, Caterpillar Safety Services (a division of Caterpillar Inc) has built a comprehensive safety product suite that includes the below components. 

Training and education: 

  • executive workshops – managers, supervisors and union leaders to achieve consensus and stakeholder support on the scope and impact of fatigue 
  • supervisor training – identification and intervention of tired shift workers
  • employee training – education and tools to reduce personal levels of fatigue and cope with shift work.


  • Fatigue Risk Assessment – a holistic employee fatigue measurement tool that provides real-time visibility 
  • fatigue risk management system development – policy, procedure development and technology strategy
  • roster/shift scheduling – recommend optimised staffing levels and work schedules to maintain manageable overtime levels
  • rapid improvement workshops – employee-led teams working on error-proofing the processes and ensuring successful and sustainable deployment.

Technology implementation and support: 

  • Cat® Driver Safety System – requirements gathering, implementation planning, change management, process integration, training and education 
  • Cat Smartband – individual actigraphy using biometric watches to gather information and present back findings to individuals on sleep and behaviour that influences their fatigue
  • Fatigue Avoidance Scheduling Tool (FAST) – fatigue modelling software that identifies areas of fatigue risk in schedule and roster design utilising individual and group sleep data to generate minute-by-minute performance predictions
  • data monitoring – with the implementation of new technologies, a wealth of real-time and historical fatigue and operational data becomes available that will be monitored to ensure continuous improvement
  • equipment telematics – ‘black box’ type technology used to transmit vital equipment and operation data to improve usage and product life.

But how can organisations manage what they don’t measure, and how can organisations measure something that they can’t see? Technologies that give organisations visibility to measure fatigue and its impact are critical. 

It’s important to consider the use of a range of technologies in order to clearly define the volume of the problem. For example, an in-cab camera system detecting operator alertness will provide the number of fatigue events occurring, but it doesn’t provide any data on that same operator’s sleep quality. Similarly, telematics data provides ample information about how the equipment is operating but provides very little information about the operator. When used as stand-alone technologies, these tools can provide valuable improvement data. However, when used together, these technologies can capture the entire picture. 

Through the use of these technologies, a more adequate assessment can be made into the current realities within any operation. During a Fatigue Risk Assessment, the combined data from these technologies is analysed to bring visibility to the current state of operations, employee effectiveness and risk. The organisation recommends a minimum 25 per cent sample population be selected for a sleep analysis using the Cat Smartband technology. Designed to be worn 24/7 for a period of approximately four weeks, the anonymous data provides insight into the current sleeping patterns of operators. Each participant in the study receives a report detailing their personal sleeping habits. Additionally, the organisation utilises the anonymous data in a FAST analysis, which creates predictive ‘heat maps’ to indicate when fatigue levels will be at their highest during shifts. The FAST tool is also used to simulate alternate shift schedules that identify maximum performance shifts.

Fatigue is a naturally occurring human response and even with the best management systems and control measures in place it remains inevitable. This is where DSS adds significant benefits. A camera-based detection system, it analyses eyelid closure and minute head movements to determine when an operator is experiencing a fatigue or distraction event during equipment operation. DSS provides real-time intervention for fatigue and distraction events through the use of an instantaneous in-cab alarm and seat vibration system. The accompanying 24/7 data monitoring system also supports a fatigue intervention plan for each detected event and customised reports to be used for analysis and continuous improvement. This technology provides an accurate measuring system for determining the success of your overall fatigue risk management system. In addition, the availability of real-time data enables the changing out of any operators who are at risk of accidents and injuries due to their fatigued state. 

Since its development, DSS has monitored more than eight million hours and driven more than 101 million kilometres in mining vehicles. Some 2641 of those kilometres have been driven while operators were fatigued. DSS has also detected more than 1.5 million distraction events in these same mining vehicles. 

Once a fatigue risk assessment is undertaken, specific and verifiable data is available from which to build an improvement strategy that engages the operators (those closest to the risk), educates the workforce and deploys an effective FRMS. 


In business, most employers see the value in properly maintaining and caring for company assets including tools, vehicles, machinery etc. However, they often forget to apply this concept of preventative maintenance to their most important asset: their employees. Employers struggle with ‘unpreventable’ accidents that seem to have no real cause. This is because they fail to see the fatigue of their workforce as a legitimate and serious causal factor. 

Fatigue has a direct impact on the safety of employees. It impacts a person’s decision-making and reduces their ability to sustain attention. This overall cognitive impairment has the ability to lead to critical errors that can have dramatic results when large heavy equipment is involved. Fatigue related accidents are typically costly in equipment damage and result in severe injuries or fatalities. 

Fatigue also affects job sites in less tangible ways. A fatigued operator is more likely to make cognitive errors (or misjudgements) which can reduce productivity. Fatigue can therefore waste valuable time, minerals and reduces customers’ product consistency and quality. 

Further, fatigue impacts employee engagement. Left unaddressed, a site’s workforce can eventually see increased absenteeism, increased turnover and low employee satisfaction and morale. 

Progressive organisations are now beginning to treat the fatigue of their workforce as a legitimate risk to their company’s financial and employee’s physical well-being. Organisations that take the time to invest in a well-reasoned and fully implemented FRMS will see an impact on multiple levels including accident reductions, increased site productivity, and increased employee health and engagement. By understanding the influences of fatigue, training opportunities, new technologies and other available fatigue interventions, organisations can now begin to effectively measure the level of fatigue risk within their operations to determine if the risk is real…or rubbish. 


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