Setting Objectives for Fatigue Detection Technologies

Posted on by Tim Bauerle, PhD; Emanuele Cauda, PhD; Imelda Wong, PhD; and Kyla Hagan-Haynes, MPH

This is the third blog in the series on fatigue detection technologies.  

Work-related fatigue can have serious consequences for worker health and safety if not properly managed. One effective option for mitigating work-related fatigue is a well-designed fatigue risk management plan, which can be informed by many approaches and tools, such as fatigue detection technologies (FDTs). However, part of using any tool is understanding the capabilities and limitations of what it can do, and FDTs are no exception. Because of the complexities of measuring and managing fatigue, no one single approach or tool will hold all the answers for every work environment. Two 2021 NIOSH Science Blog posts addressed some of these complexities by outlining different criteria for selecting FDTs and considerations for their effective implementation in the workplace. This blog post builds on the series by describing the importance of understanding and specifying your objectives in the process of managing fatigue risk. Identifying clear objectives can guide the selection of appropriate approaches and tools.  This  is the first step of the “right sensor used right” approach established by the NIOSH Center for Direct Reading and Sensor Technologies. Just as it’s better to wait to purchase tools and supplies until after a home remodeling project is planned out, it’s better to wait to choose an FDT until after deciding on a clear objective for its usage. To get started, here are five tips when thinking about objectives and FDTs:

Making your goals: Identify what you want to know and how FDTs could help provide answers

As our other posts on the topic have indicated, having a clear goal or objective in mind before choosing a particular device or sensor is a key building block to success. This concept has been traditionally applied to detection technologies for hazards such as aerosols, gas/vapor substances, and noise. Doing this for work-related fatigue, where there are no clear definitions or thresholds, may be challenging. However, as proposed in a recent Synergist article, work-related fatigue and the adoption of FDTs can be guided by an industrial hygiene approach that informs objectives through anticipation, recognition, evaluation, and control.

Based on traditional sensor objectives for risk/hazard management activities, managing fatigue might include:

  • monitoring compliance with work hour limits or other regulations
  • assessing work-related fatigue risk
  • identifying and characterizing sources and contributing factors to fatigue
  • implementing alarms when the risk of a fatigue-related safety incident is high
  • evaluating fatigue risk management strategies
  • coaching or training workers

Taking stock of what you have: Review on-hand information to guide FDT objectives

Industries and organizations often have information available that can inform objectives created for technology used in fatigue detection, even before new measures or metrics are introduced. For example, after taking stock of times when safety critical events occurred, such as the end of a shift or after several long consecutive shifts, these events can be assessed with on-hand incident investigations or worker compensation records. If meaningful trends or patterns emerge, instruments can then be incorporated to supplement this assessment in several ways, such as in recognizing and understanding the prevalence of fatigue risk, identifying contributing factors in fatigue-related safety critical events, providing biofeedback for workers to use in making healthy lifestyle decisions, and evaluating the effectiveness of an intervention or implemented hazard control. Other examples of helpful on-hand information include previous employee surveys (e.g., health and safety, engagement), presenteeism or absenteeism trends, fleet management or vehicle sensor data (e.g., abrupt acceleration or deceleration, lane deviation), or even anecdotal feedback from workers or front-line supervisors.

Considering the source: Utilize FDTs to help identify sources of fatigue

Fatigue is complex and can come from many sources. Therefore, one single solution or one single tool will not work for all organizations or individuals. However, once fatigue is recognized as a possible risk factor contributing to safety incidents, potential sources of fatigue can be confirmed. For instance, there may be a need to better understand which groups of workers or job tasks are at greatest risk for fatigue-related safety critical events, because this information will help in developing focused mitigation strategies. Additionally, it may be helpful to identify the likelihood and severity of fatigue-related safety critical events to prioritize strategies to reduce fatigue risk. For example, if incident reports indicate that most near misses among forklift operators occur between 3:00 am and 5:00 am, instruments can be used to confirm the potential role of fatigue in these events as part of a comprehensive fatigue risk evaluation. To help pinpoint various sources of fatigue, multiple FDTs can be used to provide an additional layer of information which is essential in designing effective mitigation or intervention strategies.

Measuring success: Use FDTs to gauge the effectiveness of solutions

Workplace interventions to reduce work-related fatigue risk can include, but are not limited to, revising shift scheduling, adjusting work breaks both within and between shifts, napping strategies, training on sleep hygiene or fatigue risk recognition, and lighting exposure. When implementing a new solution to lower fatigue risk, technology can be adopted to collect behavioral or physiological fatigue-related metrics (e.g., reaction time, eyelid closure) to assess the effectiveness of this solution. To gauge effectiveness, organizations will need to determine their tolerance for fatigue risk. The tolerance threshold is the level of fatigue under which a worker can continue to perform their current task safely without additional precautions in place. Ideally, the FDT used should have appropriate visual or audible alarms to alert users when thresholds are exceeded. Setting clear objectives for fatigue detection is critical to determining reasonable tolerance thresholds and guiding the development of procedures to follow when setting and responding to alarms or alerts. Another critical decision is choosing who should be alerted when thresholds are exceeded (e.g., operator, the supervisor, site safety staff, or some combination).

Preparing for the long-haul: Plan for buy-in and use FDTs beyond the initial fix

Choosing an appropriate FDT for any given environment or company should depend on whether the objective is to implement the technology in the long term. This could include considerations for data and device storage and maintenance, shelf life, and end user buy-in. For example, it is important to engage workers in any risk management plan to determine usability and acceptability. If increasing worker engagement is a specific objective, how the user interfaces with a FDT is a critical aspect. Technology with poor readability or user experiences might decrease worker engagement, thereby rendering it less effective. It is important to consider ethical decision points when developing objectives for fatigue detection, such as setting goals for collecting work-related fatigue risk information in a way that is minimally intrusive, accepted by workers, and easy to use for long-term safety planning. Building these factors into objectives from the start can help with acceptance and long-term use of FDTs.


Managing work-related fatigue risk is a complex process composed of many activities and decisions, which can be informed by FDTs. When considering FDTs, it is helpful to establish clear objectives, optimize relevant on-hand information, identify potential sources of work-related fatigue, indicate how solutions will be evaluated, and engage with workers to ensure long-term benefits. These tools, approaches, and considerations can be important resources to health and safety professionals in their efforts to better mitigate work-related fatigue risk.


Tim Bauerle, PhD, is a Research Behavioral Scientist with the NIOSH Spokane Mining Research Division.

Emanuele Cauda, PhD, is co-Director of the NIOSH Center for Direct Reading and Sensor Technologies.

Imelda Wong, PhD, is Coordinator of the NIOSH Center for Work and Fatigue Research.

Kyla Hagan-Haynes, MPH, is an Epidemiologist with the NIOSH Center for Motor Vehicle Safety.


See the other blogs in this series: 

Choosing the “Right” Fatigue Monitoring and Detection Technology

The Who, What, How and When of Implementing Fatigue Monitoring and Detection Technologies


Posted on by Tim Bauerle, PhD; Emanuele Cauda, PhD; Imelda Wong, PhD; and Kyla Hagan-Haynes, MPH

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Page last reviewed: May 30, 2023
Page last updated: May 30, 2023