Article

Research and guidelines for implementing Fatigue Risk Management Systems for the French regional airlines

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

This paper describes research that aims to provide the overall scientific basis for implementation of a Fatigue Risk Management System (FRMS) for French regional airlines. The current research has evaluated the use of different tools and indicators that would be relevant candidates for integration into the FRMS. For the Fatigue Risk Management component, results show that biomathematical models of fatigue are useful tools to help an airline to prevent fatigue related to roster design and for the management of aircrew planning. The Fatigue Safety assurance includes two monitoring processes that have been evaluated during this research: systematic monitoring and focused monitoring. Systematic monitoring consists of the analysis of existing safety indicators such as Air Safety Reports (ASR) and Flight Data Monitoring (FDM). Results show a significant relationship between the hours of work and the frequency of ASR. Results for the FDM analysis show that some events are significantly related to the fatigue risk associated with the hours of works. Focused monitoring includes a website survey and specific in-flight observations and data collection. Sleep and fatigue measurements have been collected from 115 aircrews over 12-day periods (including rest periods). Before morning duties, results show a significant sleep reduction of up to 40% of the aircrews' usual sleep needs leading to a clear increase of fatigue during flights. From these results, specific guidelines are developed to help the airlines to implement the FRMS and for the airworthiness to oversight the implementation of the FRMS process.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Today most operators use scheduling software and biomathematical models (BMM) (Cabon et al., 2012;Dawson et al., 2017;Dorrian et al., 2012) to produce legal, competitive rosters. Several regulators like the European Aviation Safety Agency (EASA) and the Australian Civil Aviation Safety Authority (CASA) made Fatigue Risk Management (FRM) mandatory to manage pilots' fatigue and fatigue risks on flight duty, if operators wanted to deviate from FTL because of operational or competitive necessities (Bendak & Rashid, 2020;Bourgeois-Bougrine, 2020). ...
... EASA links pilots' fatigue explicitly with flight safety (EASA FTL, 2014; Commission Regulation (EU) 2018/1042, 2018). Several studies support the relevance of fatigue for flight safety and pilot performance (Bandeira et al., 2018;Bendak & Rashid, 2020;Bourgeois-Bougrine, 2020;Cabon et al., 2012;Goode, 2003;Hartzler, 2014). Therefore, further research seems necessary to improve flight safety, which may save aircrews' and passengers' lives. ...
... On the other hand, "Fatigue is a feeling of strain or exhaustion; it includes physiological fatigue and pathological fatigue. Physiological fatigue, or 'normal fatigue', is induced by daily activities it lasts a short period and is usually relived by rest" (Shahid et al., 2010, p. 85) We typically refer to fatigue as physiological fatigue (Shahid et al., 2010), or accumulated fatigue (Cabon et al., 2012), which is also reflected in the fatigue definition of the International Classification of Diseases (ICD 11). ...
Article
Full-text available
Objective While previous research focused on pilots’ fatigue, rosters, potential performance-impairment and aviation-safety, this research investigates, how pilots’ work-related and psychosocial stress and rosters can affect their sleep and fatigue. Method A cross-sectional online survey was completed by 192 pilots flying for European operators, 180 Australian pilots and 34 pilots from UAE, Turkey and Asia Pacific. Pilots reported their actual duty- and flight-hours, flown sectors, standby, rest, vacation days, number of early starts, night-flights and sports-hours for the last two months. Schedule-related data, way to work, age, flight-hours on the present type of aircraft, subjective job-security and psychosocial stress were used as independent variables to investigate, which significantly predict sleep problems (JSS) and fatigue (FSS). Results 76% of the active pilots reported significant fatigue (FSS≥4), 33.4% high fatigue (FSS≥5), although pilots were rostered for only 56.25% to 61.32% of the legally allowed duty and flight hours/month. Considerable sleep problems in ≥8 nights/month were reported by 24.2% pilots. Sleep problems were strongly associated with sleep restrictions and fatigue risks experienced on flight duty. More sleep problems were predicted by more stress and fatigue risks on flight duty. Higher fatigue-severity was predicted by more sleep problems, more stress, more fatigue risks experienced on flight duty, less physical exercise and shorter ways to work. Conclusions Our findings suggest that present flight-time-limitations likely cannot prevent fatigue and potentially foster sleep-problems. In line with work-psychology and stress-research, psychosocial stress plays an important role for pilots’ sleep problems and fatigue.
... Patterns of risk can be less predictable in complex and highly protected systems such as railways, aviation, or nuclear power industry (Gander et al., 2011). In these systems, human performance deficits (due to fatigue or other causes) interact with several safety barriers such as teamwork, automation, or procedures, and as such the link between human performance and accidents is not always clear (Gander et al., 2011;Cabon et al., 2012). Despite these complexities in the relationship between fatigue and the occurrence of safety-critical events, our real-world empirical results clearly and significantly indicate that the occurrence of errors is associated with higher Hourly Risk Index values. ...
... In addition, the severity of these errors is related to a further clear increase in fatigue-related risk. The latter findings are in line with airline crew fatigue research by Cabon et al. (2012), where the number of safety events of a more serious nature was associated with higher levels of fatigue, whereas less serious errors did not exhibit the same relationship, and surprisingly even decreased with higher fatigue levels. A possible explanation for this latter phenomenon was the effect of "fatigue awareness", where aircrews, when they feel tired, rely more on automation or cooperate differently (Cabon et al., 2012). ...
... The latter findings are in line with airline crew fatigue research by Cabon et al. (2012), where the number of safety events of a more serious nature was associated with higher levels of fatigue, whereas less serious errors did not exhibit the same relationship, and surprisingly even decreased with higher fatigue levels. A possible explanation for this latter phenomenon was the effect of "fatigue awareness", where aircrews, when they feel tired, rely more on automation or cooperate differently (Cabon et al., 2012). ...
Article
Around-the-clock staffing in safety-critical environments calls for an accurate risk assessment of work schedules. In this paper we introduce and evaluate an hourly version of the “Risk Index”, an established risk model in the UK rail industry. This “Hourly Risk Index” is the first risk-based model that allows the prediction of risk at the hourly level, and is founded on the most recent scientific insights in fatigue-related accident risk. It considers the build-up of risk over consecutive shifts, recovery during days off, quick returns, and time-of-day and time-on-duty effects. Improved understanding of hourly risk is highly relevant for both ex-ante (staff rostering) and ex-post (accident and incident analysis) evaluations. We evaluated the performance of the Hourly Risk Index by analyzing a purpose-built real-world dataset from Belgium’s railway traffic control centers (containing close to 8 million round-the-clock working hours in the period 2013–2018). Results not only show that the occurrence of safety-critical errors is significantly associated with higher Hourly Risk Index values, but also that error severity is significantly related to a further increase in risk. In addition, the Hourly Risk Index outperformed the original Risk Index. Our empirical results also emphasize the importance of job demands, by indicating a higher performance of the Hourly Risk Index under conditions of low or high workload. Given these outcomes, it is currently being deployed and tested at Belgian national railways. This should allow the further refinement of the Hourly Risk Index in an iterative manner.
... Flight data monitoring is the systematic assessment of flight parameters to identify significant safety events, determine areas of operational risk and quantify existing safety margins (Cabon et al., 2012). ...
... Air safety report (ASR) is a mandatory report written by the captain whenever a safety event has happened during a flight. Cabon et al. (2012) studied 563 fatigue-related ASR's and found that there is a clear interaction between the duration of the previous rest and the workday duration. For short workdays, rest duration has no significant effect on ASR frequency. ...
... FRMS has been introduced on the basis that better safety and productivity levels might be attained from approaches that are broader, more flexible, and better tuned to modern scientific findings of key factors in reducing fatigue (Australian Civil Aviation Safety Authority, 2004). There is an ever-increasing doubt about the efficiency of prescriptive rigid regulations to prevent fatigue as they are usually not able to consider the complexity of fatigue (Cabon et al., 2012;Dawson and McCulloch, 2005a). For example, a single prescribed break will not result in the same recovery value for everyone as the timing of the break is more important than the break duration. ...
Article
Factors that cause human fatigue, like sleep deprivation, circadian rhythm abnormalities, health-related tiredness and task-induced influences, may have adverse effects on human performance. These adverse effects may include significant degradation in decision-making skills, memory sharpness, judgment proficiency, reaction time and situational awareness in aviation operations and, thus, can lead to accidents. This study, taking both academia and industry perspectives, aims to examine causes, consequences, measurement and mitigation of fatigue and the associated risk in airline operations through a systematic literature review. Articles published in peer-reviewed journals and publications from various aviation industry stakeholders that addressed fatigue in aviation were searched, collated and assessed. It was found that risk associated with fatigue in the aviation industry is of a diverse and sometimes ambiguous nature. Overall, it was observed that this risk increases substantially when the workday duration is longer than 16 h, when the pre-duty sleep duration is shorter than 6 h, and when the workday coincides with the crew's usual sleep hours. It was also found that not all aspects related to this risk have been thoroughly investigated. Recommendations for future research to investigate ways to minimise this risk further are given at the end.
... In this study, we are referring to professional or airline pilots as opposed to private pilots. In accordance with Shahid et al. (2010) we differentiate between alertness/sleepiness and more accumulated fatigue, similar to previous studies (Aljurf et al., 2018;Cabon et al., 2012;Reis et al., 2013;Reis et al., 2016a;Shahid et al., 2010). ...
... Pilots can lose up to 40% of their regular sleep time (Cabon et al., 2012;Coombes et al., 2020), due to legal but competitive rosters, often Table 1 Examples of basic flight time limitations (FTL) rules of the European Aviation Safety Agency (EASA), Civil Aviation Safety Authority (CASA) and the US Federal Aviation Administration (FAA). These EASA and CASA FTL were in force for the investigated 192 EASA-based and 180 Australian pilots, at the time of data collection from June 2018 until March 2019 (Venus and grosse Holtforth, 2021a (Brannigan et al., 2019;Little et al., 1990;Young, 2008). ...
Article
Full-text available
Introduction: Recent research has reported widespread high levels of fatigue among pilots. Pilot fatigue can affect their performance and has become a threat to flight safety. Objective: This study examines whether different flight time limitations (FTL) and rosters of EASA-based and Australian pilots were associated with different levels of stress, sleep difficulties, fatigue levels, symptoms of depression or anxiety and wellbeing. Method: 192 EASA-based and 180 Australian pilots completed a cross-sectional online survey, which asked for their schedules, stress, sleep problems, fatigue, wellbeing, and symptoms of depression and anxiety. These variables were compared for the groups of EASA-based and Australian pilots. Findings: Although EASA based and Australian pilots were scheduled for only 57–62% of maximum duty and flight hours, 71.8% EASA-based vs. 77% Australian pilots reported severe or high fatigue. Significant depression symptoms were reported by 17.2% Australian and 18% EASA-based pilots, 7% pilots reported significant symptoms of depression and anxiety. Australian pilots reported more demanding rosters, significantly more sleep problems and significantly lower wellbeing. Conclusions: Present regulations and FTL likely could not prevent high fatigue levels among EASA based and Australian pilots. Both groups were equally fatigued, although Australian pilots reported more demanding rosters. Pilots of both groups reported the same levels of stress, depression, and anxiety symptoms, while Australian pilots’ sleep and wellbeing were significantly more impaired. These results suggest that fatigue should not be regarded as an isolated problem for flight-safety. Fatigue is closely related to pilots’ physical and mental health, which may be at risk in the long run.
... This is buttressed by the work carried out by Ozdemir, Selvis, Ozkol, Aydin, Tuluce, Boyson and Besiroglu (2013) which states that shift workers score higher than their day worker counterparts on a wide range of cognitive performance measures [4]. In another development, Cabon, Deharvengt, Grau, Maille, Berechet and Mollard (2012) has it that crew operating under reduced rest provisions (a minimum of 7 hours 30 minutes not 13 hours between shifts) had a decrease in frequency of flight data monitoring events severity levels with high risk of fatigue [5]. This implies that if the rest time is small then the fatigue risk becomes higher. ...
... Availability of Corps to be equal to 87.5% with daily breaks. Productivity of Corps is increased exponentially overtime.5. Capabilities and willingness of Corps are increased as skills and personality levels/ranks increases.6. ...
Article
Full-text available
Fatigue is a physiological state of reduced mental or physical performance capabilities resulting from sleep loss or extended wakefulness, circadian phase or workload emanating from mental or physical activities. It has contributed to poor productivity level and performance, accidents, high risk as well as significant problems in security agencies and modern society. With the high demand in workplaces, long task periods, disrupted circadian rhythms, social and societal demands and insufficient sleep caused by fatigue, it effects had over time affected worker's ability to think and make decisions, reduced the ability to do complex planning and communication skills. Many scholars have assessed the causes of fatigue in aircrew workforces but for security agencies not to my knowledge. A structured questionnaire was administered to security agencies and the data got was analyzed using MATLAB software and the findings were used to formulate a Model of Fatigue and Performance Capabilities for Nigerian Security Agencies Workforce. This model was used to solve a numerical example indicating that the model aids improvement in the agility, performance and productivity of workers mentally, physically and psychologically.
... For example, proper rest in designated rest facilities or flight deck can help reduce the impact of fatigue on mobility and alertness (Hartzler, 2014). Meanwhile, the fatigue bio mathematical model can improve the fatigue caused by unreasonable scheduling (Cabon et al., 2012). However, fatigue assessment is an important part of fatigue management. ...
Article
Full-text available
This paper uses the Multidimensional Fatigue Inventory (MFI-16) to investigate the fatigue status of pilots, and the reliability and validity of the scale are tested by Cronbach’s α and exploratory factor analysis. The founding shows that mild fatigue and above accounted for 67.7%. For further quantify the impact of different flights on pilots’ fatigue, research improves the fatigue coefficient model based on the results of pilot fatigue feeling questionnaire. Combined with multifactor analysis of variance and multiple linear regression, it is found that the independent variables have different and positive effects on the dependent variables, and there is no multicollinearity. Through the actual test, its accuracy is improved by 16.7% compared with the original model.
... Occupational fatigue is an universal issue across many 24/7 industries and has been studied by international scholars in domains such as road transport, aviation, oil and petrochemical industries, railroads, health sector, maritime transport, etc. Human Factors and Ergonomics approaches have been widely used to analyse and mitigate employee fatigue by focusing on the root causes of fatigue such as sleep debt related to work and rest hours, wakefulness (time since awakening, prior duty plus time on task), circadian factors (late finish, night shift, transitions, jet lag) and operational workload and hassles (Neville et al., 1994;Härmä, 1995;Dawson and Reid, 1997;Cabon et al., 2002Cabon et al., , 2012Bourgeois-Bougrine et al., 2003a, 2003bGoode, 2003;Dawson and McCulloch, 2005;Jones et al., 2005;Folkard and Lombardi, 2006;Caldwell, 2012;Allen et al., 2007;Powell et al., 2007;Holmes et al., 2012;Signal et al., 2012). ...
Article
Full-text available
In the fragmented European airline sector, companies are operating in a highly competitive environment amid rising cost of labour, fuel and airport fees. Fatigue risk management systems (FRMS) contribute to flexibly optimizing crew “utilization” through deviations and derogations from prescriptive European limits on duty times and rest durations. However, the flexibility gained comes at a price: it introduces an internal bureaucracy to mitigate the risks associated with crewmembers’ fatigue and to develop, maintain and document fatigue related safety performance indicators. This paper questions the effectiveness of the FRMS framework and suggests that the bureaucratic process of the FRMS provides an illusion of fatigue risk control. More specifically four questions will be addressed: Why an operator needs an FRMS? Why the FRMS involves a bureaucratic process? What are the limits of the bureaucratic accountability of the FRMS and, finally, how might we manage fatigue risk effectively while keeping everyone happy, the shareholders as well as stakeholders?
... A similar but different scale is employed by Gouin et al. (2001), while a visual analog scale for momentary fatigue was employed by de Araújo Fernandes Jr. et al. (2013). Momentary sleepiness is also recorded at various times in relation to a shift by several studies, using the Karolinska Sleepiness Scale (Härmä et al., 2002;Ingre et al., 2004;Hack, 2005), with one study comparing actual sleepiness with sleepiness predicted by schedule software analysis (Cabon, Deharvengt et al. 2012). The latter also attempted to measure sleepiness objectively using EEG and EOG. ...
Technical Report
Full-text available
Field and survey studies measuring operator fatigue in land and sea transport are assessed against an argument that a broad operationalization of fatigue is required in order to fully understand it. Our assessment finds that the progress towards an understanding of fatigue in transport is restricted by a range of different but narrow conceptualisations of the construct. One result is that we know little about the relative prevalence of fatigue in different transport operators, a situation which could be improved using a standardised measurement battery for the assessment of operator fatigue. Further implications are that important contributors to fatigue, such as recovery from work during non-work life, have been neglected, as have some important outcomes such as the longer term safety impacts of operator burnout. Better management of the risks of fatigue in transport requires that future studies address important knowledge gaps by attending to the broader concept of fatigue.
... A key determinant for the effectiveness of FRM is how it is implemented in the airlines. A French paper showed that introduction of FRM resulted in increased use of biomathematical fatigue modelling as tool to improve aircrew scheduling, although it is not clear if work-related fatigue was reduced (Cabon, Deharvengt et al. 2012). ...
Technical Report
Full-text available
The overall aim with this study was to gather knowledge about countermeasures for driver fatigue (including sleepiness) in road, rail, sea and air transportation. The knowledge has been used as an input for evaluating advantages and disadvantages with different countermeasures and to estimate their potential to be used regardless mode of transportation. The method used was a literature review and a workshop with experts from all transportation modes. At the workshop the effectiveness of countermeasures for a single mode, but also regardless mode were discussed and a ranking was done. The report discuss the potential of fighting fatigue among drivers for specific mode of transport but also from a more generic point of view, considering scheduling, model prediction of fatigue risk, legislation, a just culture, technical solutions, infrastructure, education, self-administered alertness interventions and fatigue risk management (FRM). The overall judgement was that a just culture, education, possibility to nap and schedules taking the humans limitations into consideration as the most effective countermeasures to fight fatigue, regardless mode of transportation.
... A key determinant for the effectiveness of FRM is how it is implemented in the airlines. A French paper showed that introduction of FRM resulted in increased use of biomathematical fatigue modelling as tool to improve aircrew scheduling, although it is not clear if work-related fatigue was reduced (Cabon, Deharvengt et al. 2012). ...
Technical Report
Full-text available
The overall aim with this study was to gather knowledge about countermeasures for driver fatigue (including sleepiness) in road, rail, sea and air transportation. The knowledge has been used as an input for evaluating advantages and disadvantages with different countermeasures and to estimate their potential to be used regardless mode of transportation. The method used was a literature review and a workshop with experts from all transportation modes. At the workshop the effectiveness of countermeasures for a single mode, but also regardless mode were discussed and a ranking was done. The report discuss the potential of fighting fatigue among drivers for specific mode of transport but also from a more generic point of view, considering scheduling, model prediction of fatigue risk, legislation, a just culture, technical solutions, infrastructure, education, self-administered alertness interventions and fatigue risk management (FRM). The overall judgement was that a just culture, education, possibility to nap and schedules taking the humans limitations into consideration as the most effective countermeasures to fight fatigue, regardless mode of transportation.
... A consensus view is emerging that effective fatigue risk management systems (FRMS) may be achieved by policies and procedures implemented at the organizational and individual employee levels (Lerman et al., 2012). Proponents argue that a locally-tailored fatigue-risk management system can mitigate fatigue-related risks while concurrently allowing greater flexibility in the hours that employees can work (Cabon et al., 2012;Dawson and Zee, 2005;Gander et al., 2011). ...
... Due to disruption of the sleep wake pattern and the circadian rhythm, fatigue is inevitable in occupations where individuals are required to work when they normally would be asleep [1]. In the aviation industry, fatigue management strategies have been developed to minimize the health effects of these irregular working hours [2,3]. Education for flight crew members is an important component of these strategies, for which several educational programs have been developed. ...
Article
Full-text available
BackgroundMORE Energy is a mobile health intervention which aims to reduce fatigue and improve health in airline pilots. The primary objective of this process evaluation was to assess the reach, dose delivered, compliance, fidelity, barriers and facilitators, and satisfaction of the intervention. The second objective was to investigate the associations of adherence to the intervention with compliance and with participant satisfaction. Thirdly, we investigated differences between the subgroups within the target population. Methods The intervention consisted of a smartphone application, supported by a website. It provided advice on optimal light exposure, sleep, nutrition, and physical activity, tailored to flight and personal characteristics. The reach of the intervention was determined by comparing the intervention group participants and the airline pilots who did not participate. The dose delivered was defined as the total number of participants that was sent an instruction email. Objective compliance was measured through the Control Management System of the application. To determine the fidelity, an extensive log was kept throughout the intervention period. Subjective compliance, satisfaction, barriers, facilitators, and adherence were assessed using online questionnaires. Associations between the extent to which the participants applied the advice in daily life (adherence), compliance, and satisfaction were analysed as well. Finally, outcomes of participants of different age groups and haul types were compared. ResultsA total of 2222 pilots were made aware of the study. From this group, 502 pilots met the inclusion criteria and did agree to participate. The reach of the study proved to be 22 % and the dose delivered was 99 %. The included pilots were randomized into the intervention group (n = 251) or the control group (n = 251). Of the intervention group participants, 81 % consulted any advice, while 17 % did this during four weeks or more. Fidelity was 67 %. The participants rated the intervention with a 6.4 (SD 1.6). Adherence was not associated with compliance, but was associated with satisfaction (p ≤ 0.001). Pilots of 35 to 45 year old were significantly more interested in advice regarding physical activity than their colleagues, and short-haul pilots were more interested in advice regarding nutrition compared to long-haul pilots. Conclusions The MORE Energy intervention was well received, resulting in an adequate reach and a high dose delivered. The compliance and satisfaction scores indicate that engagement and functionality should be enhanced, and the content and applicability of the advices should be improved to appeal all subgroups of the target population. Trial registrationNederlands Trial Register NTR2722. Registered 27 January 2011.
... Fatigue can reduce the awareness of risk and result in accidents, particularly for the workers in specific positions. Fatigue affectation is related to a lot of areas, such as road traffic, shipping, machinery processing, construction, medical services (Akerstedt et al., 2002;Lockley et al., 2004;Fang et al., 2015;Wang and Xu, 2016;Filtness and Naweed, 2017), in which the fatigue of aviation and professional drivers is among the first (Lyznicki et al., 1998;Philip et al., 2003;Cabon et al., 2012;Jo et al., 2014;Butlewski et al., 2015). Fatigue can slow sensorimotor functions and impair information processing, impact on motorists ability to respond to sudden emergencies (Kaplan and Prato, 2012;Meng et al., 2016) and influence the attention and speed of response of the pilot and so on (Borghini et al., 2014). ...
Article
Fatigue can lead to decreased work performance and poorer safety and health condition. Fatigue is ubiquitous in production and in life, while the research on it is mainly concentrated in the automotive driving, aircraft piloting and other fields, and it is insufficient to study on the fatigue of fixed-position staff. This paper puts forward a non-contact visual image method, which can monitor the extent of fatigue of fixed-position staff. Fatigue threshold used in judgment is obtained by processing the recorded data of visual images of the experimental subjects when fatiguing and by analyzing eye closure time, percentage of eyelid closure (PERCLOS) value, frequency and number of blinks. The results show that there is significant difference among the four indicators before and after experiment subjects undergo fatigue. The fatigue of experimental subjects is obvious when eye closure time is 3.5 s/min, PERCLOS value 6%, and blink frequency 0.4 times/s. This provides a reference for a wider range of detection of fatigue and a method for avoiding mistakes and accidents.
... While the proliferation of such devices supports their potential, current barriers to effective use of CST include a lack of validation against research-grade actigraphy and polysomnography, which is the gold-standard for sleep measurement. Current international best practice in workplace fatigue management involves a Fatigue Risk Management System (FRMS) (Dawson and McCulloch, 2005;Gander et al., 2011;Cabon et al., 2012;Gander et al., 2014), which includes specific policy, education and awareness training, fatigue monitoring systems with feedback, procedures for reporting, investigating and recording fatigue-related incidents and accidents, and evaluation processes and mechanisms for testing the impact of any fatigue-interventions (Gander et al., 2011). In this context, validated CSTs may assist with fatigue monitoring, however, it is critical to consider the form of the feedback. ...
Article
Technology-supported methods for sleep recording are becoming increasingly affordable. Sleep history feedback may help with fatigue-related decision making - Should I drive? Am I fit for work? This study examines a "sleep tank" model (SleepTank™), which is analogous to the fuel tank in a car, refilled by sleep, and depleted during wake. Required inputs are sleep period time and sleep efficiency (provided by many consumer-grade actigraphs). Outputs include suggested hours remaining to "get sleep" and percentage remaining in tank (Tank%). Initial proof of concept analyses were conducted using data from a laboratory-based simulated nightshift study. Ten, healthy males (18-35y) undertook an 8h baseline sleep opportunity and daytime performance testing (BL), followed by four simulated nightshifts (2000 h-0600 h), with daytime sleep opportunities (1000 h-1600 h), then an 8 h night-time sleep opportunity to return to daytime schedule (RTDS), followed by daytime performance testing. Psychomotor Vigilance Task (PVT) and Karolinska Sleepiness Scale were performed at 1200 h on BL and RTDS, and at 1830 h, 2130 h 0000 h and 0400 h each nightshift. A 40-minute York Driving Simulation was performed at 1730 h, 2030 h and 0300 h on each nightshift. Model outputs were calculated using sleep period timing and sleep efficiency (from polysomnography) for each participant. Tank% was a significant predictor of PVT lapses (p < 0.001), and KSS (p < 0.001), such that every 5% reduction resulted in an increase of two lapses, or one point on the KSS. Tank% was also a significant predictor of %time in the Safe Zone from the driving simulator (p = 0.001), such that every 1% increase in the tank resulted in a 0.75% increase in time spent in the Safe Zone. Initial examination of the correspondence between model predictions and performance and sleepiness measures indicated relatively good predictive value. Results provide tentative evidence that this "sleep tank" model may be an informative tool to aid in individual decision-making based on sleep history.
... Fatigue Risk Management Systems (FRMS) have been defined as "scientifically based, data-driven addition or alternative to prescriptive hours of work limitations which manages employee fatigue in a flexible manner appropriate to the level of risk exposure and the nature of the operation" 21) . While a number of Fatigue Risk Management System guidelines have been developed for a range of industries 21,[103][104][105][106][107][108][109][110][111][112][113] , a set of commonalities have emerged based on the core components of SMSs (i.e. safety management policies and procedures, risk management, safety assurance and safety promotion) (Figure 2) 114,115) . ...
Article
Full-text available
A substantial body of literature indicates that shift workers have a significantly higher risk of workplace accidents and injuries, compared to workers in regular daytime schedules. This can be attributed to work during nights which require workers to stay awake during normal sleeping hours and sleep during natural waking hours, leading to circadian desynchronization, sleep disruption and cognitive impairment. A fatigue-risk trajectory model developed by Dawson and McCulloch has been used to describe the series of events which may precede fatigue-related incidents. This includes insufficient sleep opportunities, impaired sleep, fatigue-behavioral symptoms, and fatigue-related errors. The purpose of this paper is to provide examples of control measures along each level of the fatigue-risk trajectory, which include: (i) work scheduling strategies to include breaks for adequate sleep opportunities; (ii) training and educational programs to help workers make best use of recovery times for quality sleep; (iii) fatigue-detection devices to alert workers and safety managers of fatigue-related behaviors and errors. A brief introduction to Fatigue-Risk Management systems is also included as a long-term sustainable strategy to maintain shift worker health and safety. The key statements in this paper represent a consensus among the Working Time Society regarding a multi-level approach to managing occupational sleep-related fatigue.
... These factors can lead to high levels of fatigue and/or impaired pilots' performance [10]. Something that characterizes fatigue, especially in aviation, is the increasing number of errors that may endanger the flight safety [3]. To understand the influence of fatigue on flight operations, it is important to gain insight into how each factor contributes to fatigue, and more importantly, how the effects of fatigue may negatively affect the pilots' capabilities to cope with different flight situations [11]. ...
Conference Paper
Full-text available
The National Transportation Safety Board (NTSB) reports show that fatigue has been a contributing factor in many aviation accidents and near misses. The aim of this study was to improve our understanding of the relationship between pilot fatigue and task performance. A small-scale experiment was performed to investigate whether the pilots' fatigue and performance would differ between novices and expert pilots. Six pilots with different experience levels (i.e. novice and experienced) participated in flying the B-52 military aircraft from Oklahoma to Florida using a medium fidelity simulator. The results show that the mean reaction time (RT), the slowest 10% of RT, the fastest 10% of RT the number of lapses and the number of false alarms were significantly different between the novice and experienced pilots. Secondary analyses involved the pilots' eye movement analysis, and the results showed that there were significant differences between novices' and experts' eye movement characteristics such as numbers and duration on the areas of interests (AOIs). Furthermore, we were able to observe that the experienced pilots increased their visual scanning pattern complexity compared to the novices. The findings can lead to better understanding of the experts' flight strategies and how we can use the experts' visual scanning patterns to improve novice's performance.
... In the first of these papers, Cabon et al. (2012) outline a pilot FRMS program for French regional airlines. What is proposed is a fundamental shift away from the more traditional flight and duty-time limitations (FTL) that have characterised fatigue-risk mitigation in the past. ...
Article
Over the last 20 years, academic, industry and community stakeholders have been meeting at a biennial scientific conference to discuss fatigue-related research and policy in the transportation, resources and health sectors. During this period, the research conducted around the world has progressed substantially: we now better understand the basic processes of sleep and circadian physiology that underpin performance; we better understand that fatigue risk management in the absence of any discussion about sleep is fruitless at worst and inadequate at best; and we are improving the capacity of models and other technologies to assist us to predict, monitor, identify, minimise and mitigate fatigue-related risk. At the same time however, the relationship between performance on simple cognitive tasks in laboratory settings and performance on complex tasks required to operate efficiently and safely in the workplace, remains a stumbling block. This special issue brings together fifteen papers that cover the range of areas in the field of fatigue research and challenges us as researchers, regulators, industry representatives and community members to continue the work of managing the risk of fatigue.
... Occupational fatigue is an universal issue across many 24/7 industries and has been studied by international scholars in domains such as road transport, aviation, oil and petrochemical industries, railroads, health sector, maritime transport, etc. Human Factors and Ergonomics approaches have been widely used to analyse and mitigate employee fatigue by focusing on the root causes of fatigue such as sleep debt related to work and rest hours, wakefulness (time since awakening, prior duty plus time on task), circadian factors (late finish, night shift, transitions, jet lag) and operational workload and hassles (Neville et al., 1994;Härmä, 1995;Dawson and Reid, 1997;Cabon et al., 2002Cabon et al., , 2012Bourgeois-Bougrine et al., 2003a, 2003bGoode, 2003;Dawson and McCulloch, 2005;Jones et al., 2005;Folkard and Lombardi, 2006;Caldwell, 2012;Allen et al., 2007;Powell et al., 2007;Holmes et al., 2012;Signal et al., 2012). ...
Preprint
Full-text available
In the fragmented European airline sector, companies are operating in a highly competitive environment amid rising cost of labour, fuel and airport fees. Fatigue risk management systems (FRMS) contribute to flexibly optimizing crew "utilization" through deviations and derogations from prescriptive European limits on duty times and rest durations. However, the flexibility gained comes at a price: it introduces an internal bureaucracy to mitigate the risks associated with crewmembers' fatigue and to develop, maintain and document fatigue related safety performance indicators. This paper questions the effectiveness of the FRMS framework and suggests that the bureaucratic process of the FRMS provides an illusion of fatigue risk control. More specifically four questions will be addressed: Why an operator needs an FRMS? Why the FRMS involves a bureaucratic process? What are the limits of the bureaucratic accountability of the FRMS and, finally, how might we manage fatigue risk effectively while keeping everyone happy, the shareholders as well as stakeholders?
... Based on the above information and in order to achieve a forward movement, our strategies, aiming to promote wellness and mitigate burnout, should focus on approaches that address both institutional issues, such as a culture of wellness and efficiency of practice, as well as personal resiliency [6][7][8]. These strategies need to be responsive and creative and not simply prescriptive. ...
Article
Covid-19 pandemic has caused a great suffering and turmoil in our society as well as major disruptions in health care delivery. The financial impact on hospitals and universities, biomedical research, and education will be felt for years to come. Despite the broad impact of the pandemic, as surgeons, we should focus on creating novel strategies to mitigate the impact of COVID-19 on our lives and our patients.
... For instance, because of circadian rhythms, a break will not have the same recovery value depending on the time of the day, the timing of the break being more important than the duration of the break itself. This is the reason why alternatives to a prescriptive approach, such as FRMS, are becoming more popular [3]. Resilience refers to the ability for individuals to resist or recover from suffering negative experiences such as stress and fatigue [4]. ...
Chapter
Heart Rate Variability (HRV) can reflect individuals’ cognitive workload objectively. HRV measurement is a non-invasive method to evaluate relevant physiological changes in a human body. Physiological changes and cognitive processes are associated with the cardiac dynamic autonomic control, and thus to influence individuals’ ability to cope with fatigue and achieve resilience. As a dynamic process to be learned, resilience can be formed and improved through Quick Coherence Training in a short time. To study the regulatory effects of coherence training on Air Traffic Controllers’ (ATCOs) HRV and resilience ability, the HRV parameters of 34 qualified ATCOs before and after Quick Coherence Training (QCT) are collected and analysed by paired T-Test. Also, participants’ HRV at rest are recorded as baseline. The results show that the coherence, mean RR interval, SDNN, and RMSSD after QCT are significantly higher than before. The mean heart rate after QCT is significantly lower than before. The findings demonstrate that coherence has effective and efficient regulatory effects on coherence, mean RR interval, SDNN, mean heart rate, and RMSSD. Psychological coherence training can be an efficient method for ensuring ATCOs recover from fatigue and achieve resilience quickly during the short break in long-time continuing monitoring and controlling. The findings in the current research can have potential to be further developed for Fatigue Risk Management System which is required by ICAO (International Civil Aviation Organization) to be applied for Air Navigation Services providers.
Conference Paper
Safety has always been a significant challenge for aeronautical activities. For many years, dedicated experience feedback tools have been developed and implemented by airlines to assess their operational risks. Improvements have been made in collecting and analysing operational data acquired through several experience feedback channels that may encompass crew reports as well as in flight recorded digital parameters. Nowadays, large commercial airlines store huge amounts of operational data. Each type of experience feedback tool provides a specific point of view on the operational reality. In most of the airlines, the routine operation and the crew reports are both observed and analyzed through distinct channels that produce statistics and trends. Then, the results of analyzes are combined to acquire a global view of the operations. A major breakthrough could be reached by developing methodologies and tools that better reflect the links between the objective elements revealed by aircraft flight data recorders and the explanatory elements (operational conditions, threats, errors...) captured by reports. The challenge is to build a more comprehensive view of the operational context by integrating coordinated and heterogeneous data sources (digital in flight data, reports, demographic, weather...). This new type of analysis could impact the understanding of the operational reality and contribute to manage safety. This article describes a methodology, tools and results that demonstrate the feasibility and the benefit of such a combined analysis.
Article
Full-text available
Fatigue is a common phenomenon in airline pilots that can impair alertness and ability of crewmembers to safely operate an aircraft and perform safety related tasks. Fatigue can increase the risk of an incident or even an accident. This study provides the first prevalence values for clinically significant fatigue in Portuguese airline pilots. The hypothesis that medium/short-haul pilots may currently present different levels of fatigue than long-haul pilots was also tested. A survey was conducted by requesting Portuguese airline pilots to complete questionnaires placed in the pilots' personal lockers from 1 April until 15 May 2012. The questionnaire included the self-response Fatigue Severity Scale (FSS) to measure subjective fatigue and some additional questions concerning perception of fatigue by pilots. The prevalence values for total and mental fatigue achieved in the Portuguese airline pilots were: 89.3% (FSS > or = 4) and 94.1% (FSS > or = 4) when splitting the sample in two subsamples, long- and medium/short-haul pilots. Levels of total and mental fatigue were higher for medium/short-haul pilots. The analysis of fatigue levels in each type of aviator showed that medium/short-haul pilots presented the highest levels of total and mental fatigue. This study produced the first prevalence values of total and mental fatigue among Portuguese airline pilots, which represents a great step to understanding and addressing this critical phenomenon.
Article
The detrimental effects of fatigue in aviation are well established, as evidenced by both the number of fatigue-related mishaps and numerous studies which have found that most pilots experience a deterioration in cognitive performance as well as increased stress during the course of a flight. Further, due to the nature of the average pilot's work schedule, with frequent changes in duty schedule, early morning starts, and extended duty periods, fatigue may be impossible to avoid. Thus, it is critical that fatigue countermeasures be available which can help to combat the often overwhelming effects of sleep loss or sleep disruption. While stimulants such as caffeine are typically effective at maintaining alertness and performance, such countermeasures do nothing to address the actual source of fatigue - insufficient sleep. Consequently, strategic naps are considered an efficacious means of maintaining performance while also reducing the individual's sleep debt. These types of naps have been advocated for pilots in particular, as opportunities to sleep either in the designated rest facilities or on the flight deck may be beneficial in reducing both the performance and alertness impairments associated with fatigue, as well as the subjective feelings of sleepiness. Evidence suggests that strategic naps can reduce subjective feelings of fatigue and improve performance and alertness. Despite some contraindications to implementing strategic naps while on duty, such as sleep inertia experienced upon awakening, both researchers and pilots agree that the benefits associated with these naps far outweigh the potential risks. This article is a literature review detailing both the health and safety concerns of fatigue among commercial pilots as well as benefits and risks associated with strategic napping to alleviate this fatigue.
Article
European regulations restrict the duration of the maximum daily flight duty period for pilots as a function of the duty start time and the number of scheduled flights. However, late duty end times that may include long times awake are not specifically regulated. In this study, fatigue levels in pilots finishing their duty late at night (00:00-01:59 hour) were analysed and compared with pilots starting their duty early (05:00-06:59 hour). Fatigue levels of 40 commercial short-haul pilots were studied during a total of 188 flight duty periods, of which 87 started early and 22 finished late. Pilots used a small handheld computer to maintain a duty and sleep log, and to indicate fatigue levels immediately after each flight. Sleep logs were checked with actigraphy. Pilots on late-finishing flight duty periods were more fatigued at the end of their duty than pilots on early-starting flight duty periods, despite the fact that preceding sleep duration was longer by 1.1 h. Linear mixed-model regression identified time awake as a preeminent factor predicting fatigue. Workload had a minor effect. Pilots on late-finishing flight duty periods were awake longer by an average of 5.5 h (6.6 versus 1.1 h) before commencing their duty than pilots who started early in the morning. Late-finishing flights were associated with long times awake at a time when the circadian system stops promoting alertness, and an increased, previously underestimated fatigue risk. Based on these findings, flight duty limitations should consider not only duty start time, but also the time of the final landing.
Article
This article focuses on an analysis of the strategies used by pilots of the civil aviation in case of an incapacitation during flight. Incapacitation is defined in this research as any situation where the level of available aircrew resources is lower than the required level of resources needed to maintain the optimum performance with common strategies. There are different types of incapacitation depending on their severity and operational consequences. Incapacitations are a contributing factor of several events in aviation. In case of an incapacitation, aircrews use strategies to maintain their performance and manage the overall level of flight safety. This work aims at developing a methodology to perform a risk management of crew incapacitation and to identify crew strategies in order to study the potential to integrate them in the design of future cockpits and pilot's training. This paper deals with the indentification of strategies.
Article
The nature of the current rotating roster, providing 24‐h air traffic services over five irregular shifts, leads to accumulated fatigue which impairs air traffic controllers’ cognitive function and task performance. It is imperative to develop an effective fatigue risk management system to improve aviation safety based upon scientific approaches. Two empirical studies were conducted to address this issue. Study 1 investigated the mixed effect of circadian rhythm disorders and resource depletion on controllers’ accumulated fatigue. Then, study 2 proposed a potential biofeedback solution of quick coherence technique which can mitigate air traffic controllers’ (ATCOs’) fatigue while on controller working position and improve ATCOs’ mental/physical health. The current two‐studies demonstrated a scientific approach to fatigue analysis and fatigue risk mitigation in the air traffic services domain. This research offers insights into the fluctuation of ATCO fatigue levels and the influence of a numbers of factors related to circadian rhythm and resource depletion impact on fatigue levels on study 1; and provides psychophysiological coherence training to increase ATCOs’ fatigue resilience to mitigate negative impacts of fatigue on study 2. Based on these two studies, the authors recommended that an extra short break for air traffic controllers to permit practicing the quick coherence breathing technique for 5 min at the sixth working hour could substantially recharge cognitive resources and increase fatigue resilience. Application: Present studies highlight an effective fatigue intervention based on objective biofeedback to moderate controllers’ accumulated fatigue as a result of rotating shift work. Accordingly, air navigation services providers and regulators can develop fatigue risk management systems based on scientific approaches to improve aviation safety and air traffic controller's wellbeing.
Article
This paper aims to develop a critical approach to flight safety by assessing theoretical and empirical studies on fatigue risk factors in cockpit and cabin crew. This paper also builds a fundamental basis for managing fatigue risk factors in the aviation industry. The main contribution of the paper demonstrates the fact that primary and secondary fatigue risk factors in cockpit and cabin crew affect the level of job satisfaction, operational efficiency, and flight security.
Article
Full-text available
The impact of hours of work on employees’ health and safety is a critical issue given the increasing use of abnormal hours of work in a number of industries, services or transports. The prevention of fatigue associated with these hours of work is most often based on regulatory approaches that rule the duty time limitations and minimum rest time. These prescriptive approaches have several caveats, including for employees’ fatigue. This article presents an alternative for managing the risk of fatigue as close as possible to specific work constraints. The general principle of these fatigue risk management systems is presented and illustrated by a few examples. Their main limitations are also discussed.
Article
Fatigue is a physiological state of reduced performance capability resulting from sleep loss or extended wakefulness, circadian phase, or workload (mental and/or physical activity) that can impair a transport worker’s alertness and ability to work safely. Fatigue is affected by all waking activities, not only those that are work related. Consequently, fatigue management must be a shared responsibility of regulators, employers, and employees. Prescriptive hours-of-service limits, the traditional regulatory approach for managing fatigue, are increasingly being challenged with regard to their effectiveness in delivering safety and their cost to industry. Fatigue risk management systems (FRMSs) are a new regulatory approach that combines advances in the understanding of worker fatigue and accident causation with advances in safety management. FRMSs are data driven, are based on combined scientific and operational expertise, and include processes for monitoring their safety performance and for continuous improvement. Prescriptive hours-of-work limits are familiar and are arguably adequate in circumstances where fatigue-related safety risk is low. On the other hand, economic pressures are expected to continue to push transport companies to maximize use of vehicles/locomotives/vessels/aircraft with minimum safe manning levels. These pressures will drive the need for more tailored and flexible approaches to fatigue management, such as FRMSs.
Article
Full-text available
Fatigue is an inevitable hazard in the provision of air traffic services and it has the potential to degrade human performance leading to occurrences. The International Civil Aviation Organization (ICAO) requires air navigation services which providers establish fatigue risk management systems (FRMS) based on scientific principles for the purpose of managing fatigue. To develop effective FRMSs, it is important to investigate the relationship between traffic volume, air traffic management occurrences, and fatigue. Fifty-seven qualified ATCOs from a European Air Navigation Services provider participated in this research by providing data indicating their alertness levels over the course of a 24-hour period. ATCOs' fatigue data were compared against the total of 153 occurrences and 962,328 air traffic volumes from the Eurocontrol TOKAI incident database in 2019. The result demonstrated that ATCO fatigue levels are not the main contributory factor associated with air traffic management occurrences, although fatigue did impact ATCOs' performance. High traffic volume increases ATCO cognitive task load that can surpass available attention resources leading to occurrences. Furthermore, human resilience drives ATCOs to maintain operational safety though they suffer from circadian fatigue. Consequently, FRMS appropriately implemented can be used to mitigate the effects of fatigue. First-line countermeasure strategies should focus on enough rest breaks and roster schedule optimization; secondary strategies should focus on monitoring ATCOs' task loads that may induce fatigue. It is vital to consider traffic volume and ATCOs' alertness levels when implementing effective fatigue risk management protocols.
Article
Fatigue as an emerging flight safety issue in the aviation industry requires an elaborate understanding and critical approach for proactive aviation management practices. The level of flight crew stress and fatigue must be critically managed to prevent flight accidents. Additionally, stress and fatigue have a negative influence on job satisfaction levels. This paper aims to examine the critical fatigue risk factors that affect the performance and safety of airline pilots and crew in the aviation industry. This paper also analyses the relationship between burnout and job satisfaction sub-dimensions. A factor analysis with a target population of 254 international flight crew has been conducted using the Minnesota Job Satisfaction Survey and Maslach Burnout questionnaire. The main findings of the study demonstrate that (i) cockpit and cabin crews’ job satisfaction and performance have been affected by stress and fatigue, (ii) psychological depression, anxiety and personal problems of the flight crew are the main causes of emotional fatigue, (iii) extensive flight hours and dealing with problematic passengers increase flight crew fatigue, (iv) personal achievements concerns and depersonalization increase flight crew fatigue.
Conference Paper
This paper presents a safety risk management model based on possibility theory to adapt and develop the Safety Management System (SMS) in airline operation control. Fuzzy sets are used to represent the key elements among crew, meteorology, weight and balance, dispatch, coordinate, and systematic operation control by risk indicators. A fuzzy integrated judgment model is also proposed, which would quantity both the possibility and necessity of the safety space. The implications of this strategy for practitioners and future work are discussed.
Article
Full-text available
The paper discusses previous studies on the effect of fatigue among flight crews and their effect on airline businesses. Fatigue is a major concern in flight operations as many reports were issued on this problem among flight crew. The long flight duration requires them to travel several time zones, which leads to fatigue. Furthermore, the change of time zones could also lead to the occurrence of jet lag and subsequently causes fatigue too. Fatigue can occur during and after the travelling period, and it takes a while to recover from it. This study aims to observe the effects of fatigue experienced by flight crew. The results show that fatigue causes many health problems such as an increase in cancer risk, depression, mental illness and miscarriage. Additionally, fatigue reduces one's work productivity as working in a tired state reduces work performance. Furthermore, fatigue also leads to other problems such as anger, anxiety, stress and job dissatisfaction. With the studies conducted on the issue of fatigue, airlines should take appropriate actions to minimise or solve the problem to ensure that fatigue problem will not affect flight crew performance and the airline business.
Article
Objective: In this study, the aircrew rostering problem is evaluated in conjunction with fatigue factors. Background: In the mathematical models developed for crew rostering problems, the fatigue level of aircrew members is evaluated only within the scope of the flight and duty time limitations defined by the civil aviation authorities. In this study, a new model is developed in which the fatigue risk factors such as the number of flight legs, additional workload, circadian rhythm, and consecutive flights are added to the crew rostering problem. Method: A linear mathematical programming model was developed for the aircrew rostering problem. The General Algebraic Modeling System (GAMS) is used in the solution of the model. The problem is solved and the effects of the fatigue risk factors on crew rostering problems are examined by using the weekly and monthly real flight data of a Turkish air carrier. The results obtained are demonstrated in Gantt charts. Results: Although the results obtained are within the limits of flight and duty time defined by civil aviation authorities, it is found that many flight duties exceed the limits considering the fatigue risk factors. Conclusion: The model proposed can be used to minimize human error, predict the fatigue risk in various duties, and increase productivity and safety.
Article
An internal hernia is defined as the protrusion of visceral content, most commonly the small bowel, through a normal or abnormal peritoneal or mesenteric aperture within the abdominal cavity and the pelvis. An internal hernia may either be congenital or acquired in aetiology. These hernias can trap and/or twist small bowel, resulting in bowel obstruction. We herein describe an extremely rare case of a young female who presented with small bowel obstruction secondary to an incarcerated internal hernia caused by a peritoneal defect in the pouch of Douglas.
Article
Full-text available
Objectives: This paper aims to estimate the level of acute fatigue, chronic fatigue and intershift recovery among doctors working at public hospitals in Malaysia and determine their inter-relationship and their association with work-related activities during non-work time. Design: Cross-sectional. Setting: Seven core clinical disciplines from seven tertiary public hospitals in Malaysia. Participants: Study was conducted among 330 randomly-sampled doctors. Response rate was 80.61% (n=266). Results: The mean score of acute fatigue, chronic fatigue and intershift recovery were 68.51 (SD=16.549), 54.60 (SD=21.259) and 37.29 (SD=19.540), respectively. All these scores were out of 100 points each. Acute and chronic fatigue were correlated (r=0.663), and both were negatively correlated with intershift recovery (r=-0.704 and r=-0.670, respectively). Among the work-related activities done during non-work time, work-related ruminations dominated both the more frequent activities and the association with poorer fatigue and recovery outcomes. Rumination on being scolded/violated was found to be positively associated with both acute fatigue (adjusted regression coefficient (Adj.b)=2.190, 95% CI=1.139 to 3.240) and chronic fatigue (Adj.b=5.089, 95% CI=3.876 to 6.303), and negatively associated with recovery (Adj.b=-3.316, 95% CI=-4.516 to -2.117). Doing work task at workplace or attending extra work-related activities such as locum and attending training were found to have negative associations with fatigue and positive associations with recovery. Nevertheless, doing work-related activities at home was positively associated with acute fatigue. In terms of communication, it was found that face-to-face conversation with partner did associate with higher recovery but virtual conversation with partner associated with higher acute fatigue and lower recovery. Conclusions: Work-related ruminations during non-work time were common and associated with poor fatigue and recovery outcomes while overt work activities done at workplace during non-work time were associated with better fatigue and recovery levels. There is a need for future studies with design that allow causal inference to address these relationships.
Thesis
Full-text available
Computer work, as a prevalent occupation, involves different levels of mental load and fatigue with possible negative health effects. The population aging has also led to increased elderly workers highlighting the need for protective measures.Mental load and fatigue are multidimensional psychophysiological phenomena. Inefficient work routines accelerate fatigue development, associated with declined cognitive resources and increased errors. Micro-breaks are strategic solutions to counteract fatigue subject to design constraints, e.g. timing plan. Eye tracking is a promising technology for the quantification of mental load and fatigue levels. The oculometrics were aimed to be studied in association with age, mental load and fatigue, allowing early detection of fatigue, and thereby applying biologically-valid micro-breaks to decelerate fatigue development.Upon this, three Studies (I-III) involving 58 young and elderly individuals were conducted. A task, resembling computer work, was developed to induce mental load. Gaze positions and pupillary responses were recorded during the task execution to detect ocular events (saccades, fixations, and blinks), and thereby computing oculometrics e.g. fixation duration. In Study I, the task was performed on three load levels in a counterbalanced order across two days. Between-day reliability and mental-load sensitivity of 19 oculometrics were assessed, besides measuring performance and perceived workload. In Study II, fatigue development was explored in oculometrics during 40-min performance of the task while subjective fatigue and performance metrics were obtained. A predictive model of fatigue was developed in Study III based on the ocular data collected in Study II. An oculometrics-based biofeedback system was implemented in real time to detect fatigue using the developed model, which triggered micro-breaks upon fatigue detections to counteract it during the task. The optimality of the system was compared with self-triggering micro-breaks in terms of fatigue trends and workload.A group of oculometrics was sensitive and reliable to reflect mental load and fatigue in the young and elderly individuals. Similar trends in the oculometrics were observed with increased mental load and fatigue levels, implying shared neural systems for both conditions. Although age-related differences were exhibited in some oculometrics, age did not directly contribute to the predictive model of fatigue. The oculometrics-based biofeedback provided an improved solution for timing plan of micro-breaks in reducing workload and fatigue development compared with self-triggering micro-breaks. The oculometrics-biofeedback system made a benchmark towards productive and healthy computer work.
Article
Background: Establishing practical solutions to manage fatigue in health care settings could reduce errors. Predictive Safety SRP Inc.'s AlertMeter is a 2-min cognitive assessment tool currently used in high-hazard industries to identify fatigued staff. Objective: No prior study has attempted to address fatigue in emergency medicine (EM). We objectively assessed provider alertness to determine potential application of software-based fatigue recognition for risk reduction. Methods: In a double-blind, prospective evaluation from July 1 to September 30, 2016, we applied the AlertMeter to EM residents at an academic level I trauma center. The tool was applied before and after shifts to evaluate alertness in three types of shifts: day, evening, and night. All residents were invited to participate-27 of 30 enrolled. Analysis of covariance (ANCOVA) was implemented to examine shift and completion effects on alertness score using baseline score as a covariate. Additionally, three separate ANCOVAs were conducted to examine alertness score differences between portion (start vs. end) and type of shift (day, evening, or night). Results: Residents were significantly less alert at the completion of the evening shift. Scores at the end of the night shift were significantly lower than the start of the night shift. Conclusions: Alertness software can be reliably integrated into the emergency department. Alertness was lower at the end of the evening shift and end of the night shift. This work could have positive implications on shift and task scheduling and potentially reduce errors in patient care by quantifying providers' fatigue and identifying areas for countermeasures.
Article
Full-text available
This paper is concerned with whether transport accident risk tends to peak at particular times, in relation to both time of day and time on task, and with the underlying causes of such peaks. Macro-analyses confirmed the presence of a clear circadian (ca 24 hour) rhythm in road accident risk with a major peak at ca 03:00 but suggested that this rhythm could not be entirely accounted for in terms of drivers falling asleep at the wheel. Sleep propensity clearly shows a pronounced circadian rhythm and performance efficiency in wakeful subjects shows a similar trend implying that the 03:00 road accident peak may simply reflect lowered performance capabilities. However, there are 'residual' peaks in accidents at certain times of day that are difficult to account for in terms of circadian rhythmicity. It is suggested that these may reflect a time on task effect which shows a pronounced, but transient, 2-4 hour peak in risk. Only when individuals had been on duty for 12 hours or more did the risk exceed that found during the 2-4 hour peak. While an explanation for this transient peak is offered, the underlying reason for it is, as yet, uncertain and clearly warrants investigation in view of its practical implications. It is concluded that there are 'black times' when accidents are far more likely and that there is a strong need to investigate possible countermeasures.
Article
Question of the Study The computer model SAFE (System for Aircrew Fatigue Evaluation) was used as part of a procedure for evaluating the crewing requirements for the new generation of ultra-long-range-aircraft. The specific requirement was to establish guidelines for the Singapore–Los Angeles–Singapore route before the aircraft came into service. Methods The work was carried out in three phases. In Phase I, predictions of levels of alertness for a crew of four were obtained using a range of assumptions related to the timing of duty and the allocation of rest. Phase II was a validation study based on current operations. In Phase III, initial flights with the new aircraft were monitored and alertness levels were compared with the predictions. Results The predictions in Phase I suggested that levels of fatigue on the operations would remain below those in many existing operations, as long as all crews were allowed two inflight rest periods. The validation study gave general support to the model predictions, and these were confirmed by the initial reports from the new operation. Conclusions This work demonstrates that an alertness model can play a useful role in the assessment of the acceptability of future operations.
Article
In recent years, theoretical models of the sleep and circadian system developed in laboratory settings have been adapted to predict fatigue and, by inference, performance. This is typically done using the timing of prior sleep and waking or working hours as the primary input and the time course of the predicted variables as the primary output. The aim of these models is to provide employers, unions and regulators with quantitative information on the likely average level of fatigue, or risk, associated with a given pattern of work and sleep with the goal of better managing the risk of fatigue-related errors and accidents/incidents. The first part of this review summarises the variables known to influence workplace fatigue and draws attention to the considerable variability attributable to individual and task variables not included in current models. The second part reviews the current fatigue models described in the scientific and technical literature and classifies them according to whether they predict fatigue directly by using the timing of prior sleep and wake (one-step models) or indirectly by using work schedules to infer an average sleep-wake pattern that is then used to predict fatigue (two-step models). The third part of the review looks at the current use of fatigue models in field settings by organizations and regulators. Given their limitations it is suggested that the current generation of models may be appropriate for use as one element in a fatigue risk management system. The final section of the review looks at the future of these models and recommends a standardised approach for their use as an element of the 'defenses-in-depth' approach to fatigue risk management.
Article
Eight subjects were kept awake and active overnight in a sleep lab isolated from environmental time cues. Ambulatory EEG and EOG were continuously recorded and sleepiness ratings carried out every two hours as was a short EEG test session with eyes open for 5 min and closed for 2 min. The EEG was subjected to spectral analysis and the EOG was visually scored for slow rolling eye movements (SEM). Intrusions of SEM and of alpha and theta power density during waking, open-eyed activity strongly differentiated between high and low subjective sleepiness (the differentiation was poorer for closed eyes) and the mean intraindividual correlations between subjective and objective sleepiness were very high. Still, the covariation was curvilinear; physiological indices of sleepiness did not occur reliably until subjective perceptions fell between "sleepy" and "extremely sleepy-fighting sleep"; i.e. physiological changes due to sleepiness are not likely to occur until extreme sleepiness is encountered. The results support the notion that ambulatory EEG/EOG changes may be used to quantify sleepiness.
Article
Since 1995, air transport operators in New Zealand have been able to meet the flight and duty time (FDT) regulations by operating according to prescriptive FDT limits or by seeking approval to operate under a potentially more flexible company-specific FDT scheme. There has been no formal assessment of the impact of this increased flexibility on fatigue management processes. The aim of the present study was to determine the strategies and processes that commercial aircraft operators in New Zealand have in place for managing fatigue and whether these differed according to the type of FDT system under which organizations were operating. All air transport operators in New Zealand were sent questionnaires that were to be completed by an individual in a management role, a line pilot, and an individual in a rostering role. Questions were asked about the FDT system under which the organization operated, the strategies and processes in place for managing fatigue, and the consequences of the organization's approach to managing fatigue. One hundred and fifty-three responses were received from 88 organizations (55% of all air operators) and were representative of the structure of the New Zealand industry. Air operators were most likely to report that they monitored flight and duty times and pilot workload to manage fatigue (used by 90-99% and 70-90%, respectively), while educating rostering staff and reviewing the processes for managing fatigue were the least utilized strategies (used by 36-50% and 39-60%, respectively). Within the same organization, managers were more likely than line pilots to report the use of specific fatigue management strategies. There were no differences found between organizations operating under prescriptive regulations and those using a company-specific scheme on ratings of how well fatigue was managed, the number of fatigue management strategies employed, or the frequency of use of selected strategies. Across the industry as a whole, the provision of more flexible regulatory options has not greatly changed fatigue management practices, although some operators have implemented innovative strategies. The findings suggest a need to raise the level of knowledge within the industry regarding the causes and consequences of fatigue and of processes for its management. This is further supported by the discrepancies between the responses of line pilots and managers, which raise doubts about the effectiveness of some strategies nominally being employed. The regulator and other relevant industry groups should consider how to move the industry toward a mature safety culture and solid knowledge base because these are fundamental to more flexible fatigue management regimes, as is adequate regulatory knowledge, support, and oversight.
Article
Biomathematical models that quantify the effects of circadian and sleep/wake processes on the regulation of alertness and performance have been developed in an effort to predict the magnitude and timing of fatigue-related responses in a variety of contexts (e.g., transmeridian travel, sustained operations, shift work). This paper summarizes key features of seven biomathematical models reviewed as part of the Fatigue and Performance Modeling Workshop held in Seattle, WA, on June 13-14, 2002. The Workshop was jointly sponsored by the National Aeronautics and Space Administration, U.S. Department of Defense, U.S. Army Medical Research and Materiel Command, Office of Naval Research, Air Force Office of Scientific Research, and U.S. Department of Transportation. An invitation was sent to developers of seven biomathematical models that were commonly cited in scientific literature and/or supported by government funding. On acceptance of the invitation to attend the Workshop, developers were asked to complete a survey of the goals, capabilities, inputs, and outputs of their biomathematical models of alertness and performance. Data from the completed surveys were summarized and juxtaposed to provide a framework for comparing features of the seven models. Survey responses revealed that models varied greatly relative to their reported goals and capabilities. While all modelers reported that circadian factors were key components of their capabilities, they differed markedly with regard to the roles of sleep and work times as input factors for prediction: four of the seven models had work time as their sole input variable(s), while the other three models relied on various aspects of sleep timing for model input. Models also differed relative to outputs: five sought to predict results from laboratory experiments, field, and operational data, while two models were developed without regard to predicting laboratory experimental results. All modelers provided published papers describing their models, with three of the models being proprietary. Although all models appear to have been fundamentally influenced by the two-process model of sleep regulation by Borbély, there is considerable diversity among them in the number and type of input and output variables, and their stated goals and capabilities.
Fatigue Risk Management System within SMS
  • C Graeber
Graeber, C., 2008. Fatigue Risk Management System within SMS. In: Proceedings of the Aviation Fatigue Management Symposium -Partnership for Solutions, Tysons Corner.
A critical review of current fatigue and performance models and their use
  • D Dawson
Dawson, D., 2009. A critical review of current fatigue and performance models and their use. In: Proceedings of the 2009 International Conference on Fatigue Management in Transportation Operations, Boston.
Flight crew scheduling based on fatigue risk guidance
  • T Klemets
  • E Romig
Klemets, T., Romig, E., 2009. Flight crew scheduling based on fatigue risk guidance. In: Proceedings of the 2009 International Conference on Fatigue Management in Transportation Operations, Boston.