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Showing 10 results for Workload

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Volume 2, Issue 3 (12-2012)
Abstract

Introduction: Train driving is a high responsibility job in railway industry. Train drivers need different cognitive functions such as vigilance, object detection, memory, planning, decision-making. High level of fatigue is one of the caused factor of accidents among train drivers. Numerous factors can impact train drivers’ fatigue but high level of workload is a key factor. Therefore, the aim of the present study was to investigate workload and its relationship with fatigue among train drivers in Keshesh section of Iranian Railway Company.

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Material and Method: This descriptive analytical study was done among 100 train drivers in Keshesh section of Iranian Railway industry. They were selected by simple random sampling. The NASA-TLX workload scale and Samn-Perelli fatigue scale were respectively used to investigate workload and fatigue. Data were analyzed by Paired t-test and Spearman correlation coefficient.

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Result: According to the NASA-TLX results, effort and mental workload with the mean score of 74/22 and 73/31 were respectively the most important attributes of workload among train drivers. No significant relationship was observed between workload and level of fatigue before departure and half an hour before reaching the destination station (P>0.05). However, the relationship between of workload and level of fatigue half an hour before the end of shift (on the way back to the origin station) was statistically significant (P=0.048) among the sample population.

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Conclusion: Effort and mental workload were the most important attributes of workload among train drivers. By focusing on these two variables and adopting fatigue management programs, fatigue and workload can be controlled and the efficiency of the whole system can be enhanced accordingly.


Arsalan Yousef Zade, Adel Mazloumi, Milad Abbasi, Arash Akbar Zade ,
Volume 6, Issue 2 (6-2016)
Abstract

Introduction: High level of workload and its consequent cognitive failures are among factors which impact nurses’ behavior, performance, and efficiency. This study aimed to investigate the relationship between nurses’ cognitive failures and perceived workload.

Material and Method: This cross-sectional and descriptive-analytical study was carried out among 150 male and female nurses, working in different units of Emam Khomeini and Vali-e-Asr hospitals in Tehran in 2013. NASA task load index (NASA-TlX) and Cognitive Failure Questionnaire (CFQ) were used to assess workload and cognitive failures, respectively. Data were analyzed using Pearson Correlation, Independent sample t-test, and one-way ANOVA statistical tests with SPSS software version 20.

Result: Pearson and Spearman correlation coefficients test results showed a significant relationship between nurses’ mental workload and their memory for names (P-value<0.001). Moreover, there was significant association between physical workload and memory, attention and total cognitive failures (CFQ total) (P-value<0.05). Perceived frustration mong nurses was significantly correlated with memory, attention, motor functions and total cognitive failures (P-value<0.05).

Conclusion: The results showed a high level of workload among study nurses. Furthermore, the relationships between some dimensions of mental workload and cognitive failures were confirmed, so that an increase in workload dimension can lead to more cognitive failures while doing task.


Narmin Hassanzadeh-Rangi, Yahya Khosravi, Ali Asghar Farshad, Hamed Jalilian,
Volume 7, Issue 1 (4-2017)
Abstract

Introduction: Metro driving is one of the newest jobs in Iran. There are few studies in this field. Therefore, the physical workload and their influencing factors have not been identified in metro driving. The objective of this study was task and physical workload analysis of metro driving to recommend control measures.  

Material and Method: In this mixed method study, task analysis and Quick Exposure Check (QEC) were used to assessment of physical workload in metro driving. Different methods and techniques including field investigation, document reviews, individual and focus group interviews, and focus group discussions were used to analysis physical workload to recommend control measures.   

Result: Whole body exposure with physical workload was assessed unacceptable in metro driving. Although the exposures in back, shoulder/arm and hand/wrist were under threshold 70%, neck exposure lead to over physical workload in the whole body. Many themes include unsupported body; non-sufficient view on the track and on displays; awkward posture and unsuitable layout were extracted as significant factors influencing on physical workload.

Conclusion: An intervention plan was recommended to a) support body by chair, platform and footplate; b) optimize a sufficient view on the track and on displays; c) maintain body postures in seating position with easy reaching distance and sufficient view; and d) design a suitable layout for driving panel regarding to controls, keys and displays.


Asma Zare, Mahdi Malakouti Khah, Ehsan Garosi, Seifollah Gharib, Sayed Abolfazl Zakerian,
Volume 8, Issue 3 (9-2018)
Abstract

Introduction: Control room is one of the most important working environments that require optimal performance of individuals to minimize errors. Lighting is one of the environmental factors affecting the operation of the control room operators. Providing optimal lighting in the control room is very important. The purpose of this study was to determine the effect of light on workload, sleepiness, eye fatigue, and satisfaction of individuals from light conditions.

Material and Method: This was an interventional study conducted in a control room of a power plant. Intervention in the control room lighting was performed with two lighting systems including fluorescent lamps (4000 Kelvin, 200 lux) and LED lamps (4,000 Kelvin, 400 lux). Sixteen operators were evaluated under the two lighting systems in terms of workload, sleepiness, eye fatigue and satisfaction of individuals from light conditions.

Result: According to the results, eye fatigue significantly decreased after intervention (p (0.004>. Also, the higher light intensity, significantly decreased the level of sleepiness (p <0.001). In the study of workload, the amount of mental workload (p <0.001) and effort (p <0.03) decreased significantly, after intervention and the increase in the intensity of light; but physical demand, temporal demand, performance and frustration had no significant difference with the results before intervention.

Conclusion: In general, a combination of fluorescent and LED lighting systems, with 400 lux intensity, can provide optimal functional and mental conditions for control room operators. The illumination intensity of 400 lux in terms of workload, sleepiness, eye fatigue and the degree of satisfaction of individuals from light conditions provides a much better environmental condition than 200 lux.


Mohammad-Javad Jafari, Narmin Hassanzadeh-Rangi, Yahya Khosravi, Soheila Khodakarim,
Volume 8, Issue 4 (12-2018)
Abstract

Introduction: Driving a train is one of the high demand job due to high vigilance task requiring the ability to long periods monitor surrounding environment and recognizing signals. The aim of this study was to assess train drivers’ mental workload using heart rate (HR) and heart rate variability (HRV) indices.
Material and Method: An experimental design was conducted among 12 well-trained subjects to induce two different levels of mental demands in a metro simulator and to monitor mental workload levels while driving the train. The HR and HRV parameters were recorded and analysis using ECG signals.
Result: The HRV parameters including SDNNIX (p-value=0.01), RMSSD (p-value=0.00), %PNN50 (p-value=0.01), SDNN (p-value=0.07) and LF/HF Ratio (p-value=0.04) were significantly reduced in a normal operation task comparing to the abnormal one.
Conclusion: The HR and HRV (SDNN, SDNNIX, RMSSD, %PNN50 and LF/HF Ratio) were found to be sensitive to mental workload in metro train driving .It is recommended to include the HRV parameters for mental workload assessment of train drivers.
Aysa Ghasemi Koozekonan, Vahid Ahmadi Moshiran, Mohsen Sadeghi Yarandi, Hamedeh Golmohammapour, Babak Sarbaz, Seyed Abolfazl Zakerian,
Volume 11, Issue 3 (9-2021)
Abstract

Introduction: One of the most important factors affecting quality of work-life (QWL) is the workload in the form of mental and physical. The increased workload may reduce the level of performance of workers. Therefore, the present study aimed to evaluate the relation of the mental and physicalworkload with the QWLof workers in the foundry industry.
Material and Methods: This cross-sectional study was conducted on 218 male workers in a foundry industry and the work units with high work stress were selected. The NASA-TLX, physical load and the Walton questionnaires were used to collect and evaluate the workload and the QWL.The SPSS software was used for data analysis.
Results: It was clarified that there was a significant inverse relationship between QWL with physical load (P = 0.001) and mental workload (P = 0.01). The comparison of mean QWL between different groups of demographic variables showed that the only significant relationship was between different age groups and QWL (P = 0.003). Finally, it was found that the variables of physical load, mental workload and age had a significant simultaneous effect on the mean score of QWL (P<0.05).
Conclusion: The findings showed that there was a significant relationship between QWL and mental and physical workloads.
Tahereh Pourtalemi, Abdolhossein Emami Sigaroudi, Mahmoud Heidari, Nasrin Mokhtari Laleh, Ehsan Kazem Negzhad Leyli,
Volume 13, Issue 1 (3-2023)
Abstract

Introduction: Nurses are under the influence of stressful factors and high work pressure, which increases nursing errors. One factor affecting nurses’ behavior and performance is the mental workload and cognitive failures. This research has investigated the mental workload and cognitive failures in two groups of nurses with and without unsafe behaviors during the outbreak of Covid-19.
Material and Methods: This case-control study was conducted on 312 nurses during the severe period of the Covid-19 outbreak through the public hospitals in Guilan province. Sampling was performed by selecting 104 nurses in the case group (with unsafe behavior) and 208 nurses in the control group (with safe behavior) using the full count method. The data collection tool is a three-part questionnaire including demographic information, the mental workload (NASA-TLX) questionnaire, and the occupational cognitive failures questionnaire. The incidence of needle stick as a consequence of unsafe behavior was used as a criterion.
Results: The results have shown that the workload in this research was 63.96±18.26, and the total score of cognitive failures was 59.1±13.9. There was no statistically significant difference between the two groups of nurses with and without unsafe behaviors (P>0.05). Still, there was a significant correlation between the total mental workload score in all areas and the total score of cognitive failures in the group of nurses with and without unsafe behaviors (p=0.001, r=0.225).
Conclusion: According to the results, the perceived mental workload is high for the nursing job. Despite of positive correlation between mental workload and cognitive failures, it can be mentioned that there are two-way interactions through their dimensions. Therefore, the nursing job requires adopting optimal engineering and management strategies to reduce the workload.
Marzieh Izadi Laybidi , Adel Mazloumi , Jebraeil Nasl Saraji, Faramarz Gharagozlou, Amir Homayoun Jafari, Zahra Shirzhiyan, Kamal Azam ,
Volume 13, Issue 3 (9-2023)
Abstract

Introduction: Air traffic control is a very complex process, including multiple human-machine interactions. Human mental workload plays an important role in this process. Nowadays, electroencephalography indexes are considered as new indicators in the field of assessment of mental workload. The purpose of the present study was to investigate the relationship between EEG theta power and mental workload in air traffic control simulation.
Material and Methods: Fourteen air traffic controllers participated in this study. Controllers carried out two scenarios, including low and high workload, based on task load factors in an air traffic control simulator. Mental workload was assessed in these two scenarios by the NASA-TLX questionnaire. EEG signals were continuously recorded during air traffic control tasks. Afterward, absolute theta power was extracted from participants’ EEG using Fast Fourier Transform (FFT) by the MATLAB software and was compared with each other in terms of high and low workload.
Results: The results showed a significant relationship in absolute theta power during low and high workload scenarios in all regions of the brain (p < 0.05). Absolute theta power increased primarily in the frontal region during the high workload scenario. Also, there was a significant increase in the relationship between work experience and absolute theta power at the F3 region during the high workload scenario (P=0.021, r=0.607).
Conclusion: Absolute theta power provides a good parameter to assess mental workload at different levels of air traffic control tasks. Therefore, it can be used as a tool for the design of human-machine complex systems.
Seyvan Sobhani, Mohammad Sharif Hosseini, Sara Tabanfar,
Volume 13, Issue 3 (9-2023)
Abstract

Introduction: Nurses’ high workload may affect their ability to work, cause health problems, and reduce nurses’ quality of life. Considering the important role of nurses in society’s health, it is important to identify the factors affecting their physical and mental health. The current study investigates and correlates nurses’ workload, quality of life, workability, and contextual variables.
Material and Methods: In this descriptive-analytical and cross-sectional study, 142 subjects from the ICU, CCU, emergency department, and other departments of Qazvin educational-therapeutic hospital participated. Data collection tools included a demographic information questionnaire, NASA-TLX (Task Load Index), Short Form Health Survey (SF-36), and work ability index (WAI). Data were analyzed with an independent t-test, Pearson’s correlation coefficient, and a one-way ANOVA test.
Results: The mean and standard deviation of nurses’ age and work experience were 31.3±6.1 and 7.6±5.8, respectively. The mean and standard deviation of nurses’ workload score, quality of life, and workability were 80.4±13.4, 55.5±18.7, and 31.8±7.3, respectively. According to the results, nurses’ workload had a significant relationship with quality of life (P-value=0.001) and workability (P-value=0.000). Significant relationships were also observed between quality of life and workability (P-value=0.001). Quality of life had a significant negative correlation with age, work experience, and the number of nurses’ shifts per month (P-value<0.05). Nurses with higher education had lower workload and higher workability.
Conclusion: Nurses working in ICU and CCU units had a higher workload. Nurses with higher education levels had less workload and more ability to work. There was an inverse correlation between workload quality of life and nurses’ workability. It is possible to reduce nurses’ workload by reducing their tasks and working hours.
Rohollah Fallah Madvari, Reyhaneh Sefidkar, Reza Raeisi, Gholamhossein Halvani, Reza Jafari Nodoushan,
Volume 14, Issue 2 (6-2024)
Abstract

Introduction: Considering the abundance and the large number of workers employed in micro and small industrial workshops in Iran and the importance of workers’ health, the present study aimed to investigate the mediating role of chronic fatigue in the relationship between mental workload and work ability with cognitive failure using path analysis.
Material and Methods: This study was conducted using a cross-sectional design on a sample of workers employed in micro and small industrial workshops in the city of Eghlid. Data were collected utilizing various measures, including demographic and occupational information questionnaires, the NASA Task Load Index (NASA-TLX), the Work Ability Index (WAI), and questionnaires for chronic fatigue and cognitive failure. The correlation test and path analysis modeling were used in SPSS (version 24) and AMOS softwares to investigate the relationship between variables.
Results: The mean scores of mental workload, work ability, chronic fatigue, and cognitive failure  
were 69.63, 35.20, 15.58, and 53.30, respectively. The values of the goodness of fit indices lead to  
the confirmation of the conceptual model by the research data. Also, based on the findings of the path analysis, the current research model has a good fit (CFI=1.00, GFI=0.998, NFI=0.999, AGFI=0.98 and RMSEA=0.003(0.00,0.169)).
Conclusion: The path analysis results indicate that chronic fatigue plays a significant mediating role  
in the relationship between mental workload and work ability with cognitive failure. A better understanding of the mediating mechanisms and complex effects of these relationships can contribute to improving the management of chronic fatigue and enhancing cognitive performance in the workplace.
 

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