Iranian Journal of Ergonomics

Identification and Evaluation of Human Errors in Locomotive Maneuvers Using the SHERPA Technique: A Case Study in a Rail Operation Repair and Development Project

Samira Ghiyasi

Background and Objectives: ِِDespite complex technologies in many work environments, human errors are of great importance as they might lead to severe and catastrophic accidents. Therefore, in order to prevent and limit the consequences of human error, it seems necessary to identify and find the causes of them. The aim of this study was to identify and evaluate the human errors of locomotive maneuvers in the railway repair and development project, 2019.
Methods: In this cross-sectional study, the identification and evaluation of human errors in locomotive maneuvers in the MAPNA railway repair and development project using SHERPA technique was done. First, using the hierarchical task analysis method, the activities of the maneuvers are divided into their tasks and sub-tasks; in the next step, the types of human errors in each of the tasks were identified and then human errors were evaluated according to SHERPA instruction.
Results: A total of 206 errors were identified in the present study. Errors included 48.5% action error, 39.8% checking error, 10.2% information communication error and 1.5% selection error. The lowest and highest errors related to locomotive displacement error were related to hot single diesel (14.0%) and locomotive displacement error on service pit (29.6%). Of the identified errors, 23.8% had an unacceptable risk level, 51.1% had an ALARP risk level and 25.2% had an acceptable risk level.
Conclusion: The findings of the study indicated that the most unacceptable risks and ALARP were related to checking and action error, respectively. So, it is suggested that the design and implementation of control measures related to these two types of errors should be prioritized.

The Relationship Between Working Posture and Anthropometric Compatibility with Workstations: A Case Study Among Sewing Operators

Mostafa Rahmiani-IranShahi

Background and Objectives: Designing workstations in accordance with anthropometric characteristics of employees can prevent awkward working postures and reduce the risk of such disorders. The present study aimed at investigating the anthropometric compatibility of workstations in a sewing company and its relationship with working postures.
Methods: This cross-sectional study was conducted in a sewing company located in Hamadan province, Iran. Working postures were assessed in standing and sitting workstations using REBA and NERPA techniques, respectively. Anthropometric dimensions were measured in accordance with ISO 7250 and anthropometric compatibility with workstation was investigated. Mann-Whitney test was used for assessing the relationship between anthropometric compatibility and working posture.
Results: A total of 205 employees with a mean age 31.29 years participated in this study. Working postures were mostly in an unacceptable condition and the need for ergonomic intervention was evident. In sitting workstation, there was no significant relationship between working postures and anthropometric compatibility in terms of seat depth, seat width, and backrest height. In contrast, anthropometric compatibility with seat height and desk height were significantly associated with working posture (P<0.05). In standing workstations, a significant relationship was observed between anthropometric compatibility and desk height (P<0.05).
Conclusion: Anthropometric incompatibility with workstation generally deteriorated the working postures. However, anthropometric compatibility with seat height and desk height were the ones with a significant relationship with working posture. Therefore, for redesigning workstations the seat height and desk height should be considered first.

Predictive Analysis of Cognitive Errors of Control Room Operators: a Case Study in a Petrochemical Industry

Gholam Abbas Shirali

Background and Objectives: In recent decades, several major accidents have occurred in high-reliability industries such as petrochemical companies. Accident analysis shows that the occurrence of more than 90% of accidents in industries are due to human factor and only with technical-engineering measures and the establishment of safety rules and regulations can not be institutionalized safe behaviors in such industries. Therefore, despite a slight reduction in human presence in these industries, the potential for human error risks is still high. The aim of this study was to identify and assess human errors in a petrochemical plant using the technique for the retrospective and predictive analysis of cognitive errors (TRACEr).
Methods: The sample size was all the eight operators of control room working in four shifts. In the first step, all tasks were analyzed using the hierarchical task analysis in order to identify sub-tasks. Then, for all the subtasks, different error modes (external and internal), psychological error mechanism (PEM) and performance shaping factors (PSFs) were identified and recorded in TRACEr sheet.
Results: The analysis of TRACEr sheets indicated that of a total number of 1171 detected errors, the internal and external errors were 50.67% (n=593) and 49.33% (n=578), respectively. In this line, ̔timing/sequence̕ errors with 35.36% and 'quality/selection' errors with 30.03% were identified as the highest and lowest external error modes, respectively. In classifying the internal error modes, action errors with 31.87% and decision making with 10.73% were identified as the highest and lowest external error modes, respectively. Within PEMs, ̔distraction/preoccupation̓ (23.61%) was identified as the main causes of perception errors. The analysis of the PSFs shows that ‘Organization’ with 27.95% and ‘task complexity’ with 8.74% were two main factors affecting the task errors.
Conclusion: The current study could identify many of the errors and conditions that affect the performance of operators. Therefore, this study can be introduced as a basis for managers and stockholders of chemical industries with complexity and high risk in order to prioritize human error prevention programs.

The Efficiency and Usability Human-Computer Interface in Cervical Spinal Cord Injury by Game-based Electromyography Biofeedback and Electromyography Biofeedback

Amir Salar Jafarpisheh

Background and Objectives: The proliferation of computers, along with the development of software and the Internet, has revolutionized the work and life of people with disabilities, including those with spinal cord injuries with limited mobility in the arms. The efficiency and usability of the aids provided to these people is very important; because they have more limitations than ordinary people. The purpose of this study was to compare the efficiency and usability of human-computer interface in cervical spinal cord injury with two biofeedback EMG methods based on computer games and without computer games.
Methods: The sample size was 20 participants (healthy and with spinal cervical lesions) who were selected regarding availability. The statistical population of the study (that was conducted 2019-2020) was spinal cord injury patients referred to spinal cord injury clinic in Tehran. Participants received three 30-minute sessions per week for 1 month of EMG biofeedback training and game-based biofeedback interventions. SPSS version 23 was used for data analysis.
Results: Results showed that participants considered using EMG biofeedback and game biofeedback as 75/8% and 72/0% usability. Over time, the “through put” numerical values of the variable decreased in healthy individuals and spinal cord injury. Also, the numerical values of this variable were lower in healthy individuals than in individuals with spinal cord injuries. The maximum reduction in numerical values of the “through put” variable appeared between the first and sixth sessions.
Conclusion: The EMG and gaming biofeedback system can be used for interaction and control such as computers, wheelchairs, and more.

Role of Individual Factors on the Individual Resilience and Productivity of Employees in one of the Oil and Gas Companies in South of Iran in Epidemics Conditions of COVID-19

Seyed Mahdi Mousavi

Background and Objectives: Coronavirus disease 2019 (COVID-19) causes mental effects as well as physical effects, which can affect the occupational dimensions of people. The present study was aimed to determine the effect of individual factors on resilience and productivity loss of employees at epidemics conditions of Coronavirus in an occupational environment.
Methods: This cross-sectional study was performed, in Spring of 2020, on 275 personnel in one of the southern industrial companies of Iran. Data collection instruments included demographic questionnaire, researcher made questionnaire, CD-RSC resilience questionnaire, and Hershey and Gold Smith productivity questionnaire. The collected data were analyzed using SPSS software version 22.
Results: The results of one-way analysis of variance (ANOVA) showed that people older than 50 years and more than 20 years of work experience and low and medium experience in using personal protective equipment had a significantly lower resilience score (P<0.05). Also, the results of the analysis revealed that the individuals with experience of COVID-19 had significantly lower score of productivity (P<0.05). Moreover, the results showed that there was a significant positive correlation between resilience and productivity (r=0.249, P<0.05).
Conclusion: COVID-19 disease has reduced the resilience and productivity of workers. Therefore, adherence to health protocols in the workplace is necessary to reduce the risk of developing COVID-19.

Identification and Assessment of Human Error during the Process of Operating Various Types of Fire Apparatus

Omid Kalatpour

Background and Objectives: Firefighting is a difficult and dangerous job. This job requires decision-making and speed in action in critical situations. Such conditions increase the probability of human error in the firefighting activities. Setting up fire operators as the first step of emergency response is associated with high criticality. The purpose of this study is identification and assessment of the risk of human error while setting up and operating fire operators.
Methods: This descriptive cross-sectional study was performed in 2019. Tasks related to the operation of industrial firefighting operators were studied and analyzed by Hierarchical Task Analysis. Then, human errors in the operation of fire operators were identified and analyzed using the systematic human error reduction and prediction approach (SHERPA). Finally, appropriate prevention solutions were proposed to reduce the risk of errors.
Results: A total of 480 errors were detected for 130 tasks as 49.58% of them were action errors, 39.17% check type, 10.42% communication and 0.83% were selective errors and no retried error was observed. According to the results of risk assessment, 8.33% of the errors were unacceptable, 24.17% were undesirable, and 48.33% were acceptable risks but needed to be revised and 19.17% were acceptable without the need for revision.
Conclusion: The process of operating fire operators can be associated with human errors and prevent successful firefighting operations. Therefore, these errors should be identified and controlled using appropriate methods.

Comparison of Job Satisfaction and Job Stress Among Nurses, Operating Room and Anesthesia Staff

Shirdel Zandi

Background and Objectives: Paying attention to human resources is one of the basic principles for increasing productivity and quality of services in hospitals. Therefore, the present study was designed to compare the level of job satisfaction and job stress, and the association between these two components in nurses, operating room, and anesthesia staff.
Methods: This is a descriptive causal-comparative study, performed in December 2019 in Zabol hospitals with the participation of 175 nurses, operating room, and anesthesia staff. A three-part questionnaire consisting of demographic information, job satisfaction, and job stress was used to collect data. Then analysis of data was performed using SPSS 20 and the Pearson correlation coefficient, independent t-test, and ANOVA.
Results: In this study, it was found that nursing group had the highest job satisfaction and anesthesia and operating room staff had the lower job satisfaction. Also, the highest and lowest levels of job stress were related to anesthesiologists and nurses, respectively, and the differences in both variables were significant between the three groups. Moreover, the results showed that there was a significant negative correlation between job satisfaction and job stress, totally.
Conclusion: Due to that anesthesia staff was in a more unfavorable situation than others. We recommend that management planning and policies in hospitals be done by occupational groups and design and carry out the studies to assess the needs for each group.

Workplace Ostracism and Knowledge Hiding: The Mediating Role of Job Tension (Case Study of Nurses of Public Hospitals Employee's in Lorestan)

Massome Momeni Mofrad

Background and Objectives: Improving and developing service delivery requires the free flow of information and knowledge. Therefore, addressing this factor and examining the role of its determinants can lead to the reputation of the organization in providing services. One of the most important factors is the dismissal of employees in the environment, which leads to a lot of job tension. Therefore, the purpose of this study was to investigate the effect of exclusion in the workplace on knowledge concealment with respect to the mediating role of job tension.
Methods: This study is based on the applied purpose and from the perspective of how to collect data in the field of descriptive survey studies. The statistical population of this study consists of all staff of public hospitals in Lorestan province. Using stratified-random sampling method, 124 people were selected as the research sample. The data required in this study were collected using the Liu et al. (2016) Workplace Rejection Questionnaire, the O'Reilly et al. (2014) Knowledge Concealment Questionnaire, and the Peng Job Tension Questionnaire (2013) based on 5 options Likert. The data collected in this study were analyzed by structural equation modeling using Smart-pls software.
Results: The results of this study showed that rejection in the workplace can lead to the spread of knowledge concealment behaviors. Also, rejection through increased job stress can lead to the development of knowledge concealment.
Conclusion: According to the results of this study, managers of service organizations should develop strategies to improve the level of mutual acceptance of people in the workplace and prevent rejection of individuals to reduce knowledge concealment behaviors.