| 1. |
- Singh, Sarbjeet, et al.
(författare)
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Applying human factor analysis tools to a railway brake and wheel maintenance facility
- 2015
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Ingår i: Journal of Quality in Maintenance Engineering. - 1355-2511 .- 1758-7832. ; 21:1, s. 89-99
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThis paper demonstrates three techniques to extract human factor information from specific railway maintenance tasks. It describes the techniques and shows how these tools can be applied to identify improvements in maintenance practices and workflow. Design/methodology/approachThree case studies were conducted on single group of technicians (N=19) at a railway maintenance workshop in Luleå, Sweden. Case study I examined the posture of the technicians while they were changing the brake shoes of freight wagons; the study employed the Standard Nordic Questionnaire and a videotape using the Ovako Working Posture Analysis System (OWAS). Case study II looked at maintenance repair times required to change the wheel axle on freight wagons at the workshop. A video filming method suggested by the European Agency for Safety and Health at Work was used to measure actual maintenance time. Finally, case study III considered the technicians’ (N=19) perception of work demands, their control over the work and their social support while performing maintenance tasks (brake shoe and wheel axle maintenance); to this end, the case study used a demand control support questionnaire. FindingsIn the first case study, the Standard Nordic Questionnaire confirmed that technicians at this particular railway vehicle maintenance workshop suffer from back and shoulder pain. The Ovako Working Posture Analysis showed that 21% of the working time required to fit the brake wedge and cotter pin fits into two OWAS categories: category 3, where “change is required as soon as possible,” and category 4, where “change is required immediately”. Problems stem from poor workplace layout, incorrect posture and inaccessibility of tools and components. In the second study, the video analysis indicated that the working time to change the wheel axle of a freight wagon is greatly affected by poor workplace layout. The third case study showed that the technicians have lower “psychological demands” (mean=13), “higher control over work” (mean= 16) and “high social support” (mean= 22).Practical implicationsThe objective of this study was to apply knowledge about human factors to the functional relationships between maintenance personnel, tasks and the working environment to improve safety. If the workplace layout, working posture, maintenance manuals and accessibility of tools are poorly planned, maintenance performance can be adversely affected. The results of this study should assist maintenance management to design new policies and guidelines for improving the work environment.Originality/valueThree case studies were conducted at a railway maintenance workshop in Luleå, Sweden, to collect data on how human factors affect various railway maintenance tasks.
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| 2. |
- Singh, Sarbjeet, et al.
(författare)
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Developing RCM strategy for wind turbines utilizing e-condition monitoring
- 2015
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Ingår i: International Journal of Systems Assurance Engineering and Management. - : Springer Science and Business Media LLC. - 0975-6809 .- 0976-4348. ; 6:2, s. 150-156
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Tidskriftsartikel (refereegranskat)abstract
- Renewable energy sources such as wind energy are available without any limitations. In order to extract this energy efficiency, the reliability of such technologies is critical if pay back periods and power generation requirements are to be met. Due to recent developments in the field of wind engineering and in particular the expansion of installed capacity around the world, the need for reliable and intelligent diagnostic tools is of greater importance. The number of offshore wind turbines installed in the seas around Britain’s coasts is likely to increase from just fewer than 150–7,500 over the next 10 years with the potential cost of £10 billion. Operation and Maintenance activities are estimated to be 35 % against the cost of electricity. However, the development of appropriate and efficient maintenance strategies is currently lacking in the wind industry. The current reliability and failure modes of offshore wind turbines are known and have been used to develop preventive and corrective maintenance strategies which have done little to improve reliability. In addition, the failure of one minor component can cause escalated damage to a major component, which can increase repair and or replacement costs. A reliability centered maintenance (RCM) approach offers considerable benefit to the management of wind turbine operations since it includes an appreciation of the impact of faults on operations. Due to the high costs involved in performing maintenance and the even higher costs associated with failures and subsequent downtime and repair, it is critical that the impacts are considered when maintenance is planned. This paper provides an overview of the application of RCM and on line e-condition monitoring to wind turbine maintenance management. Unplanned maintenance levels can be reduced by increasing the reliability of the gear box and individual gears through the analysis of lubricants. Finally the paper will discuss the development of a complete sensor-based processing unit that can continuously monitor the wind turbines lubricated systems and provide, via wireless technology, real time data enabling on shore staff with the ability to predict degradation anticipate problems and take remedial action before damage and failure occurs
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| 3. |
- Singh, Sarbjeet, et al.
(författare)
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Evaluation of Human Error Probability of Disc Brake Unit Assembly and Wheel Set Maintenance of Railway Bogie
- 2015
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Ingår i: Procedia Manufacturing. - : Elsevier. - 2351-9789. ; 3, s. 3041-3048
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Tidskriftsartikel (refereegranskat)abstract
- The railway sector is key to the continuous expansion of industrialized nations, but the sector's working conditions and human performance requirements are qualitatively different from other industries. Human error in railway maintenance is a subject which warrants serious attention so as to achieve and sustain a competitive advantage. This paper investigates the probability of human error during the maintenance process of disc brake assembly unit and wheel set of railway bogie under various error producing conditions in railway maintenance workshop in Luleå, Sweden. The objective is to evaluate human error probability so as to take measures to reduce the likelihood of errors occurring within a system and, thus, to improve the overall levels of safety. For this paper, a case study that explores the causes of maintenance error during disassembly, inspection, maintenance, assembly and installation was derived from brain storming sessions among subject matter experts (SMEs), i.e technicians, supervisors and academic experts. In our case study, the Human Error Assessment and Reduction Technique (HEART) was implemented to evaluate the probability of human error occurring throughout the completion of maintenance task. HEART is based upon the principle that every time a task is performed on the maintenance of a disc brake assembly unit and wheel set, there is a likelihood of failure and the probability of this is affected by one or more error producing condition, for instance, shortage of time, over-riding information, inexperience etc. This paper presents the need for interventions in the human factor elements of maintenance tasks performed on railway bogie. A number of factors directly or indirectly result in a decline in human performance, leading to errors in maintenance tasks. The probability of a technician committing an error during maintenance of the disc brake assembly unit and wheel set is found to be 0.20 and 0.039 respectively. It has been observed that error producing conditions such as time pressure, ability to detect and perceive problems, the existence of over-riding information, the need to make absolute decisions, and a mismatch between the operator and the designer's model are major contributors to human error.
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| 4. |
- Singh, Sarbjeet, et al.
(författare)
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Modelling factors affecting human operator failure probability in railway maintenance tasks : an ISM-based analysis
- 2015
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Ingår i: International Journal of Systems Assurance Engineering and Management. - : Springer Science and Business Media LLC. - 0975-6809 .- 0976-4348. ; 6:2, s. 129-138
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Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the factors affecting human operators’ probability of failure when performing railway maintenance tasks. The objective is to understand the interaction of the various factors and to identify driving and dependent factors. The factors are identified through a survey of the literature and ranked using a Likert scale. The reliability of measures is pretested by applying Cronbach’s alpha coefficient to responses to the questionnaire given to maintenance personnel. An interpretive structural model is presented, and factors are classified using matrice d’impacts croises-multiplication appliquéà un classement (MICMAC). The research may help maintenance management understand the interaction of factors affecting human failure probability in railway maintenance and help management devise policies and guidelines for railway maintenance related tasks.
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