Development of a software package for ergonomic assessment of manufacturing industry

A computer software package has been developed to be used as a self-assessment tool to evaluate ergonomic improvement potential of production systems by engineers, managers and safety professionals. Production managers of manufacturing industries with no prior knowledge of ergonomics were able to identify ergonomic deficiencies successfully (81%) in the shop floors as a result of the application of the ergonomic assessment tool. This enabled them to formulate intervention strategies to improve ergonomic conditions in their industries. The software package is user friendly, self-explanatory and provides relevant information, data and guidelines. It is unique, as the users will have access to necessary ergonomics information, which is often lacking in the manufacturing industries, especially in developing countries.     

基于JACK的民机维修任务仿真及人机工效评估

在民用飞机产品的设计阶段考虑产品的可维修性,利用JACK软件对机务维修任务进行虚拟仿真以及对维修的舒适性、可达性、可视性进行人机工效评估,验证产品的可维修性并提出改进性的维修意见。首先将基于人机工效学设计的发动机UG模型导入JACK软件中创建分析对象;然后基于JACK建立虚拟人体模型,将虚拟人、维修对象导入三维虚拟环境中,并在任务仿真模块中完成维修任务的仿真;最后利用JACK软件的人机工效评估工具对维修任务仿真结果进行评估验证产品的可维修性及提出改进性的维修意见,这样既降低了飞机的维修成本,又验证了产品的可维修性。     

A multilayered ergonomic intervention program on reducing musculoskeletal disorders in an industrial complex: A dynamic participatory approach

Work-related musculoskeletal disorders (WMSDs) are closely identified with common complaints in different workplaces. This study aimed to implement an intervention program through which ergonomic measures were dynamically localized in industry. An interventional study, including three basic layers, namely, training workshops, participatory ergonomics (PE), and workstation redesign was fulfilled in an Iranian steel manufacturing complex from 2017 to 2020. A steering committee (SC) was formed following several meetings held for clarification of the project to the management team. The SC members then attended four organized workshops managed by an ergonomics specialist. Afterwards, the basics of ergonomics were transferred to action groups. After developing ergonomic assessment tools, the ergonomic problems were prioritized and numerous positive changes were made by the action groups. The findings of the tailored checklists revealed a load of WMSDs risk factors. All the three layers of the program were implemented as initiated. Ergonomics training workshops were then held and significant differences were observed between the participants' pre/posttest mean scores in all workshops (p < 0.001). Moreover, PE measures were exercised at all levels of the organization inducing enthusiastic motivation of the workforce to consider ergonomic requirements in the workplace. Consequently, the workers' innovative ideas and the managerial support yielded diverse workstation redesigns due to a growth in either the workers' ergonomics awareness or participatory culture grounding. A multilayered ergonomic intervention was implemented in this study. In conclusion, a multifaceted long-term follow-up intervention program could be applied to enhance workers’ health status and to raise system productivity.     

An investigation into the impact of safety features on the ergonomics of surgical scalpels

In the case of surgical scalpels, blade retraction and disposability have been incorporated into a number of commercial designs to address sharps injury and infection transmission issues. Despite these new designs, the traditional metal reusable scalpel is still extensively used and this paper attempts to determine whether the introduction of safety features has compromised the ergonomics and so potentially the take-up of the newer designs. Examples of scalpels have been analysed to determine the ergonomic impact of these design changes. Trials and questionnaires were carried out using both clinical and non-clinical user groups, with the trials making use of assessment of incision quality, cutting force, electromyography and video monitoring. The results showed that ergonomic performance was altered by the design changes and that while these could be for the worse, the introduction of safety features could act as a catalyst to encourage re-evaluation of the ergonomic demands of a highly traditional product.     

Corporate ergonomics programme at Ford Motor Company

The use of ergonomic principles in automobile assembly and manufacturing operations has become an important part of a comprehensive health and safety process as well as an integral part of the engineering systems. Ford Motor Company has developed an ergonomics process to manage issues related to injury and illness (e.g., musculoskeletal diseases) and to ensure the appropriate use of human resources on the plant floor. The ergonomics programme uses joint labour and management teams to identify and evaluate jobs and develop and implement solutions. This paper summarises the efforts of the Ford Motor Company in implementing and maintaining the programme. Key strategies are outlined that provide important links to internal organisational units that are critical to fully utilise the ergonomics process. In addition, the paper outlines differences between proactive and reactive efforts and shows the importance of using the information generated by the initiatives for process improvement.     

Conceptions of dentists and dental nurses about ergonomics

Abstract

Sixty-eight dentists and 90 dental nurses, all working in a municipal dental care programme in the city of Helsinki, Finland, were surveyed by a questionnaire about their knowledge of and attitudes towards ergonomics. Thirty-three per cent of the dentists and 36% of the dental nurses were of the opinion that they were at present working according to ergonomic principles. Fifty-one per cent of the dentists and 45% of the nurses could not indicate any ergonomic problem in their place of work. Of the remainder the dental unit was mentioned by 62% of the dentists, and own or counterpart's working posture and habits by 44% of the nurses as the most frequent ergonomic problem. Training in dental ergonomics during undergraduate studies was significantly more general among the nurses than the dentists. Ergonomic knowledge and attitudes were found to correlate with each other, as well as knowledge of ergonomics with training in ergonomics and ergonomic working style, but only among the nurses. The results indicate that a dental team needs functionally-designed dental equipment and instruction in ergonomic principles applied to dentistry.     

A model for calculation of the costs of poor assembly ergonomics (part 1)

In product development there are many design requirements to meet and often tough project budgets to keep. Requirements that are considered not profitable will often be neglected, which affects assembly ergonomics. The objective of this study was to develop a calculation model for application in practice that enables calculation of costs of poor assembly quality related to assembly ergonomic conditions. The model is meant to be used by engineers and stakeholders in the design or redesign of manual assembly solutions. For that purpose, manual assembly tasks of 47061 cars at high, moderate and low physical load levels were analyzed with respect to assembly-related quality errors and corresponding action costs during production and on the market. The results showed that ergonomics high risk issues had 5–8 times as many quality errors as low risk issues and the earlier these were found the less were the action costs. The action costs for errors that were discovered late in assembly were 9.2 times more costly compared to early repair of errors in the factory. The action costs for quality errors that were found and corrected on the market were further 12.2 times more expensive to correct compared to actions taken in the factory. Examples are shown of how to apply the calculation model that was developed based on the obtained quality data.     

Incorporating Tactile Cues into Human‐Centered Virtual Product Design

This study introduces a high‐fidelity tactile feedback mechanism to capture ergonomics attributes of users inside virtual product development cycle. The research question posed regards whether the tactile feedback mechanism in virtual experiment proposes high fidelity of ergonomics results when compared to physical experiment outcomes. This question was evaluated through an objective and a subjective study. Objective study was composed of an ergonomics product assessment experiment, where two different cart designs (a commercial cart and a prototype model) were evaluated for ergonomic adequacy (L4/L5 compression forces). Subjective evaluation was consisted of a questionnaire to assess subjects' preferences regarding which cart model they preferred in three different design categories; maneuverability, accessibility, and ergonomics. Results showed that tactile feedback mechanism was able to replicate the physical test conditions in virtual environment with high fidelity, and prototype cart model received higher mean ratings when compared to commercial cart model in each design category.     

Ergonomics study and analysis of workstations in Tunisian mechanical manufacturing

The workers’ performance in the mechanical manufacturing sector is the main factor for the improvement of productivity and quality. At present, it seems that the available information on the ergonomics and the working environment of the mechanical manufacturing actors is scarce. This study deals with the relationship between the working method and the workstation in injection mold manufacturing. An original methodology, based on the survey of operators using participatory ergonomic tools, is proposed in order to evaluate the ergonomic performance of 3 workstations: milling, turning, and drilling. The surveys concerned 3 operators. Obtained results showed that ergonomics play a key role in improving mechanical manufacturing. The results obtained from the analysis showed that ergonomics has a key role in the quality of the various tasks performed by operators. Using the Rapid Entire Body Assessment (RULA) and Rapid Entire Body Assessment (REBA) investigation tools, the examination of the workstations revealed 4 machining operations and 12 operator postures that have a direct influence on the performance of all machining stations. In addition, data from the analysis conducted on injection mold manufacturing revealed that neither the workstations were ergonomic nor the operators complied with the ergonomic rules. Based on the results obtained, a new standardized score is proposed for the RULA and REBA calculations. This score was applied and validated through another study conducted in a leaf spring manufacturing plant. The results of these studies were concretized by proposing the digital factory where CATIA software was used for the virtual design of the ergonomic workstations and their environments.     

人机系统中视域评估的可视化

为了达到视域评估的可视化效果,文中构建了人眼可视范围的半透明模型,并绑定到虚拟人的骨骼中,通过驱动虚拟人,以实时混合绘制技术完成动态视域评估。以龙门式数控加工中心造型设计模型为对象进行实例仿真,结果表明逼真的可视化效果使得视域评估变得简单、快捷和直观,避免了大量的人工运算,提高了视域评估的速度、降低了人为失误。该方法可直接面向工程的实际应用,满足各类布局设计的可视化评估要求。     

From theory to national application—A Finnish experiment

In 1968 the Finnish National Fund for Research and Development started a 3 year project to ‘introduce ergonomics into Finnish production’. A multidisciplinary group, comprising five persons sponsored by the Institute of Occupational Health, was formed.

The concept of ergonomics, at the time the project was founded, was relatively unknown in Finland, although as early as 1962 international course activity on the subject was begun at the Institute of Occupational Health. Little competent ergonomic knowledge existed in the realm of industry, which at that time claimed 500000 workers, and what did was poorly used.

The adopted strategy of the 3 year project was as follows: (a) an attempt was made to convince potential users of ergonomic knowledge of its utility by working out a number of examples on the application of ergonomics; and (b) the availability of ergonomic information was to be improved. By the time the project was completed in 1971, ergonomic activities had reached such a degree of acceptance that it was deemed necessary to maintain the multidisciplinary group and provide it with additional resources. These extended activities are outlined in this paper.     

Fuzzy logic-based decision support system for automating ergonomics risk assessments

Workers in the modular construction industry are frequently exposed to ergonomic risks, which may lead to injuries and lower productivity. In light of this, researchers have proposed a number of ergonomics risk assessment methods to identify design flaws in work systems, thereby reducing ergonomic discomfort and boosting workplace productivity. However, organizations often disregard ergonomics risk assessments due to a lack of convenient tools and knowledge. Therefore, this study proposes a fuzzy logic-based decision support system to help practitioners to automatically and comprehensively assess the ergonomic performance of work systems. For comprehensive assessment of ergonomic risk, the proposed decision support system considers physical, environmental, and sensory factors. Specifically, the decision support system comprises eight fuzzy expert systems that output a composite risk score, called an “ergonomic risk indicator”, that indicates the overall level of ergonomic risk present in a given work system. The performance of the proposed decision support system is then evaluated using a real-world case study in a modular construction facility by comparing the results of the decision support system with the facility's occupational injury reports. The results prove the effectiveness of the decision support system. Overall, the decision support system is capable of generating a composite risk score, the ergonomic risk indicator, and the proposed high-level architecture and design represent significant contributions for the enhancement of health and safety in the modular construction industry.     

Improving the ergonomics of British Coal's mining machinery

British Coal Corporation now require ergonomics evaluations to be undertaken on many major items of underground machinery before they are approved for use underground. Ergonomists must therefore be able to provide a service to the industry which is both consistent and reliable. It is especially important where an ergonomics evaluation could influence the purchasing decision on machines which can cost up to pound sterling 2m, that the ergonomist's conclusions/recommendations accurately reflect design issues which have both safety and performance implications. The conclusions must be consistent across assessors and over extended time periods. Ergonomists should also be able to provide designers with the detailed criteria on which their machines are assessed. The Bretby Operability Index was developed to achieve these requirements and it complements ergonomic design guidelines which have previously been developed to help ensure that ergonomics is also taken into consideration early in the design process.     

Web-based office ergonomics intervention on work-related complaints: a field study

The aim of this study was a proof of concept to examine the effects of a web-based office ergonomics intervention on subjects' individual workplace adjustments. An intervention study was conducted with 24 office workers lasting 6 weeks with three consecutive phases (before, 1 and 5 weeks after the intervention). Employees used a purpose-made website for adjusting their computer workplaces without any personal support of ergonomics experts. Workplace measurements were taken directly on site and by analysing photos taken of the employee. Self-reported complaints were assessed by filling in a questionnaire. It was found that 96% of the employees changed their workplaces on their own and retained them mostly unchanged after the intervention. Furthermore, self-reported musculoskeletal complaints and headache symptoms decreased significantly after the intervention. These findings suggest an improvement of workplace conditions so that cost-effective ergonomic web-based interventions appear promising in further research and application.     

多约束下的载人潜器舱内计算机辅助工效设计系统研究

为了能使载人潜器舱内工效设计人员加深对多约束条件下舱内人员的生理、心理 和环境约束条件的理解,有效地辅助设计方案的智能生成与优化。提出了基于虚拟人体模型参 数作为布局设计解空间的参数获取方法、基于遗传算法的舱内人-机界面布局设计方案计算智能 求解方法、基于知识推理的舱内色彩工效设计方案获取方法和基于粒子群算法的载人舱工效设 计方案智能优化方法,以此为基础,应用UG 二次开发和数据库技术,开发了载人潜器舱内人 机工效设计计算机辅助系统。通过设计实例的人机工效布局和色彩设计与方案优化验证了该系 统的可行性。     

A checklist for evaluating ergonomic risk factors resulting from awkward postures of the legs, trunk and neck

A one-page checklist for determining the presence of ergonomic risk factors associateed with awkward postures of the lower extremities, trunk and neck was developed and evaluated as part of a joint labor-management ergonomics intervention program. This checklist was used by plant personnel at four work sites to assess the postural requirements on 335 cyclical (i.e., work-cycle duration less than five minutes) manufacturing and warehouse jobs. In addition, results generated by the checklist were compared to the results of ergonomic analyses performed by persons with advanced training in occupational ergonomics.

Workers were observed using awkward postures for most of the jobs in the survey. Awkward postures of the lower extrimities were relatively uncommon, occuring in 25 percent or less of the jobs. Awkward postures of the trunk and neck were common, occuring in more than 70 percent of the jobs. Results generated by the checklist were generally in agreement with results generated by the experienced ergonomists; however, the checklist was found to be more sensitive in identifying the presence of awkward postures.

The checklist was found to be an effective rapid-screening instrument for identifying cyclical jobs that expose workers to potentially harmful postures. However, the checklist methodology did not include sufficient documentation of work methods to identify the specific job attributes associated with these exposures. Furthermore, the checklist was not used to evaluate non-cyclical jobs (e.g., maintenance and skilled trades).     

基于E/HOQ/TRIZ 的人机产品创新方法研究

为了快速准确地进行设计阶段的人机产品创新,开发了E/HOQ/TRIZ 集成模型并 描述了具体步骤,提出了基于人体工程学(E)的人机用户需求三维分类的需求获取方式;通过质 量屋(HOQ)确立人机设计关键问题与关键人机设计区域;利用发明问题解决理论(TRIZ)分析人 机设计关键问题中的冲突类型,借助TRIZ 发明原理消除冲突。E/HOQ/TRIZ 集成模型有效弥补 了单一设计理论与方法的局限性,并发挥三种理论与方法的优势,实现人机产品创新设计。通 过人机洗浴设施创新设计,论证了所提出E/HOQ/TRIZ 集成模型与方法的可行性。     

Visual ergonomics of video-display-terminal workstations: Field measurements of luminance for various display settings

Electronic visual displays have shown a rapid technological evolution in the last two decades. With reference to the ergonomic requirements for video display terminal (VDT) workstations (ISO 9241), at an international level, attention is focused on the human–system interaction. With reference to visual ergonomics, the aim of this study is to assess luminance conditions through in-field measurements in order to evaluate: luminance and contrast ratios, luminance and contrast non-uniformities. The assessment was applied to widespread flat screen displays and repeated for fourteen combinations of Contrast–Brightness. The analysis carried out by the Authors shows the importance of realizing a simple and quick procedure to determine the performance levels of displays used in VDT workstations. The proposed assessment could be used as a practical tool for staff assigned to assess the risks arising from VDT use in the workplace within the Occupational Health and Safety Assessment Procedure.     

Computer-aided ergonomics: a case study of incorporating ergonomics analyses into workplace design

One of the primary goals of computer-aided ergonomics is to develop software tools that allow ergonomics information to be accessed at the earliest stages of design. This case study discusses a PC-based software program that allows a designer to quantify a worker's biomechanical risk for injury based on a proposed workplace design. The program couples an established software tool for biomechanical analysis, the Three-Dimensional Static Strength Prediction Program (3DSSPP), with a widely used computer-aided design software package, AutoCAD. The use of this "3DSSPP/AutoCAD interface" in the proactive analysis of an automotive assembly task is described and the results compared with an independent assessment using observations of workers performing the same task. Both studies yield similar conclusions, suggesting that proactive use of software such as the 3DSSPP/AutoCAD interface may be a valid tool in evaluating proposed workplace designs. In this context, issues in the analysis of workplace designs regarding the use of supporting ergonomic tools, assumptions, and posture selection are discussed.     

Assessing the effects of positive feedback and reinforcement in the introduction phase of an ergonomic intervention

Resistance to change is common in ergonomic interventions, often resulting in negative consequences when the intervention's effectiveness is studied. A lab-based study assessed the effects of positive reinforcement during the intervention process. On Day 1 all participants performed a simple screw-driving task that placed stress on the cervicobrachial region through static loading. On Day 2 a control group received basic information about ergonomics and then performed the task using an ergonomic intervention that has been shown to reduce loading on these muscle groups. The experimental group received the same basic information but also received positive reinforcement while performing the task with the ergonomic intervention. Subjective task assessment surveys and body-part discomfort surveys were administered, and these, along with speed of performance, were assessed in both groups. The results showed a significantly (p < .05) more positive subjective impression of the intervention for the feedback group than for the control group (29%-57% improvement) with no real changes in either the performance or discomfort levels. Applications of this research include improving workers' acceptance of ergonomic interventions in industrial and other settings. The reinforcement technique evaluated in this paper has yielded consistently positive effects in our ongoing ergonomic intervention research.