| 1. |
- Bengtsson, Peter, et al.
(författare)
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Computer-Aided Planning of Production, Working and Residential Environments
- 1996
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 17:1, s. 59-68
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses a computer-aided planning methodology and its applicability for planning of industrial production and working environments as well as for planning of residential and working environments for the differently abled. The methodology has been developed and evaluated in six case studies in mechanical industries and in six case studies related to adaptations for the differently abled. The results from the case studies indicate that computer-supported modelling and visualisation may serve as a common and efficient language facilitating communication about multifaceted environmental planning issues. The methodology is a cost-effective way of demonstrating layout ideas and testing dynamic activities like manufacturing and transportation. Corporate groups comprising people involved in, or affected by, development work seem to be a fruitful approach for cooperation, one which enhances learning and creativity. Such groups may be a proper forum for the dissemination of information, exchange of opinions, utilisation of both expert and lay experiences, and for public testing of current reality or future plans in such a way that mutual understanding between different professional categories is increased, hence promoting internal commitment.
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| 2. |
- Bao, Shihan, et al.
(författare)
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Interactive effect of ergonomics and production engineering on shoulder-neck exposure — A case study of assembly work in China and Sweden
- 1997
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 20:1, s. 75-85
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Tidskriftsartikel (refereegranskat)abstract
- Ergonomic improvements of work station design have been widely embraced as a measure for reduction of physical work load (mechanical exposure) and prevention or control of occupational shoulder-neck disorders. However, other elements of work rationalization, more in the hands of production engineers, may also influence the mechanical exposure. The present study concerns shoulder-neck exposure in a Chinese and a Swedish assembly line workplace. Interactive effects of ergonomic work station design, and production engineering (in terms of assembly line balancing and sensitivity of assembly line layout to production irregularities) on shoulder-neck exposure have been studied. It was shown that the Swedish workplace has a better ergonomic work station design, reflected in more favorable work postures during assembly operations. At the same time, the Swedish assembly line is better balanced and less sensitive to production irregularities, which probably reduces the total duration of idle time during assembly compared with the Chinese line. On the Swedish assembly line, arm movements are more frequent, and trapezius and infraspinatus muscle activation is more repetitive. Muscle activation levels are similar on the two lines. However, a larger proportion of low level muscle activities were found on the Chinese line compared with the Swedish line. On the basis of these results, it is suggested that the mechanical exposure of the assembly workers is a result of counteracting effects of improved ergonomic design of work stations and more effective production engineering.
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| 3. |
- Bergquist, Karin, et al.
(författare)
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Quality function deployment (QFD) - A means for developing usable products
- 1996
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 18:4, s. 269-275
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Tidskriftsartikel (refereegranskat)abstract
- In order to develop usable products, human needs and requirements have to be taken into consideration. By employing the QFD (Quality Function Deployment) method the human needs are systematically matched with the product characteristics, which can help to improve the product quality. In this paper the use of QFD in the area of ergonomics is discussed and a case study is presented, The QFD method was used in the case study to translate the needs of safety shoe users in the cold climate into product characteristics. The QFD analysis of the safety shoes revealed that the characteristics of the steel toecap were receiving the highest overall weighting, which means that improving the design of the steel toecap would lead to higher customer satisfaction. Relevance to industryThe importance of developing products that meet the customer or human needs is a priority area in the product development process. With knowledge in ergonomics it is possible to reveal information of the human needs and requirements. However, in the product development process it also is important to match the human needs with the product characteristics, which can be achieved by using the QFD method. The knowledge of ergonomics and the use of the QFD method are therefore useful tools in designing high quality products.
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| 4. |
- Burström, Lage, et al.
(författare)
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The influence of shock-type vibrations on the absorption of mechanical energy in the hand and arm
- 1999
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 23:5, s. 585-594
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Tidskriftsartikel (refereegranskat)abstract
- In recent years there has been a discussion as to whether shock-type vibration from hand tools has stronger effects on the hand-arm system in comparison with non-impulsive vibration. The purpose of the investigation is to compare the influence of these two types of vibration on the absorption of mechanical energy in the human hand and on the grip and feed forces applied by the subjects.The energy absorption has been measured by use of a specially designed laboratory handle. The grip and feed forces applied by the subject to the handle were measured simultaneously. In the study two different frequency weighted acceleration levels were used.The outcome showed that the vibration exposure levels made a significant contribution to the vibration absorption as well as to the strength of the grip and feed forces. Moreover, it was found that the hand forces decrease while the absorption of energy increases during the experiment. Furthermore, the influence of shock-type exposure gave a significantly higher hand forces and absorption of energy compared with the non-impulsive exposure. It was, therefore, concluded that the vibration response characteristics of the hand and arm differ, depending upon whether the exposure is of shock or non-impulsive type.Relevance to industryThe paper discusses the dynamic response of the hand and arm during exposure to shock and non-impulsive vibration. Whenever possible, a tool that requires low grip and feed forces should be used as well as tools that not generate shock-type excitation. This can be helpful in choosing the proper tool for the job.
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| 5. |
- Engström, Tomas, 1950, et al.
(författare)
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Alternatives to Line Assembly: Some Swedish examples
- 1996
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Ingår i: International Journal of Industrial Ergonomics. - 1872-8219 .- 0169-8141. ; 17:3, s. 235-245
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, some criticism of Lean production has occurred, focusing among other things on the working conditions and the susceptibility of traditional assembly work in a society upgrading the demands for a more humanized work. Recently, this criticism has also concerned the technical aspects of this type of manufacturing. Because of this, alternatives to line assembly merit some attention. Experiences from some innovative production systems operated in the Swedish automotive industry during the last two decades are of particular interest. These unconventional production systems feature autonomous work groups and extended work cycles. These types of production systems are elucidated in detail by means of e.g nuance the concept of utilising buffers, i.e. there are different types of buffers (or buffer functions) as is classified (or clarified) in this publications.
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| 6. |
- Engström, Tomas, 1950, et al.
(författare)
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Data Collection and Analysis of Manual Work Using Video Recording and Personal Computer Techniques
- 1997
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Ingår i: International Journal of Industrial Ergonomics. - 1872-8219 .- 0169-8141. ; 19:4, s. 291-298
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Tidskriftsartikel (refereegranskat)abstract
- This publication initially reports on data collection and analysis of assembly systems including manual work using the so-called `loss analysis' which we have applied to the automotive industry during two decades of research and development work. In the further development of this method of analysis we have during the last few years synchronized a personal computer and a video recorder, thereby facilitating data collection of true shop floor information, as well as developing the analysis procedure to also include ergonomic aspects and work performance in the analysis. This publication reports on: (1) the background, (2) the prototype equipment used for data collection and analysis which is illustrated by empirical data using the equipment to analyze stamping of sheet metal, as well as assembly of automobile doors and drivelines, and (3) how to integrate a `loss analysis' with an ergonomic analysis of working postures (in this specific case using the so-called OWAS technique) studying assembly work on an automobile door. In this case, we noted that the division of labour loss represents over 60% of the time consumption for assembly work. This analysis indicates that from an ergonomic point of view it is primarily worth studying what activities are included in the assembly work classified as OWAS workload level 2. Relevance to industry This paper describes and illustrates methods and equipment developed consisting of a synchronized personal computer and video recorder. This promotes a design based on empirical data for specific cases through facilitating the collection and analysis of shop floor information about manual work and process efficiency of interest for the design of assembly systems.
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| 7. |
- Engström, Tomas, 1950, et al.
(författare)
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Empirical Evaluation of the Reformed Assembly Work at the Volvo Uddevalla Plant. Psychosocial effects and performance aspects
- 1995
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 16:16, s. 293-308
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the innovative, now defunct, Volvo Uddevalla final assembly plant. Theoretical frames of reference, the design process and empirical data on workgroup characteristics and working conditions are focused upon. Information regarding the Uddevalla plant has been gathered during a long-term co-operation project with the Volvo Corporation. During the closing-down period, we obtained full access to all the production engineering data and personnel files available. We also had the opportunity of studying the responses to a questionnaire distributed to a random sample of blue-collar workers. Working conditions in Uddevalla in the form of psychosocial job factors are compared with industrial blue-collar workers in general as well as with assembly workers in the closed down Volvo Kalmar final assembly plant, which had a different, more traditional, production system. The paper also compares the psychosocial job factors, performance measures and work-group characteristics in the five assembly workshops in the Uddevalla plant. In comparing assembly workshops, the paper contrasts two approaches to competence development and work structuring used in Uddevalla, namely (1) giving priority to the individual in-depth training of a specific task or (2) giving priority to a large competence overlap between individuals in a workgroup. Relevance to the industry. This paper reports and explains some results from a multidisciplinary evaluation of shop-floor work in the Volvo Uddevalla plant, a full-scale assembly plant with a parallelized flow and long cycle time, using autonomous work groups. These experiences should be of general interest to industries searching for the factory of the future.
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| 8. |
- Fernström, Elisabeth A.C., et al.
(författare)
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Alterations in shoulder muscle activity due to changes in data entry organisation
- 1999
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 23:3, s. 231-240
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate how changed work organisation and different work tasks influence shoulder muscular load and to quantify the magnitude, duration and frequency of rest periods from shoulder muscular load during a working day. Shoulder muscular load was measured in 22 females working at their data entry workplaces, during a whole working day. The activity from both trapezius muscles was measured with EMG before (1991) and after (1992) a reorganisation programme intended to redistribute repetitive work and provide new work tasks.The change in work organisation did not change the magnitude of muscular load or the duration and frequency of rest periods, but decreased musculoskeletal problems. The subjects' increased desk work involved greater muscular load than the data entry did, but also allowed more movement. The changes in work tasks seemed to be important, although small. In repetitive work, organisational changes aimed at reducing musculoskeletal disorders should focus on providing employees with tasks that afford variation in muscular load. Relevance to industry. The paper discusses the need of physical work task variation in repetitive work in order to minimise the risk of musculoskeletal disorders. It seems more important to vary the tasks than to minimise the shoulder muscular load. Copyright
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| 9. |
- Gellerstedt, Sten
(författare)
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Mechanised cleaning of young forest : The strain on the operator
- 1997
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 20:2, s. 137-143
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the paper is to map out how the operator limits the productivity in mechanised spacing and cleaning of young stands of trees. The work elements in this forestry machine work are analysed simultaneously with the measuring of the operator's workload. Proposals for technical developments are given. The design of the study follows a model which secures control of important occurring factors.Operating a forestry cleaning and spacing machine is probably the most intensive forestry machine work. The low heart rate variability indicates a high mental workload. The intense operation of the crane causes few pauses (EMG-gaps) in the trapezius muscle. Managing the machine occupies the operator's attention while biological assessments of the stand are needed. Neck and shoulder complaints are still a major problem.To keep mechanised cleaning profitable, machine, crane and cleaning head must be easier to handle. A partly robotized crane and cleaning head and better sight can help the operator to perform faster and more reliable cleaning. A self-levelling cab with a pivoting ability will give the operator a more relaxed working environment. In the future perhaps a cleaning and spacing robot might be a choice.
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| 10. |
- Karlqvist, Lena, et al.
(författare)
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Computer mouse and track-ball operation : Similarities and differences in posture, muscular load and perceived exertion
- 1999
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 23:3, s. 157-169
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Tidskriftsartikel (refereegranskat)abstract
- Posture (optoelectronic 3D motion analysis system), muscular load (EMG), perceived exertion (rating scales), preference and productivity were investigated in 20 healthy VDU-operators (10 male and 10 female) during text editing with two different data input devices, a mouse and a track-ball. Work with the track-ball entailed lower shoulder elevation and less neck/shoulder muscle activity than work with the mouse. Arm support reduced muscle activity in the neck/shoulder region irrespective of input device used. A table height lower than 3 cm above elbow height allowed arm and shoulder support without undue shoulder elevation. Work with the track-ball entailed more wrist extension than work with the mouse. Perceived exertion ratings were lower for the shoulder and higher for the hand with track-ball than with mouse operation. Thus, biomechanical demands differ between different input devices. The women elevated and rotated their right shoulder outwards more than the men during work with both input devices. The overall EMG results showed a higher activity among the women than among the men in two of the examined muscles. This may relate to anthropometric differences which also influence biomechanical load moments. Another reason could be the observed differences in working techniques between the men and the women.
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| 11. |
- Kuklane, Kalev, et al.
(författare)
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Thermal effects of steel toe caps in footgear
- 1999
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 23:5-6, s. 431-438
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated cold weather safety footwear and the possible thermal effects of steel toe caps in footwear. Two models of boots were used. Both models were manufactured in two variants - with and without steel toe cap. The boot insulation was measured with an artificial, heated foot (AHF). One model was used in experiment with subjects (n=6). Cold exposure consisted of sitting for 60 min at -10°C. There were no differences between insulation levels of boots with and without steel cap for one boot model, but the differences were statistically significant for the second model showing slightly higher insulation values for the boot without steel cap. No significant differences due to insulation dissimilarities could be found from the measurements on subjects. Statistically significant differences were found for both models regarding the rate of change of heat loss from AHF when its location was changed from warm to cold and back to warm. The rise and decrease of heat loss from AHF depended on the rate of temperature change of the boots. The results showed that a faster change in heat loss from AHF occurred for boots without steel toe caps. Data from subjects seemed to confirm this by a somewhat faster, though not significant, rise in toe skin temperatures after cold exposure in boots without steel toe caps. The effect may be attributed to the higher mass and heat contents of the boots with steel toe cap.
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| 12. |
- Liu, Xiaoxiong, et al.
(författare)
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Subjective evaluation of three helmets in cold laboratory and warm field conditions
- 1999
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 23:3, s. 223-230
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Tidskriftsartikel (refereegranskat)abstract
- Helmets are widely used in industries as a primary protection means for workers. Helmets can provide efficient protection against occupational hazards to the head, they also cause thermal discomfort to the wearers at work. To develop a reliable heat transfer testing method for helmets any objective testing method must be validated with subjective testing of the same helmets. Subjective evaluation of helmet heat transfer properties was conducted in both cold and hot conditions using three commonly used and commercially available helmets. Twenty-five subjects participated in a laboratory investigation in a simulated cold environment( + 3 degrees C and 30% RH); forty-three steel-making workers participated in a held survey in the hot environment (31 degrees C and 32% RH). Subjects were either asked to conduct certain tasks (in the laboratory investigation) or performed their regular production duties (in the filed survey) while wearing a helmet; they were then asked to answer questions in a questionnaire at the end of the surveys. The results of the subjective assessment which were compared with the objective measurements taken on a sweating manikin head using the same helmets, were found consistent.
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Eriksson, Joakim, et al.
(författare)
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Adaptation of Workplaces and Homes for Disabled People Using Computer-Aided Design
- 1996
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141. ; 17:2, s. 153-162
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Tidskriftsartikel (refereegranskat)abstract
- A computer-based tool has been developed to support the planning of adaptations for the physically disabled. The prototype development and evaluation were based on six case-studies, which also provided information on the needs and requirements in real-life planning situations. The tool was found useful in supporting an iterative planning process, where it is important to encourage and activate not only the disabled person, but also other people involved or affected. It was positively evaluated by the participants through its ability to enhance the understanding and encourage active participation. The tool was also found useful in supporting the planner's (e.g. an occupational therapist's) design and evaluation of aspects such as accessibility, clearance and reach, taking into consideration an individual's size and abilities. The present prototype's effectiveness was not satisfactory as modelling was relatively time-consuming. Besides rationalising the 3-D modelling, future development should also include an improved measurement control, collision detection and a simplified control of view-angles and objects.
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| 18. |
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