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Coping with human errors through system design: Implications for ecological interface design
the ergonomics needs and manufacturing constraints. 21.4.5 (117283)
Shahnavaz, H. Ergonomics: An emerging concept in industrially developing countries. In t J Indust Ergonomics, 1989, 4(2), 9 1 100, 11 refs. Industrialisation via technology transfer is seen as the main development strategy by many developing countries (DC). The assumption that importation of advanced technology on its own, without adapting it to the environmental, physical, mental and sociocultural needs of the workforce in the recipient country, would bring technical changes for the benefit of the majority of people has proved to be unrealistic. The failure to appreciate the characteristics and preferences of human operators has often frustrated technical development, alienated the work force and achieved little to improve the living and working conditions of the local people. Ergonomics is a useful tool for evaluating the choice of technology and its implementation and can contribute to the safe and productive transfer of technology. However, the area is fairly new or even unknown in many DC. They need asssitance to acquire and apply the knowledge to their own need and capacity. It must also be emphasised that the available b o d y of knowledge (e g, standards, recommendations, procedures, etc) concerning working conditions, occupational health and safety, which has been developed largely in industrialised countries (IC), often cannot be applied directly to DC, because of significant differences which exist in all aspects of the work system between IC and DC. Since many factors influencing the nature, extent and diversity o f problems are specific to each DC (e g, climate, people, method of work, facilities, infrastructures of technology, finance, etc) it is necessary to incorporate research into industrial development programmes.
21.4.6 (117286)
Wardell, R.W. The application of ergonomics to oilwell drilling figs. In: Proc Human Factors Assoc of Canada 22nd Ann Conf, Toronto, Ontario, 2 6 - 2 9 Nov 1989. Human Factors Assoc of Canada, Mississauga, Ontario, 1989, pp 1 3 5 139, 14 refs. An exploratory assessment of the ergonomics of oilwell drilling rigs was conducted to identify the needs and potential for ergonomic improvement and suggest directions for
future rig design. Ergonomics methods, guidelines and data were used to review jobs, tasks, equipment characteristics and usage environment, mental workload, force exertion, physiological workload, and unsafe or unhealthy conditions. Three conventional rigs were studied, as well as a slant rig with mechanical pipe handling. A scenario analysis of 134 safety incidents was conducted concurrently with the ergonomics review. Many conditions on the rigs were contrary to general ergonomics principles and guidelines, and some tasks were at the limits of human capabilities. These conditions are likely to increase safety risk and to contribute to problems in staffing, productivity and performance. Significant improvements can be made at the detail level and at minimum cost in some areas. Improvement in other areas requires basic conceptual changes in rig systems and architecture. To realise their potential, new rig concepts must be carefully and systematically designed, and ergonomics should be considered throughout their design.
Human characteristics 21.4.7 (117245) Cuomo, D.L., and Sharit, J. Human performance in computeraided architectural design. In: Designing and using h u m a n - c o m p u t e r interfaces and knowledge-based systems, Salvendy, G., and Smith, M.J. (Eds). Elsevier, Amsterdam, 1989, pp 2 4 1 249, 12 refs. The tremendous growth in the area of h u m a n - c o m p u t e r interaction has, in some cases, resulted in the implementation of technologies at a pace well ahead o f the development for assessing human performance on tasks employing these technologies. An example of such a technology is computer-aided design. The cognitive processes underlying human design behaviour require that performance measures be developed that adequately reflect these processes. Ultimately, the development and implementation of such a performance methodology could help us to establish the degree to which the computer technology supports or constrains human design activities. In this paper the authors discuss an approach that was taken toward meeting these objectives. In particular, the application area of architectural design is examined. 21.4.8 (117326)
Baddeley, A., and Bernsen, N.O. (Eds). Cognitive psychology. Research directions in cognitive science: European perspectives, Vol 1. Lawrence
Erlbaum Associates, Hove, East Sussex, 1989, 154 pp. The present volume on cognitive psychology is one in a series of five presenting the findings o f a joint European study in cognitive science 1 9 7 8 - 8 8 . The study was organised and funded as a collaborative network by the research unit F A S T (Forecast and Assessment in Science and Technology) of the Commission of the European Communities and comprised about 35 scientists from the core disciplines of cognitive science. The research disciplines respresented in the network were: cognitive psychology, logic and linguistics, cognitive neuroscience, h u m a n - c o m p u t e r interaction, and artificial intelligence. 21.4.9 (116557)
Bereiter, S.R., and Miller, S.M. Troubleshooting and human factors in automated manufacturing systems. Noyes Data Corporation, Park Ridge, New Jersey, USA, 1989, 310 pp, 59 refs. This b o o k is an empirical study of troubleshooting and human factors in automated manufacturing systems. Troubleshooting - the process of locating and diagnosing a fault in a system - is often difficult for the maintenance specialist in a computercontrolled manufacturing system. Underlying this difficulty is the fact that manufacturing systems are getting more complex. Difficulties encountered by expert troubleshooters as they acquire and use information to diagnose faults are identified. Suggestions are provided for ways to design computercontrolled manufacturing systems, and in particular process control technology, to alleviate these difficulties. The b o o k investigates how manufacturing systems can be designed and, in particular, the process control technology needed to make troubleshooting easier for the maintenance specialist. The approach employed is to understand how maintenance specialists acquire and use information during troubleshooting and the type of difficulty they encounter in doing this. 21.4.10 (117360)
Rasmussen, J., and Vicente, K.J. Coping with human errors through system design: Implications for ecological interface design. In t J ManMachine Studies, 1989, 31(5), 5 1 7 534, 22 refs. Research during recent years has revealed that human errors are not stochastic events which can be removed through improved training programmes or optimal interface design. Rather, errors tend to reflect either systematic interference between various models,
Applied Ergonomics
December 1990
337
rules and schemata, or the effects of the adaptive mechanisms involved in learning. In terms of design implications, these findings suggest that reliable h u m a n - s y s t e m interaction will be achieved by designing interfaces which tend to minimise the potential for control interference and support recovery from errors. In other words, the focus should be on control of the effects of errors rather than on the elimination of errors per se. In this paper, the authors propose a theoretical framework for interface design that attempts to satisfy these objectives. The goal of the framework, called ecological interface design, is to develop a meaningful representation of the process which is not just optimised for one particular level of cognitive control, but that supports all three levels simultaneously. The paper discusses the necessary requirements for a mapping between the process and the combined action/observation surface, and analyses of the resulting influence on both the interferences causing error and on the opportunity for error recovery left to the operator.
This paper presents a study of a combination lift and lower manual handling task and was designed to simulate the loading of grocery bags into car trunks. Eighteen male subjects performed an externally-paced task of lifting grocery bags loaded with steel shots from 15 cm above the floor and over a wooden sill. There were two different sill heights of 70 cm and 90 cm and for each of these heights there were three different sill depths of 28 cm, 43 cm, and 57 cm. The dependent variables were the maximum acceptable weight of lift. Constant conditions were temperature ( 2 3 - 2 6 ° C ) , humidity ( 5 2 - 6 2 % ) , horizontal distance of lift (136 cm), and time of day the subjects performed the lifting. A unique lifting sequence and a modified version of the psychophysical methodology were used to determine the maximum acceptable weight that subjects were willing to lift. There were no significant differences in the weights lifted across the two sill heights but weights lifted over the 28 cm sill depth were significantly more than the weights lifted for either the 43 cm depth or the 57 cm depth.
21.4.11 (116624)
De Ree, J.J.D. The use of graphs in the ergonomic evaluation of tall pilots' sitting posture. Aviation, Space and Environ Med, 1989, 60(10) Pt 1 , 1 0 1 1 - 1 0 1 5 , 9 refs. A survey has shown that the average height of KLM pilots has increased by 18 mm (0.7 in) per decade in the last 20 years. Around 6% are taller than 1905 mm (75.0 in), the upper limit of pilot height for flight deck design. With the use of graphs of the flight deck, the author established that the main problem of tall pilots is insufficient legroom. Of all KLM/NLM aircraft types, the Boeing 747-200/300 and the Douglas DC-90 are most uncomfortable for pilots taller than 1960 mm (77-2 in). In the Airbus A310, pilots of 2000 mm (78.7 in) have insufficient legroom. The other aircraft types do n o t present difficulties for pilots of up to 2030 m m (79"9 ha). Ergonomic adaptations on the flight decks of the Boeing 747-200/300 and the Airbus A310 are necessary to alleviate the problems of tall pilots. Future aircraft types should be designed to accommodate tall pilots. If ergonomic adaptation of the flight deck is impossible, anthropometric limits for pilot selection have to be employed. 21.4.12 (116638)
Rodrigues, C.C., Congleton, J.J., Koppa, R.J., and Huchingson, R.D. Maximum acceptable weight of lift for an asymmetrical combination manual handling task. l n t J [ndustr Ergonomics, 1989, 4(3), 2 4 5 - 2 5 3 , 27 refs.
338
AppliedErgonomics
21.4.13 (117402)
Wisner, A. Variety of physical characteristics in industrially developing countries ergonomic consequences. In t J Indust Ergonomics, 1989, 4(2), 1 1 7 - 1 3 8 , 103 refs. In many industrially developing countries, data concerning the physical characteristics of populations have been collected for various technical and scientific purposes and published in a very scattered way. Results obtained in 39 countries and described in 103 publications have been selected. Data evaluation is n o t so much concerned with the ethnic differences which are normally stressed than with the influence of biological, social, economic and geographic factors such as sex, age, health, condition, sociooccupational background, altitude or climate. The ergonomics consequences of this study affect the dimensional characteristics of the production locations or the industrial product. Some products such as cars may suit the purchaser population all over the world. On the other hand, industrial and especially agricultural machines and tools should be linked to users' characteristics. Further ergonomics considerations are related to the occasionally excessive physical strength limits of many populations in industrially developing countries. Efforts to be made, loads to lift and distances to cover over bad ground have moderate or dangerous effects according to the physical capacities of
December 1990
the persons in question. Highlighted as such, the actual workers' capacities have a significant effect on production and economic development. The preservation and increase of these capacities may be obtained in accordance with specific ways and means. 21.4.14 (117412) Gallagher, S. Isometric pushing, pulling and lifting strengths in three postures. In: Perspectives. Proc Human Factors Soc 33rd A n n Meeting, Denver, Colorado, 1 6 - 2 0 Oct 1989. Human Factors Soc, Santa Monica, California, Vot 1, 1989, pp 6 3 7 - 6 4 0 , 8 refs. Nine underground coal miners (mean age = 36"9 years + 6'3 SD; height = 174'5 cm-+ 7-4 SD; weight = 87"8 kg +-- 12'5 SD) participated in a Bureau of Mines study examining the effects of posture on isometric strength. Five tests of static strength (i e, maximum push, maximum pull, maximum lift with elbows flexed at 90 , maximum lift with lifting handle 45.7 cm (18 in) above floor, and maximum push up with handle at eye height) were performed in three postures: standing, kneeling on one knee, and kneeling on two knees. Results indicated that neither test of lifting strength was affected by posture (p > 0-05). However, maximum pulling strength was significantly greater when kneeling on one knee (p < 0"001) than when standing or kneeling on both knees. Also, maximum pushing strength was greater when kneeling on both knees than when standing (p < 0"05). The test of maximum push up was not affected by posture (p > 0"05), and the force generated in the three postures for this test were highly correlated (r = 0"94). Results of these strength tests may be useful when recommending appropriate postures to assume when performing specific underground materials-handling tasks. .
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O
.
21.4.15 (117914)
Adams, S.K., and Ma, X. Predictive models of hand torque strength for circular electrical connectors. In: Perspectives. Proc Human Factors Soc 33rd A n n Meeting, Denver, Colorado, 1 6 - 2 0 Oct 1989. Human Factors Soc, Santa Monica, California, Vol 1, 1989, pp 7 3 7 - 7 4 1 , 4 refs. Maintenance and its associated costs have become a serious problem for nearly all military and civilian organisations using aircraft and other complex hardware. This paper describes extensions of development work designed to provide basic elemental task configuration versus strength data for tightening and loosening circular electrical connectors by proposing
Shahnavaz, H. Ergonomics: An emerging concept in industrially developing countries. In t J Indust Ergonomics, 1989, 4(2), 9 1 100, 11 refs. Industrialisation via technology transfer is seen as the main development strategy by many developing countries (DC). The assumption that importation of advanced technology on its own, without adapting it to the environmental, physical, mental and sociocultural needs of the workforce in the recipient country, would bring technical changes for the benefit of the majority of people has proved to be unrealistic. The failure to appreciate the characteristics and preferences of human operators has often frustrated technical development, alienated the work force and achieved little to improve the living and working conditions of the local people. Ergonomics is a useful tool for evaluating the choice of technology and its implementation and can contribute to the safe and productive transfer of technology. However, the area is fairly new or even unknown in many DC. They need asssitance to acquire and apply the knowledge to their own need and capacity. It must also be emphasised that the available b o d y of knowledge (e g, standards, recommendations, procedures, etc) concerning working conditions, occupational health and safety, which has been developed largely in industrialised countries (IC), often cannot be applied directly to DC, because of significant differences which exist in all aspects of the work system between IC and DC. Since many factors influencing the nature, extent and diversity o f problems are specific to each DC (e g, climate, people, method of work, facilities, infrastructures of technology, finance, etc) it is necessary to incorporate research into industrial development programmes.
21.4.6 (117286)
Wardell, R.W. The application of ergonomics to oilwell drilling figs. In: Proc Human Factors Assoc of Canada 22nd Ann Conf, Toronto, Ontario, 2 6 - 2 9 Nov 1989. Human Factors Assoc of Canada, Mississauga, Ontario, 1989, pp 1 3 5 139, 14 refs. An exploratory assessment of the ergonomics of oilwell drilling rigs was conducted to identify the needs and potential for ergonomic improvement and suggest directions for
future rig design. Ergonomics methods, guidelines and data were used to review jobs, tasks, equipment characteristics and usage environment, mental workload, force exertion, physiological workload, and unsafe or unhealthy conditions. Three conventional rigs were studied, as well as a slant rig with mechanical pipe handling. A scenario analysis of 134 safety incidents was conducted concurrently with the ergonomics review. Many conditions on the rigs were contrary to general ergonomics principles and guidelines, and some tasks were at the limits of human capabilities. These conditions are likely to increase safety risk and to contribute to problems in staffing, productivity and performance. Significant improvements can be made at the detail level and at minimum cost in some areas. Improvement in other areas requires basic conceptual changes in rig systems and architecture. To realise their potential, new rig concepts must be carefully and systematically designed, and ergonomics should be considered throughout their design.
Human characteristics 21.4.7 (117245) Cuomo, D.L., and Sharit, J. Human performance in computeraided architectural design. In: Designing and using h u m a n - c o m p u t e r interfaces and knowledge-based systems, Salvendy, G., and Smith, M.J. (Eds). Elsevier, Amsterdam, 1989, pp 2 4 1 249, 12 refs. The tremendous growth in the area of h u m a n - c o m p u t e r interaction has, in some cases, resulted in the implementation of technologies at a pace well ahead o f the development for assessing human performance on tasks employing these technologies. An example of such a technology is computer-aided design. The cognitive processes underlying human design behaviour require that performance measures be developed that adequately reflect these processes. Ultimately, the development and implementation of such a performance methodology could help us to establish the degree to which the computer technology supports or constrains human design activities. In this paper the authors discuss an approach that was taken toward meeting these objectives. In particular, the application area of architectural design is examined. 21.4.8 (117326)
Baddeley, A., and Bernsen, N.O. (Eds). Cognitive psychology. Research directions in cognitive science: European perspectives, Vol 1. Lawrence
Erlbaum Associates, Hove, East Sussex, 1989, 154 pp. The present volume on cognitive psychology is one in a series of five presenting the findings o f a joint European study in cognitive science 1 9 7 8 - 8 8 . The study was organised and funded as a collaborative network by the research unit F A S T (Forecast and Assessment in Science and Technology) of the Commission of the European Communities and comprised about 35 scientists from the core disciplines of cognitive science. The research disciplines respresented in the network were: cognitive psychology, logic and linguistics, cognitive neuroscience, h u m a n - c o m p u t e r interaction, and artificial intelligence. 21.4.9 (116557)
Bereiter, S.R., and Miller, S.M. Troubleshooting and human factors in automated manufacturing systems. Noyes Data Corporation, Park Ridge, New Jersey, USA, 1989, 310 pp, 59 refs. This b o o k is an empirical study of troubleshooting and human factors in automated manufacturing systems. Troubleshooting - the process of locating and diagnosing a fault in a system - is often difficult for the maintenance specialist in a computercontrolled manufacturing system. Underlying this difficulty is the fact that manufacturing systems are getting more complex. Difficulties encountered by expert troubleshooters as they acquire and use information to diagnose faults are identified. Suggestions are provided for ways to design computercontrolled manufacturing systems, and in particular process control technology, to alleviate these difficulties. The b o o k investigates how manufacturing systems can be designed and, in particular, the process control technology needed to make troubleshooting easier for the maintenance specialist. The approach employed is to understand how maintenance specialists acquire and use information during troubleshooting and the type of difficulty they encounter in doing this. 21.4.10 (117360)
Rasmussen, J., and Vicente, K.J. Coping with human errors through system design: Implications for ecological interface design. In t J ManMachine Studies, 1989, 31(5), 5 1 7 534, 22 refs. Research during recent years has revealed that human errors are not stochastic events which can be removed through improved training programmes or optimal interface design. Rather, errors tend to reflect either systematic interference between various models,
Applied Ergonomics
December 1990
337
rules and schemata, or the effects of the adaptive mechanisms involved in learning. In terms of design implications, these findings suggest that reliable h u m a n - s y s t e m interaction will be achieved by designing interfaces which tend to minimise the potential for control interference and support recovery from errors. In other words, the focus should be on control of the effects of errors rather than on the elimination of errors per se. In this paper, the authors propose a theoretical framework for interface design that attempts to satisfy these objectives. The goal of the framework, called ecological interface design, is to develop a meaningful representation of the process which is not just optimised for one particular level of cognitive control, but that supports all three levels simultaneously. The paper discusses the necessary requirements for a mapping between the process and the combined action/observation surface, and analyses of the resulting influence on both the interferences causing error and on the opportunity for error recovery left to the operator.
This paper presents a study of a combination lift and lower manual handling task and was designed to simulate the loading of grocery bags into car trunks. Eighteen male subjects performed an externally-paced task of lifting grocery bags loaded with steel shots from 15 cm above the floor and over a wooden sill. There were two different sill heights of 70 cm and 90 cm and for each of these heights there were three different sill depths of 28 cm, 43 cm, and 57 cm. The dependent variables were the maximum acceptable weight of lift. Constant conditions were temperature ( 2 3 - 2 6 ° C ) , humidity ( 5 2 - 6 2 % ) , horizontal distance of lift (136 cm), and time of day the subjects performed the lifting. A unique lifting sequence and a modified version of the psychophysical methodology were used to determine the maximum acceptable weight that subjects were willing to lift. There were no significant differences in the weights lifted across the two sill heights but weights lifted over the 28 cm sill depth were significantly more than the weights lifted for either the 43 cm depth or the 57 cm depth.
21.4.11 (116624)
De Ree, J.J.D. The use of graphs in the ergonomic evaluation of tall pilots' sitting posture. Aviation, Space and Environ Med, 1989, 60(10) Pt 1 , 1 0 1 1 - 1 0 1 5 , 9 refs. A survey has shown that the average height of KLM pilots has increased by 18 mm (0.7 in) per decade in the last 20 years. Around 6% are taller than 1905 mm (75.0 in), the upper limit of pilot height for flight deck design. With the use of graphs of the flight deck, the author established that the main problem of tall pilots is insufficient legroom. Of all KLM/NLM aircraft types, the Boeing 747-200/300 and the Douglas DC-90 are most uncomfortable for pilots taller than 1960 mm (77-2 in). In the Airbus A310, pilots of 2000 mm (78.7 in) have insufficient legroom. The other aircraft types do n o t present difficulties for pilots of up to 2030 m m (79"9 ha). Ergonomic adaptations on the flight decks of the Boeing 747-200/300 and the Airbus A310 are necessary to alleviate the problems of tall pilots. Future aircraft types should be designed to accommodate tall pilots. If ergonomic adaptation of the flight deck is impossible, anthropometric limits for pilot selection have to be employed. 21.4.12 (116638)
Rodrigues, C.C., Congleton, J.J., Koppa, R.J., and Huchingson, R.D. Maximum acceptable weight of lift for an asymmetrical combination manual handling task. l n t J [ndustr Ergonomics, 1989, 4(3), 2 4 5 - 2 5 3 , 27 refs.
338
AppliedErgonomics
21.4.13 (117402)
Wisner, A. Variety of physical characteristics in industrially developing countries ergonomic consequences. In t J Indust Ergonomics, 1989, 4(2), 1 1 7 - 1 3 8 , 103 refs. In many industrially developing countries, data concerning the physical characteristics of populations have been collected for various technical and scientific purposes and published in a very scattered way. Results obtained in 39 countries and described in 103 publications have been selected. Data evaluation is n o t so much concerned with the ethnic differences which are normally stressed than with the influence of biological, social, economic and geographic factors such as sex, age, health, condition, sociooccupational background, altitude or climate. The ergonomics consequences of this study affect the dimensional characteristics of the production locations or the industrial product. Some products such as cars may suit the purchaser population all over the world. On the other hand, industrial and especially agricultural machines and tools should be linked to users' characteristics. Further ergonomics considerations are related to the occasionally excessive physical strength limits of many populations in industrially developing countries. Efforts to be made, loads to lift and distances to cover over bad ground have moderate or dangerous effects according to the physical capacities of
December 1990
the persons in question. Highlighted as such, the actual workers' capacities have a significant effect on production and economic development. The preservation and increase of these capacities may be obtained in accordance with specific ways and means. 21.4.14 (117412) Gallagher, S. Isometric pushing, pulling and lifting strengths in three postures. In: Perspectives. Proc Human Factors Soc 33rd A n n Meeting, Denver, Colorado, 1 6 - 2 0 Oct 1989. Human Factors Soc, Santa Monica, California, Vot 1, 1989, pp 6 3 7 - 6 4 0 , 8 refs. Nine underground coal miners (mean age = 36"9 years + 6'3 SD; height = 174'5 cm-+ 7-4 SD; weight = 87"8 kg +-- 12'5 SD) participated in a Bureau of Mines study examining the effects of posture on isometric strength. Five tests of static strength (i e, maximum push, maximum pull, maximum lift with elbows flexed at 90 , maximum lift with lifting handle 45.7 cm (18 in) above floor, and maximum push up with handle at eye height) were performed in three postures: standing, kneeling on one knee, and kneeling on two knees. Results indicated that neither test of lifting strength was affected by posture (p > 0-05). However, maximum pulling strength was significantly greater when kneeling on one knee (p < 0"001) than when standing or kneeling on both knees. Also, maximum pushing strength was greater when kneeling on both knees than when standing (p < 0"05). The test of maximum push up was not affected by posture (p > 0"05), and the force generated in the three postures for this test were highly correlated (r = 0"94). Results of these strength tests may be useful when recommending appropriate postures to assume when performing specific underground materials-handling tasks. .
.
O
.
21.4.15 (117914)
Adams, S.K., and Ma, X. Predictive models of hand torque strength for circular electrical connectors. In: Perspectives. Proc Human Factors Soc 33rd A n n Meeting, Denver, Colorado, 1 6 - 2 0 Oct 1989. Human Factors Soc, Santa Monica, California, Vol 1, 1989, pp 7 3 7 - 7 4 1 , 4 refs. Maintenance and its associated costs have become a serious problem for nearly all military and civilian organisations using aircraft and other complex hardware. This paper describes extensions of development work designed to provide basic elemental task configuration versus strength data for tightening and loosening circular electrical connectors by proposing