The most cited articles published since 2009, extracted from Scopus
Volume 39, Issue 2, March 2009, Pages 371-387
G. Emre Gürcanli | Uǧur Müngen
The nature of construction work ensures that uncertainties are inherent in every condition; and on-site inspections generally use linguistic expressions rather than metrics to assess the risks of workers at a construction site. Additionally legal records, statistical data and documentation produced by companies are generally insufficient for determining risk. This fact increases the uncertainty of the job site atmosphere. This paper proposes a method for assessment of the risks that workers expose to at construction sites using a fuzzy rule-based safety analysis to deal with uncertain and insufficient data. Using this approach, historical accident data, subjective judgements of experts and the current safety level of a construction site can be combined. In the scope of this study, first 5239 occupational accidents in the construction industry are identified from 40,000 unclassified occupational accidents in all industries. Next, these 5239 construction accidents are investigated and classified in detail. Combining these data and the subjective judgement of safety experts, we derive three parameters namely the accident likelihood, current safety level and accident severity and they are utilized as input parameters for the fuzzy rule-based system. The method is then implemented on a tunnelling construction site and risk level for all type of accidents is derived. Relevance to the industry: The relevance of this study to industry is linked to the possibility of providing, through the use of proposed methodology, safety level scores for the construction sites that could result in work improvement and productivity. The application of the proposed method can reveal which safety items and factors are most important in improving workers safety, and therefore decide where to concentrate resources in order to improve the safety of the work environment. © 2008 Elsevier B.V. All rights reserved.
Volume 39, Issue 1, January 2009, Pages 211-220
Liang Ma | Damien Chablat | Fouad Bennis | Wei Zhang
Musculoskeletal disorder (MSD) is one of the major health problems that are related to physical labor especially in jobs requiring manual work. In some literature, muscle fatigue is considered to be closely related to MSD, especially for muscle related disorders. In addition to many existing analysis techniques for muscle fatigue assessment and MSD risk analysis, this paper proposes a new muscle fatigue model. The new proposed model reflects the influence of external load, workload history, and individual differences. This model is simple in mathematics and can be easily applied in real time calculation, such as the application in real time virtual work simulation and evaluation. The new model was mathematically validated with 24 existing static models by comparing the calculated METs (Maximum Endurance Times), and qualitatively or quantitatively validated with three existing dynamic models. The proposed model shows high or moderate similarities in predicting the METs with all the 24 static models. Validation results with the three dynamic models were also promising. The main limitation of the model is that it still lacks experimental validation for more dynamic situations. Relevance to industry: Muscle fatigue is one of the main reasons causing MSDs in industry, especially for physical work. Correct evaluation of muscle fatigue is necessary to determine work-rest regimens and reduce the risk of MSD. © 2008 Elsevier B.V. All rights reserved.
Volume 39, Issue 3, May 2009, Pages 490-500
P. M. Salmon | Neville A. Stanton | Guy H. Walker | Daniel P. Jenkins | Darshna Ladva | Laura A. Rafferty | Mark Young
Assessing operator situation awareness is a key component of sociotechnical system design and evaluation. This article describes a study that was undertaken in order to compare two different situation awareness measures (a freeze probe recall approach and a post trial subjective rating approach) when used to assess participant situation awareness during a military planning task. The results indicate that only the participant situation awareness scores derived via the freeze probe recall method produced a statistically significant correlation with performance on the planning task and also that there was no significant correlation between the two methods, which suggests that they were measuring different aspects of participant situation awareness during the trials. In conclusion, the findings, whilst raising doubts over the validity of the post trial subjective rating approach, offer validation evidence for the use of freeze probe recall approaches to measure situation awareness during simulated tasks. The findings are subsequently discussed with regard to their wider implications for the future measurement of situation awareness in complex collaborative systems. Relevance to industry: Situation Awareness is a critical commodity for teams working in industrial systems. Accordingly, designers and analysts require reliable and valid methods for assessing the impact of new systems, interfaces, training programs and procedures on the level of situation awareness held by operators. This article presents a review and comparison of situation awareness measurement approaches for use in complex industrial systems and provides recommendations on the types of methods to use during future situation awareness assessments. © 2008 Elsevier B.V. All rights reserved.
Volume 40, Issue 1, January 2010, Pages 68-76
Yongsuk Park | Sungho Han
This study investigated effects of touch key sizes and locations on one-handed thumb input on a mobile phone. Three different touch key sizes (i.e. square shape with 4 mm, 7 mm, and 10 mm wide) and twenty-five locations were examined in an experiment. A total of thirty subjects participated in the experiment in which they preformed a task of pressing a single target on a small touch screen. Two time-related measures (first transition time and task completion time), number of errors, and subjective satisfaction (pressing convenience) were collected in the experiment. The results revealed that the touch key size of 7 mm and 10 mm provided the best performance for time-related measures, while the touch key size of 10 mm only provided the best results for the other measures. In addition, the usability of touch key locations was statistically analyzed. Touch key locations providing good usability ('good regions') were also identified for each measure. Recommendations were proposed for designing a touch user interface on a mobile phone based on the results of this study. Relevance to industry: The touch user interface is in the limelight of the handset industry. This study conducted basic research to investigate the effects of touch key sizes and touch key locations for one-handed interaction. The results of this study could be used for designing a touch user interface to enhance the usability of mobile phones and other small devices with a touch screen as well. © 2009 Elsevier B.V. All rights reserved.
Volume 39, Issue 2, March 2009, Pages 428-441
Dan Lämkull | Lars Åke Hanson | Roland Örtengren
The objective of this study was to examine to what extent ergonomics simulations of manual assembly tasks correctly predict the real outcomes in the plants and if recommended measures originating from ergonomics simulations are taken into consideration. 155 ergonomics simulation cases were used in the study and all cases were performed by nine simulation engineers at Volvo Car Corporation in Gothenburg. The evaluations of the ergonomics conditions of the simulated tasks were done by six professional ergonomists working at Volvo Car Corporation in Gothenburg. The results show that digital human modelling tools (DHM-tools) are useful for the purpose of providing designs for standing and unconstrained working postures. Furthermore, the design of various auxiliary devices and their needed space for movements is a prevalent use of DHM-tools. However, the study also identifies areas that require additional development in order to further improve the digital human modelling tools' possibility to correctly predict a work task's real outcome, i.e. hand access, push pressure and pull forces, leaning and balance behaviour and field of vision. Moreover, a better feedback of product and process changes and a more careful order description of simulation cases to the simulation engineers would lead to improved simulation results in current and future projects. Relevance to industry: DHM-tools are increasingly the major means used to perform ergonomics analyses of manual assembly tasks in the automotive industry, but there is still a need for improvements of the tools. It is of great importance to disseminate end users' experiences of the use of different DHM-tools so these can be developed and applied in a more efficient way. © 2008 Elsevier B.V. All rights reserved.
Volume 40, Issue 3, May 2010, Pages 267-281
Gert Åke Hansson | István Balogh | Kerstina Ohlsson | Lothy Granqvist | Catarina Nordander | Inger Arvidsson | Ingrid Åkesson | Jeannette Unge | Ralf Rittner | Ulf Strömberg | Staffan B. Skerfving
To explore the correlation between, and the variation in, various measures of exposure to potential risk factors for work-related upper extremity musculoskeletal disorders (UE-WMSDs), physical workload was measured in 43 types of work (713 individuals), using inclinometry for the head and upper arms, and electromyography (EMG) for the trapezius muscles.Many exposure measures were highly correlated. Head flexion (90th percentile), extension (1st percentile), and movements (50th percentile); arm elevation (99th percentile) and movements (50th percentile); trapezius muscular rest (fraction of time) and peak load (90th percentile), constitute main exposure dimensions. The variations were large: head: flexion 9°-63°, extension -39°-4°, movements 2.3-33 °/s; arm: elevation 49°-124°, movements 3.0-103 °/s; trapezius: muscular rest 0.8%-52% of time, peak load 3.1%-24% of maximal EMG. Even within work categories, e.g. "repetitive industrial" , there were large variations.Somewhat higher loads were recorded on the right as compared to the left side (differences: arm elevation 2°, arm movements 19%; trapezius peak load 18%), but these were small compared to the differences due to work.There were high correlations between movements of arm and head (rs = 0.96), as well as arm and wrist (rs = 0.92), and between, on the one hand, trapezius muscular rest and peak load, and on the other, arm and head movements (/rs/ = 0.47-0.62), as well as arm elevation (/rs/ = 0.54-0.85), which has to be considered when assessing exposure-response relations. Relevance to industry: Direct measurements provide objective and quantitative data of the main physical risk factors for UE-WMSDs, appropriate for estimating the risk, as well as giving priority to and evaluating interventions. © 2009 Elsevier B.V.
Volume 40, Issue 6, November 2010, Pages 710-732
Subhash Rakheja | Ren G. Dong | S. K. Patra | Paul Émile Boileau | Pierre Marcotte | Christopher M. Warren
Identification of most probable ranges of biodynamic responses of the human body exposed to whole-body vibration is essential for developing effective integrated human-machine system design tools, improved vibration mitigation devices and frequency-weighting for exposure assessment. The international standard, ISO-5982 (2001), defines such ranges for very limited conditions, namely for body seated without a back support and exposed to vertical vibration. The reported data on biodynamic responses of the seated and standing human body exposed to whole-body vibration along different directions and the associated experimental conditions are systematically reviewed in an attempt to identify datasets that are likely to represent comparable and practical postural and exposure conditions. Syntheses of datasets, selected on the basis of a set of criterion, are performed to identify the most probable ranges of biodynamic responses of the human body to whole-body vibration. These include the driving-point biodynamic responses of the body seated with and without a back support while exposed to fore-aft, lateral and vertical vibration and those of the standing body to vertical vibration, and seat-to-head vibration transmissibility of the seated body. The proposed ranges are expected to serve as reasonable target functions in various applications involving coupled human-system dynamics in the design process, and potentially for developing better frequency-weightings for exposure assessments. Relevance to the industry: Identification of most probable biodynamic responses of the seated and standing human body exposed to whole-body vibration is essential for developing anthropodynamic manikins, integrated human-machine system design tools for improved vibration mitigation devices and frequency-weighting for exposure assessment. This study derives ranges of biodynamic responses of the body seated with and without the back support, and those of the standing body. The ranges would serve as the target response functions for: (i) designs of anthropodynamic manikins for assessment of vibration isolation effectiveness of coupled seat-occupant system; (ii) development of human body models, which are vital for quantifying the vibration-induced stresses in different joints and for deriving integrated human-machine system design tools; and (iii) identification of alternate frequency weightings for assessment of vibration exposure. © 2010 Elsevier B.V.
Volume 40, Issue 3, May 2010, Pages 237-246
Shihwen Hsiao | FuYuan Chiu | ShuHong Lu
Industrial design attempts to enhance quality of life by designing products that meet consumer requirements. Combining concepts from various fields, including design, computer technology, aesthetics, and economics, industrial designers seek to improve quality of life by designing products that meet consumer needs. Industrial designers focus on customers' perceptions of products and their preferences for certain shapes, textures, colors, styles, linguistic variables, prices, and functions. Because new products are continuously being released, manufacturers must continually design products to satisfy customer needs to avoid displacement by market competitors. When planning strategies for marketing products to various users and consumers, managers must often consider multiple combinations of product shapes and must design products that cater to consumer tastes to minimize the risk of their products being rejected by the market. Companies with highly-skilled designers have more ideas, better and more competitive products, and shorter production times than companies with weak designers. This study analyzed product styles by applying genetic algorithms and Kansei Engineering Type II (AHP and Quantification Theory Type I). This research transforms the psychological conceptions of consumers into linguistic variables. A MATLAB program was constructed to enable designers to simulate consumer logic. The cognitive dissonance between virtual and real models was minimized by using a 3D CAD model, and the virtual model of optimum solutions in this study employed a rapid prototyping machine to generate real models efficiently. Future genetic algorithm models applying different decision theories may achieve even faster and more accurate results. Relevance to industry: Component diversification enables rapid improvement in product competitiveness. This study proposes a support model that conforms to the psychological preferences of consumers by applying a genetic algorithm method. Therefore, the model is applicable to electronic commerce websites or to other unmanned shops. © 2010 Elsevier B.V.
Volume 39, Issue 2, March 2009, Pages 447-455
Antonio Cimino | Franceso Longo | Giovanni Mirabelli
The paper proposes a multimeasure-based methodology that can be used by production engineers for the ergonomic effective design of workstations within industrial environments. In particular the authors achieve the effective ergonomic design of the workstations belonging to a real industrial plant by using an approach based on multiple design parameters, Design of Experiments (DOE) and multiple performance measures. The industrial plant being considered is made up by 8 different workstations, 14 workers and it manufactures high-pressure hydraulic hoses. The design methodology aims at considering both the interaction of the operators with their working environment and the work methods. To this end, the workstations' actual configurations are compared with several alternative scenarios by using a well-planned experimental design. As support tool for applying the design methodology the authors use Modeling & Simulation (M&S) and a virtual three-dimensional environment for recreating, with satisfactory accuracy, the evolution over the time of the real industrial plant. Relevance to industry: The authors propose a methodology for the effective ergonomic design of workstations within industrial plants. The methodology based on multiple design parameters and multiple performance measures supports the design and the evaluation of workstations in terms of both ergonomics and work methods. © 2009 Elsevier B.V. All rights reserved.
Volume 39, Issue 4, July 2009, Pages 621-627
Weisiong Tan | Dahai Liu | Ram R. Bishu
It is very important that designers recognize the benefits and limitations of different usability inspection methods. This is because the quality of the usability evaluation is dependent on the method used. Two of the most popular usability evaluation techniques are user testing and heuristic analysis. The main objective of this study was to compare the efficiency and effectiveness between user testing and heuristic analysis in evaluating four different commercial web sites. The results showed that both user testing and heuristic analysis addressed different usability problems. Analysis by severity of problems found and diminishing return analysis model on the relationship between the number of new problems discovered with users and evaluators used showed that both methods are equally efficient and effective in addressing different categories of usability problems. These significant differences found between these two methods suggested that the two methods are complimentary and should not be competing. In order for better evaluation results, both user testing and heuristic analysis are still needed. Relevance to industry: The research findings from this study will be of particular value to the web development industry and communities. Knowledge regarding the differences between user testing and heuristic evaluation will enable appropriate business decisions to be made on when and how to apply these methods to improve the overall efficiency of the design process.
Volume 39, Issue 6, November 2009, Pages 934-939
Elif Kiliç Delice | Zülal Güngör
Today people increasingly expect more from the functionality of a web site, so the web usability has emerged as an important topic. It is generally hard to renew the existing web sites to meet the changing demands of users. Therefore, the present study is aimed at detailing the usability problems of web sites. To this end, Heuristic Evaluation (HE) is used to identify the usability problems, and Analytic Hierarchy Process (AHP) is used to rate their severity. Finally, for a more user-friendly web site, a new approach to judging severity of usability problems is developed by integrating AHP into HE. Relevance to industry: There is an increasing importance for higher usability in the web development industry and communities. Different usability evaluation techniques have been developed and incorporated into the process of web site design and development. This study proposes a new approach to reveal usability problems on a web site and to define solution priority of these problems. © 2009 Elsevier B.V. All rights reserved.
Volume 39, Issue 4, July 2009, Pages 635-644
Chia-Fen Chi | Chongcheng Yang | Zhenglun Chen
The current study analyzed 255 electrical fatalities in the construction industry. Similar to our previous analysis of fatal falls, each electrical fatality was analyzed in terms of individual factors (age, gender, experience of the victim), task factors (performing task), environmental factors (wet area and confined space), management factors (company size measured by number of workers), source of injury, and causes for these accidents. These electrocution accidents were divided into five accident patterns: direct worker contact with an energized power line, boomed vehicle contact with an energized power line, conductive equipment contact with an energized power line, direct worker contact with energized equipment, and improperly installed or damaged equipment, to identify contributing factors for each. For each accident pattern, accident causes (failure to de-energize electrical systems, failure to maintain safe distances, improper use of personal protective equipment (PPE), poor work practice, accidental contact with exposed electrical parts, defective tools and equipment, lack of effective safety devices or unsafe environment) and prevention measures (safe work practices, insulation, guarding, grounding, and electrical protective devices) were developed based on the identified common scenarios. The current classification scheme can be used as a data-collection instrument that will lead to more precise and effective interventions. Relevance to industry: The current research develops a coding system that would facilitate the categorization of fatal electrocutions in terms of the cause for electrocution, performing task, source of injury, individual factor, and company size for deriving potential risk factors and effective electrocution protection strategies. Significant accident scenarios and high-risk groups of occupational electrocution were identified based on the analysis of 255 work-related electrocution fatalities. © 2008 Elsevier B.V. All rights reserved.
Volume 39, Issue 1, January 2009, Pages 221-233
Gert Åke Hansson | István Balogh | Kerstina Ohlsson | Lothy Granqvist | Catarina Nordander | Inger Arvidsson | Ingrid Åkesson | Jeannette Unge | Ralf Rittner | Ulf Strömberg | Staffan B. Skerfving
The quantitative relationship between exposure to physical risk factors and upper extremity work-related musculoskeletal disorders (UE-WMSDs) is virtually unknown. To explore the variation, objective measurements were derived in 43 types of work (686 individuals), using goniometry for the wrists and electromyography (EMG) for the forearm extensor muscles. The variations due to work were great for wrist movements, wrist positions, muscular rest, as well as peak load, ranging 1.4-54 °/s (flexion velocity; 50th percentile), -30°-3° (flexion angle; 50th percentile), 0.2-23% of time, and 3.4-41% of maximal EMG (90th percentile), respectively. Even within work categories, e.g. "repetitive industrial", there were large variations for all measures. Hence, classification without measurements has limited value. All movement measures were highly correlated (|rs| = 0.82-0.99), but only weakly so to positions (|rs| = 0.01-0.43). Muscular rest and "static load" (10th percentile), were highly correlated (rs = -0.92), but not associated to peak load (90th percentile; |rs| = 0.05 and 0.08, respectively). Most low-velocity work was accompanied by much muscular rest; however, the low velocity for mouse-intensive computer-work meant very little rest. Technical measurements are suitable as exposure measures in epidemiological studies, as well as a base for decisions about interventions. The multidimensional character of exposure - wrist movements, wrist postures, muscular recovery, and peak load - has to be considered. Relevance to industry: Direct measurements provide objective and quantitative measures of the main physical risk factors for UE-WMSDs, appropriate for estimating the risk, as well as giving priority to, and evaluating, interventions. © 2008 Elsevier B.V. All rights reserved.
Volume 39, Issue 2, March 2009, Pages 295-302
Lianyin Zhai | Lipheng Khoo | Zhaowei Zhong
Affective design, also known as Kansei Engineering, is an effective methodology for the study of interactions between human affections and design of products, so as to improve consumer satisfaction. One challenging issue of affective design is to discover the mapping pattern between consumer affections and product design elements from raw design data, which are usually characterised by non-linearity and uncertainty. In view of the insufficiency of traditional methods in dealing with such an issue, this paper proposes a new decision support approach that is based on the principles of dominance-based rough set theory for the study of interactions between consumer affective needs and product features in product design. The proposed approach is able to handle imprecise consumer perceptions and discover latent patterns to guide affective design. The result obtained from an illustrative example shows that the proposed approach provides an effective means to facilitate the affective mapping process and thus is able to improve consumer affective satisfaction with product design. Relevance to industry: This paper proposes an explicit decision support approach to facilitate the affective design mapping process and incorporate consumer affective needs into product design elements, so as to improve consumer affective satisfaction with product design. © 2008 Elsevier B.V. All rights reserved.
Volume 39, Issue 2, March 2009, Pages 403-412
Tarcísio Abreu Saurin | Cléber Fabricio Ferreira
Although the ambiguity of the impacts of lean production (LP) on working conditions is well-known, few in-depth empirical data are available concerning LP applications in contexts other than automobile plants located in developed countries. This study presents an assessment of the impacts of LP on working conditions in a harvester assembly line of an American-owned plant in Brazil. Data collection involved four main stages: (a) a qualitative assessment of the extent to which 11 LP enablers were adopted in the assembly line, based on 15 interviews with managers and supervisors; (b) interviews with six safety specialists, one safety engineer and three groups of 10 workers, in order to detect their views on both the negative and positive impacts of LP; (c) the application of two types of questionnaire to be answered by all assembly line workers - one of them aimed at assessing their views on the current working conditions and the other aimed at assessing their views on the differences between the old Taylorist-Fordist system and the new lean system; (d) a feedback meeting to discuss the results of the questionnaires with the workers. As a framework for analysis, the data collected were grouped into four constructs: work content; work organization; continuous improvement; and, health and safety. The results indicated that workers considered their working conditions were fairly good and had improved after the introduction of LP. To some extent, this positive view was due to the fact that there were many gaps between standardized work and real work. This meant that workers did not follow the assembly standards strictly and had substantial degrees of freedom. Relevance to industry: This paper presents guidelines for assessing lean production (LP) impacts on working conditions either at a plant or departmental level, which were tested on a harvester assembly line in Brazil. The impacts detected in that line may provide insights for other companies concerned with balancing lean and good working conditions. Since the method adopted for assessing the impacts is fairly simple, it is a workable alternative for companies interested in surveying how LP is affecting their workforce. © 2008 Elsevier B.V. All rights reserved.
Volume 39, Issue 1, January 2009, Pages 133-145
Hungyuan Chen | Yuming Chang
The image projected by a product depends to a large extent upon its physical form. Intuitively, it seems reasonable to speculate that a consumer's psychological response to a product is dominated by certain critical features of the product form. Establishing a precise definition of a product's form not only enables the form of the product to be explicitly described, but also provides a convenient basis for exploring the correlation between the product's specific form features and the corresponding consumer response. Accordingly, this study employs a numerical definition-based systematic approach (NDSA) to generate an explicit numerical definition of the product form, and then performs a series of evaluation trials to establish the correlation between the product form features and the consumers' perceptions of the product image. The results of the evaluation trials are used to construct mathematical models capable of predicting the likely consumer response to any product form designed in accordance with the numerical product form definition. Furthermore, the evaluation data enable the critical design variables and critical design features to be determined such that the efficacy of the design process in creating products which better meet the product image aspirations of the consumers can be improved. The feasibility of the proposed NDSA-based approach is demonstrated using the example of a knife form for illustration purposes. Relevance to industry: This study presents a numerical definition-based design approach for extracting the critical form features of a product from its generic form features. The proposed approach not only addresses the limitations of existing Kansei Engineering techniques by providing the means to generate explicit product form definitions, but also assists industrial designers in developing a comprehensive understanding of the emotional response induced in consumers by products of particular forms. The proposed method thus enhances the ability of designers to develop product forms which more closely match the consumers' product image expectations and are therefore more likely to achieve commercial success. Crown Copyright © 2008.
Volume 39, Issue 4, July 2009, Pages 628-634
Enid N H Montague | Brian M. Kleiner | Woodrow W. Winchester
Researchers across disciplines have developed measures of interpersonal trust, system trust, and trust in technology and sought to determine if measures of trust in technology should use the same trust factors as interpersonal trust measures. Studies have found evidence to support the notion that trust and distrust are considered opposites, negating the need for two separate measures to be developed and that participants rate concepts of generalized trust, interpersonal trust, system trust, and trust in technology similarly. It is not apparent if trust in medical technology is the same as trust in general technology; if the two constructs are different, existing trust in technology models may not be useful in discussions about medical technology. The studies involved in the development of a framework of trust in medical technology provide evidence to determine that trust in medical technology is empirically different from trust in technology. The methods described in the studies are based on research methods used to empirically define the constructs trust and comfort and were chosen to extend previous trust in technology models and to offer comparison and validation of findings and methods used in previous studies. Relevance to industry: Understanding how users construct trust in medical technology provides insight to how medical technologies may be used, misused, disused or abused [Parasuraman, R., Riley, V., 1997. Humans and automation: use, misuse, disuse, abuse. Human Factors 39 (2), 230-253] by patients and health care providers and health system issues such as error, malpractice, adoption and satisfaction. The factors of trust in medical technology generated in these studies may be used for the development of trust in medical technology measurement tools. As will be shown, medical technology generalizes in many ways to other technology so the methods and results presented here have broader implications.
Volume 39, Issue 1, January 2009, Pages 39-51
Emmett J. Lodree | Christopher D. Geiger | Xiaochun Jiang
Consider a human facing a variety of physically or cognitively demanding tasks, who then performs these tasks in a sequence that has been determined either strategically or arbitrarily. Just as the exhaustive scheduling literature has repeatedly demonstrated the significant impact that scheduling decisions have on system performance, the human factors literature suggests that task sequencing decisions have a profound impact on human performance and well-being. The latter claim is justified almost exclusively by empirical methods. The alternative of applying classic scheduling theory to sequencing decisions involving human tasks was proposed over a decade ago. However, these pioneering frameworks did not delineate a mathematical basis for incorporating human behavior into the machine scheduling paradigm. The purpose of this paper is to establish a framework for scheduling human tasks that account for physical and/or cognitive human characteristics and behaviors. The framework is constructed by surveying the human factors literature in an effort to identify human characteristics that are relevant to task sequencing, and by reviewing emerging areas of the scheduling literature that are auspicious with respect to modeling these human characteristics in a scheduling context. Interdisciplinary research opportunities in scheduling and human factors are also discussed. Relevance to industry: This paper is inspired by the physical and cognitive challenges associated with semi-automated order picking in warehouses. While pick schedules are often designed in practice based on metrics such as maximizing throughput and meeting delivery schedules, this paper describes a framework for task sequencing that accounts for the worker's risk and aims to maximize the worker's productivity. The proposed task-sequencing framework is general and relevant to any working environment characterized by demanding tasks, task variety, and objectives related to productivity and safety. © 2008 Elsevier B.V. All rights reserved.
Volume 41, Issue 1, January 2011, Pages 30-42
Daria Battini | Maurizio Faccio | Alessandro Persona | Fabio Sgarbossa
This work analyses how ergonomics and assembly system design techniques are intimately related. It also develops a new theoretical framework to assess a concurrent engineering approach to assembly systems design problems, in conjunction with an ergonomics optimization of the workplace. Its purpose is to provide professionals with a new and detailed approach to assembly system design procedures that includes ergonomics issues.The methodological framework offered takes into account technological variables (related to work times and methods), environmental variables (i.e. absenteeism, staff turnover, work force motivation) and ergonomics evaluations (i.e. human diversity) to create a comprehensive analysis.At conclusion of the study, the work reports data and insights from two real industrial cases, where an advanced simulation software is used, to validate the procedure and support methodology applicability. Relevance to industries: This work provides an extremely valuable methodological framework to companies who recognize the link between assembly and ergonomics. The methodology underlines the necessity to analyze and classify the assembly system layout configuration in relation to both technological and environmental parameters- as reported in the framework. © 2010 Elsevier B.V.
Volume 41, Issue 3, May 2011, Pages 233-246
Carmen Llinares | Álvaro F. Page
Kansei Engineering is a product development tool used to identify users' perceptions and find quantitative relationships between their subjective responses and design features. This paper proposes the use of Kano's model in this process to analyse the impact of different subjective attributes on consumers' purchase decisions. A practical example of real estate promotions design is presented. In the first stage, semantic differential is used to measure the subjective component of the emotional state. In the second stage, regression analysis and Kano's model are used to define the relative weight of each emotional attribute in the purchase decision. Besides linear attributes, Kano's model identified two other kinds of attributes that present a non-linear performance: basic attributes and exciting attributes. Therefore linear models could underestimate the effect of such kind of attributes. Relevance to industry: This information is very relevant for architects and designers as it enables them to determine the extent to which they must direct their efforts at improving certain attributes with the object of improving the global evaluation. © 2011 Elsevier B.V.
Volume 39, Issue 5, September 2009, Pages 866-875
Ezgi Aktar Demirtas | Ahmet Sermet Anagün | Gülser Köksal
In this study, a two-stage integrated approach is proposed and implemented to explore user perceptions about kitchen faucet styles and to find optimal levels of design parameters related to product appearance. At the first stage, a group of representative users have been asked to judge 38 systematically selected different faucet designs by using a semantic differential (SD) scale for 11 image (kansei) words about their visual perceptions. Then the relations between overall preference and kansei word scores of users are investigated by Ordinal Logistic Regression (OLOGREG). The model obtained helps understand how customers describe highly preferred designs. It can also be used to confirm if a product design will be highly preferred. At the second stage, the relations between overall preference scores and design parameter levels related to the product appearance are modeled using again OLOGREG, and then the best design parameter levels for visual perceptions are found by maximizing the overall preference scores. The results are confirmed and discussed. They are also compared to those of a commonly used approach in the literature, Conjoint Analysis (CA). This comparison has showed that the OLOGREG approach is superior to traditional CA. Finally, it is discussed how the product style design optimization approach presented and demonstrated in this study for the case of some kitchen faucets can be used in general for other products. Relevance to industry: Developing a user-centered product is an important policy of an enterprise in today's highly competitive marketplace. To reach this objective, a systematic method is proposed by integrating several techniques. This method will be useful to any industry that designs and produces consumer products. These products more fit the consumer needs and the competitiveness of them are improved. © 2009 Elsevier B.V. All rights reserved.
Volume 39, Issue 1, January 2009, Pages 202-210
Nancy A. Nelson | Richard E. Hughes
The objective of this investigation was to use published literature to demonstrate that specific changes in workplace biomechanical exposure levels can predict reductions in back injuries. A systematic literature review was conducted to identify epidemiologic studies which could be used to quantify relationships between several well-recognized biomechanical measures of back stress and economically relevant outcome measures. Eighteen publications, describing 15 research studies, which fulfilled search criteria were found. Quantitative associations were observed between back injuries and measures of spinal compression, lifting, lifting ratios, postures, and combinations thereof. Results were intended to provide safety practitioners with information that could be applied to their own work situations to estimate costs and benefits of ergonomic intervention strategies before they are implemented. Relevance to industry: This investigation uses published literature to demonstrate that specific changes in workplace biomechanical exposure levels can predict reductions in back injuries. Results provide safety practitioners with information that can be applied to their own work situations to estimate costs and benefits of ergonomic intervention strategies before they are implemented. © 2008 Elsevier B.V. All rights reserved.
Volume 41, Issue 5, September 2011, Pages 573-583
Michel José Anzanello | Flávio Sanson Fogliatto
Learning curves (LCs) are deemed effective tools for monitoring the performance of workers exposed to a new task. LCs provide a mathematical representation of the learning process that takes place as task repetition occurs. These curves were originally proposed by Wright in 1936 upon observing cost reduction due to repetitive procedures in production plants. Since then, LCs have been used to estimate the time required to complete production runs and the reduction in production costs as learning takes place, as well as to assign workers to tasks based on their performance profile. Further, effects of task interruption on workers' performance have also being modeled by modifications on the LCs. This wide variety of applications justifies the relevance of LCs in industrial applications. This paper presents the state of the art in the literature on learning and forgetting curves, describing the existing models, their limitations, and reported applications. Directions for future research on the subject are eventually proposed. Relevance to industry: The Learning Curve (LC) models described here can be used in a wide variety of industrial applications where workers endeavor new tasks. LC modeling enables better assignment of tasks to workers and more efficient production planning, and reduces production costs. © 2011 Elsevier B.V.
Volume 39, Issue 2, March 2009, Pages 333-340
Stephen Bao | Peregrin O. Spielholz | Ninica L. Howard | Barbara A. Silverstein
This paper addresses the issue of quantifying forceful exertions of lifting, pushing/pulling, pinch and power griping with several commonly used methods (direct measurement, force-matching, ergonomist estimation based on observation and worker's self-report). The aims were to study differences of ergonomists in making decisions of collecting forceful exertion data, ability of the studied force quantification methods in detecting exposure differences between jobs, and relationships between measurements obtained by different methods. Seven hundred and thirty-three (733) subjects participated in the study, and 2482 forceful exertions were quantified with the selected force quantification methods. Results showed that the determination of whether a forceful exertion was considered important enough to be measured was very subjective. More objective criteria need to be developed. Although the different force quantification methods could detect exertion-level differences between different types of jobs, the sensitivity of detecting the difference varied. Direct measurement of lifting and pushing/pulling forces seems to be slightly more sensitive than ergonomists' estimates, and the force matching of grip forces may be more sensitive than workers' self-reports. Ergonomists estimations through observation seem to be a good alternative for measuring forceful exertions. Pearson correlation coefficients between force estimations obtained by the different methods were between 0.28 and 0.71. The degrees of the correlations between the different measurement methods varied. This indicates that the different methods might quantify different aspects of the forceful exertions. These methods may not necessarily be used interchangeably in job evaluation tools. Different weights and/or cut-points may need to be developed when different force quantification methods are used. Relevance to industry: Objective criteria of collecting forceful exertion data in job evaluations need to be developed. Different forceful exertion quantification methods may be used in job evaluations. However, different cut-points classifying jobs risk levels should be used when different exertion quantification methods are used. © 2008 Elsevier B.V. All rights reserved.
Volume 40, Issue 4, July 2010, Pages 455-469
Asil Oztekin | Zhenyu James Kong | Özgür Özmen Uysal
This paper proposes a new usability evaluation checklist, UseLearn, and a related method for eLearning systems. UseLearn is a comprehensive checklist which incorporates both quality and usability evaluation perspectives in eLearning systems. Structural equation modeling is deployed to validate the UseLearn checklist quantitatively. The experimental results show that the UseLearn method supports the determination of usability problems by criticality metric analysis and the definition of relevant improvement strategies. The main advantage of the UseLearn method is the adaptive selection of the most influential usability problems, and thus significant reduction of the time and effort for usability evaluation can be achieved. At the sketching and/or design stage of eLearning systems, it will provide an effective guidance to usability analysts as to what problems should be focused on in order to improve the usability perception of the end-users. Relevance to industry: During the sketching or design stage of eLearning platforms, usability problems should be revealed and eradicated to create more usable and quality eLearning systems to satisfy the end-users. The UseLearn checklist along with its quantitative methodology proposed in this study would be helpful for usability experts to achieve this goal. © 2010 Elsevier B.V.