Ergonomics--costs and benefits

Ergonomics is primarily concerned with improving the performance of man or of man-machine systems. Although many applications have produced evident improvements, the terms of reference and the results are not often expressed in measures that are easily converted into financial savings. However, there is a growing demand for cost-benefit data of ergonomic improvements, and several examples in which the application of ergonomic principles has resulted in tangible benefits, are reviewed.Cases are cited of increases of productivity resulting from equipment redesign and of savings achieved from the reduction of accidents, and from improvements in the working environment. It is concluded that there is, as yet, no large body of well-documented cases of financial savings accruing from the application of ergonomics, due in many cases to the difficulties of costing actual changes in performance in the work situation. The need for further studies is debated, and it is suggested that the use of ergonomic data in a design programme should not necessarily be based on the prediction of financial benefits.     

Business case for implementing two ergonomic interventions at an electric power utility

Ergonomics analysis of line workers in the electric power industry who work overhead on utility poles revealed some tasks for which less than 1% of the general population had sufficient strength to perform. During a 2-year study, a large Midwestern US electric utility provided a university with a team of represented workers and management. They evaluated, recommended, and monitored interventions for 32 common line worker tasks that were rated at medium to high magnitude of risk factors for musculoskeletal disorders (MSDs). Two of the recommended ergonomic interventions-the battery-operated press and cutter-were selected by the team as having the greatest potential for reducing risk factors of MSDs. Only overhead distribution line worker tasks were evaluated. A business case was formulated that took into account medical injury and illness statistics, workers' compensation, replacement worker and retraining costs. An outline of a business case formulation and a sample intervention payback calculation is shown. Based on the business case, the utility committed over US dollars 300000 to purchase battery-operated presses and cutters for their overhead distribution line crews.     

Determining the cost-benefits of ergonomics projects and factors that lead to their success

Managers usually can justify financially supporting a proposed ergonomics project only when it is supported by a sound cost-benefit analysis. The factors to consider and sources of information for calculating the costs and benefits of proposed ergonomic projects are described. Based upon his experience and review of numerous ergonomics projects, the common characteristics of successful ergonomics interventions gleaned by the author are described and then illustrated by actual documented cases.     

Fatigue and human reliability revisited in the light of ergonomics and work psychopathology

In the process control human-beings are actually information processors, solving many problems, especially covariance-problems which involve various interconnected and interactive factors.

The purpose of this experiment was to investigate the types of cognitive strategy and information-processing procedure used in solving covariance-problems, and to evaluate and determine the best strategy.

Fifty-five subjects participated in the experiment to solve two-factor covariance-problems. Verbal protocols and structural analysis were used to record and analyse the cognitive processes of covariance-problem solving. Verbal protocols were coded and analysed to differentiate the basic operators and thence explore the various strategies.

The results indicated that under two-factor covariant conditions, there were nine kinds of cognitive strategy. The 'biconvex-lens’ strategy was the most effective. All nine strategies can be classified into three categories, trial-and-error, analytic and intuitive.

This experiment research was the first study on cognitive strategies in solving covariance-problems. New topics for further study are put forward.     

The relation between OSH and ergonomics: a 'mother-daughter' or 'sister-sister' relation?

Despite the growing importance of ergonomics and ergonomists worldwide, the position of ergonomics in companies is often not clear. Today, in many countries ergonomics is mainly (or even only) associated with the reduction of risks of work-related musculoskeletal disorders (WMSDs). Therefore, many companies consider ergonomics a part of occupational safety and health (OSH) that focuses mainly on the reduction of risks. This paper aims to analyse the links between occupational ergonomics and OSH. The position of occupational ergonomics in legislation, the presence of ergonomics in OSH networks, and the position of ergonomics in OSH company services are discussed. In addition, the added value of ergonomics to companies is examined. From these discussions, it becomes clear that ergonomics should be part of the OSH policy of companies, and should be integrated into today's company strategies to improve labour conditions. If ergonomics is considered as a discipline in its own right, a clear legislative context should be developed that goes beyond voluntary guidelines and the goodwill of employers, and necessitates the presence of ergonomics professionals in companies.     

Focus of B-to-B e-commerce initiatives and related benefits in manufacturing small- and medium-sized enterprises

Empirical research into business-to-business e-commerce issues involving manufacturing small- and medium-sized enterprises (SMEs) is still embryonic. In an attempt to partially fill this gap, this paper presents empirical data from an electronic survey conducted among 96 manufacturing SMEs to investigate e-commerce initiatives and their related benefits. E-commerce initiatives are assessed using a set of 36 business processes that can be conducted electronically. These processes were classified according to their focus: customer (downstream), supplier (upstream) or in-house. The research findings point to four main profiles of manufacturing SMEs with different e-commerce focuses. The first group seems to lack any focus or may still be exploring e-commerce opportunities. The second and third groups are supplier- and customer-focused, respectively. The fourth group consists of the more involved SMEs that have leveraged their e-commerce initiatives with both their customers and their suppliers. Results also suggest the existence of a close alignment between e-commerce focus and related benefits.An earlier and much shorter version of this paper was published in the Proceedings of the 37th Hawaii International Conference on System Sciences (HICSS-37). Helpful comments from two anonymous reviewers were greatly appreciated. The authors gratefully acknowledge financial support from SSHRC, FCAR and NSERC.     

一个划算的回归测试用例排序的成本-收益模型

回归测试是一个昂贵的测试过程,它验证修改的软件,确认是否给已经测试的代码引进了新的错误.因为在软件开发的过程中,测试人员给测试包中增加了新的测试用例,使软件确认更加困难.为了使回归测试更经济划算,提出了很多技术和方法.测试用例选择,测试包缩减,测试用例排序可以帮助我们减少需要运行的测试用例数目,同时能够更快地满足测试目标.测试用例排序是在满足某个性能目标的基础上,保证在测试过程中首先执行更重要的功能.以前的研究提出了一个性能目标:缺陷发现率(APFD),以及很多改善缺陷发现率的技术.但是这些技术运用起来非常昂贵,而且可能不会减少回归测试的成本.在以往研究的基础上,提出了一个成本-收益模型,为比较各种排序算法提供了一定依据.并在此基础上,提供了一个测试用例排序算法.     

A survey of tools and methods used by certified professional ergonomists

A survey of Certified Professional Ergonomists (CPEs) was conducted to gather information on the types of basic tools, direct and observational measurement techniques, and software used by practitioners. The motivation for the survey was to better understand what types of tools and methods practitioners use, their opinions of these tools, and to potentially gain an understanding of the constraints or preferences that influence this selection. Reasons for using or not using a selection of tools were also surveyed. Of 578 surveys that were delivered to CPEs and Associate Ergonomics Professionals, 308 were returned for a response rate of 53%. The respondents tended to be biased towards physical ergonomics, as the survey primarily focused on this area of ergonomics. A high percentage of respondents reported using tape measures, video cameras, stopwatches and digital cameras. The most commonly used observational methods were those involving manual materials handling, whereas the most commonly used direct measurement tools were pinch and grip dynamometers and push/pull gauges. The frequency and type of checklists, software, and anthropometric data used are summarized.     

The three-year economic benefits of a ceiling lift intervention aimed to reduce healthcare worker injuries

Ceiling lifts are frequently advocated to mitigate risk of injury to healthcare workers when lifting, transferring, or repositioning patients. A longitudinal case-study was conducted in an extended care facility to evaluate the efficacy of overhead lifts in reducing the risk of injury beyond that previously reported for the first year post-intervention (Am. Assoc. Occup. 50 (3) (2002) 120-127, 128-134). Analysis of injury trends spanning 3 years pre-intervention and 3 years post-intervention, found a significant and sustained decrease in days lost, workers' compensation claims, and direct costs associated with patient handling injuries. The payback period was estimated assuming that pre-intervention injury costs would either continue to increase (0.82 years) or plateau (2.50 years) in the year immediately preceding intervention. The rapid economic gains and sustained reduction in the frequency and cost of patient handling injuries beyond the first year strongly advocate for ceiling lift programs as an intervention strategy.     

Toward more effective management of information technology benefits

A critical issue facing senior executives is how to improve the return on their information technology (IT) investments. The results of numerous studies are inconclusive as they have failed to show conclusively that IT investments produce expected payoffs. The purpose of this paper is to offer an explanation for the perceived lack of IT payoff and show how managers can improve the return on their IT investments. We argue that IT can provide significant benefits, but in many cases these benefits are not captured by the firm that made the investment. Instead, a large portion of the benefits are reaped by a variety of participants or stakeholders. The implications of this for managers is that they need to view IT payoff as a portfolio of benefits across many stakeholders. They must also understand and manage the distribution of the benefits within the portfolio to assure that benefits are transferred to the bottom line. The paper offers a framework for analyzing the nature and distribution of IT benefits among various stakeholder groups and concludes with a set of guidelines for measuring and managing these benefits.     

Measurement instruments and data collection: a consideration of constructs and biases in ergonomics research

Theoretical assumptions become valid only when they are tested empirically. Whenever measurement instruments are used one needs to be sure that they yield accurate information for the construct of interest. This article outlines the measurement instruments properties and their impact on research as well as the differences and similarities between biases that could occur in different measurement and data collection procedures. Important criteria that must be met when developing a new measuring tool are presented in detail. The purpose of this review paper is to gather and organize the relevant information regarding measurement bias in research. It outlines important steps that will lead to a decreased error in measurement and data collection. As more and more ergonomic decisions are taken, based on the research outcome, the impact of the quality of measurement in various intervention programs becomes increasingly critical.

Relevance to industry

Ergonomic interventions, ergonomic work and work place designs based on investigational results can only be sustainable if they are valid. Considerations regarding reliability and validity of these strategies are of importance to industries.     

Development and design of a dynamic armrest for hydraulic-actuation joystick controlled mobile machines

Standard armrests used in conjunction with joysticks of heavy mobile machinery have been proven to inadequately meet operator needs, resulting in excessive static loading of shoulder musculature. During joystick operation, the trajectory of the user's forearm is governed by the motion of the controller, which creates horizontal and vertical movement of the forearm. The vertical motion of the forearm in the forward and backward motion create postures that stationary armrests cannot support thereby generating increased muscle activation and risk of repetitive strain injuries. The current paper describes the design process used in creating a dynamic armrest that replicates the operator's natural motion trajectories. By incorporating the natural motion paths into a dynamic armrest, the postural requirements and muscular activation of the operator's shoulder may be reduced.     

《商务办公应用》课程改革与创新

为了响应国家教委关于加强学生应用动手能力的指示精神,早在2005年,江西农业大学南昌商学院为了提高学生应用动手能力,更好地与市场人才需求相结合,江西农业大学南昌商学院开始以商学文化、商学素养、商务能力为目标,提出抛开以计算机等级考试为目的的应试性计算机基础教学,开设更加实用,应对市场需求的课程,以提高学生真实计算机操作水平。     

Source document position as it affects head position and neck muscle tension

Abstract

Measurements of head position, mechanical load at C7, and level of muscle EMG activity in the muscles of the neck were compared across six document positions in both a reading task and a typing (word processing) task. Source documents, identified as a primary visual task, were placed in two positions in front of the subject, flat on the table to each side of the keyboard, and on a document stand at each side of the keyboard. Each of the 20 subjects performed both a reading task and a typing task in each of these document positions while measurements were taken. It was found that the greatest variations in head position occurred in head rotation with documents flat on the table. This document position on each side also produced the greatest level of muscle tension in both the neck extensors and, to a lesser degree, the sternocleidomastoid muscles. In addition, greater variability between document position measures was found in the typing condition.     

Forty years of IEA: some reflections on the evolution of ergonomics

This paper is the IEA Presidential Address to the 1997 IEA Triennial Congress in Tampere, Finland. The evolution of ergonomics prior to and after the foundation of the International Ergonomics Association in 1957 is reviewed. Ergonomics has broadened from considering work activities to include all types of human activities. The recent introduction of computers has changed many of the premises for work and leisure activities, and cognitive ergonomics is now as important as the ‘biological’ emphasis that was mentioned in the founding documents of IEA. Ergonomics is a science of design. There are three important targets for ergonomics design activity: to improve safety, productivity and operator satisfaction. A systems approach is presented to define how these parameters interact and how they can be measured.     

Corporate-internal vs. national standard – A comparison study of two ergonomics evaluation procedures used in automotive manufacturing

Manufacturing corporations sometimes use corporate-internal procedures to evaluate and monitor the ergonomic status of the workplace. This article describes an industrial case study in the Swedish automotive sector, where an internally developed evaluation procedure was compared with a procedure based on a Swedish national standard provision.It was found that the national standard procedure tended to give more severe ratings and statistical support shows that the two evaluation procedures are not equivalent. The ability of the methods to identify body segments at risk was also compared.The quantitative comparison was followed up with interviews, where the influence of professional tasks and objectives became evident, as well as the fact that evaluation criteria are quantified differently by the two procedures. The main finding is that unforeseen differences in analysis procedure, criteria of acceptability and levels of detail can cause use-related difficulties for different professional groups when methods are used interchangeably.

Relevance to industry

Industrial corporations wishing to monitor ergonomics consistently are advised by the authors to ensure that ratings from internal evaluations are interpreted the same way by all involved personnel, and that they at least have criteria levels equivalent to those of a national standard.     

Effect of Task Complexity and Stimulus Duration on Perceptual-Motor Performance of Two Disparate Age Groups

Abstract

This study was concerned with two task dimensions, complexity and stimulus duration, which previous research had shown to accentuate or reduce performance. differences between age groups. Young and old groups made an unguided movement at the onset of one stimulus light in a four-light display. Task complexity was varied by altering the number of response alternatives (1 or 2) while holding the display constant. Two stimulus durations were used: 0110 sec and 2.0 sec. Old subjects reacted 30 per cent slower and moved 7G percent slower than young. Both reaction time and movement time were slower for the complex task than for the simple. The difference between simple and complex movement time was significantly greater for old subjects than for young./ Young subjects moved faster with the 0.110 sec stimulus while old subjects moved faster with the 2.0 sec stimulus.