Ergonomics: Basics, Scope and Benefits

---

The term ergonomics, which was used for the first time by Wojciech Jastrzebowski in 1857, is literally derived from the Greek ergo (meaning work) and nomos (meaning law). While it has its roots in several branches of study such as work physiology, biomechanics, and workstation design, its close synonym, Human Factors, has its origin in experimental psychology with the focus in human performance and systems design. Use of the term human factors tends to be a North American phenomenon with individuals concerned with above the neck processing (perceptual and cognitive processes as in research, teaching and practicing).

Whereas in the rest of the world, ergonomics is used to refer to both above the neck and below the neck processing. Despite these differences between them, the two approaches are coming closer, and there appears to be a growing consensus that human factors and ergonomics refer essentially to the same body of knowledge. For all practical purposes these two terms may be used interchangeably in all situations.

The breadth of this field of knowledge depends on how critically the term work is defined. It may be interpreted as

1. Activities directly associated with the occupation the humans engage in, and
2. Physical expenditure of energy to accomplish the intended purpose.

Thus, the activities or tasks being performed by the humans, including the bodily processes, constitute what is considered to be the work of an individual. Analysis and design of this work in its totality is the main concern of this important field of study.

A number of definitions of ergonomics, as they are found in various literature, are given in Tables 1 (a) and (b).

Table 1(a): Example Definitions

Brown, O., and Hendrick, H.W. (1986)	The relations between man and his occupation, equipment, and the environment in the widest sense, including work, play, leisure, home, and travel situations.
Chapanis, A. (1995)	Is a body of knowledge about human abilities, human limitations and other human characteristics that are relevant to design.
Hancock, P.A. (1997)	Is that branch of science which seeks to turn human-machine antagonism into human-machine synergy.
Mark, L.S. and Warm, J.S. (1987)	Attempts to optimize the fit between people and their environment.
Howell, W. and Dipboye, R. (1986)	Person-machine system design.
Meister, D. (1989)	The application of behavioral principles to the design, development, testing and operation of equipment and systems.
Clark, T.S. and Corlett, E.N. (1984)	Study of human abilities and characteristics which affect the design of equipment, systems, and jobs and its aims are to improve efficiency, safety, and well being.
Sanders, M.S. and McCormick, E.G. (1993)	Designing for human use.
Wickens, C.D. (1992)	Is to apply knowledge in designing systems that work, accommodating the limits of human performance and exploiting the advantages of the human operator in the process.

Table 1(b): Definitions - Major Focus

1. Designing and engineering human-machine systems.
2. Applying science to people performing in working environments.
3. Studying man's limited capabilities related to safe job operation.
4. Improving knowledge on the fit between users and tasks.
5. The interface between people and machines in systems.

Problems at the Workplace and Ergonomics

There are various kinds of problems related to

1. The work or the task to be performed,
2. The humans responsible for the work or the task,
3. The environment where humans work, and
4. The interfaces between work, humans, and environment.

All of the above affect and determine the level of human performance and production output at the workplace.

Irrespective of the type and level of technology employed at the workplace, the problems related to these aspects cannot be eliminated completely as the technology in use is being assessed continuously, and no two persons can work exactly in the same way on the same job because of differences in inherent capabilities and responses to work environment and work systems among humans.

The primary concern of ergonomics being the design of the workplace as a system so as to achieve the best possible performance from the humans consistently and continuously, an interdisciplinary knowledge in relevant fields, such as work physiology, biomechanics, psychology, engineering, systems design and cybernetics, is needed to

1. To formulate systems goals,
2. To understand functional requirements,
3. To analyze the system,
4. To design a new system, and
5. To implement the system.

Thus, to resolve any problem of this nature at the workplace, ergonomics is most likely to offer a set of solutions (not only one, but a set of alternatives) leading to

1. Increase in productivity of resources and efficiency in production equipment,
2. Safe working methods,
3. Improved health of humans with minimization of hazards, and
4. Design and maintenance of a comfortable work environment.

In the long run, the operations at the workplace are required to be obtained with minimum cost and maximum quality of products and/or services ensuring an acceptable and standard quality of work life for the humans. As ergonomists come from a variety of professional fields, it becomes easier for them, as a group, to approach the problems at the workplace in an integrated and holistic manner.

However, due to several reasons, the potential of ergonomics has not yet been fully explored. Except in some developed Western countries, industries in developing countries have hardly implemented ergonomics in their workplaces. In a survey, it has been mentioned that people outside this field are hardly aware about its importance. However, as technology becomes complex, and design of interface between growing technical systems and their human users becomes crucial, in the near future the need to successfully implement ergonomics at the workplace is expected to be felt by the designers and the users alike.

In this article, an attempt has been made to highlight certain critical aspects of workplace system in industries which need to be assessed through the tools and techniques of ergonomics. A general methodology to conduct investigation and research in ergonomics for industrial operations and resources with the objective of ergonomic improvements is suggested.

Basic Approaches in Ergonomics

Ergonomics originated as a consequence of the design and operational problems presented by new work systems that have evolved with the advance of technology. In this context, two approaches, viz., fit the man to the job (FMJ) and fit the job to the man (FJM), have been suggested as a viable alternative to improve and sustain productivity and economy of human-machine work systems with job satisfaction, health, and capability of the humans as the core issue or objective. It has also become clear that FJM is almost always the superior approach to the design of work system. The underlying assumptions of the FJM approach are that a suitable set of operator/human characteristics can be specified around which a job can be designed, and that this can be done for any job. The content of ergonomics is primarily directed to describing these characteristics at the anatomical, physiological, and psychological levels, and explaining their design implications.

Only under extreme circumstances the FMJ approach may be the only option. For example, the workers requiring acclimatization have to work in hot conditions which cannot be changed. But, there may be several FJM options like designing a better work-rest schedule, providing protective clothing, etc.

A Brief History of Ergonomics

Although the emergence of ergonomics as a separate branch of study is a recent phenomenon, the concept of ergonomics used to be applied even in ancient times, and hence ergonomics is nothing new. Even during the Stone Age, individuals used to design hand tools to fit the user and the task. During the Industrial Revolution, efforts were made to apply the concept of a human-centered design to tools, the objective being allocating interesting jobs to the humans and repetitive tasks to the machines.

When the field of ergonomics was introduced after the World War II in the UK, its focus was on equipment and workspace design, and its relevant subjects were anatomy, physiology, industrial medicine, design, architecture, and illumination engineering. In Britain, the Ergonomics Research Society was established in 1950. In other parts of Europe, notably France, Germany, Netherlands, and the Scandinavian countries, ergonomics is a well-established discipline and research field with even labor unions taking an active interest in its promotion as being important for safety, health, comfort, and convenience.

In USA, human factors emerged as a discipline also in the early fifties. As has already been pointed out, human factors have much in common with ergonomics. But their development has moved along somewhat different lines. Human factors have achieved remarkable success in the design of large systems in the aerospace industry (in NASA and space programs). But, the applications in manufacturing are fairly recent. Eastman-Kodak and IBM are the two companies, among others, where ergonomics has been applied substantially, and most of these programs have been undertaken by industrial engineers and company nurses. Some other agencies in this field have sponsored research on civilian applications, such as design of highways and road signs, human capabilities and limitations in space, design of cars, effects of drugs and alcohol on driving, ergonomics in underground mining, safe design of consumer products, injuries at workplaces, industrial safety, work or job stress, design requirements for nuclear power plants, and aviation safety. Recently, the Human Factors Society in the USA has changed its name to the Human Factors and Ergonomics Society.

Both human factors and ergonomics take the FJM approach and state that jobs should be made appropriate for people rather than the other way around. The basic human characteristics in the context of job design and analysis have been investigated by the ergonomists. However, as it is an evolving and interdisciplinary subject, the boundaries of ergonomics are not clear.

In India, the application of ergonomics has been very limited till now, considering the enormous size of our industrial and agricultural base. Only a few attempts at the individual levels have been made. When the design of a productive work systems run by motivated, healthy, and efficient humans becoming a core issue so as to stay competitive with cost-effective methods and procedures being employed, it is essential that organizations of any type apply this important concept for a better design of the products, services, and working environment in future.

Modern Ergonomics

Ergonomics these days contributes to the design and evaluation of work systems and products. The ergonomist has an important role to play at the conceptual, detailed design, prototyping, and evaluation phases of existing products and facilities. The various ways ergonomics can contribute in the design of work systems are briefly explained in the following sections.

Standard Format for Describing Human-Machine Systems

It involves description of the technology, and the user or operator. As machines or technologies are usually described in detail, and less detailed information on humans are made available, a major task of the ergonomist is to describe the humans in detail at all levels appropriate to the particular system. This entails a physical description in terms of the following characteristics of the user:

1. Dimensions (anthropometry) and abilities.
2. Physiological factors such as age, gender, and fitness.
3. Skills, knowledge, experience, motivation, and ways of working.

Identification and Classification of Design Issues

A major role of ergonomics is to identify design issues which involve the human component of the work system, and to classify them in order to render them amenable to further analysis using appropriate knowledge. Many a time, a standard method is required to enable system-specific design issues to be identified and interpreted in general terms amenable to analysis using available data. However, there could be classification problem in a situation where physical changes in work system may be accompanied by physical complaints, though they may not be the direct cause of these complaints. For example, headaches by VDT-workers may be caused by problems in work organization, not by a change in workspace design.

Proper classification of design issues and their implications is a crucial step in the design or redesign process. It is the task of the ergonomist to investigate the problems of say, accidents, breakdowns, or low productivity in a work system from a systems perspective to determine the relative contributions of inappropriate human behavior, and inappropriate system design. Analysis may be undertaken to determine the following:

1. Which aspects of the design of the work system degrade performance, and
2. How the system can be redesigned to solve the problem.

Task and Human-Machine Interaction Analysis

At this stage, task analysis is done formally by breaking tasks down into their various components in a structured manner to identify the behavioral characteristics required of the humans in the context of application of fundamental ergonomics principles in the work system. Ergonomists have developed formal ways of analyzing tasks, which include hierarchical representation of task behaviors, observational techniques for data collection on behavior involved in carrying out the task, and representation of dynamic aspect of human-machine interaction. The outcome of a typical task analysis consists of

1. Description of the behaviors required to carry out the task,
2. Description of the system states that occur when the task is done, and
3. Mapping of the task behaviors on to the system states.

Although this kind of analysis may produce enormous volume of data about system operation and human behavior, it is often essential to describe tasks at this level of detail, particularly for complex systems, which provides a context for the application of ergonomics principles and guidelines. It assists the design team in prioritizing issues according to their importance to system operation regardless of personal preferences and skill profiles of the team members.

Specification of System Design and Human Behavior

Many kinds of standards and guidelines for better and efficient control of working condition have been developed by the researchers in ergonomics. The areas where they are available are lighting design, noise control, indoor climate, manual handling, seating, and anthropometry.

Table 2: Some Sources of Published Standards and Guidelines

	United States	Europe
Lighting	IES Handbook, illumination Engineering Society (IES) of North America	British Standard CP3, British Standards Institution (BSI) CIBS Code for Interior Lighting, London, UK Commission Internationale de Iâ Eclairage (CIE) publications
Noise	Industrial Noise Manual, American Industrial Hygiene Association Occupational Safety and Health Administration (OSHA) exposure limits American National Standards Institute (ANSI) publications	International Organization for Standardization (ISO) publications, e.g., ISO 1999 (1972) BSI publications
Climate	American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) publications OSHA publications	ISO publications, e.g., ISO 7243 (1982) BSI publications (reactions to surface temperatures)
Manual handling	NIOSH (National Institute of Occupational Safety and Health) Work Practices Guide (1981, weight limit equation revised 1993). DHHS (Department of Health and Human Services) (NIOSH) Publication no. 94-110.	University of Surrey, U.K. Force Limits in Manual Work European Community (EC) Directive on Manual Handling (1991) HSC (Health and Safety Commission, U.K.) Proposals for Regulation and Guidance, 1992
Seating/VDTs	ANSI/HFS 100-1988 National Standard for Human Factors Engineering of VDT Workstations	EC Directive on Work with Display Screen Equipment, 1990. HSC Proposals for Regulation and Guidance, 1992
Anthropometry	NASA Anthropometric Source Book	Pheasant, 1986.

Table 2 summarizes available sources of these standards, which are applicable mainly in the USA and Europe. For any professional ergonomist, it is essential to develop a deeper understanding of these standards, particularly to know when to look for the standards, how to find them, and how to apply them.

Identification and Analysis of Core Trends

Ergonomics has until now generated many design guidelines and recommendations which are readily made available to engineers and designers. However, they should be used with utmost caution and be interpreted in the context of specific and critical problems, say back injury or heat stress. As ergonomists know the rationale for a given guideline or standard, they are required to modify it in accordance with local requirements.

Generation and Implementation of New Concepts

The ergonomist has an important role to play at the concept generation stage, and must analyze the reasons for current or proposed design, and suggest improvements and alternative concepts. There could be several schemes of recommendation for ergonomic improvements and they should be prioritized in the following ways:

1. Implement recommendations immediately (design flaw/defect or working conditions threatening employee health, or system reliability)
2. Implement recommendations soon (current method of working is not satisfactory, but there is no immediate danger)
3. Implement when equipment is shut down (wait until the system is shut down for regular maintenance or repair)
4. Implement when cost-benefit ratio is acceptable
5. Implement when equipment is purchased or introduced

Evaluation of Socio-Technical Implications

As ergonomists are involved in the design or redesign of a new or existing work system, they must determine their implications for the organizational climate, and anticipate future problems. For successful implementation of new designs in the workplace, participatory approach to system design and development may become very crucial.

Future Directions

Ergonomics as a discipline has been developing in several directions. Important areas where ergonomics may be playing a pivotal role are many. Some of these areas are follows:

1. With rapid developments in information and communications technology, the problems of human information processing and its integration with machine information processing need to be addressed, and recommendations and guidelines for interfacing these two systems need to be developed under different work situations.
2. As ergonomists are concerned with the effect of work system design on the health of the workers, epidemiological research into the effects of good and bad design on health has become a critical issue,
3. As standards and guidelines are to be developed and implemented in work systems for ergonomic improvements, it is necessary to draft implementable, and objectively assessable standards for workplace design in different industries. As the ergonomic applications are very few in Indian industries, the types of approaches (example - NIOSH approach for manual lifting tasks, which have already been implemented in developed countries) have to be taken up. The other areas where ergonomists should engage themselves in on priority basis include applied anthropometry in workspace and equipment design, computerized design aids to facilitate visualization of physical interaction between users and work or hardware, like SAMMIE (system for aiding man-machine interaction evaluation, designed by SAMMIE CAD Ltd., UK), study on working postures for industrial jobs, determination of acceptable workload and work capacity of humans in different occupations, and design of physical environment.

The so-called technology push may be identified as one of the main factors influencing the direction and growth of this discipline. Many of the techniques developed by ergonomists in industrialized countries can be directly applied to the study of problems in developing countries as well. Ergonomics provides a standardized approach to the analysis of work systems with main emphasis on interactions between humans and machines.

---