Introduction to Human Factors and Ergonomics

Robert Bridger

• Editore: CRC Press
• Anno: 2017
• ISBN:
  9781498795968
• Edizione: 4
• Argomento: Technology & Engineering
• Categoria: Industrial Engineering

Building on the success of previous editions, the 4th edition of 'Introduction to Human Factors and Ergonomics' provides a comprehensive and up to date introduction to the field. The new edition places the subject matter into a system context using a human-machine model to structure the chapters and a knowledge application model to structure the organisation of material in each chapter. Every chapter covers: Core Concepts, Basic Applications, Tools and Processes, and System Integration issues regardless of topic. Includes over 200 exercises and essays (at least ten per chapter). An Instructor's Manual, A Guide to Tutorials and Seminars and and over 500 powerpoint slides are available for academic users from the publisher. All chapters contain 'HFE Workshop' sections with practical guidance and worked examples. Please see the TOC for more information.

1

Human Factors and Ergonomics from the Earliest Times to the Present

General Requirements for Humans in Systems

1.1Equipment is operable and safe

1.2Tasks are compatible with people’s expectations limitations and training

1.3An environment that is comfortable and appropriate for the task

1.4Job aids and training are appropriate to the work

1.5A system of work organization that recognizes peoples’ social and economic needs

In the past, the man has been first; in the future, the system must be first.

Taylor, 1911

Core Knowledge: Understanding Human Factors and Ergonomics

Every time we use a tool or a machine we interact with it via an interface (a handle, a steering wheel, a computer keyboard and mouse, etc.). The core knowledge of HFE describes how best to design tools and machines in order to optimize these interactions and also the effect of the ambient environmental conditions when the interaction takes place. The aim is to maximize compatibility between system components with the main focus on the user.

Compatibility: Matching Demands to Capabilities

Compatibility between the user and the rest of the system can be achieved at a number of levels: biomechanical, anatomical, physiological, behavioral, and cognitive levels. In order to achieve compatibility, we need to assess the demands placed by the technological and environmental constraints and weigh them against the capabilities of the users. The database of modern HFE contains much information on the capabilities and characteristics of people, and one of the main purposes of this book is to introduce the reader to this information and show how it can be used in practice.

Poor system functioning can be caused by a lack of compatibility in some or all of the interactions involving the human operator. This incompatibility can occur due to a variety of reasons. For example,

•Human requirements for optimum system functioning were never considered at the design stage (a failure to integrate HFE in the design process).

•Inappropriate task design (e.g., new devices introduce unexpected changes in the way tasks are carried out and these are incompatible with user knowledge, habits, or capacity or they are incompatible with other tasks)—essentially a failure of succession.

•Lack of prototyping (e.g., modern software development is successful because it is highly iterative. Users are consulted from the conceptual stage right through to preproduction prototypes).

Brief History of Ergonomics

Ergonomics came about as a response to the design and operational problems presented by technological advances in the twentieth century. It is a hybrid discipline that emerged when applied scientists came together to solve complex cross-disciplinary problems, and it owes its development to the same historical processes that gave rise to other disciplines such as industrial engineering and occupational medicine. The core sciences from which ergonomics is drawn are as follows:

•Psychology

•Anatomy

•Physiology

•Physics (particularly mechanics and environmental physics)

•Engineering

It has also been heavily influenced by other emergent disciplines, notably,

•Industrial engineering

•Industrial design

•Systems theory

Scientific Management and Work Study

Scientific management, developed by Taylor, and work study, developed by the Gilbreths, are precursors of ergonomics. Both were developed at the beginning of the twentieth century and were based on the realization that productivity could be improved by redesigning the way work was done and not just by using better machines. Taylor (1911) was a mechanical engineer who is famous for his book, The Principles of Scientific Management (although he also wrote a book about concrete, for which he is not famous). Scientific management was a reaction against the prevalent management methods inherited from the Victorians. Factory owners supplied premises, power, raw materials, etc., and hired foremen to organize the work. These foremen acted rather like subcontractors and were left to themselves to organize the basic industrial tasks as best they could. Management was concerned only with output and had just a global notion of productivity, regarding the work itself with disdain. Incentives were provided for employees to suggest improvements and profits depended on getting a “good man” in to organize the workers.

Taylor realized that there were many drawbacks to this “incentive and initiative” style of management. Nobody was directly responsible for productivity and the system was open to corruption and exploitation of workers. Weekly “kickbacks” to supervisors were common as was the sexual harassment of women workers (Stagner, 1982). There were few formal ways of generating better designs of systems or work procedures or of evaluating current practice on a day-to-day basis. Workers, by being too narrowly focused on carrying out daily work activities, might be unaware of the scope for improvement through the implementation of new methods, or even unaware of the methods themselves. They might be unwilling to suggest changes that might be in the best interests of the company, but not in their own best interests. Management, on the other hand, through its failure to focus on the way basic tasks were carried out, was incapable of maximizing productivity. As Taylor, himself, put it (1911, p. 7):

… the remedy for this inefficiency lies in systematic management, rather than in sea...