Part 4 - Ergonomics, the scientific study of work

Ergonomics, or the scientific study of work, is a branch of science which involves the consideration of people at work in terms of;

a) their human characteristics;

b) the tasks they undertake;

c) the machinery they operate;

d) the environments within which they work.

Ergonomics is also concerned with how these various factors affect what is known as 'the total working system'. A more appropriate definition might be "human factors engineering" or "fitting the task to the individual".

Ergonomics embraces a number of disciplines including physiology, anatomy, psychology, engineering and environmental science.

It examines, in particular, the physical and mental capacities and limitations of workers taking into account, at the same time, psychological factors, such as learning, individual skills, perception, attitudes, vigilance, information processing and memory together with physical factors, such as strength, stamina and body dimensions.

Ergonomics is concerned with maximising human performance and, at the same time, eliminating, as far as possible, the potential for human error.

Main areas for consideration

1. The human system

People are different in terms of physical and mental capacity. This is particularly apparent in the case of the physical elements of body dimensions, strength and stamina, coupled with the psychological elements of learning, perception, personality, attitude, motivation and reactions to given stimuli.

Other factors which have a direct effect on performance include the level of knowledge, training received, personal skills and experience of the work.

2. Environmental factors

Consideration of the working environment in terms of layout of the working area and the amount of individual workspace available, together with the need to eliminate or control environmental stressors, is an important feature of ergonomic design.

Environmental stressors, which have a direct effect on health of people and their subsequent performance, include noise, vibration, extremes of temperature and humidity, and poor levels of lighting and ventilation.

3. The man-machine interface

Machines are designed to provide information to operators through various forms of display, such as a temperature gauge. Similarly, the operator must ensure the correct and safe operation of the machine through a system of controls, such as push-button "STOP" and "START" controls, foot pedals or manual devices.

The study of displays, controls and other design features of vehicles, machinery, automation and communication systems, with a view to reducing operator error and stress on the operator, is a significant feature of design ergonomics.

Factors such as the location, reliability, ease of operation and distinction of controls together with the identification, ease of reading, sufficiency, meaning and compatibility of displays are all significant in ensuring correct and safe operation of work equipment.

4. The total working system

The ergonomic approach can be summarised under the 'total working system' thus:

Human characteristics

Body dimensions, strength, physical and mental limitations, stamina, learning, perception, reaction

Environmental factors

Temperature, humidity, lighting, ventilation, noise, vibration, airborne contamination

Man-machine interface

Displays, controls, communications, automation

Total working system

Fatigue, work rate, posture, productivity, accidents and ill health, health and safety protection

All of these factors need consideration in the design of working systems to achieve the best level of performance.