The fact that people are able to use poorly designed equipment, often under difficult working conditions, shows that people are adaptable. They can tolerate small departures from optimal designs of the equipment they use and the environments in which they work. However, there is a limit to the amount of adaptation a person may reasonably be asked to make. Beyond this there is a cost. The cost can be in terms of efficiency in doing a job, discomfort, frustration and dissatisfaction on the part of the user, and the potential for accidents and personal injury. If the user is attempting to use a marketed product such as a software package, the difficulty of use experienced is likely to affect the market success of the product.

These problems can be avoided if an ergonomics approach is used. This is particularly the case where ergonomics is applied in conjunction with systematic design and evaluation techniques which emphasise the central place of the user.

A user-centred approach to design and evaluation may produce these benefits:
- lower injury and accident rates
- improved reliability
- products that are easier to use
- systems and products that operate efficiently
- greater user comfort
- faster learning times
- fewer errors
- easier maintenance
- improved aesthetics
- a general increase in job satisfaction
- less absenteeism
- less labour turnover (with less recruitment, training time, down-time costs).
- improved competitiveness of products and services
- increases in productivity.

The following three examples illustrate what can occur when resources are invested in the application of ergonomics:

Example 1: User-friendly invoices
An invoice format used by Telecom Australia was responsible for 46% of customer complaints or enquiries phoned through to the company. Ergonomic redesign reduced this to 4%. Users were involved in tests of the invoices at several stages of the redesign process.

Example 2: Redesign in an assembly plant
In a study spanning 12 years, an ergonomics approach was used to solve problems of work-related illness, high staff turnover, and low company productivity in a Norwegian telephone assembly plant. Following ergonomic redesign of the workstations and the work environment, long-term sick leave and labour turnover decreased markedly, while company productivity increased. The net savings to the company were estimated at NKr 3.3 million (an eight-fold return).

Example 3: VDU workstation and job redesign
An ergonomic study evaluated VDU operalions in an airline computer centre in Singapore. Changes were made to the workplace, lighting, and the design of jobs. As a result, reports of muscle fatigue decreased by 50%, visual fatigue decreased by 30%, and keystrokes per hour improved by 25% with an error rate reduction from 1% to 0.1%.