The Assessment of Ergonomics and Usability of Consumer Products - Four Case Studies on Hand Tools

Abstract

Manufacturers are seeking solutions for gaining an advantage over their competitors. Improvement of ergonomics and usability of consumer products can give increased market value and has a major impact on the users safety and pleasure as well as the performance and productivity of work. In the competitive marketplace manufacturing firms are forced to design better performing products at a remarkably rapid pace. This creates new challenges for the integration and testing of ergonomics and usability.

The objective of this study was to find ways to integrate ergonomics and usability issues into the process of development and design of consumer products using hand tools as an example. The purpose was to find ways to support the development and design process in order to be able to create more usable products.

Four different approaches supporting a user-centred process of designing consumer products in the area of ergonomics and usability are described: 1) collection of ergonomic design criteria based on existing information and classifying them to be used as supportive material in hand tool design, for example with the Quality Function Deployment method (QFD); 2) use of a questionnaire and risk analysis method to investigate the ergonomics and usability of hand tools used by electricians working on telecommunications and electricity transmission masts in a cold climate; 3) assessment of the ergonomics and usability of hand tools by electromyography (EMG) and subjective opinions during the process of designing a garden pruners; 4) investigating the force demands during simulated cutting using lacquered, chromium-coated and polytetrafluoroethylene- (PTFE) coated cutting hand tool blades. The first two approaches can be used as pre-screening methods for gaining information which can be applied in product design. The latter two are more direct methods based on the measurement of certain product characteristics and provide results and improvement suggestions for particular design cases.

Ergonomic design criteria for pliers-like hand tools were found and collected from literature. The data is presented as a detailed list and classified to be used as supportive material for hand tool design, for example in conjunction with the QFD method. It was possible to investigate the usability and ergonomics of hand tools using a questionnaire and a risk analysis. The falling of hand tools was ranked as the main risk in working on telecommunications and electricity transmission masts in a cold climate. Physiological and subjective methods were used to assess the usability and ergonomics of garden pruners during the process of designing a new tool. By performing the measurements in two parts and comparing different tools and prototypes, it was possible to integrate ergonomics and usability into the design process. PTFE-coated blades were found to create the lowest force demands compared with chromium-coated and lacquered blades.

The main benefit of these different approaches was that they provided information which could be applied in different settings in further design cases as well as direct results applicable in current product design. As a result of the research, more ergonomic and usable hand tools were supplied to the market.

Keywords: Ergonomics, usability, human factors, design, hand tool, safety, telecommunications, electricity transmission, PTFE