An ergonomics study of the check-out system for self-service shops in Sweden

This thesis is concerned with the design and evaluation of a checkout system in self-service shops in Sweden. The aims were (a) to study the ergonomics of the development of a new check-out system which is to be part of a new automatic data handling system in retailing, and (b) to evaluate certain ergonomics methods used in a system development programme. The thesis falls into five parts. The first deals with a system analysis of check-out systems in self-service shops. The second consists of a literaturereview of the ergonomics of keyboards relevant to cash register design. The third describes an experimental evaluation of two keyboards suitable for use with cash registers. The fourth describes surveys, involving interviews, cuestionnaires and observational studies, on customers and cashiers using and working in self-service shops. In the fifth and final part experimental and survey results are discussed and interpreted. The principal results obtained can be summarised as follows. (a) For ten button keyboards speed and accuracy of performance is better with the keys 123 on the top row and the keys 789 on the bottom row, than conversely. Cashiers generally prefer the 123 to the 789 keyboard. (b) A new cash desk (into which the 123 keyboard may be placed) incorporating two moving conveyor belts, which has recently been introduced into self-service shops has improved working conditions for cashiers. Suggestions are made on how the cash desk may be further improved from the point of view of both cashiers and customers. (c) Important relationships between results obtained from interviews involving the reporting of critical incidents, questionnaires and observational studies are reported and the methodological implication of these relations reviewed.