A product with good interaction quality regarding the interplay with the user produces good performance, is experienced easy, pleasant and enjoyable to use, is preventing the user of committing errors, and has no adverse physical or mental impact on the user. The aim of the presented work was to propose a framework for interaction quality, and to develop and test a methodology for analysis of interactions between humans and machines. The driver-(warehouse)truck system was used as a case for empirical evaluation. In total 29 pallet truck drivers were involved in the work that consisted of three empirical studies performed at Swedish distribution companies. In addition, statistical data from truck related diseases and accidents was analysed.

The proposed framework includes the following factors that are considered as indicators of interaction quality: performance (e.g. learning times), subjective experiences (e.g. driving feeling), safety (e.g. character of accidents) and physical & mental impact (e.g. back pain). The methodology consists of existing methods in the ergonomics field that assess the framework factors (e.g. physical discomfort ratings to measure physical impact).

In the evaluation of the design of different parts of the truck, examples of both good and insufficient interaction were identified. As an illustration of this, the empirical studies showed that the lowlifting truck platform caused deficient interaction due to its suspension and physical dimensions. As a result a new platform design (a prototype) was developed with a new principle of suspension.

It was concluded that the proposed framework and methodology give valuable input for the evaluation of the interaction quality between drivers and trucks.