Analysis of interaction quality in human-machine systems: applications for forklifts

The aim of the work presented here was to propose a methodology for analysis of interactions between humans and machines. The driver-truck system in a warehouse context was used as a case for empirical evaluation. The work consists of three empirical studies and one analysis of statistical data. In total 29 pallet truck drivers have been involved in the studies which were performed at two Swedish distribution companies. A framework is proposed, where effects on performance, safety, subjective experiences and physical and mental impact on the humans are used as indicators of the quality of interactions. The results show that the methodology proposed supports appropriate input for the evaluation of the interaction quality between humans and technology. One example of this is musculoskeletal loads and discomfort, which could be related to the task and the design of the steering arm. Another conclusion from this work is that many factors outside the warehouse truck affect the interaction in the human-truck system, for example the design of loading ramps. This supports the importance of having a holistic ergonomics view when studying a human-machine system.