A comparative study for the assessment of marker-less mixed reality applications for the operator training

With the rising concept of Industry 5.0, the worker’s needs and well-being are placed at the center of the production process. The use of extended reality can be exploited to provide the operator with interactive training, allowing independent, step-by-step learning in the real environment, with instructional digital contents, superimposed over the machinery in the workplace. This kind of training promotes the operator’s skills, and consequently empowers the industrial competitiveness. The aim of this paper is to assess and compare the effectiveness of two different marker-less mixed reality (MR) applications to train the operator in the wire harness activities over a tractor’s drivetrain. An application based on Azure Spatial Anchors by Microsoft and another one based on the CAD model of the tractor’s drivetrain have been developed and tested through the comparison with the traditional paper-based instructions. On-field trials have been accomplished with 10 end-users. User experience, usability, perceived workload, and training effectiveness have been assessed through specific questionnaires and by analyzing user performances. Even if the Anchors-based app showed better outcomes in terms of effectiveness and acceptability, both MR applications resulted in good usability. Operators’ willingness of using this technology as a standard tool for training and support emerged