To efficiently leverage digitalization potentials for large proportions of manual processes, workers must be integrated in the digital world in a seamless manner. This paper contributes to the ongoing research on Digital Assistance Systems. In particular, manual assembly processes in aircraft production are scrutinized to identify specific requirements for such a system. Following the resulting analysis, we propose a concept for user-centric digital assistance that uses smart, localized hand tools and provides workers with information based on a digital twin of the product and the production process. The proposed digital assistance system accurately tracks the tool position and enables event-based and bidirectional data flow between workers and a digital twin. The tools are automatically configured with the correct process parameters based on their current position. Quality and progress are documented and ultimately operations and everyday efforts are simplified. The concept is examined for its potentials on productivity and quality in manual assembly processes. The results show that further development of the concept promises significant improvements in manual work.
