## 2 Related Literature
### AR Assistance in Processes
Research presented in [35] confirms that picking guidelines provided via AR tools to the operator improve the time efficiency of the process and the accuracy of the picking itself. The results of the tests in [36] indicate the competitiveness of the use of AR solutions in terms of the accuracy of reaching a set location. Support of the precise identification of the location and the navigation of the work of the operators is also confirmed by the research presented in [37]. In addition, the results described by [PERSON] et al. [37] show that, by providing operators with information and checking their correct execution with AR tools, it was possible to reduce the execution time of individual operations and improve the efficiency of the entire process. There is a much smaller proportion of studies on the application of AR in other key warehouse processes. However, as [PERSON] et al. [38] demonstrate, implementing this technology in receiving, storing and shipping processes has similar effects to those noted in the picking process. In [39], authors present interesting results from a study in which a few AR pieces of equipment have been examined (handheld versus head-mounted) to determine which have the largest impact on adult learners' ability to retain information. The learning tools have been tested at the National Holocaust Centre and Museum in Newark. It has been found that adult audiences react differently than child-teenage audiences and that the amount of information retained in the immediate aftermath of a learning experience is higher after a classroom lesson than after the use of the AR tool. It shows that the effect of AR use depends on conditions and the form (determined often by an used AR tool) in which the technology is implemented. In addition, research by [PERSON] et al. [34] indicates that familiarity and experience with AR tools are critical individual factors that significantly affect results. Their tests clearly indicate that those familiar with the technology benefit more from using AR tools. Consequently, [PERSON] et al. [34] emphasize the need to adapt implemented AR tools to the specific needs and characteristics of the workforce. AR solutions have also been applied and tested in the air industry. The majority of findings are reported from studies in which the AR technology is used for operators' training (e.g., simulators for pilots [6], training programmes for operators inspecting aircrafts during the de-icing procedure before take-off [40] or the trainings of air accident investigators [5]), for supporting an operator's work in an airport control tower [41], for supporting the navigation of passengers in airports [22], for the support of an operator in an airport cargo warehouse [42] and for dynamic route-planning of the airport baggage handling systems [43]. Digitalization in air-transport-related areas usually has the main function of assisting human decision-making by making information and data more accessible [6]. [PERSON] at al. [6] present a review of the scientific literature on digital needs at airports and present ideas for future air transportation development in this area.. The authors find that over 45% of analyzed papers on digital tools used in air transport areas relate to the profession of pilots. The second biggest group of tools supporting airport operations is the group supporting passengers and baggage screening processes for security control. Summarizing, even though papers examining the AR technology used in airports have been found, they have not considered the assistance involved in the handling of special cargo transported by air.