Augmented Reality (AR) systems have seen a rapid adaptation in both training and in virtual assembly instructions. AR systems assist the operator by enhancing user perception of reality, reducing the defects, and lead-time. However, there is a significant lack in the existing literature to compare AR systems and conventional work instructions. The aim of this research is to provide an empirical evidence of comparing task completion time, number of errors, workload index and system usability of AR and conventional paper-based work instructions. For this purpose, we designed an experiment where participants use paper based instructions and AR instructions to assemble a planetary gearbox. The task was assessed using NASA-TLX and System Usability Scale (SUS) tests, which allowed further analysis using descriptive statistics. Moreover, the qualitative interview at the end of the experiment gave more insights about participant’s overall experience.

The concept of the circular economy (CE) is receiving encouraging attention among scholars and practitioners, as a convenient solution to move away from the linear economy concept without neglecting the goals of sustainable development. The main goals of the CE are the closing of resource loops and the keeping of resources in the system for as long as possible at the highest utility level. However, as a result of the lack of internationally accepted definitions of the CE and several unsolved barriers, an excessive and inconsistent number of different CE applications exist. Most fields are mainly focusing on making a linear system circular instead of applying the CE principles in a holistic way. This paper presents a strategy to close the mentioned inconsistency gap, by contrasting currently discussed CE barriers and goals and thereof deriving two areas with a need for action (1. identifying the needed collection, sorting, and recovery infrastructure, and 2. developing circular product design guidelines). The strategy itself consists of connecting these two areas through an improved information exchange between the end-of-life (EOL) and beginning-of-life (BOL) of products. The result is CE design guidelines which are in accordance with the available or needed collection, sorting, and recovery infrastructure. The proposed strategy presents an innovative solution to apply CE principles in a holistic manner, based on EOL-driven product design.

Augmented Reality (AR) applications are beginning to see rapid adaptation in the manufacturing sector. AR systems in the manufacturing industry can assist operators in simple manufacturing tasks, such as virtual instructions, as well as complex remote assistance and maintenance tasks. There are many ways to interact with AR content, commonly known as interaction modalities. These modalities are classified into three categories: touch, touchless, and wearable, or sometimes a combination of more than one modality known as multimodal interfaces. However, in the manufacturing industry, there is no one-size-fits-all solution regarding the interaction with AR content. Current research explores various input interaction modalities in AR and assesses the advantages & disadvantages associated with them in the manufacturing context. We adopt both touch and touchless modalities in our case study of assembling a planetary gear and present the merits and demerits of each modality assessing the extent of natural user interaction with AR content. Interaction with a wearable AR system is not part of this investigation.

A revolutionary computer-generated environment called mixed reality (MR) combines the real and virtual worlds. The MR environment can be created using two rapidly developing technologies: augmented reality (AR) and virtual reality (VR), with varying degrees of awareness of reality. With the introduction of Industry 4.0 (I4.0) in the manufacturing systems, AR and VR technologies have seen adoption in various stages of the product life cycle. AR can improve the manufacturing tasks such as quality inspection, assembly instructions, maintenance, and safety by enhancing reality with virtual aides. On the other hand, VR can be a beneficial technology for training activities. This chapter mainly focuses on different AR systems and their interaction modalities. Moreover, the chapter also covers system architectures for two different AR systems (handheld devices and head-mounted devices) and validates the architectures with relevant case studies. Finally, a brief description of the VR technology is presented with a relevant case study. <!----> <!----> <!----> <!---->