# Augmented Reality in a Lean Workplace at Smart Factories: A Case Study
## 1 Introduction  
The fourth industrial revolution, or Industry 4.0, has captured the attention of academics and organizations due to the significant changes in technology and manufacturing processes in recent years [1]. It is being compared with the previous three industrial revolutions that occurred in the last centuries [2] and can be described as a complex technological system that is focused on the creation of smart products and processes, using smart machines and transforming conventional manufacturing systems into smart factories [3]. This new industrial paradigm holds a huge potential and will bring new opportunities to organizations that are moving toward Industry 4.0, having further impacts on the industry, markets, economy, products, and business models and completely changing the current workplace and the work environment [4, 5]. Augmented Reality (AR) is one of the disruptive technologies that are also emerging with Industry 4.0, combining the physical world with computer-generated visuals, offering an intuitive interaction experience. It provides real-time interaction between virtual and physical objects, improving work performance and efficiency in manufacturing environments [6, 7, 8], enabling the combination of digital knowledge into the user's physical world in many other areas, such as healthcare, education, retail, Information Technology and entertainment [9, 10]. Moving toward the Industry 4.0 paradigm and implementing emerging disruptive technologies such as AR will enable new types of interactions between humans and machines, transforming the current industrial workforce and workplace and leading to deep impacts on worker tasks and demands in the work environment [11; 12]. To mitigate these impacts, AR tools must be developed with functionalities that allow a user-friendly collaboration between humans and technology, improving performance and awareness in a non-intrusive way to meet industrial requirements, and making people more efficient and effective in their tasks [13]. At the same time, it is important that humans develop such tasks without overburdening or stress or, even, accidents due to workplace unevenness that are considered, normally, symptoms of waste, i.e., all activities that do not add value from the client's point of view [14]. The main goal of Lean Production is \"doing more with less\" [14], where less means less human effort, fewer stocks, fewer resources, less space, and less product development time. Lean Production solutions represents a huge potential for current industrial landscape that integrated with automation, Lean Automation, brings several opportunities for the smart factories context [15]. Nevertheless, less attention has been paid to logistic activities in warehouses or supermarkets, particularly, in the manual handling operations, such as loading and unloading of parts on shelves. This continues to be a highly manual activity in many companies, which increases the ergonomics risks and contributes to the development of MSD. The project described in this paper aimed to evaluate how Industry 4.0 technologies are affecting the HF and workplaces at smart factories, particularly in logistics activities, through the implementation of AR in a Lean industrial environment. The main focus is the improvement of HF, ergonomic conditions and mitigation of Occupational Safety and Health (OSH) risks, studying the potential of Human Augmentation (HA) in logistics activities. HA relies on the use of technologies such as AR to enhance human senses, augmenting their capabilities and cognition. Thus, the project also aimed to address Industry 5.0 principles, solving emerging societal needs through the introduction of industrial developments, and driving the transition to human-centric, sustainable and resilient systems [16]. By utilizing flexible and adaptable technologies, the Industry 5.0 paradigm promotes the agility and resiliency of systems [17]. The implementation of new technologies must be aligned with workers' physical and safety conditions.