# Design of Cognitive Assistance Systems in Manual Assembly Based on Quality Function Deployment
## 1 Introduction  
Factories of the future will be connected by combining and integrating operation and information technologies [1]. There is a technology leap towards the fourth industrial revolution, also referred to as Industry 4.0 [2]. The digitization of production connects humans, machines and processes within cyber-physical systems or cyber-physical production systems [3], even along the entire value chain in real-time [4]. The term Industry 4.0 covers a wide range of technologies and applications, such as assistance systems, robotics and cobots, additive manufacturing, cloud computing, data mining, artificial intelligence, etc. [5], and follows the overall goal of enabling the manufacturing of highly individualized products at the cost of mass production [6]. Overall, Industry 4.0 is intended to make companies and their production systems more automated, efficient and flexible [7] while, at the same time, enabling them to expand their business model with smart products by digitizing parts of the products and developing new services [8]. At the same time, humans will remain an important part of the factory with their flexibility, intuition and creativity [9]. However, in the context of Industry 4.0, the role of workers in the factory is also changing significantly: workers collaborate with technologiesin human-cyber-physical systems; i.e., they are assisted by systems in the qualification, execution and monitoring of more complex work processes [10; 11; 12]. This can increase process performance and transparency, the product/process quality and, in the best case, increase job satisfaction [13]. The new and evolved Industry 5.0 addresses this relationship between humans and technologies aiming at combining human intelligence with autonomous systems [14], focusing on aspects that have been given limited attention to date regarding the disadvantages for humans resulting from the more intensive use of information technology and automation in production activities [14; 15]. In summary, Industry 4.0 is more technology-focused, while Industry 5.0 concentrates more on the human-centered perspective [16; 17]. Industry 5.0 work systems can, therefore, be understood as a symbiotic collaboration between humans and machines [12] in which technology adapts to humans in an interplay and both follow shared goals. These assistance systems help people by overcoming skill gaps and try to increase social innovation, worker satisfaction and comfort [18; 19]. Production processes and manual assembly processes will be needed in the future [20]. The challenge will lie in how the different workers (age, preferences, skills, etc.) can be supported by intelligent assistance systems [21]. Today, systems are already in use to support workers in assembly tasks by providing work instructions [22], notices about errors, performing automated quality checks [23], documenting process data [24] and more [25]. For the realization of the assistance functions, different technologies such as augmented reality [26; 27; 28], mobile devices [29], wearables [30; 31; 32], projection technologies [33; 34; 35], artificial intelligence [36; 37; 38] as well as different interaction modalities such as voice/speech, gesture/posture control, touchscreen and others are used [39]. These systems have already been validated, revealing that they have productivity advantages and that the workers are more satisfied [40; 41; 42; 43; 44; 45; 46]. This may also be related to the fact that the assistance systems can provide workers with greater autonomy to make their own decisions, or, furthermore, the systems can also be used to perform more challenging tasks and to focus on human strengths, such as communication, social behavior and the ability to work in a team [47]. On the other hand, it must be considered that people may be afraid of being replaced by technology or that they lose their autonomy and flexibility instead of increasing it in performing the work task and feel more controlled. This can reduce acceptance [48].