## 2 Review and Analysis of Industry 4.0 Aspects  
### Automotive Industry  
Automotive manufacturing and production are already undergoing two major changes: (1) defining their perspective on I4.0 and (2) vehicle design automation/simulation. Although these changes can be satisfied by increasing the technological resources within the factory, their scope involves a new approach regarding ways of thinking about technology and its role within the production environment [4]. The essential components of this new industrial scenario are machines working with humans, where both work collaboratively to meet the specific needs of the society or the client. This interaction is important to achieve the fusion between virtual and real production systems (cyber-physical systems), and therefore the product is designed and tested virtually in order to foresee possible errors before the final product is manufactured [5].  
Through digitization and automation of the production processes within the factory, I4.0 can integrate different technologies in a cyber-physical network to reduce costs and improve market response and resilience. This implies a redefinition of the production processes without overlooking the requirements of cost reduction and early market deployment as new competitors emerge.  
The four main characteristics of I4.0 that must be considered in designing and developing such factories are: (1) vertical networking of production systems, (2) horizontal integration of global value-chain networks, (3) end-to-end engineering of overall value chains, and (4) the use of high-impact disruptive technologies.  
Disruptive technologies encompass artificial intelligence (AI), augmented reality (AR), and 3D printing, and they include a significant use of smart systems such as collaborative and specialty robotics, advanced sensors and microsensors, and automation components for microprocessors and microcontrollers. The use of these technologies has already led to advancements in major areas such as the Internet of Things (IoT) and cyber-physical systems (CPS), big data (BD), and communications infrastructures [6].  
Virtualization technology involves the creation of a \"digital twin\", based on creating virtual models of real systems and digitizing physical objects to simulate their behavior [7]. These virtual models are capable of understanding the state of physical entities through data detection, to predict, estimate, and analyze dynamic changes, where physical objects respond to changes according to an optimized simulation scheme [8]. Finally, virtual reality and augmented reality (VR/AR) enable human-machine interaction systems that fulfill three basic features: a combination of real and virtual worlds, real-time interaction via online platforms, and accurate 3D registration of virtual and real objects. In VR/AR, the virtual-digital model is capable of being controlled in the same way that the physical model would be, and in addition, the latter must respond to the changes made in the virtual model. In particular, VR/AR is an interactive experience of a real-world environment where the objects that reside in the real world are enhanced by computer-generated perceptual information, sometimes across multiple sensory modalities including visual, auditory, haptic, somatosensory, and olfactory [9].