# On the Development of a Surrogate Modelling Toolbox for Virtual Assembly
### Integration in the Context of Industry 4.0  
The concept of Industry 4.0 comprises the consolidation of information and communication technology (ICT) within the scope of the manufacturing industry through converging both physical and virtual (digital) threads, aiming to create an economical benefit through flexible and reconfigurable smart factories [9; 10; 11]. In short, Industry 4.0 hence deals with the digitization of industry [9]. The field of ICT continuously gained importance due to the emerge of embedded computing and wireless networks, allowing to include new concepts and technologies into the manufacturing context [8; 9; 12]. Industry 4.0 is the first a-priori recognized industrial revolution aiming to secure the competitiveness of a nation's industrial production in global competition and to overcome skill shortage due to demographic change [9]. [PERSON] et al. [13] and [PERSON] et al. [8] proposed productivity gains of 20% to 30% for Germany until 2025 in the automotive and machinery industries. This potential was already demonstrated in several industrial use cases [12]. However, especially large companies nowadays achieve a relatively high Industry 4.0 maturity level, as they i.a. increasingly have a sufficient digital infrastructure [14]. According to [PERSON] et al. [8], Industry 4.0 is based on the three features of \"_horizontal integration through value networks, end-to-end engineering of engineering processes across the entire value chain, (and) vertical integration and networked manufacturing systems\"_[8] (p. 6). However, [PERSON] et al. [15] mention further building blocks of Industry 4.0 comprising \"_autonomous robots, big data and analytics, augmented reality, additive manufacturing, the cloud, cybersecurity, the industrial Internet of Things, (...)_ (and) _simulation\"_ ([15], p. 3). The realization of Industry 4.0 relies on central concepts such as the digital twin, cyber-physical systems (CPS), smart factories, products and materials, the digital shadow of production as well as the Internet of Things [10; 16]. The idea behind the digital twin was first formed at NASA [17], where [PERSON] and [PERSON] [18] defined the digital twin as a digital representation of a considered physical system including all relevant data from all product lifecycle phases, which allows mirroring the behavior of the corresponding physical twin by simulation. Its main purpose is to verify and validate the product design and to define product characteristics [19]. At NASA, the digital twin allows replacing the Earth-bound physical twin of a spacecraft, which during a mission was used to emulate the behavior of the spacecraft [17]. CPS are defined as \"_systems of collaborating computational entities which are in intensive connection with the surrounding physical world and its on-going processes, providing and using, at the same time, data-accessing and data-processing services available on the Internet_\" ([10], p. 621). Hence, CPS enable to represent the behavior of a physical system in the virtual domain. The digital shadow of production according to [PERSON] et al. [16] enables the real-time collection and provision of relevant manufacturing data, following the maxim of supplying the \"(...) _right information at the right time and the right place in the right quality (...)\"_ ([16], p. 70). In recent literature, the concept of Industry 4.0 outlined by [PERSON] et al. [8] and [PERSON] et al. [15] is extended as a response to criticism on the incompleteness of existing models of Industry 4.0 [20]. Thus, advanced approaches such as the augmented holistic Industry 4.0 model by [PERSON] [20] were developed. Here, the author extents the model of Industry 4.0 to twelve technologies by introducing the aspects of engineering materials, manufacturing technologies (corresponding to so called technological machines) as well as living and bioengineering machines [20; 21].