## 2 Literature Review
### Content Analysis  
In the 80s and 90s the so-called CIM addressed the first attempts to define hierarchy structured in smart factories [14]. CIM and FMS was the key topic [15], and things such as dynamic scheduling [16] and reactive MES [17] were invented then. After that, holonic manufacturing [18] and IMS was established. A Holonic Manufacturing System (HMS) is a manufacturing system where key elements, such as machines, cells, factories, parts, products, operators, teams, etc., are modeled as 'holons' having autonomous and cooperative properties. The decentralized information structure, the distributed decision-making authority, the integration of physical and informational aspects, and the cooperative relationship among holons, make the HMS a new paradigm, with great potential for meeting today's agile manufacturing challenges [19]. Information management was a challenge in a virtual enterprise environment characterised by distribution, autonomy and co-operation. Distributed information management architecture was one of the key topics for production planning and control. It provided not only basic services but also advanced services, like notification, security control, subscription, and data sending [20]. Some of the proposed models and concepts are missed, but the ideas still were appointed in sources, for example focusing on the optimization of the accuracy of the wire electro-discharge machining process [21] or the manufacturing of five-axis high speed milling of complex parts [22]. The smart factory is the integration of all recent IoT technological advances in computer networks, data integration, and analytics to bring transparency to all manufacturing factories. The Internet of Everything (IoE) is a concept that extends the Internet of Things (IoT) emphasis on machine-to-machine (M2M) communications to describe a more complex system that also encompasses people and processes. The steps to creating a smart factory are the followings [23]:  
* data transmission: get data to communicate from robot to machine to person,
* connection: get this data to a large capacity IoT server,
* big data processing: make the data visible and actionable to people for analysis. Several new edge computing devices were launched recently. In Japan there is a general movement about first using common sense and later technology. Special processes are those in which more CPS (cyber-physical systems) are in use because models are closely related to machine controls. In EDM and other works about lasers, welding, etc., CPS are spreading. For instance, EDM edge computing is  
Figure 5: Distribution of papers according to Web of Science categories. becoming a leading research line [24]. 5G and IoT will be key to enhancing and enabling the advances in manufacturing. 5G networks offer manufacturers and telecom operators the chance to build smart factories and truly take advantage of technologies such as automation, artificial intelligence, augmented reality for troubleshooting, and the Internet of Things [25]. The research in the field of manufacturing processes indicated a huge number of articles reporting the results of research projects in all fields of engineering and economic sciences. These researches are discussing a wide range of manufacturing solutions, from traditional manufacturing to cyber-physical manufacturing systems [26]. The improvement of 3D printing led to the appearance of a new decision to be made by production companies: how to make components for final products? Products can be produced either with traditional technology or with additive manufacturing. Additive manufacturing has a great impact on related supply chain and logistics solutions; therefore, it is important to put more and more effort into the research of additive manufacturing solutions [27].