## 2 Materials and Methods
### SMEs and Industry 4.0
In fact, 90% of registered companies in Europe are small- or medium-sized [34]. The authors identified problems with the implementation of Industry 4.0 technologies in small- and medium-sized enterprises in terms of finances and time needed to learn about these technologies. The results of the survey show that companies are interested in implementing Industry 4.0 technologies and digitisation. Big Data, Machine Learning, Autonomous Robots and an ERP or Manufacturing Execution System (MES) have been identified as technologies with great deployment and high complexity. They identified Sensors, Simulation, Predictive Maintenance and 3D printing as high-benefit, low-complexity technologies. Article [35] explains the strategy for implementing Lean Manufacturing first, and then digitisation for SMEs. It describes that first it is necessary to focus the company's values on the customer, and only then start implementing individual technologies of Industry 4.0--first Big Data and Horizontal and Vertical Integration, then Simulation, Digital Twins and Artificial Intelligence. The article also found the benefit of greener production, as digitised businesses generate less waste. Study [36] summarises surveys conducted on German companies. They found that a large number of companies are aware of the importance of digitisation, but as the size of companies decreases, so does the effort to deploy digitisation. SMEs make up the vast majority of all companies, and it is important that the gap between large and small- and medium-sized enterprises does not widen as large companies deploy digitalisation and have more potential/capital to deploy new technologies. The authors recommend that research should focus on reducing mistrust in new technologies, especially in the field of data security. In [37], the authors highlight the need for companies to implement Industry 4.0 technologies. Businesses that implement these technologies are growing faster and have a better chance of surviving in the market. The authors identified the important aspects in the deployment of IoT in production. According to the results, companies deploying IoT in production should consider the criteria of technology, communication and safety in particular, with important sub-criteria of device heterogeneity, network security and hardware structure. A survey [38] conducted with a sample of 125 respondents, of which one-third were small enterprises, one-third medium enterprises and one-third large enterprises, focused on the deployment of Industry 4.0 technologies as of December 2021 and showed alarming results. One of the results is the stagnation and decline of the introduction of digitisation in companies, where about half of the respondents stated that they had not yet started the Industry 4.0 application, one-fourth had started implementing it, and one-fourth of the respondents are working with Industry 4.0 teams. Over the last year, the perception of the need for digitisation has been declining--in 2020, 74% of respondents considered digitisation to be very important for the future, in 2021 there was a decrease to 46% of respondents. The survey shows that managers are a major barrier to digitalisation, which is clear evidence of stagnant digitalisation. Almost 66% of companies do not have an implementation strategy in place, 42% of companies have not started creating a strategy at all, and large companies have teams in charge of creating a strategy for implementing Industry 4.0 elements. Almost 77% of small- and medium-sized companies do not have an Industry 4.0 solution team. From the point of view of employee education, 30% of companies perceive the need for employee education in the field of digitisation. The companies see the biggest shortage of the required skilled workforce in the areas of system solutions for digitisation, artificial intelligence and industrial engineering and automation. From the results of the survey, small- and medium-sized enterprises can be expected to gradually lose orders due to their low competitiveness [38].