**6. Conclusions**

To conclude this paper, we summarize the results of the research. The paper deals with the analysis of the level of Industry 4.0 implementation in SMEs. Based on cluster analysis, we developed a categorization of the enterprises which consists of four groups, namely top I4 technological enterprises, advances I4 enterprises, I4 starting enterprises, and I4 noobs enterprises. The largest group is formed by SMEs, which are just-introduced Industry 4.0 technologies. Depending on their classification, enterprises differ in the use of preferred technologies. Generally, SMEs are more used technologies that can be found at lower levels of the VPi4 index (data collection, analysis, Cloud, IS, IT, and mobile platforms). At the same time, SMEs with a higher level of implementation of Industry 4.0 reported enough skilled human resources.

The research examined hypotheses about the differences between SMEs and large enterprises in the implementation of Industry 4.0. Results of comparisons show that SMEs have, so far, a lower level of Industry 4.0 implementation. This confirms the assumption that large enterprises have greater opportunities to use new technologies and transform them into smart factories. However, this situation may change in the future if new technologies become more accessible (for example, using leasing financing) and more appropriate for investment of SMEs.

As part of future research, we plan to conduct a deeper analysis of the implementation of Industry 4.0 in SMEs, focusing on the main barriers. Case studies on specific enterprises will be appropriate. These case studies could explain why SMEs are not ye<sup>t</sup> implementing Industry 4.0 to a greater extent. We plan to show the procedure of how to rank the implementation steps or technologies in a single enterprise. It may be interesting to compare the current and required (or expected) level of Industry 4.0 in SMEs. Other challenges for future research include developing a methodology (step-by-step roadmap) to implement Industry 4.0 in enterprises. SMEs often do not have much information on how they can turn their business into a digital form; however, in the current situation (pandemic of coronavirus), they are forced to use home office and reduced working hours. New Industry 4.0 technologies can help them with this current challenge.

**Author Contributions:** Conceptualization, M.P. and J.V.; data curation, M.P. and J.V.; formal analysis, M.P. and J.V.; funding acquisition, M.P. and J.V.; investigation, M.P. and J.V.; methodology, M.P. and J.V.; project administration, M.P. and J.V.; resources, M.P. and J.V.; software M.P. and J.V.; supervision, M.P.; validation, M.P. and J.V.; visualization, M.P.; writing—original draft, M.P.; writing—review and editing, M.P. and J.V. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by "EF-150-GAJU 047/2019/S".

**Acknowledgments:** The authors thank the enterprises taking part in the research.

**Conflicts of Interest:** The authors declare no conflict of interest.
