## 2 Materials and Methods
### Industry 4.0 Development Framework  
Industry 4.0 aims to develop intelligent manufacturing systems and to implement smart technologies in current manufacturing systems. Cyber-physical systems (CPS), the Internet of Things (IoT), big data analysis, intelligent manufacturing and the new disruptive technologies--robotics, artificial intelligence, virtual reality and simulation techniques--are the main components of Industry 4.0. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Research Area** & **Problems Addressed** & **References** \\ \hline Basic concepts & Toyota Production Systems (TPS) Concept & [PERSON] (1988) [2]: \\  & & [PERSON] et al. (1990) [4]: \\ \cline{2-3}  & The Basics of Lean Thinking & [PERSON] \& [PERSON] (1996) [26]; \\  & The Concept of Lean Manufacturing & [PERSON] \& [PERSON] (2003) [27]; \\  & & [PERSON] \& [PERSON] (2011) [29]; \\ \cline{2-3}  & The Kaizen Concept & [PERSON] (2013) [28]. \\ \hline  & Identifying and Reducing Waste & [PERSON] (2020) [24]; \\  & Reducing Costs & [PERSON] (2020) [30]; \\  & Continuous Improvement & [PERSON] et al. (2018) [31]; \\  & Standardized Work Efficiency & [PERSON] et al. (2019) [6]; \\  & Improving System Performance & \\ \cline{2-3}  & Lean Tools: & [PERSON] et al. (2021) [23]; \\  & VSM (Value Stream Map) & [PERSON] et al. (2021) [32]; \\  & Visual Management & [PERSON] (2021) [33]; \\  & 5S Method & [PERSON] et al. (2019) [34]; \\ \cline{2-3}  & Lean practices: & [PERSON] (2013) [33]; \\  & - & Lean Startup Methodology, Organizational Culture & [PERSON] et al. (2014) [5]; \\  & and Soft Lean Practices & [PERSON] et al. (2019) [35]; \\  & - & Applications and Models of Lean Practices in & [PERSON] et al. (2019) [36]; \\  & - & Manufacturing, SMEs, Health and Tourism & [PERSON] et al. (2020) [37]; \\  & - & Lean Practices and Process Innovation & [PERSON] et al. (2020) [38]; \\ \hline  & Lean Integration Models for Sustainable Improvements: & - & Lean Management and Quality, Environmental and \\  & & Occupational Health and Safety Management Systems & [PERSON] \& [PERSON] (2018) [40]; \\  & - & Lean Management and Supply Chain & [PERSON] et al. (2019) [41]; \\  & sustainable development & Management (SCM) & [PERSON] et al. (2019) [42]; \\  & - & Lean Management and Green Production & [PERSON] et al. (2019) [43]; \\  & - & Lean Principles and Applications of Environmental & [PERSON] et al. (2019) [44]; \\  & - & Management in Manufacturing & [PERSON] (2020) [45]. \\  & - & Environmental Sustainability in the Social Dimension & \\ \hline Lean research & Current Status and Future Research Directions & [PERSON] et al. (2018) [16]; \\  & Bibliometric Analysis of Lean Applications in & [PERSON] et al. (2021) [46]; \\  & Production Management & [PERSON] et al. (2020) [47]. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Lean management: literature review. Recent specialized studies [49; 50; 51] have estimated that switching to Industry 4.0 will lead not only to technology changes but also to changes in business models, followed by social changes. Certain difficulties faced by industrial companies when implementing Industry 4.0 have arisen, even at the operational level of production floors [52] such as human resource training issues for learning new digital skills and competences, human-machine integration, and data security. It is necessary to have the best possible knowledge of industry practices so that the adaptation of current Lean management methods to smart manufacturing can be carried out efficiently.