## 3 Conceptual Model Development
### Integration of Improvement Strategies and Industry 4.0 Technologies  
After having described the generic process and the areas, tasks and factors where improvements could be required to enhance production capabilities up to the required level, it is the moment to identify first the improvement options, as presented in Section 2.3, as well as to determine how the options can work together in a logical and efficient way to develop a generic model. To integrate the Industry 4.0 related technologies with relevant improvement strategies, a matrix was developed to syndicate when it is recommended to initiate Industry 4.0 projects in relation to the lean optimization steps. As a result, Figure 4 shows that it is recommended to perform the improvement strategy projects before, after or in parallel with Industry 4.0 projects related to new technologies. The technologies used for integration are the fundamental and core Industry 4.0 technologies extracted from the literature [34]. In addition, the integration matrix is built based on the main characteristics of the technologies and of the lean steps. The matrix should be read as follows in order to understand its logic. How to read the matrix: \"It is recommended to perform T1 (Sensors and actuators) projects before analyzing the current state of the production system\" as T1 would enable more data to be gathered, and therefore, more information would be available, increasing, as a consequence, the accuracy of the current state of analysis. The following recommendations can be read in Figure 4: before (B), in parallel (P), after (A), before and in parallel (BP), before and after (BA), in parallel and after (PA);  
Figure 3: Manufacturing functions assessment model based on areas and factors (own elaboration). Based on Figure 4 and the classification of recommendations (B, PA, BP, BPA, PA, A) included in it, clusters can be built. As a result of this clustering, Figure 5 allows us to describe the integration of improvement strategies and Industry 4.0 related technologies in five steps called the \"GUVEI-Model\", which stands for the get, use, virtual, expand, improve (GUVEI) model. 1. Cluster 1--Monitoring and data gathering phase: it consists of sensors and actuators (T1) as well as RFID and RTLS (T2) for the system monitoring enabling, and also works to collect data about products, equipment, staff, tools, etc. This phase is recommended to be implemented before starting the lean optimization process. This cluster makes it possible to have less product, equipment, staff coordination, data quality failures, and less production lead time as it would be easy to find and know the status of any element, as well as less reaction time for maintenance activities as breakdowns would be known in real time. 2. Cluster 2--Make use of data phase: from the data collected, the second phase deals with the transformation of this data into usable information in order to support decision-making activities at the strategic, tactical and operative levels. For this purpose, phase 1 serves as the basis and T8, data analytics and artificial intelligence, serve as means. This step is recommended to be applied as soon as data are available  
Figure 4: Integration of improvement strategies and Industry 4.0 technologies (own elaboration). Figure 5: GUVEI-Model for Industry 4.0 technologies implementation (own elaboration). and therefore it can be tackled in parallel or after the analysis of the current state or in any moment of the lean optimization steps, as soon as reliable data is available. 3. Cluster 3--Applying and sharing information knowledge for specific purposes phase: information from the previous phase can be shared with different locations at any time with cloud technology (T11), with cybersecurity (T12) and also applied for specific purposes.