# Trends and Recommendations for Enhancing Maturity Models in Supply Chain Management and Logistics
## 3 Results
### Bibliometric Results
The keyword analysis was represented by using two graphic visualization tools: the co-occurrence map and the thematic map. The co-occurrence map displays the relevance and relationships between keywords based on co-occurrence analysis. The analysis considered index keywords and utilized a minimum occurrence value of 3. Figure 9 illustrates the results, focusing on 43 keywords out of a total of 544, which were classified into six clusters. Appendix A (Table A3) provides additional information on the clusters, occurrences, and total link strengths (TLSs) of the keywords. The top five most frequently occurring keywords are \"maturity model\" (Occurrence = 31, TLS = 109), \"supply chain management\" (Occurrence = 27, TLS = 88), \"supply chains\" (Occurrence = 26, TLS = 91), \"software engineering\" (Occurrence = 11, TLS = 44), and \"sustainable development\" (Occurrence = 11, TLS = 43). These keywords form the foundation of the research on MMs for SCML. Notably, the keyword \"logistics\" has fewer occurrences (Occurrence = 3, TLS = 7) compared to other frequently used keywords. Within these, it is interesting to note that the context of software engineering is persistent, revealing that MMs have established themselves within that area. Furthermore, the term \"sustainable development\" is also gaining ground within this theme. The 43 keywords were grouped into six clusters, each representing specific focus areas. Cluster 1 (red) consists of 12 keywords related to the topic of digital transformation and Industry 4.0. Cluster 2 (green), comprising nine keywords, reflects performance optimization, mathematical models, and data analysis. Cluster 3 (blue), with eight keywords, focuses on the application of MMs in the areas of supply chain and logistics. Cluster 4 (yellow), containing seven keywords, explores sustainability and sustainable development. Cluster 5 (purple), consisting of five keywords, is specific to the maturity modeling. Finally, Cluster 6 (pale blue) encompasses only two keywords specific to the construction and project management sector. Figure 8: The representation involves conducting a bibliographic coupling analysis to identify the relationship between authors who share common references in the field of MMs for SCML. The thematic map, on the other hand, allows groups of keywords to be analyzed according to four classifications [61]. This map analyses the groups of keywords by means of two quantities on two orthogonal axes. The first quantity shows the degree of relevance (centrality) of keywords, while the second shows their degree of development (density). The intersection of the two dimensions divides the space into four quadrants representing different subject areas. On the top right are the highly developed and research-relevant areas labeled as motor themes. In the upper left-hand quadrant are very specific themes with few relationships, referred to as niche themes. The lower left quadrant describes emerging or declining themes, which are underdeveloped topics. Finally, in the lower right-hand quadrant are groups of keywords that are relevant for the search but general in their treatment, referred to as basic themes. Although the thematic map reports the results of a specific range, several studies use this technique dynamically to represent the evolution of keywords within the scientific research [66; 67]. For this reason, three time periods were selected, which, in this case, divided the 137 selected scientific papers almost evenly. The three reference sub-periods are the intervals 2001-2016 (44 publications, approx. 32%), 2017-2020 (46 publications, approx. 34%), and 2021-2023 (47 publications, approx. 34%). Figure 10 shows the thematic map for the three sub-periods and that of the entire time interval. An analysis of the keyword groups reveals five clusters of interest: (1) supply chain management, (2) maturity model, (3) risk management (describing conceptual frameworks and accident prevention), (4) digital transformation, and (5) sustainability.