Figure 9
The thematic map with four-quadrants has the vertical axis labeled “Development degree (Density)” and the horizontal axis labeled “Relevance degree (Centrality).” The quadrants are labeled as “Niche Themes” (top left), “Motor Themes” (top right), “Emerging or Declining Themes” (bottom left), and “Basic Themes” (bottom right). Each quadrant contains colored bubbles of varying sizes, each accompanied by a set of terms. In the “Niche Themes” quadrant (top left), a bubble at the top contains the term “internet of things (iot),” while a bubble below it contains “additive manufacturing.” In the “Motor Themes” quadrant (top right), a bubble at the bottom left contains the terms “circular economy practices,” “bibliometric analysis,” and “sustainable performance.” A bubble overlapping with the bottom right quadrant has the terms “supply chain,” “barriers,” and “systematic literature review.” In the “Basic Themes” quadrant (bottom right), a bubble at the top center has the terms “internet of things,” “artificial intelligence,” and “big data.” A large bubble at the right has the terms “circular economy,” “industry 4.0,” and “sustainability.” An overlapping bubble on the left has the terms “industry 4.0,” “0,” and “sustainable development goals.” In the bottom center of the map, overlapping the upper border between “Emerging or Declining Themes” and “Basic Themes,” a bubble has the text “digital transformation.” In the “Emerging or Declining Themes” quadrant (bottom left), a bubble on the right contains the term “supply chain management”.Thematic map-Industry 4.0 and circular economy. Source: Constructed based on Biblioshiny software