Exploring Grey Systems in Uncertain Environments: A Bibliometric Analysis of Global Contributions and Research Themes

Grey systems theory, through the special mathematics and methods offered, such as through seeing numbers as intervals rather than fixed values, provides a bridge between the two extreme cases in which a system under investigation might find, namely, a white system, easy to read and understand, and a black system, completely unknown to the investigator. Since its appearance in 1982, the theory has contributed to solving various challenges traditionally addressed through complex means. The paper provides a comprehensive perspective on the evolution of the grey systems domain over the 42-year period analysed, spanning from 1982 to 2024. Utilizing a dataset extracted from the Clarivate Analytics' Web of Science Core Collection database, the paper conducts a bibliometric analysis that includes the identification of key journals, affiliations, authors, and countries, as well as the collaboration networks among authors and countries. It also analyses the most frequently used keywords and authors' keywords. The annual growth rate of 12.99% indicates a sustained interest among researchers. Using the Biblioshiny 4.2.3 library in R version 4.4.1, a variety of visualisations have been created, including thematic maps and WordClouds. A detailed review of the most cited papers has been performed to highlight the role of grey systems in advancing intelligent decision-making techniques. In terms of results, it has been observed that the university with the highest contribution to the field is the Nanjing University of Aeronautics and Astronautics while the most influential figure in the area of grey systems in terms of the number of published papers is Sifeng Liu. As expected, China, the home of grey systems theory, is the country with the most notable contribution in terms of published papers and international collaboration networks.