Industry 4.0 research in the maritime industry: a bibliometric analysis

Industry 4.0 (I4.0) is currently a major topical concern in the literature on maritime industry. Maritime 4.0 is the area concerned with the integrated implementation of digital processes and technologies in the maritime industry. There is, however, a shortage of review studies that can reflect the research directions and various important issues in Maritime 4.0. The purpose of this study is to explore and categorize academic publications concerned with Maritime 4.0 to identify its current research status, main subject categories, emerging trends, current gaps, and future research directions. To provide a comprehensive review of the publications, the study used bibliometric analysis to conduct citation analysis (publication distribution, productive journals, and cross-country collaborations), cooccurrence of the subject categories, cocitation analysis, and keyword frequency analysis. In doing so, the study utilized the Web of Science (WoS) dataset and software packages for data analysis. Finally, the study proposed a research framework composed of five themes to link current research topics with future research trends in Maritime 4.0. The five themes observed were "digitalization technology, " "methodology and techniques, " "management, " "safety and security, " and "environmental issues. " The results revealed that, although scholars and practitioners focused on Maritime 4.0, this area remained underdeveloped. Many scopes under the five themes were left unexplored, such as emerging paradigms of Internet of things (IoT) and blockchain under the theme of "digitalization, " hybrid models (e.g., game theory and genetic algorithms) under the theme of "methodology and techniques, " and social responsibility under the theme of "environmental issues. "