# Development and Future Trends of Digital Product-Service Systems: A Bibliometric Analysis Approach
## 2 Methodology  
### Data Collection and Analysis  
One of the most popular databases for bibliometrics research, Scopus, was used by the authors to gather their data. The authors made the decision to gather information from all pertinent journals and conference papers that were listed in the Scopus database. Scopus is a large and well-known bibliographic database that includes a wide range of fields. Our decision to use Scopus was based on the greater range of articles published in the appropriate journal and conference proceedings in the field of digital PSS. The following collection of terms was used in this study: (TITLE-ABS-KEY (\"digital product-service system\") OR TITLE-ABS-KEY, (\"digital servitization\") OR TITLE-ABS-KEY, (\"servitization 4.0\") OR TITLE-ABS-KEY, (\"digital service business model\" AND \"manufacturing\") OR TITLE-ABS-KEY, (\"digital product-related service\") OR TITLE-ABS-KEY, (\"smart product-service systems\") OR TITLE-ABS-KEY, (\"digital services in manufacturing\")). Only papers submitted in English were subject to evaluation from 2014 to 2022 during the examination period for published papers. The authors picked a timeline beginning in January 2014,since that is when the first publication in the field of digital PSS was issued. Prior to this time, servitization research was mostly focused on classical PSS. December 2022 was utilized as a crucial date to finish a 9-year time span, which is the focus of our proposed research. The authors created a thorough search strategy that made use of a variety of relevant keywords, topic areas, and publishing kinds. This method sought to cast a wide net and collect a varied range of publications, lowering the danger of overlooking relevant studies. Within the confines of our study topic (i.e., digital PSS), the authors' inclusion criteria were intended to be as inclusive as possible. By collecting a wide range of papers, the authors wanted to reduce the unintended omission of research that might provide significant insights. According to this strategy, the authors conducted a sensitivity analysis and validation of key results to ensure that all papers are in the field of digital PSS according to the mentioned string. Through this analysis, the authors detected 20 papers that are not in the field of digital PSS, and according to this finding, they reduced the database from 280 to 260 papers. The graphical analysis of the bibliographic data was performed using VOSviewer software 1.6.19. Figure 3 depicts the data collection and analysis procedure.  
The authors began the data analysis process after the data collection process, in accordance with the suggested study structure. Understanding the author, company, and country cooperation, as well as information dissemination, benefits from collaboration analysis. A network of authors who reference one another was presented via co-citation analysis, along with information on the influence of the authors and articles in the area. The most pertinent journals and conferences that released articles in the area were revealed by a study of related sources. Researching the co-occurrence of keywords is an effective way to look into scholarly areas, as well as potential future effects and directions of study. The 260 research papers used in this study are linked to the top five topic areas listed as follows:  
Figure 3: Data collection and analysis procedure.  
engineering (53%); business, management, and accounting (50%); computer science (47%); decision sciences (21%); and environmental science (11%). Furthermore, this database includes 95 pertinent sources, 162 journal articles, and 98 conference papers. The average number of citations per article is 19.93, and the overall number of references is 12710. The overall number of authors is 587, with foreign co-authorship accounting for 42.53% of the total. Finally, the yearly growth rate for articles in this area was 62.24%.