This section provides the results of the analyses conducted in this study, as well as the related interpretations.
4.2. Geographical Distribution
The country distribution analysis and country collaboration network are other ways of explore development in project management, DT, and sustainability. The results of the country distribution analysis can be seen in Table 1
and Table 2
, which depict the top 10 countries based on frequency and the top 10 countries based on centrality. Frequency is the number of publications at a certain citation number, and centrality identifies the boundary-crossing potential that could result in transformative discoveries [19
shows the ten countries with the highest frequency in this research field, and the Peoples’ Republic of China tops the list with 38 publications. Other countries with a high frequency are England, Germany, and the USA. The hotpots of project management, DT, and sustainability research show a regional imbalance; more researchers in Europe have focused on this topic, represented by England, Germany, Spain, Italy, Portugal, Sweden, and Russia. Although Asia is in second place, countries in Asia have been introducing new digitalisation offers and applying them to project management faster than countries in Europe [20
], so the gap in the number of publications will gradually shrink. The analysis of the number of publications alone does not give a clear visualisation of the core countries involved in this field of research. Centrality in CiteSpace is a graph-theoretic concept used to quantify the importance of a point’s position in a network.
demonstrates ten core countries based on centrality in descending order. The betweenness centrality scores are normalised to the unit interval of [0, 1]. This research project defines countries with a centrality greater than 0.05 as core countries that concentrate the research on DT, sustainability, and business model. Table 1
and Table 2
show a strong positive correlation between frequency and centrality, where the countries with more publications also rank highly in terms of centrality. There is an exception, as Saudi Arabia is not in the top 10 countries based on frequency but is in fourth place with a high centrality of 0.17. This indicates that the country’s research on DT and sustainability projects is limited but highly influential.
Once the data analysis was performed in CiteSpace, the visualisation was selected. The node display type chosen for this research project is the tree-ring history, whose size reflects the frequency, and the ring of the node represents the number of citations in a given year [22
]. The wider the ring for a specific year, the more the citations or the higher the frequency for that year. Moreover, purple rings indicate nodes with high centrality in the outermost area.
In terms of the country’s collaboration network, the size of the ring highlights the frequency of the country’s issuance. The colour indicates the year of publication, and the outer purple ring shows countries with high centrality. Collaboration between countries can be analysed by colour and links. The colour indicates when the two countries first cooperated; the strength of the links reflects the closeness of the collaborative relationship between countries.
As evidenced by the results shown in Figure 3
, the network of collaborating countries consisted of 58 nodes and 137 links between 2011 and 2022. The visualisation of the top 10 countries based on frequency and centrality is consistent with the results in Table 1
and Table 2
. The ten countries have primarily established cooperative relationships, as indicated by the lines’ colours, in the past five years. Compared to other countries, Germany collaborated with the USA, China, and Portugal earlier in 2014, and has close relationships with them. As time progressed, the countries in Europe collaborated more closely with each other, while there was not so much collaboration among the countries in Asia. The country collaboration network shows that the topics of DT and sustainability projects have attracted scholars from various countries to collaborate in recent years. Therefore, the next section will investigate the authors involved in DT and sustainability projects.
4.3. Leading Authors
In this sub-section, the following analyses are provided: the list of the most prolific authors (see Table 3
), author collaboration network (see Figure 4
), the author co-citation network (see Figure 5
), and the most cited authors (see Table 3
shows the authors with the most publications in a particular year. As can be seen, the frequency of two publications in a year was set out as a threshold value, based on which it is observed that there are eight authors who have the highest number of publications in a year.
reveals that there are 155 nodes and 173 links in the author collaboration network. After the clustering algorithm in CiteSpace, the modularity is 0.8529, and the mean silhouette is 0.8951, representing good reliability and validity. The network for the project management, DT, and sustainability areas shows an overall fragmentation. Most clusters of the network lack strong connections among themselves, despite a large number of participants. This illustrates that more scholars have been working on DT and sustainability projects in recent years, but they have not been collaborating frequently. Apart from a few scholars collaborating in this field in 2017, most of the collaborations have occurred in groups of three or four in recent years. Additionally, Asian authors collaborated with Western authors relatively infrequently; they tend to collaborate more with local authors. Differences in DT and sustainability projects across geographical areas [21
], regional constraints, and cultural differences between East and West may lead to the problems described above.
Author co-citation analysis refers to two or more authors citing other authors simultaneously, but it relies on a simple co-citation count and does not consider the content of the citations. The network allows the identification of influential scholars, and the clustering analysis provides insight into the distribution of similar research topics in this field. To offer a more comprehensive outlook on the general distribution of author co-citations and core authors in the research domain of project management, DT, and sustainability, visual representations of the author co-citation network and the top 10 most frequently cited authors are generated. This provides additional insights into the research area and enhances the understanding of the relationships between various authors and their contributions to the field.
The top cited author is Yin RK, with a score of 16 in frequency and 0.02 in centrality. According to Figure 5
, he mainly explores digital technology in the field of DT and sustainability projects. In comparison to Table 2
, the top 10 most productive authors and the top 10 most cited authors are not correlated with the top 8 most influential authors. Table 4
shows fewer authors from Asia and more authors across the country compared to Table 3
, indicating that Asian authors are committed to publishing DT and sustainability project articles, but the frequency of citations is not proportional to the number of publications. Thus, scholars must focus on the publication numbers and the quality of their articles to increase their influence in the field of DT and sustainability projects.
4.4. Leading Institutions
Similar to the contributing authors’ analysis of sustainability projects in DT, the analysis explores the institutions that have researched the field more intensively from a meso perspective. Core institutions were identified based on the frequency of publication (Table 5
), and the contribution of institutions in the research area of this discipline was explored based on the visualisation of each institution’s collaboration network (Figure 6
). It is noteworthy that in a scientometric review paper, frequency analysis can be used to identify the most productive institutions within a field of study. The analysis can be conducted at different levels, such as the number of publications or the number of citations. By comparing the frequency of publications or citations for different institutions, it is possible to identify which institutions are the most active in a particular field. In a scientometric review paper, frequency analysis can be used to identify the most productive institutions within a field of study. The analysis can be conducted at different levels, such as the number of publications or the number of citations. By comparing the frequency of publications or citations for different institutions, it is possible to identify which institutions are the most active in a particular field.
A preliminary demonstration of the number of publications by different institutions is provided in Table 5
. The frequency of publication also shows that sustainability in DT projects is a relatively new topic; the University of Aveiro ranks first on the list, with only three publications in 2022. The other nine institutions have published two relevant articles in the last four years. Most of these research institutions are university institutions, which suggests that university and educational institutions dominate most research sites for project management, DT, and sustainability. In addition to prestigious universities, CSIRO Land and Water has produced knowledge on DT and sustainability projects. CSIRO Land and Water is an organisation that focuses on delivering biophysical and socioeconomic outcomes across land, water, and ecosystems. This illustrates that sustainability projects in DT are a broad research topic, and that collaboration between institutions is shown in the next section.
shows that 143 institutions and 95 collaboration links were formed between 2011 and 2022. A relatively loose structure and fewer close relationships indicate that this research community is relatively young. Combined with Table 4
and Figure 6
, most institutions collaborating are core institutions with higher frequency, and cross-country collaboration still accounts for a portion of the limited cooperation. Although The University of Aveiro, the University Institute of Lisbon, and Portucalense University are situated in Portugal, other institutions cooperate with each other from different countries. For instance, the National University of Distance Education in Spain and Bayer AG in Germany established a cooperative relationship around 2021. Moreover, it is evident that the cooperation with green links among the Graz University of Technology in Austria, Chinese Culture University in China, Institute for Systems and Computer in Portugal, etc., started in 2014. In short, while the sustainability projects in DT are an emerging trend, as evidenced by the number of publications, the analysis of countries, authors, and institutions, the cross-national collaboration between institutions is moving in a positive direction.
4.5. Co-Citation Analysis
Journal co-citation analysis provides a distribution of significant sources of knowledge in the field, enabling end users to understand which journals are cited in the field and the links between journals. Journal citations reflect the quality of articles in journals and provide a snapshot of their role and impact in the global research community. The following, therefore, shows the top 9 most cited journals based on their co-citation frequency (Table 6
) and a visualisation of the journals’ co-citation network (Figure 7
presents data on the top ten most cited journals that serve as sources for articles that collectively discussed project management, DT, and sustainability from 2011 to 2022. All of the journals listed are in Quartile 1 (Q1) lists, meaning that they are among the top 25% journals for at least one of their classified subdisciplines. While articles in this field have only been frequently discussed in recent years, these journals have been cited quite frequently. The journals cover a broad range of topics, including sustainability, business research, information management, and engineering management.
The three most highly cited journals are Sustainability, Journal of Cleaner Production, and Technological Forecasting and Social Change. These journals interconnect social, environmental, and economic sustainability. This initial indication suggests that the majority of high-quality articles related to DT and sustainability projects are from sustainability-focused journals. The two journals with the highest centrality are Management Information Systems Quarterly (0.12) and the International Journal of Production Economics (0.10). MIS Quarterly is a research journal, published quarterly, on information systems management and relevant technologies, while the International Journal of Production Economics focuses on issues at the intersection of engineering and management. To obtain more information, the core journals will be examined using the journal co-citation network.
By selecting the cited journal as the node type in CiteSpace, the imported journal information was debugged several times, and clustering analysis was performed to create Figure 7
. In CiteSpace, the “tf*idf
” algorithm was used to extract noun terms from the titles of the cited documents for naming the clusters, including #0 manufacturing sector, #1 IotT-enabled smart, sustainable cities, #2 functional area, #3 soil, #4 digital transformation, #5 first step, #6 transdisciplinary process, #7 smartphone crisis, #8 European cities, #11 digital technologies. The distribution of journals around Cluster #4, digital transformation, and Cluster #11, digital technology, is mainly on the environment, ecology, and information technology categories. DT and sustainability are closely related. The keyword-related analysis, through which we can explore the underlying relationship between DT and sustainability projects, is shown in the next section.
The knowledge base for project management, DT, and sustainability can be analysed in the document co-citation analysis and journal co-citation analysis. Document co-citation helps identify scholarly communities that have received peer recognition by exploring patterns in different the literature. With the introduction of journal co-citation analysis, a dual-map overlay can powerfully visualise the association between the allocations of the cited and citing journals and, thus, enhances the transdisciplinary pursuit [23
Document co-citation analysis is one of the most prominent features of CiteSpace, and was the first function to be theorised when CS was developed. Thus, this research project performs a timeline co-citation map of the document to analyse the relevant reference of sustainability projects in DT. By adjusting the fisheye slider in CiteSpace, one can observe from the timeline visualisation that there have been many publications in recent years. As seen in Figure 8
, documents in the same clusters are positioned on the same horizontal line, with the specific time of the document at the top of the visualisation. An area where more studies are concentrated is considered more critical. Beyond this, the period of the document in the clusters can be seen on the map, further reflecting the temporal characteristics of the clusters.
The node display type chosen for the timeline co-citation map is the tree-ring history with 293 nodes and 864 links. The larger the ring, the higher the citation frequency of the nodes. It is clear that while the highest frequency of cited documents is between 2019 and 2021, the majority of the nodes in the visualisation is concentrated in 2021. It shows that the co-citation of documents on sustainability projects in DT has only frequently commenced, in the past two years. It is also a period of high growth in project management, DT, and sustainability research.
According to latent semantic indexing (LSI) on CiteSpace, cluster labels are generated on the right side of the visualisation. Clusters with dots mean that the data are too sparse to select meaningful features, and the largest cluster is Cluster #0, followed by Cluster #1. Figure 8
demonstrates that the relevant data are sparse and difficult to summarise, but exact keywords are available on CS, including DT, digital technology, sustainability, sustainable innovation, sustainable projects, lean management, business integration, stakeholder collaboration, etc. Those clusters are analysed in combination with the keyword visualisation in the next section.
4.6. Research Front and Emerging Trends
This section highlights keywords from the literature to identify research hotspots in project management, DT, and sustainability because the keywords represent a comprehensive summary of the article. Thus, a visualisation of the keyword co-occurrence network (Figure 9
), timeline co-occurrence map of keywords (Figure 10
), and top 10 keywords with the strongest citation bursts during the research history of sustainability projects in DT (Figure 11
) are presented as follows.
Keywords with a higher frequency in the network are shown as larger nodes. Figure 9
shows 234 nodes and 909 links formed between 2011 and 2022. This can be observed by the size of the tree-ring history. Keywords with a higher frequency are “digital transformation”, “innovation”, “management”, “system”, “sustainability”, “framework”, etc. These keywords are not limited to project management, DT, and sustainability derivatives but also encompass terms from business, industry, and information technology. It follows that the diversification and gradual refinement of managing sustainability projects in DT will inevitably become a trend.
To further investigate the change in hot topics in this review study, the CiteSpace was used to plot a timeline co-occurrence map of keywords. Similar to the observation in Figure 8
, the horizontal axis indicates the year, the connecting link represents the co-citation relationship, the colour of the link signifies the year of publication, and the clusters are on the right side. According to the colour of the links, the research on Cluster #2 digital economy and Cluster #8 green technology started early in 2017. However, there has been increased interest in this area of research since 2021. Apart from that, all other keyword clusters have become hot research topics in the last two years. To better understand the keyword frequency rate of the changes, the figure of the top 10 keywords with the strongest citation bursts during the research history of sustainability projects in DT is shown below.
By using the burst detection technique available in CiteSpace, a word burst is identified as a higher-than-normal occurrence of a word, combined with the temporal distribution of its frequency. This not only indicates the frequency of a word but also predicts research frontiers and trends in managing sustainability projects in DT. This technique is helpful in identifying important and emerging topics that are gaining traction in the field, and can assist in guiding future research in the area. The keywords with the most robust citation bursts, summarised in Figure 11
, are information system, governance, stakeholder, digital innovation, challenge, business model innovation, framework, supply chain, product, and tool. Those keywords represent the research trends in DT, sustainability, and business models in project management. The period of keywords with the strongest citation bursts varies from 1 year to 7 years. In the group year 2012, the top keyword with the strongest citation bursts was an information system with a burst strength of 1.75, while the burst lasted for six years from 2012 to 2018. Six keyword bursts ended before 2020, and researchers focused on the framework, supply chain, product, and tool in the same year.
4.7. In-Depth Discussion
Based on the above results, outputs, and analysis, this sub-section discusses the findings on managing sustainability in DT regarding antecedents, processes, and outcomes. Although related keywords with a high frequency of occurrence have been explored earlier on, the discussion still focuses on the keyword-related visualisations, combined with the networks of countries, authors, and journals to identify similarities and discrepancies in theory when compared with previous studies and literature reviews.
The keywords associated with the antecedent in Figure 9
are summarised as the application of digital technology, the background of sustainable management, and factors of organisational management.
First of all, the emergence of digital technology has promoted the implementation of DT and also facilitated the success of some projects that are undergoing DT [24
]. Artificial intelligence and big data analytics will upgrade communication channels and accelerate product innovation in DT projects. However, DT is not a result but a dynamic process concentrating on sustainable management [24
]; this characteristic does result in DT receiving inadequate attention from managers. As indicated in Figure 9
, the frequency of research on sustainability is not exceptionally high. Even more, organisational management factors, such as decision making and implementation, are more attractive to scholars. Managers hope to fundamentally change the pattern of organisational operation according to the features or variations of the project itself to effectively lower the project costs and improve employees’ work efficiency [24
]. Especially in project management, project managers are inclined to create an effective workplace and implement more efficient strategies to increase the firm’s performance [24
]. These actions are a manifestation of decision making or implementation.
The process-related keywords exhibited in Figure 9
include “management”, “impact”, “project management”, “automation”, “innovation”, “framework”, “performance”, “business model”, etc. Proportionate to the antecedents, the previous section describes the time when high-frequency processes relating to co-occurrence keywords embrace their radical transformation. It briefly introduces the orientation that inter-domain scholars have discussed in recent years. As many cases of collapsed DT projects still exist [24
], this study focuses on different keywords concerning this process, and builds an effective bridge for project management, DT, and sustainability.
This procedure can be broken down into two primary parts: the process of DT and project sustainability. Similar to DT, the development of digital technology and the abundance of data sources profoundly affect how an enterprise creates and captures value. Furthermore, it provides technical and resource support for the innovation of corporate business models, products, digital services, and organisations. As can be retrieved from Figure 9
, digital technology does not only has a linkage to keywords associated with digital technology, but it also reveals a close relation with strategic concepts, such as innovation, framework, and business model. This dual connection is consistent with the DT strategy as Matt [25
] proposes, who focuses on product, process, and organisational transformation. This strategy is employed to support the change resulting from the integration of digital technologies and the management of the enterprise after that, emphasising the concept of a blueprint. In other words, the digital business strategy looks at a sustainability state.
Process of Managing Projects’ Sustainability
In managing project sustainability, scholars tend to combine the critical elements of project management and sustainability-related dimensions. For example, they integrate a project’s life cycle with social, environmental, and economic aspects to create a framework for promoting project sustainability [26
]. However, the keywords in Figure 9
do not allow for the extraction of economically, environmentally, and socially relevant terms. Reasonably, Fernández-Sánchez and Rodríguez-López [8
] pointed out that there has indeed been little research available on joint problems involving project management and socially relevant sustainability factors up till now. Unexpectedly, based on Figure 9
and Figure 10
, it can be surmised that scholars have also not explored the social and environmental aspects of DT and sustainability intensively. Nevertheless, some scholars have recognised that rapid economic growth raises ecological issues and have updated their conceptual framework to address the problems associated with sustainability projects [7
]. In the context of DT, the external aspects of society, environment, and economy in projects should still be considered and can be further explored in future studies.
In contrast to the authors’ concerns, relatively few institutions focus on DT. Most core journals in this field (Table 6
) are relevant to sustainability, including Sustainability
(MDPI), Journal of Cleaner Production
, Technological Forecasting and Social Change
, and International Journal of Production Economics
. DT is a new field of study compared to sustainability, so there may be fewer core institutions involved. A surge in the number of related articles published in 2019 (Figure 2
) suggests that an increasing number of journals will start to investigate the problems of DT and sustainability combined in the future.
Aiming to bridge the gap between DT and sustainability projects, this research project research has chosen a business model, which is also a keyword seen in Figure 9
to represent “process”. Although business models have been studied for a considerable period, business models related to DT and sustainability projects have only started being frequently discussed in 2020. The concentration ratio of this topic was declining in 2021. As there has not yet been a consensus on whether there is a standard answer to the effective management method of sustainability projects under DT and sufficient research has not been conducted in its short life cycle, it is unknown whether more scholars will regather to discuss business models in the future. This finding is visualised in detail through CiteSpace, which would have been difficult to detect by only reviewing the previous literature.
Having said that, a review of the previous literature shows that digital and sustainable business models have been studied in the last two years, effectively linking DT and sustainability fields [4
]. As can also be seen in Figure 9
, these two models have not been widely discussed, and there is not much experimentation to prove that the probability of project success can be quickly increased with these two models. Therefore, future research could continue to examine the effect of digital business models or sustainable business models in managing sustainability projects in DT. In conjunction with the critical words relating to DT and sustainability projects, innovation, socio-environmental, and economic factors can also be regarded in the business model research.
According to the keyword co-occurrence network (Figure 9
), the results of DT and sustainability projects have a wide range of outcomes, including organisational and economic effects. Keywords related to the organisational level are “design” and “perception”. The impact of DT on sustainability projects entails enhancing employees’ ability to perceive digital applications [28
] and designing digital ecosystems. The keywords most relevant to the economic dimension are “performance” and “firm performance”. As evidenced by the size of the nodes, there is less focus on “firm’s performance” than on “performance”. The emphasis of scholars on firm performance is in agreement with the earlier section, which noted that while numerous researchers have delved into the combination of digital transformation and sustainability, only a few have done so at the level of the firm or project [29
]. Thus, the focus on firm or project performance is also lower. When the problem is broken down to the organisational or project level, the dimensions considered are different, and the probability of sustainability project failure may be reduced during the DT process. Similar to the conclusions of the process, the main keywords in terms of project management, digital transformation, and sustainability are barely summarised at a social level. As a result, socially related elements need to be considered by future scholars in the investigation of managing sustainability projects in DT.
The findings obtained in this review paper offer several managerial and theoretical implications. As regards the managerial implications, unravelling the interconnection between DT and sustainability in project management can lead to increased environmental responsibility; digital tools can be used to monitor and reduce carbon emissions, track resource usage, and promote sustainable practices. Additionally, the integration of sustainability and DT in project management can improve resource efficiency. With digital tools, project managers can monitor and optimise resource usage, reduce waste, and promote circular economy principles. Moreover, such a combination can lead to better stakeholder engagement in project management. By promoting sustainable practices, project managers can engage with stakeholders on environmental and social issues, leading to improved relationships and increased stakeholder satisfaction. Furthermore, it can help project managers to identify and mitigate sustainability-related risks. By using digital tools to monitor sustainability performance and identify potential risks, project managers can take proactive steps to address them and improve project outcomes. On top of all that, the utilisation of such an amalgamation can promote innovation in project management. By using digital tools to track sustainability metrics and identify areas for improvement, project managers can create new innovative approaches to sustainable project management, leading to increased competitiveness and improved project outcomes.
Apart from the above-stated practical implications, several theoretical implications are provided as follows. Firstly, the integration of digitalisation and sustainability in project management requires the development of new theoretical frameworks that can explain the complex relationships between digitalisation, sustainability, and project management. The findings of this research can help us develop new theoretical frameworks that can advance project management theory. Secondly, research on the integration of digitalisation and sustainability in project management can help us identify best practices that project managers can use to promote sustainability and digitalisation in their projects. These best practices can be used to develop guidelines and standards for sustainable project management. Thirdly, the findings of research on the integration of digitalisation and sustainability in project management can inform project management education. The findings attained from this research help project management programs develop new courses and curricula that cover sustainability and digitalisation in project management. Fourthly, the findings of this review paper on the integration of digitalisation and sustainability in project management can inform policy development. Governments and regulatory bodies can use this research to develop policies and regulations that promote sustainable project management practices. Finally, the findings of this research on the integration of digitalisation and sustainability in project management can help advance the practice. Project managers can use this research to adopt new tools, techniques, and practices that promote sustainability and digitalisation in their projects.