Sustainable port operations and environmental initiatives in Malaysia: A focus on environmental sustainability

Muhamad Safuan Shamshol Bahri; Shariff, S. Sarifah Radiah; Nazry Yahya Article Sustainable port operations and environmental initiatives in Malaysia: A focus on environmental sustainability Asian Journal of Shipping and Logistics (AJSL) Provided in Cooperation with: Korean Association of Shipping and Logistics, Seoul Suggested Citation: Muhamad Safuan Shamshol Bahri; Shariff, S. Sarifah Radiah; Nazry Yahya (2025) : Sustainable port operations and environmental initiatives in Malaysia: A focus on environmental sustainability, Asian Journal of Shipping and Logistics (AJSL), ISSN 2352-4871, Elsevier, Amsterdam, Vol. 41, Iss. 1, pp. 38-51, https://doi.org/10.1016/j.ajsl.2025.01.002 This Version is available at: https://hdl.handle.net/10419/329755 Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. 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If the documents have been made available under an Open Content Licence (especially Creative Commons Licences), you may exercise further usage rights as specified in the indicated licence. https://creativecommons.org/licenses/by-nc-nd/4.0/ Sustainable port operations and environmental initiatives in Malaysia: A focus on environmental sustainability Muhamad Safuan Shamshol Bahri a , S.Sarifah Radiah Shariff a,b,* , Nazry Yahya c a Malaysia Institute of Transport (MITRANS), Universiti Teknologi MARA, Shah Alam, Malaysia b School of Mathematical Sciences, College of Computing, Informatic and Mathematics, Universiti Teknologi MARA, Shah Alam, Malaysia c Johor Port Skills Centre, Malaysia ARTICLE INFO Keywords: Sustainable port Port performance Sustainable port initiatives ABSTRACT Sustainable port growth remains a major concern in Asia and the Pacific, where more than half of the busiest ports are located and where two-thirds of the world’s maritime trade is now concentrated. Most ports continue to strive to improve their performance and productivity to compete with the growing volume of sea trade, as well as the quality of their inland connections. At the same time, various air and water pollutants, as well as other harmful environmental externalities caused by port activities, the Port also needs to address urgent environmental issues to ensure the sustainability of this sea trade. In this study, the essential elements of sustainable port operations are explored through a comprehensive systematic literature review, which is not just a collection of existing studies, but it also analyzes and synthesizes various approaches to evaluate port performance from an environmental sustainability perspective. The transition from theory to practice, in the second part through the focus group discussion of this study, has analyzed the views of the management of some leading Ports in Malaysia to understand how the concept of sustainability theory is implemented in practical situations. The results of this study provide a detailed view of the environmental initiatives and strategies implemented by interacting with those directly involved in the operation and management of Malaysian ports. It records the challenges, successes and ambitions of Malaysian ports in their efforts towards sustainability. 1. Introduction Sustainable port operations have become a critical priority in global maritime logistics, as ports serve as key hubs for international trade while contributing significantly to environmental challenges. Around the world, ports are increasingly adopting green initiatives aimed at reducing carbon emissions, improving energy efficiency, and minimizing their ecological impact. This growing focus on sustainability reflects a global recognition that ports as industrial and logistical centres must enhance their environmental performance to mitigate the negative effects of their activities on surrounding ecosystems and communities. Malaysia as home to several strategically located ports, plays a pivotal role in Southeast Asia’s maritime industry. As such, the country’s ports are also embracing sustainability practices to ensure they remain competitive and compliant with global environmental standards. Major ports such as Kuantan, Penang, and Klang are implementing green port initiatives, reflecting Malaysia’s broader national commitment to sustainability, including its National Green Technology Policy. However, the adoption and effectiveness of these initiatives vary, presenting both challenges and opportunities in achieving a greener port industry. This paper seeks to evaluate sustainable port performance from Malaysian perspectives. The first section presents a systematic review of the global literature on environmentally sustainable port performance and evaluation. This review critically examines key frameworks, methodologies, and indicators used worldwide to assess sustainability in ports, identifying trends and gaps in current knowledge. It provides a comprehensive view of how ports across the globe are tackling sustainability challenges, which sets the context for understanding Malaysia’s position within this global landscape. The second section transitions from global theory to local practice, focusing on sustainability efforts within Malaysian ports. Through focus group discussions with senior management at Malaysia’s major ports, the study explores how global sustainability principles are being implemented at the operational level. The discussions provide valuable insights into the challenges faced by Malaysian ports in adopting sustainable practices, the successes they have achieved, and their strategic * Corresponding author at: Malaysia Institute of Transport (MITRANS), Universiti Teknologi MARA, Shah Alam, Malaysia. E-mail addresses: [email protected], [email protected] (S.SarifahR. Shariff). Contents lists available at ScienceDirect The Asian Journal of Shipping and Logistics journal homepage: www.elsevier.com/locate/ajsl https://doi.org/10.1016/j.ajsl.2025.01.002 Received 16 April 2024; Received in revised form 7 November 2024; Accepted 27 January 2025 The Asian Journal of Shipping and Logistics 41 (2025) 38–51 Available online 11 February 2025 2092-5212/© 2025 The Author(s). Published by Elsevier B.V. on behalf of The Korean Association of Shipping and Logistics, Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). goals for the future. By combining insights from the systematic literature review and focus group discussions, this paper aims to quantify the effectiveness of sustainability initiatives in Malaysian ports and provide actionable recommendations. These insights are intended to inform policymakers, industry practitioners, and academics on how to further drive sustainable development in Malaysia’s port sector while aligning with global best practices. 2. Literature review 2.1. Global context of sustainable port performance Sustainable port performance is an increasingly important topic in global maritime logistics. The concept involves minimizing the negative environmental impacts of port operations while maintaining or improving operational efficiency. Globally, various frameworks, methodologies, and evaluation indicators have been developed to assess the sustainability of ports. A systematic literature review by Lim et al. (2019) identified several key approaches to evaluating port sustainability including the development of green performance indicators, carbon emission reduction strategies, and the adoption of renewable energy technologies in ports. Another comprehensive review by (Tijan et al., 2021), which discusses the significant role of port authorities in governance and implementing systems that enhance sustainability in port operations. However, while much of the global research focuses on large, developed ports in North America and Europe, there has been increasing interest in understanding how ports in developing countries, such as those in Southeast Asia are addressing sustainability challenges. This is particularly relevant to Malaysia, where ports are crucial to the national economy and trade. Therefore, it is essential to review the initiatives undertaken by Malaysian ports to align with global sustainability trends. 2.2. Sustainability in Malaysian ports: key studies In Malaysia, several ports including Kuantan, Penang, and Klang are actively pursuing sustainable initiatives. These efforts reflect a broader national strategy to align with the Sustainable Development Goals (SDGs) and contribute to Malaysia’s National Green Technology Policy. 2.2.1. Port performance and environmental impact in Asia and Malaysia Studies examining the environmental performance of Malaysian ports highlight both the challenges and successes in achieving sustainability. Salleh et al. (2020) explored how Malaysian ports have adopted Lean, Agile, Resilience, and Green (LARG) paradigms in supply chain operations. Their study found that while ports like Klang and Penang have made significant strides in implementing green practices, there are still considerable challenges in fully integrating environmental sustainability into operational performance. Another important study by Lirn et al. (2013), provides a comprehensive green performance framework for sustainable ports in Asia focusing on major ports which is China, Hong Kong, and Taiwan. It identifies key environmental performance indicators (EPIs) such as carbon emissions, energy consumption, and waste management which are critical for enhancing the sustainability of ports. These indicators have been employed to measure the overall green performance of ports in Asia. 2.2.2. Challenges and barriers in achieving sustainability Despite efforts to implement sustainability initiatives, several challenges hinder the full-scale adoption of green practices in Malaysian ports. Research by Md Sapry et al.(2020) highlights the Green Port Initiative at Johor Port, which revealed significant gaps in communication and awareness among port staff, leading to lower levels of commitment toward environmental objectives. These challenges indicate the need for more effective training programs and mechanisms to monitor the success of green policies. Similarly, Bin Ibrahim et al. (2023) explored sustainable green port practices at Northport Malaysia, emphasizing the role of regulatory frameworks and benchmarking as critical tools for maintaining environmental performance. Their study suggests that while efforts are being made, the absence of stringent and cohesive regulations creates inconsistencies in sustainability practices across different ports. Beleya et al. (2015) further corroborates this by discussing how Malaysian seaports are working to align with global sustainability trends, but regulatory challenges and inconsistencies in policy enforcement continue to be major obstacles. They point out that while some seaports are progressing toward sustainable development, the lack of comprehensive regulations impedes the widespread adoption of green practices. Another challenge is the limited integration of renewable energy, partly due to space constraints and aging infrastructure. Penang Port, for instance has encountered difficulties in installing rooftop solar systems because of structural limitations in its older facilities (Penang Port Commission, 2023). Additionally, the slow pace of technological upgrades and the high cost of new equipment pose significant financial barriers for ports aiming to transition to greener technologies. 2.2.3. Opportunities for improvement Despite these challenges, there are significant opportunities for Malaysian ports to enhance their sustainability efforts. Collaboration between government agencies and private stakeholders, as well as increased investment in renewable energy technologies could accelerate the transition towards greener ports. A study by Di Vaio and Varriale (2018) emphasized the importance of adopting management innovation strategies and creating performance-based incentives to encourage ports to adopt energy-efficient technologies. This approach could be particularly beneficial for Malaysian ports, where financial and regulatory support could help overcome the current challenges. Moreover, integrating digital technologies and automation into port operations presents a significant opportunity for improving both operational efficiency and environmental performance in Malaysian ports. The adoption of smart port technologies such as digital monitoring systems and the Internet of Things (IoT) has already demonstrated its potential to optimize operations and reduce emissions in other regions. Yau et al. (2020) emphasize that smart ports utilize information and communication technologies to improve resource management, helping ports reduce greenhouse gas emissions while maintaining competitiveness. Similarly, Philipp et al. (2021) highlight how automation and renewable energy technologies can be integrated into port operations to support green port initiatives which is directly applicable to Malaysia as it seeks to enhance sustainability through the modernization of its ports. Furthermore, D’Amico et al. (2021) discuss how digitalization through the use of AI, Big Data, and real-time monitoring can optimize port logistics making it easier to reduce resource waste and emissions in port cities. As ports worldwide increasingly adopt these technologies, Malaysia has the potential to follow suit, leveraging smart port solutions to improve its environmental footprint and enhance operational capabilities. 3. Methodology This section outlines the research methodologies employed to evaluate sustainable port performance through a systematic literature review (SLR) and focus group discussions with key stakeholders in Malaysian ports. The two approaches were used in tandem to ensure a comprehensive understanding of both theoretical and practical perspectives on sustainability initiatives in the Malaysian port sector. M.S.S. Bahri et al. The Asian Journal of Shipping and Logistics 41 (2025) 38–51 39 3.1. Systematic literature review (SLR) A systematic literature review is a research technique that tries to locate, assess, and synthesise all the literature that is currently accessible on a certain subject or research question. It is an exhaustive and transparent method that includes a thorough search of pertinent databases, screening of papers using predetermined inclusion and exclusion criteria, and critical evaluation of the quality of the included research. A systematic literature review’s objective is to present a thorough and unbiased summary of the available data on a given subject so that decision-makers in practise, policy, or research may be better informed. The systematic literature review methodology normally entails several processes, including developing the research question, creating a search strategy, screening and selecting studies, extracting data, evaluating the quality of the studies, synthesising the findings, and publishing the results (Xiao & Watson, 2019). To guarantee that the evaluation is thorough, unbiased, and repeatable, the approach must be accessible and easy to understand. This study’s methodology focuses on a quantitative approach. After formulating specific research questions, the next subsequent step involved selecting search databases to identify pertinent studies addressing the research questions. A comprehensive analysis is done of the articles’ content that deals with environmental sustainability, green port, performance, and eco port. The process of locating studies encompassed three search strategies: delineating search term groups, identifying relevant literature databases, and establishing inclusion and exclusion criteria. 3.1.1. Research questions The SLR was structured around the following research questions: 1. What are the current research trends for port environmentally sustainable performance and evaluation? 2. How is the execution of measures for port environmentally sustainable performance and evaluation conducted? 3. What discernible gaps and challenges exist within the research field? 3.1.2. Search strategy Based on the research questions, five (5) search term groups were formed for this study. By combining the studies on the port industry from the perspective of environmental sustainability, the study was able to examine the degree of correlation between the themes researched using the five (5) combinations. The search terms group are as following: Group 1: Green Port AND Sustainable Group 2: Green Port AND Environmental Performance Group 3: Environmental Sustainability AND Port Industry Group 4: Environmental Sustainability AND Maritime Group 5: Eco Port AND Sustainable OR Environmental Performance Next, the database for literature searches. The sample articles were collected using Elsevier’s Scopus database. For academics, this database offers several benefits. It is a vast archive of high-caliber academic material, which makes it simpler for scholars to find relevant study. Scopus also provides a productivity and popularity ranking to journals. Next, compared to other databases like Web of Science, Scopus provides a more recent citation index. Additionally, Scopus offers a platform for the bibliometric analysis of research papers from journals, which can be seen using tools like VOSviewer and NVivo 12 Plus. 3.1.3. Inclusion and exclusion criteria To ensure the relevance of the articles selected, the following inclusion and exclusion criteria were applied: •Inclusion Criteria: o Full-text articles published in English. o Only article published with timeframe from 2007 to 2023. o Only studies that focus on evaluating the environmental performance of ports. o Only articles discussing criteria and methodologies for performance evaluation. o Only full articles and conferences papers that published in Scopus. •Exclusion Criteria: o Book chapters, dissertations, and theses, as well as other "grey" materials such reports, working papers, official documents, and white papers (Petticrew and Roberts, 2008) . o Studies focused purely on developing conceptual frameworks and approaches as well as anything unrelated to port environmental sustainability 3.1.4. Data extraction and analysis After gathering the sample articles, a method of research known as content analysis was used to each manuscript, which were independently reviewed the content of each article to assess its conformity with the research questions. The final list of sample articles underwent processing to generate a file structured and formatted as required for network analysis conducted using VOSviewer software. This software is an open-source tool that is used for envisaging and creating bibliometric networks. VOSviewer is a powerful software tool for bibliometric analysis that enables the visualisation and study of co-authorship, co-citation, and co-occurrence analysis in relation to bibliographic coupling. The search procedure unfolded in two primary stages: initially, the review sought papers pertinent to the research questions, followed by a bibliometric analysis of the selected articles. The first stage progressed through the following sequence: (i) conducting database searches; (ii) analysing content; (iii) assessing eligibility; and (iv) finalizing data processing. A comprehensive approach to the first phase’s sequence is shown in Fig. 1 to ensure the methodology’s validity. Using the search terms group, the initial search found 268 articles in total. The viewpoint served as the basis for the inclusion and exclusion criteria for this study. At this point, articles that did not meet the inclusion requirements, such as those without full text access, book chapters, and non-English articles were filtered out. Also, seven (7) articles were removed due to duplications resulting from the repetitive search terms. A large number of articles were removed during the screening phase due to reasons: 86 articles were excluded due to articles not related to topic interest, 13 articles were excluded due to non-accessibility to full text, and 37 articles were excluded due to articles not related to the subject area. It should be clarified that this study only focuses on environmental science, social sciences, and decision sciences. 78 articles that did not fall into the inclusion document type were also excluded. Lastly, only one article was removed due to a non-English article. Finally, a thorough assessment of the context for the eligibility of the article to be included in this analysis with an emphasis on the research questions mentioned in Section 3.1.1. A total of 19 publications that had valuable material for answering the research questions were chosen after a further 27 were removed after considering the article’s entire context. The number of papers underwent a reduction from 268 to 19 during the iterative filtering process, primarily attributable to two factors: articles that failed to meet the inclusion criteria and a scarcity of literature addressing empirical evidence concerning environmental sustainability within the context of performance evaluation and assessment 3.1.5. Focus group discussions (FGD) In recent years, the global community has intensified efforts to address environmental concerns and promote sustainable development. In response to the global imperative for sustainable development, Malaysia embarked on a transformative journey within its maritime sector, specifically targeting the establishment of green ports. The focus group discussions aimed to complement the findings from the SLR by providing practical insights into how sustainability initiatives are M.S.S. Bahri et al. The Asian Journal of Shipping and Logistics 41 (2025) 38–51 40 implemented in Malaysian ports. The primary objectives of the FGD were to determine which port authority functions contribute the most with respect to environmentally sustainable ports, gain a nuanced understanding of the existing green port initiatives in Malaysia, identify the challenges faced by stakeholders, and identify potential strategies to enhance sustainability within Malaysian ports. 3.1.6. Participant selection The profile of three (3) respondents from different ports in Malaysia are presented in Table 1. As shown in the table, the respondents hold a high level position and one of the top management members. This is significant since the respondents not only play a key role as decision makers in their respective organisations but they are also at the forefront of strategic planning and policy execution. Their knowledge of the operational difficulties and innovative solutions related to environmental sustainability in port management is extensive, making them a valuable resource. Interacting with upper management facilitates access to a multitude of experience and expertise, guaranteeing that the conversations are enhanced by a high-level, realistic viewpoint that is essential for developing an in-depth knowledge of current state and future prospects of sustainable practices in Malaysian ports. 3.1.7. Data collection The focus group discussions were conducted during the 21st ASEAN Ports and Shipping 2023 Exhibition and Conference in Bangkok, Thailand, where participants were actively involved. The discussions took place over two days and were guided by a semi-structured questionnaire designed to explore the following topics: •Current sustainability initiatives and their effectiveness. •Challenges faced in implementing sustainable practices. •Future sustainability goals and strategies. •Which port authority functions contribute the most with respect to environmentally sustainable ports. Each discussion lasted approximately 15–20 minutes, and all sessions were recorded and transcribed for analysis. 3.1.8. Data Analysis The transcripts from the focus group discussions were analysed using thematic analysis. Specific attention was given to identifying recurring challenges, such as regulatory gaps and infrastructure constraints, and opportunities for improvement, such as technological innovations and policy enhancements. The focus group results were then compared to the findings from the Articles identified from Scopus: (n = 268) Duplicate articles removed: ( n = 7 ) Articles screened: (n = 261) Articles excluded (n = 215) Not about topic of interest (n = 86) Full text article not available (n = 13) Not related with subject area (n = 37) Not related with document type (n = 78) Article not in English (n =1) Full-text articles assessed for eligibility: ( n = 46 ) Full articles excluded (n = 27) Review paper (n = 14) Did not measure variables of interest (n = 6) Did not study on environmental performance (n = 7) Included studies: (n = 19) Identification Screening Included Eligibility Fig. 1. PRISMA flow diagram. Source: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLoS Med 6(7): e1000097. doi:10.1371/journal.pmed1000097. Table 1 Profile of Respondents. No. Respondent Port Designation 1. Mr. A Kuantan Port Consortium Sdn. Bhd General Manager Operation 2. Mrs. B Penang Port Commission Senior Operations & Regulatory Manager 3. Mr. C Port Klang Authority Manager (Internal Audit) M.S.S. Bahri et al. The Asian Journal of Shipping and Logistics 41 (2025) 38–51 41 systematic literature review to assess the extent to which global sustainability frameworks are being implemented in Malaysian ports. This combined analysis provided a robust understanding of both theoretical and practical elements of sustainable port performance in Malaysia. 3.1.9. Ethical considerations and limitations of the study All participants in the focus group discussions provided informed consent before participating in the study. Confidentiality was maintained by anonymizing all responses, ensuring that individual ports and participants were not directly identifiable in the final report. While this study provides a comprehensive view of sustainability efforts in Malaysian ports, it is important to acknowledge several limitations. The focus group discussions, although highly informative, were limited to senior management at three key ports, potentially excluding perspectives from other operational levels or smaller ports. Additionally, while the SLR covered a broad range of global studies, the research may not capture the most recent developments that have occurred after the study period. 4. Data analysis and results This section presents the findings from both the systematic literature review and the focus group discussions. The findings provide insights into how global sustainability frameworks apply to the Malaysian context, specifically in terms of environmental performance evaluation and the sustainability initiatives implemented at Kuantan Port, Penang Port, and Port Klang. The focus group discussions with senior port management offer additional qualitative insights into the operational challenges and strategic plans for green port development in Malaysia. Each subsection presents the insights gathered from the systematic literature review and the focus group discussions with Malaysian port management, highlighting both global perspectives and Malaysiaspecific sustainability initiatives. 4.1. Systematic literature review findings 4.1.1. Keyword analysis The overall articles were analysed with VOSviewer. The most often used keywords in the article titles are depicted in Fig. 2, which also presents the network visualisation map of the author keywords in the titles. In the figure, the size of the nodes (keywords) represents the frequency of the keyword’s appearance in the title, while the lines between the nodes indicate that those keywords appear together within one or more articles. The colour coding is used to distinguish between distinct clusters within the network, and the thickness of the lines indicates the strength of the co-occurrence. The keyword analysis from the VOSviewer identified four dominant nodes which is “green port,” “sustainability,” and “sustainable development,”. These terms are essential in understanding how port sustainability is framed in the global literature and applied in the Malaysian context. The keywords ‘Green Port’ and ‘Green Ports” should be consolidated due to their synonymous implications, mainly reflecting the same focus on the adoption of environmental practices within port operations. “Green Port” and “Green Ports” emerged as a frequently discussed topic, reflecting the focus on reducing the environmental impact of port operations. In Malaysia, this is evident through the implementation of hyrid RTG cranes at Port Klang and Penang Port, as well as the shore power projects at Kuantan Port. These initiatives align with global trends toward energy efficiency and emission reductions, underscoring Malaysia’s commitment to achieving green port status. “Sustainability” is another key theme, encompassing a range of practiced aimed at balancing economic, environmental, and social goals. In Malaysian ports, sustainability efforts focus on reducing emissions through renewable energy project such as Kuantan Port’s solar energy installations and waste management. These efforts reflect a broader international shift toward making ports environmentally and operationally sustainable. Another significant node is "sustainable development," which highlights its importance as an overall goal that affects various aspects of port management and operations. This key theme in the port sector Fig. 2. Network visualization map of the author keywords. M.S.S. Bahri et al. The Asian Journal of Shipping and Logistics 41 (2025) 38–51 42 emphasizes the long-term viability of infrastructure that supports both current and future needs. Malaysia ports like Penang innovating within space constraints as can be seen with their floating solar panel initiative. This solutions contributes to the global sustainable development narrative by offering creative solutions to local challenges. The bibliometric visualization serves as a map of the research landscape, indicating which themes are more established and which might be emerging. Concept maps can be used to evaluate the development of ideas and the effectiveness of their connections, as well as to describe the degree of links between concepts (Yu & Liu, 2004). When words are matched by colour, it shows how frequently they occur, revealing the database’s thematic background. The primary keywords utilised by different authors are shown in Table 2. 4.1.2. Publication trends During the study period (2007–2023), the examination reveals a notable surge in the topic’s prominence beginning around 2013, as evidenced by a dynamic analysis of publication years and the increasing number of studies in the dataset. This trend aligns with the rising global awareness of the environmental impact of port operations and the urgent need to adopt green initiatives. Fig. 3 illustrates this trend, indicating a rise in documents focusing on environmentally sustainable ports, notably from one (1) in 2019 to four (4) in 2020, signifying a peak in interest during that year. For further insight into the distribution of works across different publication years, a detailed breakdown is provided in Table 3. A surge in publications was noted in 2020 and 2021, reflecting the increasing focus on green ports and the adoption of energy efficient technologies in response to global climate challenges. For Malaysian ports, this trend is mirrors by the adoption of several key sustainability initiatives during the same period such as the shore power project at Kuantan Port and the hybrid RTG crane project at Penang Port. 4.1.3. Authorship and research collaboration The most frequently cited authors in the fields of environmental sustainability and port performance are presented in Table 4. The most notable researchers are Wooldridge and Darbra since they both collaborate on many research projects with multiple researchers from various nations. The level of collaboration amongst a total of 29 authors from various nations is depicted in Fig. 4. Collaboration among authors is essential for progress in any field of study, and the field of environmentally sustainable ports is no exception (Turner & Baker, 2020). Collaboration fosters information sharing and resource pooling among authors, leading to successful initiatives and scientific advancement (Ou et al., 2012). Figs. 5 and 6 illustrate the nations with the most significant publishing presence within the network. Germany, Belgium, the United States, Croatia, Denmark, and Greece emerge as the most influential countries in terms of cooperative efforts, as demonstrated in these figures. Co-authorship preferences are influenced by a variety of variables, including language, geography, and cultural ties (Schubert & Schubert, 2020). The results of the current study make it clear that geopolitical affinity and language are important factors in determining cross-country co-authorship. It is interesting to note that Malaysia is not listed among the countries in the dataset, this highlights the need for more research on cooperation, particularly between the most powerful nations. The absence of strong international research collaboration has implications for how Malaysian ports approach sustainability. Without access to the latest global research findings and frameworks, Malaysia may face difficulties in implementing the most cutting edge port practices. Furthermore, the limited collaboration also restricts the ability of Malaysian researchers to influence the global discourse on port sustainability which could lead to a narrower focus in domestic research efforts, potentially missing out on innovative approaches. 4.1.4. Citation analysis Table 5 shows the articles with the most citations. With 181 citations, the article by Acciaro et al. (2014) titled "Environmental sustainability in seaports: a framework for successful innovation" tops the list. This article evidently serves as a foundational piece in the field, offering key insights and framework that have guided subsequent research and practice. Furthermore, as shown by their high citation counts of 93 and 91 respectively, the studies by Lirn et al. (2013) in green performance criteria for sustainable ports and Schipper et al. (2017) on the sustainability assessment of ports have also emerged as significant contributions. The 19 articles highlight a wide range of approaches, from innovative frameworks and sustainability evaluations to the creation of green performance standards and key performance indicators. The cross disciplinary focus of these articles reflects the multifaceted approach required to tackle the complex challenges of sustainability in port operations. Many authors, including Acciaro, Sys, Ferrari, Vanelslander, and many more, have made a substantial contribution to the body of knowledge in this area. Many of the high impact studies on the environmentally sustainable port performance come from institutions in Europe and North America, where researchers from multiple countries share their knowledge and creating comprehensive frameworks. In contrast, there is a no representative form Malaysia in these global research networks. Malaysian researchers and institutions have generally not been as active in publishing research studies on port sustainability particularly in highranking journals. This gap suggests that Malaysian ports may not be benefiting from the same level of academic innovation or global best practices as ports in more collaborative regions. 4.1.5. Proportional analysis The bar chart that illustrates the distribution of the number of articles using various data analysis methods is presented in Fig. 7. This provides a quick visual depiction of how frequently each technique is applied when evaluating port performance in environmentally sustainable ports. With four (4) publications, AHP is the most often used technique while technique like GAP analysis, Content analysis, and Delphi method are used in two (2) articles. Other techniques such as Discrete Choice Analysis appear less frequently. In the context of evaluating port performance in environmentally sustainable ports, the proportional analysis offers a more sophisticated knowledge of the data analysis techniques. AHP represents the greatest proportion of utilisation, including around 18.18 % of all articles. This suggests that it is highly preferred or appropriate for these kinds of investigations. About 9.09 % of the articles use techniques like GAP Table 2 Top Keywords. Author Keywords Occurrences Total link strength Green port 20 22 Sustainability 15 21 Sustainable development 12 18 Environmental sustainability 14 17 Green ports 12 11 Port 4 11 Shipping 7 11 Ports 4 9 Maritime spatial planning 3 8 Blue growth 3 5 Container terminal 2 5 Cold ironing 3 4 Decarbonization 2 4 Environment 3 4 Green energy 2 4 Green performance 2 4 Maritime shipping 2 4 Maritime transport 3 4 Digitalisation 2 3 Energy 2 3 M.S.S. Bahri et al. The Asian Journal of Shipping and Logistics 41 (2025) 38–51 43 analysis, Content analysis, and Delphi method, suggesting a modest degree of utilisation. A range of other techniques, including Discrete Choice Analysis, Thematic Analysis, Cluster Analysis, Analytic Network Process (ANP), Best Worst Method, Fuzzy AHP, Balanced Scorecard, Ordinal Scale, PROMETHEE, Fuzzy TOPSIS-AHP, Entropy, and Evidence-based Knowledge Scores, are less frequently employed, each constituting approximately 4.55 % of the articles. This diversity in methodology reflects the evolving nature within this research area. The analysis shows how researchers in the field employ a wide range of techniques, and it also emphasises how methodologies are dynamic and always adapting to meet the complexities of environmental sustainability in port operations. Particularly in the specific context of port operations, the dynamic nature of methodologies in environmental sustainability indicates a responsive response to the complex, multidisciplinary, and evolving nature of sustainability concerns. Researchers consistently develop and incorporate novel approaches to efficiently investigate and provide resolutions for these dynamic problems. 4.1.6. Summary of port authority functions in past studies Table 6 outlines the four (4) main functions of port authority that are identified and used in 19 distinct research studies. Landlord function, regulatory function, operator function, and community function are the four main port functions that have been adopted from the research of Acciaro et al. (2014). These functions are critical in evaluating the efficiency and effectiveness of port management. However, the literature reveals that not all studies use all four port authority functions for their evaluations, indicating a gap in comprehensively assessing port performance. Among the four (4) main functions of port authority, the Regulatory Function appears as the most extensively explored function, being the focus of research in 17 of the 19 studies. This emphasis highlights the crucial function of regulatory practices in port management and operations. However, the Landlord Function is studied in a relatively smaller number of research papers with only 7 out of 19. This could be a potential gap or a specific niche in port authority study. The Operator and Community functions are also important, covered in 11 and 13 studies respectively, demonstrating their important in the holistic operation of port authorities. These functions collectively indicate the various responsibilities of port authorities, ranging from direct operational control to encouraging community relations. The review of past studies shows that while many authors use a combination of these four functions, few studies comprehensively integrate landlord, regulatory, operator, and community functions into their evaluations of port performance. For instance, Lirn et al. (2013) and Teerawattana and Yang (2019) only include a subset of these functions which focusing solely on the community or operator functions, overlooking the broader roles port authorities play. Additionally, some studies focus on specific port areas such as seaside and yard rather than adopting a holistic view of overall port performance. This could limit the understanding of port authorities full impact on sustainability and efficiency. For the future study, the researcher will address this gap by using all four port authority function to evaluate the performance on Malaysian ports comprehensively. By applying this complete framework, the study will provide a more nuanced and holistic understanding of how Fig. 3. Document by Year. Table 3 Year of publications. Year Frequency % (N =19) 2013 1 5.26 2014 1 5.26 2015 0 0.00 2016 0 0.00 2017 2 10.53 2018 1 5.26 2019 1 5.26 2020 4 21.05 2021 5 26.32 2022 4 21.05 Total 19 100.00 Table 4 Most cited authors. Author’s Name No. of Citations Darbra R.M 33 Wooldridge C. 28 Puig M. 27 Lam J.S.L 23 Acciaro M. 14 Notteboom T. 13 Yang Z. 11 Vanelslander T. 11 Michail A. 10 Walker T.R 9 Casal J. 9 Ferrari C. 8 Van De Voorde E. 8 Kapros S. 7 Sys C. 7 Ronza A. 7 Total Authors =1691 M.S.S. Bahri et al. The Asian Journal of Shipping and Logistics 41 (2025) 38–51 44 Malaysian port authorities manage infrastructure, enforce regulations, handle operations, and engage with their communities. This approach will not only fill the gaps identifies in past studies but also offer valuable insights into how Malaysian ports can enhance their sustainability efforts and operational efficiency by leveraging all the functions. 4.2. Focus group discussion findings The focus group discussions with senior port management from Kuantan Port, Penang Port, and Port Klang provided in depth insights into the practical implementation of sustainability initiatives in Malaysia. Fig. 4. Network visualization map of the co-citation. Unit of analysis =Cited authors; method =Full counting; Minimum number of citations of an author =6. Fig. 5. Network visualization of the co-authorship. Unit of analysis =Countries; Counting method =Full counting; Minimum number of a country =2; Minimum number of citations of a country =0. Fig. 6. Distribution of researchers countries based on geographical location (Source: Author). M.S.S. Bahri et al. The Asian Journal of Shipping and Logistics 41 (2025) 38–51 45