Setting Sail for a Sustainable Growth in Small/Medium Ports

Abstract

Small- and medium-sized ports (SMSPs) face multifaceted challenges, including environmental pressures (pollution, resource depletion) as well as socio-economic strains (community impacts, trade dynamics). Governance complexities, regulatory fragmentation, limited funding, and stakeholder conflicts further exacerbate these challenges. This study identifies context-driven sustainability indicators for SMSPs and proposes best practices to enhance their resilience. Four small/medium-sized ports (SMSPs) in Crete, Greece—Souda (CHA), Heraklion (HER), Rethymnon (RET), and Sitia (SIT)—were evaluated to benchmark their sustainability performance using tailored indicators. The primary objectives were the following: (a) to identify sustainability indicators relevant to SMSPs, focusing on economic, environmental, and social aspects, and (b) to propose best practices for enhancing sustainability in these ports, considering their unique characteristics and constraints. A combination of the Best Worst Method (BWM) and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) analysis was employed. The findings revealed that “environmental monitoring and management” and “security of employment and social protection” are top priorities for medium-sized ports, while “competitiveness” was a crucial indicator for small ports, emphasizing the need for financial sustainability in the context of global trade. These results offer a strategic roadmap for policymakers, guiding interventions aimed at improving the sustainability and resilience of SMSPs, thereby supporting regional economies and international trade networks.

1. Introduction

More than 90 per cent of international trade occurs on the world’s oceans, making the maritime sector crucial to the global economy [1,2,3]. Within this framework, the significance of ports in addressing global sustainability challenges is widely recognized [4,5]. Numerous global initiatives have been implemented to evaluate the sustainability of port facilities [6]. Ports are continuously expanding, modernizing, and increasing their capacity to meet global trade demands, contributing significantly to the financial, environmental, and technological sectors [7,8]. As critical links in the worldwide supply chain, ports have a unique opportunity to spearhead sustainable practices [9]. While larger ports often dominate the headlines, small/medium-sized ports (SMSPs) are making significant strides toward sustainability [10].

In the 21st century, it has become imperative for SMSPs to prioritize sustainability for several reasons. First and foremost, sustainability aligns with the worldwide imperative to address climate change and mitigate environmental consequences [11]. SMSPs can significantly reduce their environmental footprint by adopting environmentally friendly measures, such as electrifying equipment, utilizing renewable energy sources, and implementing innovative technologies [12]. Furthermore, with the growing emphasis on sustainability among consumers and businesses, SMSPs that stress environmental friendliness are more likely to attract shipping companies and cargo owners seeking to minimize carbon emissions. By adopting sustainable practices, SMSPs enhance their prospects for growth, as they become more attractive to potential collaborators, investors, and funding sources, thereby reinforcing their significance in local and national economies. Fundamentally, improving the sustainability of SMSPs is a strategic necessity that can yield environmental, economic, and operational benefits.

As sustainability becomes increasingly pivotal in the global maritime sector, it is essential to establish a standard for evaluating these ports’ environmental, financial, and societal effectiveness [13]. Port sustainability encompasses various dimensions and can be adequately assessed using diverse indicators. Incorporating sustainability indicators into port management procedures is imperative to promote a more environmentally conscious, socially accountable, and economically sustainable future for these crucial hubs of global trade and commerce [14]. By systematically monitoring and evaluating these indicators, ports can assess their sustainability initiatives and identify areas that require improvement [15]. This enables them to make well-informed decisions to enhance their overall sustainability performance.

While several studies have attempted to compare sustainable indicators across ports, significant scientific gaps remain that warrant further investigation. A notable research gap is the scarcity of comparative studies across various ports worldwide. While numerous studies focus on practices at individual ports, there is a need for more study that directly compares sustainability performance among different ports. Such comparative studies are vital for identifying best practices, benchmarking performance, and facilitating knowledge sharing and collaboration between ports. Moreover, ports vary significantly in size, capacity, and operational activities. However, research gaps exist in adequately considering the influence of port size and type on the selection and performance of sustainable indicators. Larger ports with extensive infrastructure and operations may face different sustainability challenges than smaller ports with limited resources. This article seeks to address these research gaps by exploring the following questions:

What core sustainability indicators benchmark SMSPs’ performance regarding environmental, social, and economic sustainability, and how do these indicators vary across different regions and port sizes?

The novelty of this study lies in its focus on the sustainability needs of small- and medium-sized ports, which should be more noticed and often overlooked in favor of larger ports. It proposes a set of tailored sustainability indicators that address the unique challenges faced by these smaller ports. These indicators encompass environmental, economic, and social dimensions, such as environmental monitoring and management, energy efficiency, competitiveness, and social protection for employees. Each indicator plays a significant role in assessing the sustainability performance of SMSPs in terms of resilience, regulatory compliance, and economic viability. Furthermore, the originality of this study resides in promoting knowledge exchange and facilitating collaboration among SMSPs. Traditionally, these ports have operated with few opportunities to share challenges and successes. This study makes a significant contribution by developing a mechanism to share the best practices and lessons learned among these ports.

Our study delves deeper into the indicators for assessing the sustainable performance of ports using a combination of the BWM and VIKOR methods. While methods such as the Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) are commonly used in multi-criteria decision-making (MCDM), they involve more intricate pairwise comparisons and require greater computational effort [16,17]. These methods are effective but may not always yield precise results in cases with conflicting criteria. In contrast, BWM simplifies the process by asking decision-makers to identify only the best and worst criteria, reducing the cognitive load. VIKOR, on the other hand, is chosen for its ability to identify a compromise solution, making it well suited for contexts where decision-makers need to balance trade-offs between multiple sustainability objectives.

In this study, four different ports located in Crete (Greece) were used as case studies. The regional focus on Crete highlights the Mediterranean’s intricate balance between environmental conservation, cultural heritage preservation, and economic development in port sustainability. However, globally, variations in sustainability priorities among ports emerge due to diverse geographical conditions, economic activities, and regulatory frameworks, influencing their emphasis on environmental impact mitigation, community engagement, and industry-specific sustainability measures. The subsequent sections of the paper are organized as follows: Section 2 is dedicated to conducting a comprehensive literature review. The text examines sustainable development, which forms the foundation for environmental indicators, and analyzes the critical indicators of sustainable port development. Section 3 pertains to the methodology. Section 4 presents the study outcomes. Section 5 discusses the findings, while Section 6 contains concluding remarks.

2. Literature Review

Sustainable port operating procedures have been studied and researched in several ways [18]. However, due to the interconnectedness of numerous internal and external factors, it is not easy to define specific evaluation indicators [19]. To address this complexity, researchers have developed a diverse array of quantitative indicators.to assess sustainability performance within the context of ports. Various tools and evaluation methods, such as the Environmental Management Systems and Eco-Management and Audit Scheme, have been used to assign relative importance to each indicator [20].

The relevant literature has identified various methodologies to enhance the sustainability of ports by increasing competitiveness and improving customer service [21,22]. Ref. [23] utilized multiple indicators to assess the progress of port authorities toward environmental sustainability. Furthermore, Ref. [24] employed the self-diagnosis technique, enabling ports to evaluate their environmental management. The outcomes provided insights into various environmental management metrics, with environmental policy securing the highest percentage (96.7%) and environmental legislation taking the second position with a rate of (95.7%). Ref. [25] created a comprehensive collection of workable Circular Economy (CE) indicators for ports. These indicators evaluate how effectively port activities and infrastructure minimize waste, optimize resource use (e.g., energy, water, materials), extend product life cycles, and regenerate natural systems [26]. By focusing on CE indicators, ports can reduce their environmental footprint while enhancing operational resilience through resource conservation and waste minimization, contributing to long-term sustainability. The study offers a practical set of KPIs to aid the CE transition’s associated activities and communication.

Despite the growing study on port sustainability [27,28], significant gaps exist in understanding how regional differences impact the applicability of sustainability indicators, particularly for small- and medium-sized ports (SMSPs) in the Mediterranean [29,30,31].

Table 1. Critical analysis of similar studies/Contribution of this study.

Shortcomings of Existing Research	Contribution of this Study
Limited focus on small- and medium-sized ports (SMSPs) Most studies focus on large ports, often neglecting SMSPs and their specific challenges	This study examines simplified methods to bridge the gap by focusing exclusively on SMSPs, offering tailored sustainability indicators that address the unique operational and resource constraints of smaller ports.
Lack of regional analysis Existing studies do not adequately consider regional differences in sustainability priorities, such as geographic, economic, and regulatory variations.	This study addresses regional differences by analyzing SMSPs in the Mediterranean, testing them in Crete, highlighting how environmental conservation and local economic development shape sustainability practices.
Inconsistent applicability of sustainability indicators Many studies propose indicators without considering their applicability to SMSPs, which may operate under different constraints.	According to the authors, this study develops regionally adaptive indicators tailored to the specific socio-economic and environmental conditions of SMSPs, ensuring relevance and practical applicability.
Use of complex methodologies not suited for SMSPs Some studies employ complex MCDM methods such as AHP and TOPSIS, which may not be ideal for smaller ports with limited resources.	This study employs simplified yet effective decision-making tools (BWM and VIKOR) to evaluate sustainability indicators, which are more suitable for SMSPs’ limited resources and capabilities.
Limited integration of social and economic dimensions Previous studies often emphasize environmental indicators, overlooking the social and economic aspects of sustainability.	This study integrates social and economic indicators, such as employment security and competitiveness, reflecting the critical importance of these dimensions in SMSPs.

highlights the gaps in previous studies and how the current study addresses these shortcomings, contributing to the understanding of sustainability in SMSPs.

Over recent decades, the United Nations (UN) has emerged as a central actor in advancing sustainable development through multilateral policy frameworks. The UN framework aims to improve the quality of life, protect the environment, and reduce inequality by 2030 [32]. The Sustainable Development Goals (SDGs) represent a collective vision for a better world based on the definition of sustainable development [33]. Furthermore, the SDGs set priorities and define the guiding goal for global development and sustainable transition. On the other hand, sustainable indicators are the means to measure and assess progress toward these goals. In this context, the indicators provide the tools to monitor progress and identify areas requiring further efforts. The SDGs significantly influence the global maritime sector, particularly SDG 14 [34], which focuses on Life Below Water, and SDG 9, which focuses on Industry, Innovation, and Infrastructure. For example, SMSPs that invest in renewable energy systems, such as solar panels or wind turbines, contribute to sustainable industrialization and infrastructure resilience. The integration of digital technologies for port operations, such as real-time cargo tracking and automated systems, promotes innovation and efficiency, thereby further supporting SDG 9. Similarly, SMSPs can align with SDG 14 (Life Below Water) through indicators like environmental monitoring and pollution control. By reducing emissions, implementing waste management systems, and monitoring water quality, ports can minimize their environmental footprint and protect marine ecosystems. Through these specific indicators, SMSPs can actively contribute to achieving global sustainability targets. Beyond the SDGs, international frameworks such as the International Maritime Organization (IMO) regulations, the World Ports Sustainability Program, and initiatives tied to the Paris Agreement shape sustainability efforts in ports globally. These frameworks guide ports in reducing emissions, implementing safety standards, and engaging in collaborative sustainability initiatives, aligning the sector with environmental stewardship, social responsibility, and economic resilience goals. The EU Corporate Sustainability Reporting Directive (Directive 2022/2464) requires companies, including ports, to disclose their environmental effects and sustainability risks as per the United Nations Sustainable Development Goals.

2.1. Sustainable Indicators

In advancing the sustainability of ports, indicators for sustainability have been formulated and applied to gauge, observe, and enhance the environmental, economic, and social performance of ports in the following manner:

2.1.1. Environmental Sustainability/Indicators

The first environmental indicators in ports emerged decades ago, addressing environmental challenges such as water pollution. However, due to advancements in scientific research and the emergence of a worldwide consciousness regarding sustainability, environmental indicators have evolved to encompass more intricate elements, such as safeguarding biodiversity, effectively managing waste, and utilizing renewable energy sources. Numerous emerging trends and innovations have been observed globally, showcasing a commitment to environmental sustainability [35]. Some key trends and notable initiatives from different regions are described, as follows: The Port of Los Angeles & Long Beach (USA) has invested in zero-emission equipment and infrastructure. Initiatives include the Clean Trucks Program, the Clean Air Action Plan, and the development of hydrogen fuel cell trucks and electric cargo-handling equipment. The Port of Vancouver (Canada) has implemented shore power facilities, enabling ships to plug into electrical power at berth, reducing the need to run their engines and cutting emissions significantly. The Port of Singapore utilizes innovative technologies for efficient traffic management, which reduce vessel waiting times, optimize routes, and minimize fuel consumption and emissions. These examples illustrate a global shift toward environmentally sustainable practices in ports, encompassing various strategies and technologies to reduce emissions, conserve natural resources, and promote a greener future for maritime operations.

2.1.2. Economic Sustainability/Indicators

Ports serve as vital catalysts for economic growth and global interconnectedness, functioning as strategic nodal points that facilitate the transnational movement of commodities, capital, and innovation [5]. The economic contribution of ports extends far beyond their immediate vicinity as they form integral components of supply chains, supporting industries and trade networks on a regional and international scale [36]. Globally significant ports, such as Shanghai (China), Los Angeles (United States), and Rotterdam (Netherlands), exemplify this critical role, demonstrating how port infrastructure substantially contributes to national economic performance through multiple channels. Contemporary evaluation frameworks have consequently evolved to incorporate sophisticated metrics that assess port competitiveness, capital investment patterns, employment generation capacity, and macroeconomic contributions, reflecting the increasingly complex role of ports in modern economic systems.

2.1.3. Social Sustainability/Indicators

Ports are crucial in driving economic growth and delivering substantial significant social benefits to the communities within their operational areas. Beyond the bustling terminals and cargo handling, ports serve as hubs of social interaction and engagement, fostering community development and offering various opportunities for social advancement. The Port of Antwerp in Belgium collaborates with stakeholders to ensure that goods passing through its terminals adhere to ethical standards, fostering responsible trade practices and supporting socially sustainable supply chains [37]. The Port of Barcelona in Spain promotes sustainable mobility by supporting public transportation projects, reducing traffic congestion, and enhancing connectivity for residents living near the port area [38].

2.2. Key Sustainability Indicators for Port Evaluation

Key sustainability indicators identified in the study include energy consumption, emissions reduction, and resource efficiency, which are essential for evaluating ports’ environmental performance. Additionally, the development of a performance assessment tool tailored to small ports highlights the need for targeted environmental management practices to improve sustainability outcomes. The insights gained from these indicators can guide policymakers and port authorities in implementing effective strategies that align with global sustainability goals [39]. For this study, the following main sustainability indicators (Table 2) were used:

2.2.1. Green Infrastructure (GI)

Green infrastructure has emerged as a transformative paradigm for addressing environmental challenges across multiple sectors, with its application in ports garnering increasing attention [40]. Embracing green infrastructure practices allows ports to improve environmental performance and foster sustainable development [41]. This article compares green infrastructure initiatives at different ports, highlighting their approaches, successes, and challenges while identifying key points that can enhance the understanding and implementation of green infrastructure in the port sector.

2.2.2. Environmental Monitoring and Management (EMM)

Monitoring can prove helpful in ensuring that port policy is pursued and in assessing the efficacy of each management choice [42]. Monitoring involves the systematic and repetitive measurement of the direct or indirect effects of human activity or contaminants on the ecosystem. An effective monitoring strategy makes it easier to address issues like adherence to particular regulatory standards, examination of pollution patterns, provision of research data, measurements for establishing standards, and early notification of involved actors on essential changes in specific project parameters.

2.2.3. Management of Energy (ME)

Examining energy management practices across diverse ports offers valuable insights into the range of approaches and the effectiveness of different strategies. This analysis investigates the adoption of renewable energy technologies, energy efficiency measures, and innovative practices through comparative case studies and typologies. The implementation of Port Energy Management Plans has demonstrated efficacy in facilitating targeted energy efficiency improvements while enhancing stakeholder engagement. Notably, the integration of smart energy systems and renewable energy sources, such as solar and wind, significantly reduces dependence on fossil fuels and decreases greenhouse gas emissions [43]. Furthermore, ports prioritizing equipment electrification not only improve operational efficiency but also contribute to broader decarbonization initiatives within the maritime sector [44]. The regulatory landscape has been significantly influenced by the Alternative Fuels Infrastructure Regulation (AFIR), which mandates that major European ports provide shore-side power for vessels by 2030, thereby reducing fossil fuel consumption during port calls. This legislative framework improves alternative fuel infrastructure, facilitating the transition to renewable energy sources and supporting the achievement of EU decarbonisation objectives.

This comparative analysis enables port authorities, policymakers, and stakeholders to identify transferable solutions from successful implementations and promote the adoption of sustainable practices across port infrastructure [45].

2.2.4. Technology (TE)

Technology has transformed port operations into efficient, interconnected global trade centers [46]. Container tracking and management systems are examples of automated systems that have streamlined processes, reduced human error, and increased overall productivity [47]. The application of advanced data analytics enables ports to optimize operations through analyzing real-time data of vessel schedules, cargo volumes, and logistical data. This data-driven approach improves decision-making, empowering port authorities to allocate resources effectively, alleviate congestion, and improve overall efficiency. Consequently, after all, policymakers need to support the development and integration of such technologies to strengthen operational resilience and maintain competitiveness within the maritime sector.

2.2.5. Approaches for Waste Management and Recycling (WM&R)

The effective management of waste and the implementation of recycling strategies are critical components of sustainability in the maritime sector. As primary nodes in international trade and network transport, ports significantly play a pivotal role in minimizing waste generation, reducing environmental impacts, and advancing circular economy principles. Implementing efficient waste management and recycling strategies at ports can conserve resources and reduce pollution [48]. Studies indicate that ports can enhance environmental stewardship through robust waste management systems. This analysis compares waste management and recycling strategies across different ports, evaluating their respective approaches, achievements, and challenges while identifying research gaps to inform sustainable practices and policymaking in the maritime industry. Policymakers can utilize port practices to promote recycling, reduce waste, and enhance resource efficiency, thereby creating a circular economy. Effective policy implementation ensures stakeholder participation, promoting communication and performance at all levels [49,50].

2.2.6. Training of Employees in Environmentally Responsible Practices (EET)

The International Labor Organization has established comprehensive guidelines emphasizing competency-based training methodologies to enhance skill development and promote occupational health and safety in port environments. These guidelines advocate for a structured training framework that aligns with national qualification systems, facilitating labor mobility and enhancing workforce capabilities. Consequently, port operators should prioritize comprehensive training programs to ensure continuous professional development, enable adaptation to evolving industry requirements, and foster sustainable maritime practices.

2.2.7. Security of Employment and Social Protection (SE&SP)

Ensuring employment security and providing adequate social protection for workers constitute fundamental elements of a sustainable and inclusive maritime sector. Numerous regulatory frameworks, guidelines, and best practices have been developed to enhance port safety and security [51]. The International Maritime Organization’s statutory requirements [52], which include those listed below, are among the most significant; (a) the Convention for Safety of Life at Sea, (b) the Seafarers’ Training, Certification, and Watch-keeping Code, and (c) International Safety Management. Through adequate employment security and social protection measures, ports can safeguard workforce welfare, enhance productivity, and contribute to equitable industry.

2.2.8. Competitiveness (CMS)

In the contemporary globalized economy, ports serve as critical facilitators of international trade and commerce. To maintain competitiveness in this dynamic environment, ports worldwide have adopted diverse strategies to enhance their competitiveness and maintain a leading position in the market [53]. This comparative analysis explores different ports’ competitive strategies and assesses their effectiveness in achieving growth, efficiency, and customer satisfaction. Through examination of these, the study identifies key factors and best practices in port management.

Table 2. Main and sub-indicators.

Main Indicators	Sub-Indicators	Gode	Description	Authors
GI	a. Green infrastructure design	GI 1	Climate and the environment are less negatively impacted by its design, construction, or operation, and positive effects may also result from these factors.	[54,55]
	b. Energy-saving strategies	GI 2
	c. Eco-friendly parking space at the port	GI 3
	d. Solar energy storage capacity facilities	GI 4
	e. Functional and aesthetic infrastructure planning	GI 5
EMM	a. Environmental and energy management certification	EMM 1	Policymakers, international organizations, and the general public can be informed on environmental trends and conditions and promote policy development with environmental monitoring.	[56,57]
	b. Mitigating the emission of greenhouse gases	EMM 2
	c. Recommendations for the framework for a clean development project	EMM 3
	d. Recommendations for the framework for a clean development project	EMM 4
	e. Implementation of policies and regulations for green areas	EMM 5
ME	a. Energy control equipment system for lighting, heating, etc.	ME 1	Energy management is the proactive, planned, and systematic coordination of energy production, delivery, and consumption to satisfy demand while considering both environmental and financial objectives.	[58,59]
	b. Energy management plan	ME 2
	c. Replace old-fashioned equipment with greener technology	ME 3
	d. Use of RES	ME 4
	e. Monitoring system of energy consumption	ME 5
TE	a. Cyber security measures	ΤΕ 1	Technology is revolutionizing the port world, altering how goods are handled and enhancing overall efficiency and security. Technological advancements in recent years have reshaped the port industry, significantly improving operations, logistics, and safety measures.	[60,61]
	b. Green technology	ΤΕ 2
	c. Automated systems	ΤΕ 3
	d. Real-time systems	ΤΕ 4
	e. Smart technology	ΤΕ 5
WM&R	a. Use of online tools for monitoring waste	WM&R 1	Waste management aims to promote waste treatment alternatives that are appropriate for the waste, particularly favoring reuse and recycling.	[62,63]
	b. Increase awareness of waste management among stakeholders	WM&R 2
	c. Financial incentives for stakeholders	WM&R 3
	d. Penalty paid due to illegal dumping of waste	WM&R 4
	e. Waste prevention plan	WM&R 5
EET	a. Education seminars for energy conservation	EET 1	Green training and development equip staff with practices that ensure adequate resource utilization, reduce waste, promote energy conservation, and mitigate the causes of environmental degradation.	[64,65]
	b. Cooperation with other ports for lessons learned	EET 2
	c. Collaboration with the appropriate organization	EET 3
	d. Participation in projects to increase sustainability	EET 4
	e. Incentives (financial and social, professional) for their involvement in educational programs	EET 5
SE&SP	a. Security plan	SE&SP 1	This sector at ports aims to equip governments, enterprises, employees, and other stakeholders with the resources they need to reduce the threat posed by illicit activities.	[66,67]
	b. Safety plan	SE&SP 2
	c. Adopt measures and create appropriate infrastructure for the safety of ships from external factors (e.g., weather conditions, etc.)	SE&SP 3
	d. Staff training on security and safety issues	SE&SP 4
	e. Cooperation with other bodies for the exchange of information on security issues	SE&SP 5
CMS	a. Economy	CMS 1	Competitiveness refers to a port’s ability to attract customers by providing superior goods, services, and other amenities.	[68,69]
	b. Employment	CMS 2
	c. Tourism	CMS 3
	d. Research and development	CMS 4
	e. Technology	CMS 5

Table 2. Main and sub-indicators.

Main Indicators	Sub-Indicators	Gode	Description	Authors
GI	a. Green infrastructure design	GI 1	Climate and the environment are less negatively impacted by its design, construction, or operation, and positive effects may also result from these factors.	[54,55]
	b. Energy-saving strategies	GI 2
	c. Eco-friendly parking space at the port	GI 3
	d. Solar energy storage capacity facilities	GI 4
	e. Functional and aesthetic infrastructure planning	GI 5
EMM	a. Environmental and energy management certification	EMM 1	Policymakers, international organizations, and the general public can be informed on environmental trends and conditions and promote policy development with environmental monitoring.	[56,57]
	b. Mitigating the emission of greenhouse gases	EMM 2
	c. Recommendations for the framework for a clean development project	EMM 3
	d. Recommendations for the framework for a clean development project	EMM 4
	e. Implementation of policies and regulations for green areas	EMM 5
ME	a. Energy control equipment system for lighting, heating, etc.	ME 1	Energy management is the proactive, planned, and systematic coordination of energy production, delivery, and consumption to satisfy demand while considering both environmental and financial objectives.	[58,59]
	b. Energy management plan	ME 2
	c. Replace old-fashioned equipment with greener technology	ME 3
	d. Use of RES	ME 4
	e. Monitoring system of energy consumption	ME 5
TE	a. Cyber security measures	ΤΕ 1	Technology is revolutionizing the port world, altering how goods are handled and enhancing overall efficiency and security. Technological advancements in recent years have reshaped the port industry, significantly improving operations, logistics, and safety measures.	[60,61]
	b. Green technology	ΤΕ 2
	c. Automated systems	ΤΕ 3
	d. Real-time systems	ΤΕ 4
	e. Smart technology	ΤΕ 5
WM&R	a. Use of online tools for monitoring waste	WM&R 1	Waste management aims to promote waste treatment alternatives that are appropriate for the waste, particularly favoring reuse and recycling.	[62,63]
	b. Increase awareness of waste management among stakeholders	WM&R 2
	c. Financial incentives for stakeholders	WM&R 3
	d. Penalty paid due to illegal dumping of waste	WM&R 4
	e. Waste prevention plan	WM&R 5
EET	a. Education seminars for energy conservation	EET 1	Green training and development equip staff with practices that ensure adequate resource utilization, reduce waste, promote energy conservation, and mitigate the causes of environmental degradation.	[64,65]
	b. Cooperation with other ports for lessons learned	EET 2
	c. Collaboration with the appropriate organization	EET 3
	d. Participation in projects to increase sustainability	EET 4
	e. Incentives (financial and social, professional) for their involvement in educational programs	EET 5
SE&SP	a. Security plan	SE&SP 1	This sector at ports aims to equip governments, enterprises, employees, and other stakeholders with the resources they need to reduce the threat posed by illicit activities.	[66,67]
	b. Safety plan	SE&SP 2
	c. Adopt measures and create appropriate infrastructure for the safety of ships from external factors (e.g., weather conditions, etc.)	SE&SP 3
	d. Staff training on security and safety issues	SE&SP 4
	e. Cooperation with other bodies for the exchange of information on security issues	SE&SP 5
CMS	a. Economy	CMS 1	Competitiveness refers to a port’s ability to attract customers by providing superior goods, services, and other amenities.	[68,69]
	b. Employment	CMS 2
	c. Tourism	CMS 3
	d. Research and development	CMS 4
	e. Technology	CMS 5

3. Methodology

3.1. Case Studies/Identification of Ports—Experts

The current section involves identifying key expert stakeholders with a deep dive into port case studies. Four different SMSPs were examined for the current research needs. The identified case studies are in Crete, the fifth-biggest island in the Mediterranean and one of the most populous Greek islands. The four ports were selected to compare their efficacy in terms of sustainability and to collect data to assist port operators in future port design. The selection of these specific ports was based on a combination of factors that ensure a diverse and comprehensive assessment. These factors include geographical diversity, economic roles, operational scale, and environmental challenges, which collectively offer insights into various contexts faced by SMSPs globally. The chosen ports vary in their operational capacities and services, ensuring that the findings are applicable across a spectrum of SMSPs, with different economic dependencies and environmental impacts. This diversity enables the research to draw broader conclusions about sustainability practices and challenges that can be applied to other SMSPs. On the other hand, these ports are representative, making their results replicable to the rest of small- to medium-sized Mediterranean ports because they achieve the following:

• Primarily support local and regional trade rather than functioning as global mega-hubs like Piraeus or Valencia;
• Cater to passenger ferries, fishing activities, and limited cargo operations, which are typical of island ports;
• Hold strategic or tourism significance;
• Boast a notable historical heritage.

Figure 1, Figure 2, Figure 3 and Figure 4 present yearly data per port, providing a comprehensive overview of their operations. The respective Coast Guard authorities have provided the data. The procedure for collecting expert responses spanned approximately four months (December 2023 to March 2024). This period was chosen to optimize the number and the quality of feedback from the carefully selected target group, because the alternative timeframes (April–November 2024) were heavily occupied with addressing the island’s overtourism challenges.

3.1.1. Port of Souda, Chania (CHA)

As one of the Mediterranean’s largest and most secure ports, CHA serves various purposes, including passenger transportation, tourism, water sports, and fishing. Substantially benefiting from its strategic location at the intersection of major maritime routes, Chania has experienced notable commercial, tourism, and economic growth in recent decades.

3.1.2. Port of Heraklion (HΕR)

HER is a key passenger and freight hub in the Mediterranean basin. Passenger and commercial ships visit the port frequently throughout the year, and HER has become one of the leading cruise ship destinations in the Mediterranean [70].

3.1.3. Port of Rethymnon (RET)

RET is the third-largest city of Crete, located between Chania and Heraklion. Its ferry connections with other areas vary, so a connection should be taken seriously yearly. The ferry is also used to transport goods, while several tourist boats offer day cruises in the summer.

3.1.4. Port of Sitia (SIT)

SIT is the port of the easternmost prefecture of Crete and an ideal holiday destination, as it combines some of the most beautiful elements of Crete. There is a ferry connection with other areas, but it is less frequent than other ports of Crete.

From the analysis above, the port with the most significant activity is the HER. The second most visited is the CHA, followed by the SIT and RET. For this study, based on site visits, HRA and CHA are classified as medium ports, while RET and SIT are small ports.

3.2. Survey Analysis

This study adopted a structured, multi-phase methodological approach to evaluate and compare sustainability indicators across ports (Figure 5). The research process consisted of three key phases: First, we conducted a comprehensive identification of research gaps. As discussed in the previous section, the critical points of this study are identifying best practices in sustainable development and the benefits of sharing knowledge and lessons learned. For the second phase, we implemented a rigorous expert selection process. Five domain experts were carefully chosen based on stringent criteria, including a (1) minimum of ten years emphasizing their professional experience in relevant fields (port management, maritime economics, and environmental sustainability) and (2) current active involvement in either port operations, regional governance, or academic research related to sustainable development. This carefully considered selection guarantees a well-rounded understanding of both practical and theoretical aspects of port sustainability, adding credibility and consistency to their evaluations. The third phase involved developing and validating our sustainability indicator framework through stakeholder engagement, literature review, and consideration of international standards. Elsevier and Google Scholar were used to conduct a literature search at this stage. Elsevier was chosen as the source for the literature search for articles, whereas Google Scholar was utilized for the literature search for dissertations and other material forms. The keywords used include “indicators,” “Small/Medium Ports”, and “Sustainability”. Following this, we engage experts to validate and prioritize the identified indicators. Finally, we applied robust analytical methods, initially calibrating indicators using the BMW and then conducting comprehensive evaluations through the VIKOR methodology to assess sustainability performance across our case study ports.

3.3. BWM and VIKOR Methods

3.3.1. Best Worst Method (BWM)

A description of the steps is provided below [71], as follows:

Step 1: Choosing the attributes to be analyzed after reviewing the literature and consulting experts.

Step 2: The experts were asked to rate all indicators and select the best and worst of every category.

Step 3: The experts were requested to categorize the selected attributes as a result of step 2 based on the worst attribute as the initial point of reference.

Step 4: The optimum weights (w₁*, w₂*,……., w_n*) were determined for each attribute. The study aims to establish attribute weights so that the greatest absolute differences for each j may be reduced to the smallest possible value for {|w_B − α_Bjw_j|, |w_j − α_jWW_w|}. The subsequent model will be acquired: min max {|w_B − α_Bjw_j|, |w_j − α_jWW_w|}.

$$\mathrm{s}.\mathrm{t}.{\sum }_{ij}{w}_j=1$$

w_j ≥ 0 for all j

(1)

Model (1) is presented below and then changed into a linear model, which provides results in a more demonstrative way, as follows:

minξ^L

s.t.

|w_B − α_Βjw_j| ≤ ξ^L, for all j

|w_j − αj_WW_w| ≤ ξ^L, for all j

$${\sum }_j{w}_j=1\hspace{1em}{w}_j\ge 0 \mathrm{for} \mathrm{all} j$$

(2)

Model (2) can be solved to provide the best weights (w₁*, w₂*,……, w_n*) and the best value for ξ^L. Attribute comparisons (ξ^L) are preferred to be consistently close to 0.

3.3.2. VIKOR Analysis

The following steps depict the VIKOR approach [72,73]:

Step 1: Using the magnitude presented in

Table 3. Scale for comparison matrix according to the VIKOR methodology.

VIKOR Technique Scale
Significant Scale	Grade
Extremely significant	1
Very strong significant	2
Strongly significant	3
Significant	4
Low significant	5

, creating a matrix of indicators and options was necessary.

Step 2: The average decision matrix was discovered using Equation (3).

$$F={\displaystyle \frac{1}{k}}{\sum }_{k=1}^k{F}_k$$

(3)

where F represents the typical matrix, and k represents the number of experts.

Step 3: Equations (4) and (5) are used to determine the best $f_b^{\mathrm{*}}$ and worst $f_b^{-}$ values for all the indicators, b = 1, 2, n.

$$f_b^{\mathrm{*}}=Max\left(f_{\alpha b}\right)$$

(4)

$$f_b^{-}=Min\left(f_{\alpha b}\right)$$

(5)

where $f_b^{\mathrm{*}}$ is the optimal solution’s positive and $f_b^{-}$ negative values for both attributes, respectively.

Step 4: Sa and Ra values should be calculated for a = 1, 2,………, n utilizing Equations (6) and (7).

$$S_a={\sum }_{b=1}^n{W}_b[(f_b^{\mathrm{*}}-f_{ab})/(f_b^{\mathrm{*}}-f_b^{-})]$$

(6)

$$R_a={Max}_b\left[{\displaystyle \frac{W_b\left(f_b^{\mathrm{*}}-f_{ab}\right)}{f_b^{\mathrm{*}}-f_b^{-}}}\right]$$

(7)

The solutions offered by Sa and Ra are based on the indicators of the least individual regret of the opponent and the most significant group utility, respectively. Wb denotes the weights of the indicators.

Step 5: To calculate the scores for Qa, Equation (8) was used.

$$Q_a=v\left({\displaystyle \frac{S_a-S^{\mathrm{*}}}{S^{-}-S^{\mathrm{*}}}}\right)+(1-v)\left({\displaystyle \frac{R_a-R^{\mathrm{*}}}{R^{-}-R^{\mathrm{*}}}}\right)$$

(8)

S⁻ = MaxaSa, S* = Mina Sa, R⁻ = Maxa Ra, R* = Mina Ra, where v gives the weight of the strategy of “the majority of indicators” (or the most extensive group utility); in this case, v = 0.5. Within a decision-making procedure, such as the “vote by majority rule” (when v > 0.5 is required), “by consensus” (when v = 0.5), or “with veto” (when v < 0.5). Qa indicates the VIKOR index.

Step 6: The alternatives were ranked using Qa values.

Step 7: The alternatives were ranked according to the minimum Qa values derived by concurrently fulfilling the following two conditions:

Condition 1. Q(A(1)) is chosen if Q(A(2)) − Q(A(1)) ≥ 1/n − 1, where A(2) is the alternative that came second in the analysis, and n represents the total alternatives.

Condition 2. According to both Sa and Ra values, Q(A(1)) achieves the first rank.

Step 8: As an alternative, the minimum score in Qa achieved is ranked first.

4. Results

4.1. Best Worst Method

The BWM was applied to evaluate the relative effectiveness of sustainability indicators for the port of HER. Following expert ratings, criterion weights were computed using Equation (2) with the identified best and worst indicators for HER presented in

Table 4. Total number of experts who selected specific indicators as best and worst, respectively, at HER.

Main Indicators	Selected as the Best Sub-Indicator by Experts	Chosen as the Worst Sub-Indicator by Experts	Main Indicators	Selected as the Best Sub-Indicator by Experts	Chosen as the Worst Sub-Indicator by Experts
GI			WM&R
GI 1		1	WM&R 1		3
GI 2		3	WM&R 2		1
GI 3		1	WM&R 3
GI 4			WM&R 4		1
GI 5	5		WM&R 5	5
EMM			EET
EMM1		2	EET 1	3
EMM2			EET 2
EMM3		3	EET 3
EMM4			EET 4		5
EMM5	5		EET 5	2
ME			SE&SP
ME 1			SE&SP 1
ME 2	5		SE&SP 2
ME 3			SE&SP 3
ME 4			SE&SP 4		5
ME 5		5	SE&SP 5	5
TE			CMS
TE 1		2	CMS 1	2
TE 2			CMS 2	1
TE 3			CMS 3	2
TE 4		3	CMS 4		3
TE 5	5		CMS 5		2

. The aggregated weights derived through Equation (4) and subsequent averaging are comprehensively displayed in

Table 5. Aggregate weights of main and sub-indicators for all experts (HRA-port).

Main Indicators	Weights of Main Indicators	Sub Indicators	Weights of Sub-Indicators	Global Weights	Ranking
GI	0.033	GI 1	0.356	0.004	39
		GI 2	0.189	0.007	33
		GI 3	0.081	0.003	40
		GI 4	0.158	0.005	38
		GI 5	0.217	0.014	25
EMM	0.331	EMM 1	0.172	0.037	9
		EMM 2	0.133	0.05	5
		EMM 3	0.16	0.032	10
		EMM 4	0.38	0.136	1
		EMM 5	0.165	0.076	3
ME	0.1	ME 1	0.134	0.019	19
		ME 2	0.416	0.041	6
		ME 3	0.188	0.017	20
		ME 4	0.158	0.015	23
		ME 5	0.106	0.008	32
TE	0.133	TE 1	0.168	0.014	24
		TE 2	0.275	0.025	13
		TE 3	0.174	0.027	12
		TE 4	0.098	0.013	27
		TE 5	0.284	0.054	4
WM&R	0.056	WM&R 1	0.203	0.006	37
		WM&R 2	0.208	0.008	31
		WM&R 3	0.126	0.011	28
		WM&R 4	0.114	0.008	30
		WM&R 5	0.347	0.023	15
EET	0.08	EET 1	0.185	0.027	11
		EET 2	0.201	0.014	26
		EET 3	0.131	0.01	29
		EET 4	0.241	0.006	36
		EET 5	0.242	0.023	16
SE&SP	0.2	SE&SP 1	0.344	0.038	8
		SE&SP 2	0.256	0.024	14
		SE&SP 3	0.209	0.016	21
		SE&SP 4	0.118	0.082	2
		SE&SP 5	0.072	0.04	7
CMS	0.067	CMS 1	0.328	0.019	18
		CMS 2	0.165	0.015	22
		CMS 3	0.108	0.02	17
		CMS 4	0.269	0.06	35
		CMS 5	0.131	0.007	34

. Appendix A contains the outcomes for the remaining ports (CHA-RET-SIT). Additionally,

Table 6. Results for each port and each sub-indicator, considering all expert responses.

	HRA	CHA	RET	SIT	fb*	fb−
GI 1	0.004	0.004	0.009	0.011	0.004	0.004
GI 2	0.007	0.01	0.011	0.008	0.011	0.007
GI 3	0.003	0.004	0.003	0.003	0.004	0.003
GI 4	0.005	0.005	0.004	0.005	0.005	0.004
GI 5	0.014	0.01	0.006	0.006	0.014	0.006
EMM 1	0.037	0.026	0.048	0.046	0.048	0.026
EMM 2	0.05	0.052	0.028	0.024	0.052	0.024
EMM 3	0.032	0.045	0.016	0.022	0.045	0.016
EMM 4	0.136	0.136	0.075	0.082	0.136	0.075
EMM 5	0.076	0.072	0.033	0.026	0.076	0.026
ME 1	0.019	0.019	0.012	0.011	0.019	0.011
ME 2	0.041	0.041	0.027	0.023	0.041	0.023
ME 3	0.017	0.018	0.012	0.009	0.018	0.009
ME 4	0.015	0.011	0.005	0.005	0.015	0.005
ME 5	0.008	0.011	0.011	0.019	0.019	0.008
TE 1	0.014	0.009	0.011	0.011	0.014	0.009
TE 2	0.025	0.014	0.025	0.025	0.025	0.014
TE 3	0.027	0.012	0.029	0.027	0.029	0.012
TE 4	0.013	0.005	0.011	0.01	0.013	0.005
TE 5	0.054	0.027	0.024	0.027	0.054	0.024
WM&R1	0.006	0.008	0.005	0.06	0.008	0.005
WM&R2	0.008	0.015	0.008	0.09	0.015	0.008
WM&R3	0.011	0.014	0.011	0.014	0.014	0.011
WM&R4	0.008	0.01	0.009	0.06	0.01	0.006
WM&R5	0.023	0.033	0.023	0.021	0.033	0.021
SE&SP 1	0.027	0.045	0.05	0.06	0.05	0.006
SE&SP 2	0.014	0.021	0.031	0.01	0.031	0.01
SE&SP 3	0.01	0.016	0.016	0.014	0.016	0.01
SE&SP 4	0.006	0.011	0.011	0.021	0.021	0.006
SE&SP 5	0.023	0.04	0.029	0.029	0.04	0.023
EET 1	0.038	0.037	0.015	0.05	0.05	0.015
EET 2	0.024	0.027	0.01	0.023	0.027	0.01
EET 3	0.016	0.018	0.018	0.019	0.019	0.016
EET 4	0.082	0.082	0.026	0.031	0.082	0.026
EET 5	0.04	0.036	0.011	0.01	0.04	0.01
CMS 1	0.019	0.019	0.124	0.136	0.136	0.019
CMS 2	0.015	0.007	0.029	0.071	0.071	0.007
CMS 3	0.02	0.017	0.042	0.034	0.042	0.017
CMS 4	0.006	0.005	0.076	0.037	0.076	0.005
CMS 5	0.007	0.008	0.06	0.053	0.06	0.007

presents the results for each port and criterion, encompassing all expert responses.

The results by the BWM (Figure 6) revealed a clear hierarchy of indicators’ importance with EMM, SE&SP, and CMS emerging as the highest ranked indicators. Conversely, WM&R and GI were taken to the lower ranks. EMM is crucial for all ports for multiple reasons. Firstly, ports are major hubs of economic activity, facilitating trade and transportation on a global scale. EMM also allows ports to track and assess their impact on air quality [74], water quality, noise levels, and other environmental parameters. Additionally, another indicator that ranked prominently in our study was SE&SP. This indicator is more important for larger and medium ports than small ports. Firstly, larger and medium ports typically handle a significantly higher cargo volume, making them more attractive targets for criminal activities such as smuggling, theft, and terrorism. Secondly, larger = medium often have a more diverse range of stakeholders, including international shipping companies, government agencies, port authorities, and various service providers. Another important indicator important for smaller ports is CMS. In the dynamic and evolving international trade landscape, small ports are viable alternatives to larger ports, offering specialized services, personalized attention, and cost-effective solutions. Small ports contribute to a diverse and resilient port network through their competitiveness, providing customer options and driving industry innovation. The significance of competitiveness for small ports cannot be overstated, as it is the key to their success in the face of intense competition and the pathway to their continued growth and relevance in the global trade market.

Based on the analysis of the results (Table 5,

Table A1. Aggregate weights of main and sub-indicators for all experts (CHA-port).

Main Indicators	Weights of Main Indicators	Sub Indicators	Weights of Sub-Indicators	Global Weights	Ranking
GI	0.033	GI 1	0.12	0.004	40
		GI 2	0.288	0.01	30
		GI 3	0.128	0.004	39
		GI 4	0.176	0.005	36
		GI 5	0.288	0.01	29
EMM	0.331	EMM 1	0.08	0.026	14
		EMM 2	0.158	0.052	4
		EMM 3	0.136	0.045	6
		EMM 4	0.41	0.136	1
		EMM 5	0.216	0.072	3
ME	0.1	ME 1	0.188	0.019	17
		ME 2	0.41	0.041	7
		ME 3	0.18	0.018	19
		ME 4	0.11	0.011	27
		ME 5	0.112	0.011	26
TE	0.067	TE 1	0.128	0.009	32
		TE 2	0.208	0.014	23
		TE 3	0.174	0.012	25
		TE 4	0.08	0.005	38
		TE 5	0.41	0.027	12
WM&R	0.08	WM&R 1	0.096	0.008	34
		WM&R 2	0.186	0.015	22
		WM&R 3	0.18	0.014	24
		WM&R 4	0.128	0.01	31
		WM&R 5	0.41	0.033	11
EET	0.133	EET 1	0.338	0.045	5
		EET 2	0.16	0.021	15
		EET 3	0.12	0.016	21
		EET 4	0.08	0.011	28
		EET 5	0.302	0.04	8
SE&SP	0.2	SE&SP 1	0.188	0.037	9
		SE&SP 2	0.136	0.027	13
		SE&SP 3	0.088	0.018	18
		SE&SP 4	0.41	0.082	2
		SE&SP 5	0.178	0.036	10
CMS	0.056	CMS 1	0.338	0.019	16
		CMS 2	0.12	0.007	35
		CMS 3	0.302	0.017	20
		CMS 4	0.096	0.005	37
		CMS 5	0.144	0.008	33

,

Table A2. Aggregate weights of main and sub-indicators for all experts (RET-port).

Main Indicators	Weights of Main Indicators	Sub Indicators	Weights of Sub-Indicators	Global Weights	Ranking
GI	0.033	GI 1	0.324	0.011	25
		GI 2	0.252	0.008	33
		GI 3	0.096	0.003	40
		GI 4	0.136	0.005	38
		GI 5	0.192	0.006	34
EMM	0.2	EMM 1	0.23	0.046	6
		EMM 2	0.12	0.024	15
		EMM 3	0.112	0.022	18
		EMM 4	0.41	0.082	2
		EMM 5	0.128	0.026	13
ME	0.067	ME 1	0.166	0.011	26
		ME 2	0.338	0.023	16
		ME 3	0.138	0.009	32
		ME 4	0.08	0.005	39
		ME 5	0.28	0.019	21
TE	0.1	ANC 1	0.112	0.011	27
		ANC 2	0.252	0.025	14
		ANC 3	0.266	0.027	12
		ANC 4	0.096	0.01	29
		ANC 5	0.274	0.027	11
WM&R	0.056	WM&R 1	0.112	0.006	35
		WM&R 2	0.15	0.009	31
		WM&R 3	0.252	0.014	23
		WM&R 4	0.112	0.006	36
		WM&R 5	0.374	0.021	19
EET	0.08	EET 1	0.08	0.006	37
		EET 2	0.12	0.01	28
		EET 3	0.174	0.014	24
		EET 4	0.266	0.021	20
		EET 5	0.36	0.029	10
SE&SP	0.133	SE&SP 1	0.374	0.05	5
		SE&SP 2	0.174	0.023	17
		SE&SP 3	0.142	0.019	22
		SE&SP 4	0.23	0.031	9
		SE&SP 5	0.08	0.01	30
CMS	0.331	CMS 1	0.41	0.136	1
		CMS 2	0.216	0.071	3
		CMS 3	0.104	0.034	8
		CMS 4	0.112	0.037	7
		CMS 5	0.158	0.053	4

and

Table A3. Aggregate weights of main and sub-indicators for all experts (SIT-port).

Main Indicators	Weights of Main Indicators	Sub Indicators	Weights of Sub Indicators	Global Weights	Ranking
GI	0.033	GI 1	0.288	0.009	33
		GI 2	0.338	0.011	25
		GI 3	0.08	0.003	40
		GI 4	0.12	0.004	39
		GI 5	0.174	0.006	26
EMM	0.2	EMM 1	0.238	0.048	6
		EMM 2	0.142	0.028	12
		EMM 3	0.08	0.016	21
		EMM 4	0.374	0.075	3
		EMM 5	0.166	0.033	8
ME	0.067	ME 1	0.18	0.012	23
		ME 2	0.41	0.027	13
		ME 3	0.172	0.012	24
		ME 4	0.08	0.005	38
		ME 5	0.158	0.011	27
TE	0.1	TE 1	0.104	0.011	30
		TE 2	0.252	0.025	15
		TE 3	0.294	0.029	10
		TE 4	0.112	0.011	29
		TE 5	0.238	0.024	17
WM&R	0.056	WM&R 1	0.088	0.005	37
		WM&R 2	0.142	0.008	35
		WM&R 3	0.202	0.011	26
		WM&R 4	0.158	0.023	34
		WM&R 5	0.41	0.056	18
EET	0.133	EET 1	0.374	0.05	5
		EET 2	0.238	0.031	9
		EET 3	0.12	0.016	20
		EET 4	0.08	0.011	31
		EET 5	0.188	0.025	16
SE&SP	0.08	SE&SP 1	0.18	0.015	22
		SE&SP 2	0.128	0.01	32
		SE&SP 3	0.228	0.018	19
		SE&SP 4	0.324	0.026	14
		SE&SP 5	0.14	0.011	28
CMS	0.331	CMS 1	0.374	0.124	1
		CMS 2	0.088	0.029	11
		CMS 3	0.128	0.042	7
		CMS 4	0.23	0.076	2
		CMS 5	0.18	0.06	4

), it can be concluded that the sub-indicators with the highest scores for the medium/small ports were EMM 4 and EMM 5. The initiatives for a sustainable development plan in SMSPs hold great significance for various reasons [75]. Despite their smaller operational scale, these ports have a considerable environmental influence, making the adoption of sustainable practices essential for improving local environmental quality and protecting adjacent ecosystems. In a broader context, the sustainable development of small/medium-sized ports contributes to the SDGs. For the smaller ports, the sub-indicators that scored the highest were from the category of “competitiveness”. The competitiveness of small ports holds particular significance compared to that of medium ports, due to their unique characteristics and operational challenges. Small ports often operate in more constrained environments with limited resources and infrastructure. Therefore, maintaining a competitive edge becomes crucial for their survival and growth in the industry. Moreover, small ports’ competitiveness is paramount in the maritime sector. These ports face unique challenges due to their size and resources, but they also have distinct advantages, such as regional connectivity, flexibility, and adaptability.

4.2. Ports Assessed Using the VIKOR Method

The subsequent phase employed the VIKOR methodology to rank the selected ports based on weighted sustainability indicators. Through the application of Equations (6)–(8), we computed the critical VIKOR parameters (S, R, and Q values for each port. The Q values of the ports were compared, and the one with the lowest value was selected as the optimal one.

Table 7. S, R, and Q values.

	S	Rank	R	Rank	Q	Rank
HRA	0.27	2	0.023	1	0.03	2
CHA	0.222	1	0.026	2	0.122	1
RET	0.405	3	0.072	3	0.938	3
SIT	0.418	4	0.075	4	1	4
	S− = 0.222		R− = 0.023
	S* = 0.418		R* = 0.075

shows the CHA rank with the lowest grade for S and Q. Moreover, Q (CHA) − Q(HRA) < 1/(4-1) and Q (CHA) − Q (RET) > 1/(4-1). Therefore, the VIKOR method proposes a compromise solution between CHA and HRA.

The analysis helps identify which ports are the most effective in balancing these diverse sustainability factors, providing decision-makers with valuable insights into which ports lead the way in sustainable practices. By examining the compromise solutions and the corresponding rankings, stakeholders can pinpoint areas where ports excel and others where they need improvement. As evidenced in Table 7, the final sustainability ranking positioned CHA as the top performer, followed sequentially by HRA, RET, and SIT. These results substantiate the need for a balanced approach incorporating the best sustainable practices from both CHA and HRA, as neither port demonstrated clear dominance across all evaluated criteria.

5. Discussion

This study advances the discourse on port sustainability by demonstrating the value of indicator-based approaches for SMSPs. It contends that these approaches offer a standardized framework that facilitates benchmarking and comparison across different ports, enabling a more systematic evaluation of their performance. This standardization is crucial for establishing best practices and fostering a collective learning environment within the maritime industry.

Compared to existing relevant studies, this article positions itself at the forefront of discussions on port sustainability assessment by explicitly advocating for the prioritization and adoption of indicator-based approaches tailored specifically for SMSPs. Previous studies have acknowledged the importance of sustainability in larger ports [76]. On the contrary, this article highlights smaller ports’ unique challenges as they often operate in diverse geographical, economic, and social contexts, necessitating a more flexible methodology. Regarding the results of this study, the BWM indicated that EMM, SE&SP, and CMS are significant priorities for port sustainability. The prominence of EMM indicators, particularly EMM4 and EMM5, underscores their importance in addressing both local ecosystem impacts and regulatory compliance requirements [77]. For medium-sized ports like Chania (CHA) and Heraklion (HRA), these environmental indicators were complemented by strong performance in SE&SP measures, reflecting the complex stakeholder ecosystems and labor dynamics characteristic of larger port operations.

Moreover, the use of CMS in smaller ports supports the argument that competitiveness and stakeholder engagement are crucial for ensuring the long-term viability of such facilities [78]. Small ports encounter difficulties in a globalized sector because of constrained resources. They depend on specialized services and adaptable operational frameworks for sustenance. The World Ports Sustainability Program’s emphasis on local economic development resonates particularly with these findings, as smaller ports must capitalize on regional advantages while adopting innovative solutions like digitalization and green technologies.

CMS indicators assist small ports in capitalizing on their distinctive advantages, particularly in regional markets and specialized sectors, so assuring their sustainability. Additionally, the VIKOR-based rankings demonstrated CHA’s superior sustainability performance, although the close results with HRA suggest potential benefits from inter-port collaboration. Notably, the suboptimal performance of Rethymnon (RET) and Sitia (SIT) in environmental management and social engagement highlights areas for targeted improvement. These findings align with broader industry trends where well-structured governance frameworks enhance both operational efficiency and attractiveness to international partners.

By drawing lessons from successful indicator-based initiatives in different port settings, the article aims to create a foundation for a collaborative framework. It underlines the importance of learning from the experiences of various ports, underscoring the need for a dynamic and adaptable approach to sustainability that incorporates the lessons learned and shares best practices. By conducting a comparative analysis of different studies’ efforts in the domain, this article highlights the unique contributions of indicator-based approaches and positions itself within a broader discourse on refining sustainability practices within the port maritime industry. Utilizing indicator-based methodologies in sustainability evaluations for small- and medium-sized ports (SMSPs) may profoundly influence and guide policy formulation in the marine industry. By implementing a standardized approach for assessing port performance, policymakers may better understand the distinct problems and possibilities encountered by SMSPs.

6. Conclusions

This study has developed a comprehensive and regionally adaptive evaluation framework for SMSPs’ sustainability performance, employing rigorous multi-criteria decision-making methods (BWM and VIKOR). These methods allowed for an in-depth examination of sustainability indicators across environmental, economic, and social dimensions, providing a balanced and nuanced perspective on the diverse challenges faced by SMSPs.

The findings of the study revealed distinct sustainability priorities. For medium-sized ports, such as the Ports of Souda (Chania) and Heraklion, EMM demonstrateded as the paramount priority. This aligns with the increasing regulatory pressures and global sustainability goals, particularly those focused on reducing emissions, improving waste management, and implementing renewable energy systems. SE&SP were also identified as critical factors for these ports, reflecting the need to ensure stable employment and safeguard the well-being of the local communities that depend on port activities. In addition, the emphasis on social protection highlights the importance of maintaining labor standards and ensuring fair working conditions in the context of growing international trade and tourism.

Smaller ports (Rethymnon and Sitia), by contrast, prioritize CMS as the pivotal sustainability factor, reflecting their need to leverage specialized services and operational flexibility in competitive markets. This is particularly relevant given the limited resources and operational scale of these ports, which often compete with more established facilities. The study emphasizes that improving CMS in smaller ports involves enhancing operational efficiency and adopting innovative solutions, such as digitalization, green technology, and strategic partnerships, to remain viable in an increasingly competitive maritime landscape. These smaller ports must leverage their regional strengths and integrate sustainability practices to attract investment and foster long-term growth.

Despite the valuable insights provided by this study, several limitations should be acknowledged. First, the analysis focuses on four small- and medium-sized ports (SMSPs) located in Crete, which limits the generalizability of the findings to other geographic regions with different economic, environmental, and regulatory contexts. Future research should expand the scope to include ports from diverse areas to validate the applicability of the sustainability framework.

Second, the evaluation of sustainability indicators was based on expert opinion from a relatively small group of five experts. While these experts were carefully selected for their experience and expertise, a larger sample of stakeholders, including port operators, policymakers, and community representatives, could enhance the robustness and reliability of the findings.