1. Introduction
A city’s structure has been metaphorically considered by researchers and urban planners as a living and growing organism, since the comparison of a city with a human facilitates the understanding of the city’s dynamic socio-economic, technical, and policy environment [
1]. Approximately 80% of people live in urban areas in Europe, and cities generate 85% of the European Gross Domestic Product (GDP) [
2]. The substantial growth of urban areas results in intensive economic and social activities and the consumption of major energy resources—approximately 70% of global resources are consumed by cities, which implies an even higher demand for delivering products among citizens or companies within the urban environment. On the other hand, the rapid growth of cities introduces serious difficulties to their sustainable development [
3]. In particular, the sustainability of urban freight transportation services in terms of environmental, social, and mobility impacts (i.e., CO
2 and GHG emissions, safety issues, congestion, noise, emissions) constitutes a great challenge for city logistics planners due to the heterogeneity and complexity of the urban freight system.
Taking into consideration the European Commission’s objective for “CO
2 free city logistics” and a 50% reduction in GHG emissions [
4] by 2030, the need for “smart” solutions and ideas for the achievement of an efficient and effective urban freight transportation system is essential [
5]. The term “smart city” was introduced in literature in the 1990s, referring to a city that effectively deploys information and communication technologies (ICT) in order to develop integrated and modern infrastructure [
6], which was maintained by several researchers who related the term “smart city” with the use of ICT by the city (e.g., network of sensors, smart tools, and devices for monitoring the city’s infrastructure) [
7,
8]. A contradictory approach, though, strongly supports the necessity to integrate the city’s soft infrastructure (e.g., human capital, quality of life) to achieve a smart and sustainable city [
9,
10]. Despite the various interpretations or ambiguities of the “smart city” notion, the research community seems to converge on the fact that the main success factor for a city to become “smart” is to effectively combine the human capital, the social capital, and the use of information and communication technology (ICT) infrastructure [
11] for the implementation of smart and efficient solutions [
12].
In terms of city logistics, following the global developments and the path towards the digitalization of everything, the need for secure, fair, and sustainable city logistics operations implies the constant use of smart tools and techniques [
13]. The significance of smart city logistics within the framework of the broader urban/city freight planning envisages the implementation of new innovative business models for cargo utilization; the use of smart, innovative, and integrated intelligent transport systems (ITS) or information and communication technologies (ICT); and the implementation of new coordination mechanisms such as control towers and dashboards, which would enable the efficient integration of city logistics planning [
14]. Effective and efficient urban freight transportation planning implies the understanding of the current state of a city’s urban freight transportation (UFT) system along with its strengths and weaknesses. Gaining a clear insight, though, on the current performance—in terms of the effectiveness and efficiency of the existing city logistics system—is still considered a challenge for public authorities and city planners mainly due to the heterogeneity and business-oriented nature of city logistics structure, which had as a consequence, on the one hand, city planners paying attention until recently mainly to passenger transportation [
15], and on the other hand, to the lack of easily available information to the public authorities about the characteristics of city logistics operations [
16]. Even less is known about how a city performs in terms of “smart city logistics” not only because the term “smart city” is quite new [
17] but also due to the fact that the ideal “smart city logistics system” has not been clearly defined yet. More specifically, several attempts can be found in literature on the assessment and ranking of a city’s smartness. Some indicative examples are the evaluation framework developed by [
17], the “Smart City Wheel” developed by [
18], the ICT-oriented assessment framework developed by [
19], as well as the Smart Cities Maturity Model and Self-Assessment Tool [
20]. All aforementioned efforts propose structured frameworks for assessing and comparing the level of “smartness” mainly among medium-sized and large cities, without specific consideration of the role of city logistics in the broader city ecosystem. It is therefore practically intractable to measure the impact of city logistics operations on the general performance of a city with respect to “smartness”.
From another viewpoint, two recent studies pursued the development of assessment frameworks for city logistics. Nathanail et al. [
21] demonstrated an evaluation framework for assessing ex-ante and ex-post the performance of urban logistics initiatives and measures throughout the main lifecycle stages: (1) creation: designing/planning the measure, (2) construction: setting up the measure, (3) operation: testing/demonstrating the measure, (4) maintenance: maintaining the measure, and (5) closure: disposal of the measure’s implementation (ISO 14040, ISO 14044). Debnath et al. [
22], on the other hand, dealt with the smartness of the transportation system as a whole and proposed a detailed methodological approach on how to implement a comparative assessment of the cities’ transportation systems—also taking into account the movements implemented by commercial vehicles in terms of their level of smartness—and proposed a generic matrix of indicators for assessing the different components of a smart transportation system. The previous analysis reveals a gap in the current state of the smartness of a city’s logistics ecosystem by considering all factors that might influence the city logistics system, the main characteristics of a city logistics ecosystem, and the different stakeholders that are involved in this system [
23].
In response to this gap, this paper proposes a conceptual multi-criteria and multi-stakeholder Smart City Logistics Assessment Framework (SCLAF) to:
Gain clear insight on the main elements of a smart city logistics system;
Support the public authorities and any interesting party in identifying the level of smartness of a city’s city logistics system;
Facilitate the comparative assessment among different cities or urban areas/regions.
2. Materials and Methods
This paper follows an extensive literature review to identify the current gaps in defining a smart city logistics system and follows a meta-synthesis approach to build a coherent framework to deeply understand its components and main requirements.
More specifically, the methodological approach followed consisted of three main steps:
Understanding the (smart) city logistics system: an extensive analysis on existing research for defining a smart city first and after a smart city logistics system is implemented. The ground basis for this analysis lies in deeply understanding the main characteristics and influencing factors of a city logistics system, its main challenges, and the significance in planning for a smart and sustainable city logistics system. The research question that this paper comes to answer in this section is: Why is smart city logistics important and how is it defined?
Examining past experiences in assessing a (smart) city logistics system: during this second methodological step, deep analysis of existing assessment methodologies and frameworks for measuring the smartness of a city and more specifically of a city logistics system.
In pursuit of this aim, the literature review implemented in the first two methodologies consisted of different types of publications such as scientific publications (i.e., journal articles and books), research reports about ongoing or recently completed research projects, official policy documents and directives, and handbooks.
The third and final step of the analysis concerned the development of the Smart City Logistics Conceptual Assessment Framework. Following the thorough examination of the inter-related research studies by the researchers, the findings were synthesized and integrated appropriately to provide insight into these elements that best define the smartness of a city logistics system (see
Figure 1).
4. The Smart City Logistics Conceptual Assessment Framework (SCLAF)
4.1. Past Experiences on Comparative and Self-Assessment of a City’s Performance
The term “evaluation” is known worldwide as a technique for examining the performance of any subject of interest (e.g., process, project, program, people, city/country) based on specific set of criteria and/or sub-criteria or indicators. The main purpose of an assessment process is to enable judgements on the efficiency and effectiveness of the subject and consequently facilitate the decision-making for corrective actions towards the improvement of the evaluation subject [
57]. For the implementation of this process, the collection and analysis of information—either quantitative or qualitative—on specific assessment criteria and/or indicators is required. The general assessment, however, and the conclusion to specific results can be implemented by plenty of different methods and techniques depending on the initial scope of the assessment [
58]. As far as the assessment of cities is concerned, benchmarking of cities’ performance through city rankings enjoys great popularity nowadays and attracts significant attention from the public. Especially due to the worldwide economic and technological changes over the last decades, cities and regions aim at improving their general performance in terms of the three sustainability factors, namely, economy, society, and environment, in order to achieve a comparative advantage and improve their position in the European and national urban system [
59]. In addition, taking into account the European’s Commission main agenda for sustainable and effective cities by 2030 [
4], city rankings have become an important empirical base for disclosing comparative advantages and sharpening specific profiles and consequently for defining goals and strategies for future development. Two main attempts can be found in the literature, which implemented city rankings based on the level of smartness of each city. The first one relates to the evaluation framework developed by Giffinger et al., which was implemented to compare the level of “smartness” among medium-sized and large cities [
17], and the second being the “Smart City Wheel” suggested by Cohen [
18]. The foundation of both evaluation frameworks is based on the fragmentation of the term “smart city” into six main sub-areas of analysis: (i) smart economy: measuring the entrepreneurships, the productivity, the innovation, and the flexibility of the labor market of a city; (ii) smart governance: examination of the political participation of people and the efficiency and effectiveness of the administration, etc.; (iii) smart living: analyzing aspects such as culture, health safety, tourism, social aspects, etc.; (iv) smart people/citizens: assessing the level qualification/education and the openness of people socially; (v) smart environment: examining the effort towards environmental security and the attraction of natural and renewable resources; and (vi) smart mobility: assessing the use/availability of information and communication technologies (ICT) and intelligent transport systems (ITS) as well as modern transport systems.
The main structure of these frameworks was based on a hierarchical model that comprised three main levels, with each level further analyzed by the results of the level below. More specifically, the first level consists of the six main sub-areas, which are further analyzed in the second level by different factors. Giffinger identified 31 factors and Cohen 18 factors, which further split into the third and final level by numerous key performance indicators (KPIs) [
17,
18]. Following an extensive analysis of both frameworks and their results in real applications in European cities, it was noticed that although urban freight transportation plays an important role in the mobility of a city’s environment, the term “smart mobility” was exclusively oriented toward the smartness of passenger transportation. Thus, it was practically difficult to understand the interrelations among the performance of a city logistics system and the general performance of a city in terms of smartness and how they affected each other.
In addition to city rankings, the self-assessment of a city’s performance in terms of attaining specific strategic goals is also crucial and necessary for urban planning and development. Self-assessment provides grounds to a city to continuously improve a strategic idea or initiation both during its implementation (adaptive management) and after its completion through the replication of good practices (DOs) and information provision for the avoidance of mistakes (DONTs). Conducting a self-evaluation leads to the assessment of the degree to which initial goals and objectives have been met and the realization of possible future actions needed for the improvement of the city’s performance [
60]. Past relevant experiences are the ICT-oriented assessment framework developed by the International Telecommunication Union (ITU) of the United Nations; the Smart Cities Maturity Model and Self-Assessment Tool, both representing self-assessment tools of the smartness of a city in general [
20]; and other efforts on assessing the capability of cities in terms of digital transportation [
61].
In terms of self-assessment tools dedicated to city logistics, two recent studies have been identified. The first one, which was published in 2015 by the EU-funded Novelog project [
21], focused on assessing ex-ante and ex-post the performance of urban logistics initiatives and measures on the four main lifecycle stages: (i) creation, (ii) construction, (iii) operation, and (iv) maintenance and closure. The evaluation process followed was based on a structured evaluation framework consisting of four modules: (i) impact assessment, (ii) social cost–benefit analysis, (iii) adaptability and transferability analysis, and (iv) behavioral modeling. The second study, identified in the literature, concerns a benchmarking tool for smart transport cities developed by Debnath et al. [
22]. The proposed methodological framework initially defined the general concept of the smartness of an urban transport system (including passenger mobility as well as urban freight transportation), where four basic and three advanced smart system capabilities were identified, namely:
Basic:
The collection of detailed and accurate information;
The processing of this information and the extraction of valuable knowledge;
The actions for implementing the decision made;
The communication among the previous steps.
Advanced:
The ability of the system to accurately predict problems or other scenarios;
the ease of a system to heal and recover from potential problems;
The ability of the system to prevent potential failures.
Following the concept analysis and definition, a generic matrix of indicators appropriate for assessing each of the abovementioned capabilities was identified. Finally, a benchmarking exercise among 26 big cities—in terms of population size—of economically developed countries was conducted. Although these frameworks were dedicated to city logistics and urban freight transportation, they were focused on specific aspects of the city logistics system, i.e., the assessment of the UFT system and the assessment of the effectiveness of specific UFT measures without explicit consideration of the performance of the city logistics ecosystem as a whole [
62]. In the subsequent section, we capitalize on past relevant efforts and integrate assessment frameworks for smart cities and city logistics in order to develop the comprehensive, multi-criteria, and multi-stakeholder Smart City Logistics Assessment Framework (SCLAF) for either self-assessing the smartness of a city logistics system as a whole or implementing comparative assessment among different cities or regions.
4.2. SCLAF Foundation
The main purpose of the development of an assessment framework for the smart city logistics ecosystem is to systematically monitor the performance of the urban freight environment, portraying the complexity of city logistics systems in terms of the several factors influencing the city logistics system as well as the various actors involved. The SCLAF resulted from a synthesis of various components, criteria, and key performance indicators (KPIs) employed by existing frameworks dealing with the assessment of either the smartness of a city [
17,
18,
19,
20] or the effectiveness of specific aspects of the urban freight transportation system [
22].
The final structure of the SCLAF is based on three main aspects:
Finally, for the identification of the main assessment elements and thematic areas, the interrelations of city logistics with other urban systems (e.g., passenger, land-use patterns, types of goods, regional development, employment, and socio-economic environment) were also examined.
4.3. The SCLAF’s Main Structure and Components
Considering the smart city classification proposed by Giffinger and Cohen and the main characteristics and influencing factors of a smart city logistics system, the SCLAF proposes the fragmentation of the smart city logistics system into four main impact areas, which will also constitute the basis of the assessment framework [
17,
18]. These are:
SCLAF Impact Area 1—Smart Governance: Smart governance in city logistics refers to the tools a public administration uses/provides to enable efficient and effective city logistics, as well as the role of private UFT actors towards public initiatives and planning [
17].
SCLAF Impact Area 2—Smart Economy: The assessment of the general city logistics economy aims at capturing the UFT stakeholders’ financial condition, being one of the main influencing factors of city logistics operations [
42] and the general behavior of the UFT actors towards new technological developments and innovations.
SCLAF Impact Area 3—Smart Actors: According to a study implemented by [
63], one of the main obstacles in the development of smart city logistics lies in the lack of digital culture and training in freight transportation and logistics companies. The third impact area aims at identifying and measuring the smartness of city logistics actors in terms of responsiveness, responsibility, and visibility of the UFT operations.
SCLAF Impact Area 4—Smart Environment: Freight vehicles that operate in urban areas emit a greater proportion of certain pollutants per kilometer traveled than other means of transportation. This is due to the high fuel consumption per unit of distance traveled and the fact that many of them use diesel as a fuel [
64]. A smart city logistics environment presupposes the minimization of environmental impacts while maximizing the effectiveness of the city logistics operations. Therefore, the main purpose of the Smart Environment” impact area is to quantify the level of ecological awareness of the UFT actors and the extent to which a city promotes and uses environmental management techniques in UFT operations.
The SCLAF structure is based on a four-level assessment pyramid—as is shown in
Figure 2—where the top of pyramid constitutes the main smart city logistics impact areas, and then each impact area is further fragmented into specific criteria and sub-criteria (second assessment level) that aim to clarify further the area of influence of each impact area and facilitate the assessment process. Following the identification of the main criteria and sub-criteria describing the main impact areas, it is necessary to examine how these criteria can be measured, either qualitatively or quantitatively.
Therefore, the SCLAF proposes two alternative performance measurement processes of each criterion and sub-criterion and lets the user of the tool choose which one suits the city’s needs and current situation best, i.e., availability of resources, data, time, etc., which are:
The qualitative approach (third assessment level): The SCLAF proposes a set of easy-going and well written questions to qualitatively assess each criterion and sub-criterion. The use of qualitative research questions can provide quite rich and detailed information on specific topics that cannot be measured easily by KPIs. The expression of each questions was careful chosen and studied in order to avoid any misunderstandings of the questions by the evaluators or the provision of long text answers that might cause problems in the extraction of the respective outcome. One method for implementing this process is to follow semi-structured methods such as interviewing a sufficient number of experts in the field together with observation techniques [
65].
The quantitative approach (fourth assessment level): The SCLAF proposes a sample set of the most appropriate KPIs for measuring the performance of each criterion and sub-criterion. However, considering the size of the SCLAF, the identification of the most appropriate KPIs for each impact area and the conclusion of the final list of KPIs still remains a future research subject and requires a significant number of resources to be sufficiently achieved. Thus, the presented paper focuses on presenting mainly the qualitative approach.
Taking into consideration the obstacles that might occur in collecting reliable data and enough of it (either qualitative or quantitative) for a city logistics system due to the business nature of the system and the involvement of several and different types of stakeholders with usually conflicting interests and needs, the SCLAF was designed as a multi-stakeholder tool. More specifically, the SCLAF highlights the need to involve in the assessment process a sufficient number of stakeholders that operate in the city’s city logistics environment in order to extract valuable information about the performance in terms of the smartness of a city logistics system.
A detailed representation of the SCLAF assessment pyramid and each assessment level is presented in
Figure 3, and a detailed analysis of the three assessment levels (impact areas, criteria/sub-criteria, qualitative assessment questions) follows.
4.3.1. Impact Area 1: Smart Government
Following an extended literature review on the possible measures and actions that could be implemented by governing bodies towards a more sustainable and smarter city logistics environment, a cluster of two main areas of interest related to smart governance were identified. The first one is dedicated to the general resources provided by the city authorities in order to facilitate the city logistics operations, whereas the second one is related to the stakeholders’ engagement process, which is considered necessary for the viability of public initiatives and measures [
66]. More specifically, this impact area splits into the following criteria and sub-criteria:
4.3.2. Impact Area 2: Smart Economy
Smart economy aims to measure mainly the economic stability and productivity of the urban logistics sectors as well as to identify the level of the introduction and implementation of new, smart ideas. Therefore, the second impact area can be further analyzed in the following two criteria:
Criterion 1 (smart productivity): The economic stability and the financial condition of the UFT actors in general is one of the major factors that may influence the smartness of the city logistics sector. The investment in any new and innovative solution requires a low risk of failure in order to be widely accepted by the interested actors. Wealthy enterprises are more likely to invest in new and innovative information and communication systems that would facilitate their operations. Finally, evidence shows that public funding initiatives by city authorities constitute a strong motivation factor for private actors to invest in smart systems and operations [
71] (
Table 6).
Criterion 2 (smart entrepreneurial): Over the past decades, a change has been observed in the logistics sector towards the development of micro-trends and start-ups, which promote new technological developments and innovations to facilitate logistics operations. In some cases, logistics operators have already started collaborations with such start-ups, whereas others breed their own in-house innovations [
13]. In that respect, this criterion examines the level of investment by the UFT actors on research and development activities and city logistics start-ups (
Table 7).
4.3.3. Impact Area 3: Smart Actors
As is strongly expressed by the research community, the complexity of the urban logistics sector lies mainly in the involvement and coordination of plenty of different actors with different and in some cases conflicting interests and needs. Therefore, the analysis and assessment of the smartness of the actors that are involved in the sector and their ability and willingness to use smart tools and techniques in the framework of their occupation is crucial. This impact area is further broken down into two main criteria:
Criterion 1 (smart UFT operations): This pertains to the identification of how smartly the UFT actors operate by measuring whether the UFT stakeholders have access to modern technologies and the use of smart tools such as Internet-connected operations, e.g., the use of smart devices for communication and data exchange, dedicated route guidance systems, big data analytics methods for predicting demand and supply and analyzing user preferences, the use of cloud services for the facilitation of data exchange, in-vehicle safety systems, GPS, traffic flow prediction system, sensor technologies, etc. Finally, the difficulty of gathering data about private operations due to heterogeneity and competition is another main factor that influences the efficient operation of freight movements. More specifically, the lack of visibility along the supply chain represents one of the main barriers to both urban freight planning and effective private operations. For that reason, as part of this criterion, we aim to assess the level of visibility along the supply chain by assessing the willingness of the stakeholders to share data and use smart tools such as cloud logistics, real-time delivery information sharing on mobile devices, interconnected ERP systems for data exchange, etc. (
Table 8).
Criterion 2 (smart thinking): This criterion focuses on the identification of the UFT actors’ attitude towards innovative solutions such as the use of driverless vehicles for last-mile distribution, 3D printing, and unmanned aerial vehicles, and their level of experience in using smart systems [
13] (
Table 9).
4.3.4. Impact Area 4: Smart Environment
The last impact area splits into the following criteria:
Criterion 1 (smart ecological awareness): This criterion deals with the identification of the ecological awareness of the city logistics actors through their attitude towards the development of synergies with other actors (e.g., cargo consolidation, shared logistics/warehousing) in order to minimize these impacts, as well as the use of alternative modes of transport or electric mobility for UFT operations (
Table 10).
Criterion 2 (sustainable planning): The assessment of sustainable planning towards a smarter environment consists of two main areas of interest. The first area considers the identification of the current situation of the city in terms of air and noise pollutants due to UFT operations, and the second area concerns the activities of the governmental bodies to facilitate and motivate UFT actors to achieve more environmentally friendly UFT operations. (
Table 11)
This section may be divided by subheadings. It should provide a concise and precise description of the experimental results, their interpretation, and the experimental conclusions that can be drawn.
5. Discussion
This paper presents a conceptual framework for assessing the level of smartness of a city logistics ecosystem. Following an extended literature review on the smart city concept and on the main trends and drivers that affect the city logistics sector along with its main characteristics and the actors involved, the proposed framework, called the Smart City Logistics Assessment Framework (SCLAF), is structured as a four-level assessment pyramid. Based on a top-down assessment approach, the SCLAF’s foundation, and the top of the pyramid, is based on the main impact areas of the smart city logistics concept, meaning smart economy, smart environment, smart governance, and smart actors. Each impact area is further expressed in criteria and sub-criteria, and the final two levels of the pyramid provide guidance directions on how to eventually measure the performance of each impact area either qualitatively through a holistic set of questions or quantitatively based on a sample set of KPIs proposed within the framework of the fourth assessment level.
The main purpose of the proposed Smart City Logistics Self-Assessment Framework is to constitute a practical tool that will aid any beneficiary in self-assessing the current situation of a city’s urban freight transportation and logistics environment and facilitate the development of more sustainable cities in line with the 11th Sustainable Development Goal for Sustainable Cities and Communities defined by the United Nations. A second usage of the tool could also be the implementation of cross-comparisons among cities in terms of the smartness of their city logistics environment. The future scope of this research is to integrate the existing conceptual model with the necessary mathematical model to be able to use it and conclude on empirical results in terms of a city’s smart city logistics index. Analytical step-wise guidelines will be provided to the potential users of the tool on how to apply this model either for self-assessing the current state of a city logistics system or making a comparative assessment among different cities. Finally, a validation process on the structure and components of the framework, by means of any consensus building methods with the participation of recognized logistics experts, might be very fruitful.