Trams: Bridging the Past and Future—Example Guidelines for Tram Redesign Illustrated by a Case Study from Korea

Abstract

This study was inspired by an emerging trend in contemporary cities: the transformation of trams into mobile spaces for recreation, education, and work. Despite the growing popularity of this concept, which is linked to the search for more sustainable transport options, there is a marked lack of guidelines, methodological frameworks, and reference case studies necessary to support these projects. This study fills this gap by illustrating the design guidelines developed for a project in Gwangmyeong, a new Korean town. These guidelines provide a structured framework for converting existing trams into mobile venues such as restaurants, classrooms, and work and conference spaces. Employing the design thinking approach, the guidelines comprise three primary design phases—Understand, Define, and Materialize—each consisting of two sub-phases, and specify the technical tools, roles, and outputs needed. The proposed guidelines are illustrated using material from the Gwangmyeong project. As the first of their kind, these guidelines provide a valuable case study and reference materials for designers, offering possible benchmarks for the technical and financial evaluation of such projects. This study hopes to stimulate discussions on the development and refinement of similar methodologies, addressing the growing interest in design discourse.

1. Introduction

As one of the oldest forms of public transportation, trams have been operational since the Second Industrial Revolution and have been widely adopted worldwide. With notable resilience, they have withstood significant changes in urban landscapes with few modifications to their physical and mechanical characteristics [1,2]. In recent years, the growing emphasis on sustainability has led to a re-evaluation of trams as “green” modes of transportation. Consequently, several cities have expanded their existing tram networks or are considering the integration or reintroduction of trams into their transportation infrastructure [3,4,5]. Trams have also been subject to innovative applications beyond transporting passengers, including their use for goods delivery and waste transport [6,7,8].

Among these innovative uses, the recent trend of repurposing trams into spaces that serve as hubs for relaxation, education, work, or commerce deserves further attention. This trend has seen the reorganization of tram spaces to host restaurants, bars, offices, and shops and has typically included the restoration of vehicles that hold historical and cultural value [2,4,9]. One of the earliest examples was Helsinki’s pub tram, the SpåraKoff, which was opened in 1995 [10]. This trend has only grown in popularity, with several cities successfully integrating themed trams into their transit systems with the aim of offering residents a unique amenity while also attracting tourists. Notable examples include Brussels (Belgium), The Hague (the Netherlands), Bern (Switzerland), Nuremberg (Germany), Milan (Italy), Turin (Italy), Brno (Czech Republic), Timișoara (Romania), and Moscow (Russia) [11].

Although recent years have witnessed notable progress in technological and methodological tools for the design and management of rail transportation systems (see Section 2.1), in the specific field of tram redesign, despite the numerous examples mentioned above, there are no theoretical references for carrying out these projects. Indeed, to date, no design guidelines, protocols, handbook sections, or analytical studies have been published. Most designs have been experimental, relying solely on the individual creativity of the designer. While some case studies have been illustrated, they do not detail the design process and the tools used [11]. There has never been a concerted effort to develop and share a methodology for repurposing tram spaces. On the one hand, the relative novelty of this subject may have contributed to the scarcity of research. On the other hand, this lack of theoretical foundation is in stark contrast to other areas of design, where extensive theoretical research supports and underpins practical application [12,13].

We contend that this design topic is equally important as others and deserving of serious attention. Besides the recognized environmental benefits of trams as a mode of transport [14], the strategy of adapting trams for leisure and work spaces is becoming an increasingly vital component of city marketing and branding in many urban areas. Several studies have confirmed the impact of this strategy in activating positive economic dynamics, further enhancing the city’s appeal and vitality [15,16]. Moreover, using trams as social spaces transforms otherwise wasted transit time into productive use, thereby contributing to the social sustainability of contemporary cities [17].

The lack of shared methodological tools and debate on this topic highlights a significant knowledge gap in design. A structured method offers several benefits. First, it can guide designers in project development, reducing the downtime and inefficiencies associated with creating a design strategy from scratch for each project. Second, having a design protocol can facilitate quality control. Once there is a consensus on the process, verifying that a project has adhered to all of the necessary steps can be used to certify its technical validity. Finally, a shared method for executing projects can facilitate their economic evaluation, which is essential for work assignments, contracting, competitions, and other phases [18,19,20].

Based on the foregoing, this study addresses this knowledge gap by presenting a case study of guidelines for redesigning tram spaces for alternative uses. We developed these guidelines during a 2019 project in South Korea, where we were commissioned to create a design concept for the public transport system of Gwangmyeong New Town (see Section 3.1). The assignment involved studying the use of trams for special functions—such as catering, education, and work—and designing spaces that could be implemented on decommissioned trams through refurbishment. Recognizing the lack of methodological references during the exploratory phase, we divided the task into two steps. The first step involved designing a methodological framework for the project, the basis of the guidelines presented in this study. In the second step, we applied this method in drafting the actual design. Recognizing the benefits that the guidelines brought to the project, we decided to systematize and present them in this study, illustrating their application and value using material from the Gwangmyeong project. The result is a framework comprising a sequence of design phases, each complemented by specific methodologies and tools (see Section 4, Section 5, Section 6 and Section 7).

These guidelines represent a pioneering effort and, together with the project, serve as a referential collection of exemplar materials for space planners facing such design tasks, including architects, product designers, and interior designers. As the first of their kind, these guidelines will likely ignite a debate questioning their validity, potentially leading to a discussion of shared methodologies. To facilitate this discussion, Section 8 presents an initial critical evaluation of the guidelines. If the debate proves fruitful, works like this could evolve beyond serving as references for designers to become protocols for both the quality control and economic evaluation of projects. In this context, potential stakeholders include public bodies and companies interested in investing in this sector.

The rest of this paper is organized as follows. Section 2 describes the materials and methodology used to draft the guidelines. Section 3 outlines the Korean and ATMosfera projects, which serve as the context and precedent for this work, respectively. Section 4, Section 5, Section 6 and Section 7 details the guidelines, while Section 8 discusses their validation. Finally, Section 9 presents this study’s conclusions and limitations.

2. Materials and Methods

2.1. Preliminary Survey: Bibliographical and Experiential Sources

The project began with a comprehensive bibliographic review, highlighting that, over the last decade, the rail transportation field has undergone significant advancements in the adoption of digital technologies, particularly Building Information Modeling (BIM) and Digital Twin (DT) software. These tools, increasingly utilized across various domains and frequently adopted as complementary systems [21,22,23], have been extensively explored in railway and subway sectors, focusing on design and construction [24,25], management and maintenance [26,27,28], and lifecycle assessment and sustainability [29]. The tram and light rail sectors have also embraced this trend, particularly in maintenance research [30] and design methodologies, addressing both theoretical and practical applications [31,32]. Additionally, studies not explicitly focused on trams—such as those examining autonomous driving and speed detection [33,34]—have offered valuable insights for the field.

However, in stark contrast to the vitality of technological research, the field of tram space design—and particularly redesign—proved to be notably underdeveloped, showing no significant references (cf. Introduction) and highlighting this area as largely unexplored. The only relevant resources were studies that proposed methods and guidelines for projects in other fields [35,36,37,38]. These studies were revisited when the guidelines for the Gwangmyeong project were created. Of these, Zappia’s “Italian yachts restoration. Possible tools for the ‘new’ business of nautical heritage” [38] proved particularly useful. This study, too, explores a largely overlooked field, and provides valuable references and insights, particularly in suggesting the use of the design thinking approach for structuring guidelines (see Section 2.4).

Although valuable, bibliographic sources were insufficient. Therefore, the search for references was expanded to include concrete expertise. Notably, some of the design team members had relevant past experience: the design of the ATMosfera restaurant tram in Milan, which was completed in 2006 (see Section 3.2). While this work has never been subject to theoretical examination, reports, drawings, and experience of the procedures and tools used during the project were collected, organized, and archived, providing important insights when drafting the guidelines.

2.2. Guideline Elaboration and Scope

In the second phase, we compared methodologies, theoretical and technical tools, and design procedures from reference papers and direct design experience, critically analyzing common points and differences to identify materials to be retained or discarded. For instance, many of the technical tools used in the ATMosfera project were found to be obsolete and replaced. BIM technology, in particular, proved to be a fundamental working resource, warranting its inclusion among the digital tools recommended for various phases of the guidelines (see Section 5, Section 6 and Section 7, Integration of Digital Tools).

Based on this comparative analysis, general guidelines were designed, outlining the steps that the design team should follow. A total of six design phases were envisioned: Inquire, Analyze, Explore, Focus, Verify, and Implement. Informed by design thinking principles, each phase comprises methods, technical tools, and desired outputs (see Section 4, Section 5, Section 6 and Section 7). It is crucial to note that this method focuses on space design, with the guidelines concluding at the design development stage. This choice was made for methodological consistency. In tram redesign projects, the phases that follow design development, such as construction documentation, require a completely different approach, roles, and tools. In this respect, mechanical technicians with expertise in transport vehicles play a dominant role and have the final say in many decisions.

2.3. Application, Refinement, and Illustration

The design team consistently followed the guidelines outlined above in drafting the project, refining some aspects during the process. For example, the importance of certain digital tools for real-time data sharing among group members was recognized and integrated.

Although some parts of the project remained under development at the time of writing (cf. Section 3.1), their general lines align with the pre-established objectives. This alignment demonstrates the utility of the guidelines, leading the team to formally and systematically structure and illustrate them in this paper. At this stage, the phases mentioned in Section 2.2 were grouped into three macro areas: Understand, Define, and Materialize, with each phase accompanied by explanatory materials from the project (cf. Section 4, Section 5, Section 6 and Section 7).

2.4. Conceptual Framework and Validation

The guidelines presented in this study are intended to serve as a reference for designers undertaking similar projects. They aim to provide concrete examples of how theory and practice can converge, suggest ideas, and illustrate possible problem-solving approaches. While their content is not analyzed here according to the canonical principles of research through case studies—an approach recognized for its scientific validity and established methodologies since at least the 1990s [39]—they could nonetheless serve as foundational material for future case study-based research or more in-depth investigations on the subject.

It is worth emphasizing, however, that the guidelines, given their novelty, are essentially a project in themselves.

While architects have long utilized design as a research tool [40], Frayling’s 1993 study [41] formalized the concept of research through (art and) design. Frayling emphasized the unique epistemology of such disciplines, proposing that knowledge in these fields develops not only through research for (supporting artistic creation) or into (analyzing artistic objects) but also through the practice itself. This perspective, which prioritizes a flexible, intuition-driven approach over the quantitative methodologies of the hard sciences, has since shaped numerous studies on the ontological, epistemological, and methodological aspects of research through design [42]. A central concern within this discourse is identifying effective conceptual and practical tools for communicating research outcomes. Scholars contend that neither text (e.g., reports, essays) nor the object (i.e., the design) alone is sufficient, advocating for hybrid tools that integrate and bridge these media [43]. This would accommodate the peculiarity of architectural design as research, whose nature lies “in-between” pure research and pure design [43,44]. Another critical challenge in such research is the validation of its achievements. Designs, whether conceptual or realized, cannot, by their nature, be assessed using traditional methods such as reproducibility. To address this, two alternative validation principles, adapted from other research approaches, have been identified as particularly effective: Recoverability and Theoretical Sensitivity [42] (pp. 6–7). The recoverability principle requires that the design process be transparent and traceable, allowing others to critically examine its rigor. If the process demonstrates methodological rigor, this rigor serves to validate the outcomes. The principle of theoretical sensitivity emphasizes the researcher’s ability to draw on personal and professional experiences, as well as relevant literature, to interpret the research situation and data in innovative ways, unlocking their theoretical potential. The responsibility of demonstrating that this principle has been adhered to rests with the researcher.

Given the design-oriented nature of this study and its aim to contribute to the research-through-design discourse, ensuring scientific consistency is essential. Accordingly, the work has been structured with close adherence to the principles outlined above. Regarding the appropriateness of communication tools, the study integrates the guidelines and their framework (text) with their illustration through a project by the authors (object), ensuring that these dimensions are cohesively interwoven rather than presented independently (Section 5, Section 6 and Section 7). The validation challenge is addressed in Section 8 using the principles of theoretical sensitivity and recoverability. The former is evaluated by comparing the results with the professional experiences of ATMosfera in Milan and Zappia’s contribution in the academic literature, which provided the methodological framework for the guidelines (cf. Section 2.1). This comparison reflects on the theoretical potential of the study’s achievements. Recoverability was discussed on two levels; the first pertains to the rigor of the process that led to the drafting of the guidelines, and the second to the methodological rigor of the guidelines themselves.

With regard to the latter, the logical coherence of the proposed guidelines is grounded in design thinking, a methodology that has gained prominence in design fields since its codification in the late 1980s [45] (cf. Section 4). Structured into five steps—Empathize, Define, Ideate, Prototype, and Test [46] (Ch. 3)—this approach emphasizes a user-centered, collaborative process with active stakeholder involvement [46,47]. The Empathize phase involves developing a deep understanding of the problem through research, followed by the Define phase, where observations are synthesized to pinpoint core issues. In the Ideate phase, diverse solutions are generated using brainstorming and other creative techniques. The Prototype phase tests these solutions through low-cost, scaled-down models, and the Test phase evaluates the prototypes to determine the most effective outcomes. Initially developed for design-specific contexts, design thinking has since expanded into fields like business and other areas requiring creative problem solving [48,49,50]. Despite its popularity, design thinking has faced growing criticism after initial enthusiasm. Skeptics question its applicability beyond traditional design disciplines [46] (Ch. 3), with some even labeling it a “failed experiment” [51] (p. 286). Critics within the design community argue it merely repackages established practices (“a different name for what good designers have always done” [51] (p. 289)) or dismiss it as a collection of clichés forced into an unnecessary framework [52].

We do not believe design thinking should be dismissed outright, nor do we regard it as a universal solution to all problems. However, as discussed in Section 4.1, we consider it as a practical framework for structuring coherent project proposals, particularly in the unexplored domain addressed by this study. Its rigorous yet adaptable approach ensures process control while allowing for necessary adjustments and rethinking. Furthermore, its proven effectiveness in academic and educational contexts [46] (Ch. 11)—environments dedicated to knowledge production—reinforces its relevance and applicability.

3. Study Context and Precedent: Gwangmyeong and ATMosfera

Before illustrating the guidelines, it is worth outlining the project that provided the opportunity to develop them in the first place, namely, Gwangmyeong New Town in South Korea, as well as the project that set a precedent: ATMosfera in Milan.

3.1. Gwangmyeong New Town

Gwangmyeong New Town will be a new district in southern Seoul, South Korea, designed to host 237,000 inhabitants. The urban plan promoted by the local Union of Land Owners was developed between 2019 and 2021. Coordinated by ATEC Architects of Seoul (http://m.atec.co.kr/main, accessed on 15 January 2025), the design team included international professionals and experts from various fields. For more information on the project’s history and urban aspects, see the publication of the Gwangmyeong Urban Planning Research Team [53] and work of Bruno et al. [17].

The authors of this study participated in designing the urban layout of Gwangmyeong New Town and were responsible for the design concept of the mobility system (Figure 1). The plan included a tram network where, besides transporting passengers, some vehicles would serve as freight and waste transport, and others would opportunely be refurbished as catering, education, and work spaces [54] (cf. Section 5.2.1: Context Definition). In 2022, the urban plan met several bureaucratic challenges and is currently on hold. Nevertheless, in agreement with the client, we continued to develop a design for the vehicles to be refurbished.

3.2. ATMosfera Restaurant Tram

ATMosfera was integrated into Milan’s tram network in 2006 [56] (Figure 2). Carried out by a technical team from the Azienda Trasporti Milanesi (“Milanese Transport Company”, hereinafter ATM) and faculty from Politecnico di Milano, the redesign project involved the historic ATM Serie 1500 (ATM Class 1500), also known as type 1928, originally designed in 1927 and adopted in 1928. The redesign focused on various aspects, including interior design (the main focus), technical systems, and external visual communication.

ATMosfera offers passengers a unique dining experience within the urban landscape. The project addressed citizens’ sensitivity to familiar spaces by refurbishing the vehicle environment for optimal comfort, while maintaining the original tram atmosphere and minimizing waste of the original material. For instance, remodeling the original teak wood benches created twenty-four seats, divided into four tables on each side. Adding service spaces such as kitchens, toilets, and wardrobes, which are typically unavailable on public transport, contributed to a cozy, homey feeling. The design strategy aimed to maintain historical traditions while establishing new ones [57].

We refer to ATMosfera again when discussing the validation of the guidelines (Section 8).

Figure 2. The ATMosfera restaurant tram in Milan, Italy [58].

Figure 2. The ATMosfera restaurant tram in Milan, Italy [58].

4. Guidelines for Redesigning Tram Spaces for Alternative Uses: Premise

4.1. A Design Thinking Approach

As outlined in Section 2.4 (refer to the section for detailed references), the guidelines presented in this study are based on the principles of the design thinking approach, a methodology that addresses design problems through successive in-depth studies, from preparatory research to the identification of objectives, and finally, to testing the developed solutions. The process is not linear but iterative, and each phase can be revisited as needed, allowing for further investigation and refinement.

Design thinking has been selected as an effective framework for ensuring the logical coherence of the guidelines, with the aim of supporting their validation (see Section 2.4). Moreover, the features of design thinking are considered particularly suitable for developing a proposal for tram redesign guidelines for the following reasons:

• User-Centric Focus: Design thinking emphasizes understanding the needs and experiences of end users. When repurposing trams into spaces like cafés, bars, or educational areas, it is crucial to consider the user experience to ensure that the spaces are functional, comfortable, and appealing.
• Iterative Process: The iterative approach of design thinking is particularly beneficial for novel projects, such as tram repurposing, where initial ideas can be tested, feedback gathered, and solutions improved in multiple cycles.
• Creativity and Innovation Encouragement: Repurposing trams as alternative spaces requires innovative thinking, as this process involves transforming traditional transportation vehicles into vibrant social hubs. Design thinking fosters creativity through brainstorming sessions and encourages the exploration of a wide range of ideas. This creative approach can lead to unique and effective solutions that might not emerge through conventional design methods.

4.2. Guideline Structure

The refinement of the subsequent phases and an iterative process constitute the basis of the guidelines for tram redesign. The guidelines consist of six design phases: Analyze, Explore, Focus, Verify, and Implement (Figure 3). Each phase is supplemented with specific methods, tools, and expected outputs, and exemplified by material from an actual project. The six phases are grouped into three stages: Understand (cognitive stage), Define (creative stage), and Materialize (application stage). Each of these three stages has a final output: the Objectives Report, Key Design Principles Index, and Final Dossier (i.e., a conclusive document of the process).

The Inquire phase includes obtaining feedback from the client and collecting data, case studies, and research material to facilitate a thorough understanding of the design task. During the Analyze phase, the materials collected in the first phase are refined and analyzed, leading to the identification of project objectives, which serve as the framework for the entire process. In the Explore phase, the team produces several design solutions by reworking previously selected case studies and condensing the proposals into pre-projects. The Focus phase involves identifying the most promising pre-projects and extracting key design principles to guide the final design phases. During the Verify phase, these principles are condensed into a final project proposal, which is illustrated using a prototype and tested. The Implement phase concludes the process by examining the design proposal in depth, including the materials and other technical specifics. The outputs of the three stages of the process are then synthesized into a final comprehensive dossier.

Although Figure 3 presents the guidelines in a linear form progressing from the top to bottom for clarity, the guidelines, in accordance with the design thinking approach, recognize that temporary deviations from this path are legitimate and desirable. Unforeseen circumstances, uncertainties, and the need for reconsideration can lead to modifications in the design process. This may require revisiting earlier phases or undertaking “horizontal” explorations of the theme before progressing.

The following sections detail each phase and describe the associated tools, methods, and outputs.

5. Understand

The Understand stage is the first of the three-stage design process, and comprises the Inquire and Analyze phases (see Figure 3). It is referred to as the “cognitive” stage because it involves collecting and processing relevant knowledge to define the project’s objectives. This knowledge should enable a comprehensive understanding of client needs, the feasibility of their desires, and the context in which a project will be executed. At the conclusion of the Understand stage, a set of well-defined project objectives should be documented in a formal Objectives Report.

5.1. Inquire

The Inquire phase consists of two parts developed simultaneously: A. Direct Discussion with Client and Stakeholders and B. Research (Figure 3 and

Table 1. Outline of the Inquire phase.

ACTIVITY	DESCRIPTION	METHODS/TOOLS	OUTPUT
Direct Discussion with Client and Stakeholders
Initial Meeting	Gathering of initial project requirements with all stakeholders	Meeting/Minutes, Videos, (1), (2)	Initial Requirements Report
Ongoing Dialogue	Continuous discussion and refinement of project requirements	Meetings/Minutes, Videos, (1), (2)	Updated Requirements Reports
Research
Bibliographic Surveys	Comprehensive literature investigation	Surveys/Online Databases, Libraries, (1), (2)	Bibliographic and Iconographic Databases
Interviews	Engagement with professionals and experts	Interviews/Recording, Videos, (1), (2)	Interview Transcripts
Field Investigations	On-site visits and observations	Field Visits/Photos, Videos, (1), (2)	Field Investigation Reports, Iconographic Database
Integration of Digital Tools
(1) Sharing Platforms	Information collection and sharing	Google Drive, Dropbox	Accessible Data
(2) Collaboration Software	Tasks management and research progress tracking	Asana, Trello, Microsoft Teams	Research Progress Sharing

). The objective of the former is to maintain continuous contact with clients and stakeholders and ensure the uninterrupted exchange of project information. The objective of the latter is to collect data based on predefined research hypotheses, which are then examined in the subsequent Analyze phase.

Maintaining direct contact with stakeholders ensures their active participation in the design process, rather than limiting them to passive observation. This principle is fundamental to the design thinking approach that underpins this work. Additionally, the research phase is crucial not only for addressing the practical needs of the project but also for elevating it beyond a mere object, enriching it with the qualities of a text (cf. Section 2.4).

A.

Direct Discussion with Client and Stakeholders

Regular and well-documented meetings are key to achieving good results. This can be achieved as follows:

• • Initial Meeting: An opening session involving all stakeholders, including the client, designers, and other relevant parties. All design team members should attend this meeting to ensure a unified understanding of the project’s basic requirements. During the meeting, clients should outline their vision and requirements, including the schedule of completion and budget.
  • Ongoing Dialogue: Following the initial meeting, the design team should split into two groups. One group should be responsible for maintaining continuous dialogue with the client and stakeholders to gather feedback and refine the project requirements as needed.

B.

Research

The second group will engage in research. This group must maintain constant contact with the “dialogue” group to keep the client and stakeholders updated and respond to their requests in real time. The research should be conducted in a systematic and structured manner, and include these steps in particular:

• • Definition of Research Questions: Identify clear and focused questions to guide the study. While questions will vary depending on the specific project context, they may include the following:
    • Context: What are the cultural, social, economic, and technological characteristics of the context in which the project must be developed? What might the project’s reception be in this context?
    • Case Studies: Are case studies relevant to the context in question? Can they be adapted to the situation?
  • Selection of Research Tools: Choose tools and methods for collecting research material. Common research tools include:
    • Bibliographic Surveys: Comprehensive literature reviews to gather relevant data, theoretical frameworks, and best practices.
    • Interviews: Engagement with industry professionals and experts to gain insights and validate feasibility.
    • Field Investigations: On-site visits and observations to understand contextual factors and practical constraints.

C.

Documentation and Outputs

Each activity during this phase should be recorded and archived in an appropriate format. Specifically, this should be done through the following steps:

• • Reports and Transcripts: Meetings, field trips, and interviews should be documented through detailed reports and transcripts (simple minutes for minor meetings). These records should capture all significant discussions, decisions, and observations.
  • Research Databases: Extensive bibliographic and iconographic databases should be used to meticulously record the collected data.

D.

Integration of Digital Tools

Smart digital tools should be used to complete the tasks of this phase efficiently. Among existing tools, the following may be particularly useful:

• • Sharing Platforms, such as Google Drive and Dropbox, enable information collection and sharing. These tools ensure that all team members can access and review the collected data.
  • Collaboration Software, such as Asana, Trello, and Microsoft Teams, can be used for task management and tracking research progress. Although real-time collaboration on design features is not the primary focus at this stage, these tools can help maintain the organization and accountability of research and development.

E.

Alternatives

Depending on the organization and size of the design team, the members of the two groups formed during this phase can either remain fixed (i.e., unchanged throughout the design process) or rotate periodically, enabling members of the team to exchange roles.

Table 1 summarizes the Inquire phase, including an overview of activities, tools, and expected outputs (for further reference, see [46,47]).

5.1.1. Applicative Example: The Inquire Phase in the Gwangmyeong Project

Premise: The numbering of the paragraphs in the sections related to the project aligns with the numbering in the guidelines to facilitate direct comparison between theory and practical application. However, in the project sections, some paragraphs may be omitted or combined to enhance the clarity of the presentation.

A.

Direct Discussion with Client and Stakeholders

1.

Initial Meeting. The Gwangmyeong project began with an initial meeting in Seoul, which was attended by all involved parties: the client (Union of Land Owners), the urban plan design team, the public transport concept team (including the authors of this study), and technicians from various fields (including landscape and infrastructure designers) who would consult throughout the project. During this meeting, the client and master plan designers expressed their desire to use trams as a means of public transport. The proposed solution included a multipurpose system in which vehicles, in addition to normal passenger transport, could handle freight delivery and waste disposal. More directly related to this study, the decision was made to explore the feasibility of installing special functions such as catering, education, and work on selected traditional vehicles, which would be purchased and remodeled for this purpose.

2.

Ongoing Dialogue. In accordance with the guidelines, after this meeting, the design team was divided into two groups: the dialogue group and research group. Composed of team members based in Korea, the former was responsible for maintaining regular contact with the client, master plan designers, and technicians through periodic meetings.

B.

Research

The second group embarked on the research phase and addressed the research questions suggested in the guidelines (i.e., Context and Case Studies). In doing so, the research group gathered information on the current state of the Korean tram transportation industry, industry advancements and the social implications thereof, the present and future urban context of Gwangmyeong, and relevant international case studies.

Recognizing the need for field trips, the research group explored environments with innovative transportation solutions and urban sustainability projects. These field trips were intended to establish connections between public and private entities in order to provide valuable insights. The field trips were primarily conducted in Europe, specifically in Milan, Madrid, and Barcelona. The team also consulted notable figures, included Salvador Rueda, director of the Urban Ecology Agency of Barcelona (https://iaac.net/dt-team/salvador-rueda/, accessed on 15 January 2025), members of the Ministry of Transport and Sustainable Mobility in Madrid (https://www.transportes.gob.es/, accessed on 15 January 2025), and architect Stefano Boeri, principal of the Stefano Boeri Architetti in Milan (https://www.stefanoboeriarchitetti.net/en/, accessed on 15 January 2025).

C.

Documentation and Outputs

The results of the meetings, research, interviews, and field trips were recorded, archived, and shared among the design team members and stakeholders using the tools and methods outlined in the guidelines and described in the previous section.

5.2. Analyze

In the Analyze phase (Figure 3 and

Table 2. Outline of the Analyze phase.

ACTIVITY	DESCRIPTION	METHODS/TOOLS	OUTPUT
Data Organization	Organization of data collected during the Inquire phase	Sorting by categories and topics/(1), (2)	Organized Data Sets
Data Analysis and Synthesis
Context Definition	Delineation of the social, technical, and economic context	Bibliographic and Iconographic Data, Transcripts, and Reports comparison and analysis/(2), (3)	Contextual Analysis Report
Case Study Identification	Recognition and illustration of case studies compatible with the context	Bibliographic and Iconographic Data, Transcripts, and Reports comparison and analysis/(2), (3)	Case Study Report
Project Objectives Identification	Formulation of project objectives based on previous analyses	Contextual Analysis Report and Case Study Report comparison and analysis/(2), (3)	Objectives Report
Integration of Digital Tools
(1) Data Management Software	Organization and maintenance of data	Astera, Collibra	Organized Data
(2) Sharing Platforms	Information collection and sharing	Google Drive, Dropbox	Accessible Data
(3) Data Analytics Software	Comparison and analysis of data	Alteryx, Tableau	Analytical Reports

), the research data collected during the Inquire phase should be systematically organized (A) and analyzed (B) according to the research questions. The findings of this analysis will guide the definition of the project objectives (C), which is the ultimate goal of the Understand stage. The project objectives should include a deeper exploration and expansion of the initial project requirements. Condensed in the Objectives Report (D), they should establish the key issues that the project must address in the following phases.

The data analysis phase is a critical stage in any research process and must be approached with a systematic method and suitable tools (see further: Data Analysis and Synthesis: Research Findings). Analysis should not be viewed as a neutral or mechanical step; its structure can significantly influence the final outcome, in this case, the definition of project objectives, steering it in various directions [59].

A.

Data Organization

The data collected and archived in the previous phase should be systematically organized through cataloging, categorization, and tagging using appropriate tools (see E. Integration of Digital Tools, 2) to facilitate the subsequent analysis phase. Although the research group should take primary responsibility for handling data organization and processing, the dialogue group should continue delivering feedback to and from the client and stakeholders throughout this phase, thereby ensuring that the research group’s work aligns with their requests. If additional data are required during this process, a return to the Inquire phase is necessary.

B.

Data Analysis and Synthesis: Research Findings

The scope and results of the analysis depend on the predefined research questions. For instance, if referring to the questions suggested in Section 5.1 Inquire, the findings of the research should include:

• • Context Definition: Delineation of the social, technical, and economic conditions of the project context.
  • Context and Project Reception: Investigation of the possible reception of the project in this context.
  • Case Study Identification: Recognition and illustration of case studies compatible with the context.
  • Case Study Adaptability: An evaluation of the adaptability of these case studies to the context.

C.

Project Objectives Definition

The research group should synthesize the project’s objectives based on the research findings and the feedback received from clients and stakeholders. The research might confirm, reject, or expand the initial project requirements that emerged from the first meetings. While recognizing that these objectives are highly influenced by the specific conditions of the project, a checklist of objectives might include the following:

• • Model Selection: Identification and study of the model, type, and origin of the vehicle to be refurbished.
  • Functions Selection: Identification of the functions (e.g., catering, education, commerce) to be implemented in the vehicle.
  • Materials Strategy: Definition of the approach towards the current features of the vehicle (materials, colors, and forms) to ensure that they align with the desired character. This includes options such as the conservation/restoration for a traditional atmosphere or renovation for a modern appearance.
  • Sustainability Strategy: Definition of the level of sustainability that needs to be achieved in the final product (through materials, systems, manufacturing processes, and so on).
  • Technical Equipment: Specification of technological apparatus of the vehicle.
    • Note: Depending on the specific case, points 1 and 2 may have been established during the initial meeting. In this scenario, the Research phase should focus on verifying the validity of these objectives.

D.

Documentation and Outputs

Together with some intermediate outputs, as detailed in Table 2, the main output of the Analyze phase is an Objectives Report.

• • Objectives Report: A comprehensive document condensing the results of the Analyze phase. This should include a synthesis of the analytical process and a detailed graphic and narrative illustration of the project objectives. Concluding the Understand stage, the Objectives Report is the first document formally delivered to the client and serves as the master reference document for subsequent project phases.

E.

Integration of Digital Tools

Smart digital tools should be used to complete the tasks of this phase efficiently. Among existing tools, the following may be particularly useful:

• • Data Management Software, such as Astera and Collibra, can be used to organize and maintain data.
  • Sharing Platforms, such as Google Drive and Dropbox, enable information collection and sharing.
  • Data Analytics Software, such as Alteryx and Tableau, can be used to process, compare, and analyze data.

F.

Alternatives

Depending on the specific case, points 1 and 2 of the project objectives may already have been established during the initial meeting. In such instances, the Research phase should focus on verifying the validity of these objectives.

The set of objectives proposed here as an example may vary significantly if the context lacks an existing tram network. In this scenario, technical considerations related to the creation of a new network will need to be addressed, inevitably influencing the definition of the objectives.

Table 2 summarizes the Analyze phase and provides an overview of the activities, tools, and expected outputs (for further reference, see [46,47]).

5.2.1. Applicative Example: The Analyze Phase in the Gwangmyeong Project

A, B.

Data Organization; Data Analysis and Synthesis: Research Findings

In the Analyze phase, the research group analyzed the information collected during the Inquire phase once the data were appropriately organized. Although not all analysis outcomes can be detailed here, some of the main findings related to the research questions are worth highlighting.

• • Context Definition: According to the team in charge of the urban plan design [53], Gwangmyeong will feature roads with cross-sections not exceeding 20 m, unlike most modern Korean districts where streets can be up to 45 m wide [60]. These roads will be intersected by tram railways forming two types of rings: medium- and low-speed rings (Figure 4). New-model smart trams will operate on these rings for passenger transport, with some carriages dedicated to other functions (e.g., freight transport and waste disposal [54]). The remodeled trams included in this study will operate on the medium-speed ring. The rail network will conform to the world standard track gauge of 1435 mm [61].
  • Context and Project Reception: The implementation of trams in Korea aligns with current trends and sustainability goals. Several Korean cities are actively integrating tramways into their transportation networks and receiving positive public feedback in this respect [62]. Trams also have historical significance in Korea, with Seoul operating a tram system from 1899 to 1968 [63].
  • Case Study Identification: ATMosfera in Milan was deemed particularly relevant to the project for a number of reasons. Notably, its wheelset, measuring 1445 mm [64], is compatible with the world standard track gauge set for Gwangmyeong, being only 1 cm wider but much closer than other global gauges, which range from 610 mm (India) to 2134 mm (the United Kingdom) [61]. Moreover, the Milanese vehicle is notably agile due to its compact size and space optimization, and can accommodate up to 24 customers. This is suitable for Gwangmyeong, where trams share relatively narrow roads with private vehicles.
  • Case Study Adaptability: Adapting international examples such as ATMosfera to the Korean context was found to be feasible. The goal was to ensure that the spaces and functions of these trams were aligned with how Koreans use and experience them in everyday contexts (e.g., restaurants, offices). The research highlighted that Korean customs related to public activities, such as eating or meeting, are now closely aligned with global habits. Additionally, adopting non-domestic styles often makes these spaces appear “exotic” and appealing to Korean customers [65,66].

C.

Project Objectives Definition

Based on the research results, the analysis was completed by defining the project’s objectives (cf. Section 5.2), which were as follows:

• • Model Selection: The tram models to be refurbished will be sourced from abroad, as the Korean market lacks historical examples. At the time of writing, the specific source of these models remained undetermined due to ongoing negotiations between the client and potential suppliers.
  • Function Selection: The refurbished trams will fulfill the following functions: Catering, Classroom, Work (Office/Co-Working), Conference Room, and Multifunctional Use (Figure 5).
  • Materials Strategy: Modifications to the tram’s interior and exterior will be made as necessary to meet functional requirements, while maintaining the original and traditional aesthetics as much as possible. This approach aims to highlight the tram’s foreign identity, providing customers with a unique and “exotic” experience without compromising comfort.
  • Sustainability Strategy: The project will prioritize sustainability by adopting environmentally friendly materials and low-impact processes.
  • Technical Equipment: Smart technologies will be integrated to facilitate seamless communication between service management and customers, while respecting the design integrity and traditional aesthetics mentioned in point 3.

6. Define

The Define stage (Figure 3) is the “creative” stage because it marks the transition from preliminary research and objective setting to actual design work. This stage comprises two phases: Explore and Focus. In the Explore phase, designers should develop design solutions by reworking the case studies collected in the previous phase. In the Focus phase, designers should select the more compelling solutions, analyze them, and suggest one or more key design principles, that is, design concepts to guide the development of the final project in the Materialize stage. These principles should be captured in a document called the Key Design Principles Index.

6.1. Explore

The designers should maintain the division of the team into two groups until the process concludes. The dialogue group will continue handling client and stakeholder relations, while the research group will become the design team. The size and composition of these groups can be adjusted as needed.

In the Explore phase, the design team should explore several design solutions. These solutions should not involve working from scratch but reworking (i.e., modifying and reinterpreting, (A)) the case studies selected in the Analyze phase while addressing the Objectives Report. The outputs of these efforts will be a series of pre-projects (B).

Working with case studies is especially beneficial in a niche and underexplored field like tram redesign. By examining successful past solutions, designers can adapt proven practices to address the unique challenges of a new context. Case studies provide a foundation of real-world examples that inform the design process while allowing for customization to meet specific project requirements. This approach not only grounds the new design in practical experience but also encourages innovation by refining and extending existing solutions.

A.

Case Study Reworking

To address the task of modifying and reinterpreting the case studies, the design team should consider temporarily splitting into smaller groups, each tasked with developing an independent design idea. This approach will enhance productivity and creativity through competitiveness.

In reworking the case studies, the designers can follow their own design philosophy. As an example, these guidelines suggest a “deconstructive” approach based on the following steps:

• • Component Identification: Break the case study down into its fundamental components, such as spatial units, functional elements, materials. In this respect, the nature of the components depends on the characteristics of the vehicle, where one feature or another may dominate.
  • Component Analysis: Evaluate the purpose and physical and technical features of each component, as well as their contribution to the overall design.
  • Component Reorganization: Develop alternative configurations or applications of the components to fit the specific needs of the project. This should include the exploration of different spatial arrangements, materials applications, or functional performances to meet the Objectives Report.

Given the iterative methodological approach, this linear process can be paused and modified as needed. For instance, we recommend instituting periodic brainstorming sessions, as well as feedback loops with the client and stakeholders to facilitate the continuous refining of ideas.

B.

Documentation and Outputs

Together with some intermediate outputs, as detailed in

Table 3. Outline of the Explore phase.

ACTIVITY	DESCRIPTION	METHODS/TOOLS	OUTPUT
Case Study Reworking
Component Identification	Breakdown of the case study into its fundamental components	Analysis/(1), (4), (5)	List of Components
Component Analysis	Evaluation of the purpose, effectiveness, and contribution of each component	Analysis/(1), (4), (5)	Components Analysis Report
Component Reorganization	Development of alternative configurations or applications of the components	Design/(2), (3), (4), (5)	Pre-Project
Integration of Digital Tools
(1) Data Analytics Software	Comparison and analysis of data	Alteryx, Tableau	Analytical Reports
(2) Modeling and Visualization Software	Development and communication of spatial ideas	AutoCAD, Illustrator, Rhino	2D and 3D Models
(3) BIM Software	Generation, analysis, modification, and development of spatial ideas	Revit, Navisworks	Detailed 3D Models
(4) Collaboration Software	Task management and tracking of project progress	Asana, Trello, Microsoft Team	Design Progress Sharing
(5) Sharing Platforms	Information collection and sharing	Google Drive, Dropbox	Accessible Data

, the main outputs of the Explore phase are pre-projects.

• • Pre-Projects: Design ideas delivered through various documents such as sketches, diagrams, drawings, and digital or physical models. The topics should cover conceptual space arrangement, including initial material and furniture choices and basic measurements, as well as initial technical systems and equipment choices. A report should integrate these documents, illustrating the logic behind the design solutions and providing an outline of potential developments towards the final project.

C.

Integration of Digital Tools

Smart digital tools should be used to complete the tasks of this phase efficiently. Among existing tools, the following may be particularly useful:

• • Data Analytics Software, such as Alteryx and Tableau, can be used to process, compare, and analyze data.
  • Modeling and Visualization Software, such as AutoCAD, Illustrator, and Rhino can be used to develop and communicate spatial ideas.
  • BIM (Building Information Modeling) Software, such as Revit and Navisworks, can be used to generate, analyze, modify, and develop spatial ideas.
  • Collaboration Software such as Asana, Trello, and Microsoft Teams, can be used to manage tasks and track the design progress.
  • Sharing Platforms, such as Google Drive and Dropbox, enable information collection and sharing.

D.

Alternatives

Instead of dividing the design team into smaller groups, all team members can collaborate sequentially on different cases. While this approach may limit the variety of proposals, it can enable a more in-depth exploration of each individual design alternative.

The deconstructive approach mentioned earlier is just one possible strategy for addressing this phase of the project. Alternatively, the design team may choose a holistic approach rather than an analytical one, prioritizing the emotional aspects of the project over its functional elements [67].

Table 3 presents an outline of the Explore phase, providing an overview of activities, tools, and expected outputs (for further reference, see [68,69,70,71]).

6.1.1. Applicative Example: The Explore Phase in the Gwangmyeong Project

A.

Case Study Reworking

The task of this phase involved reworking ATMosfera, the case study selected in the Analyze phase (Section 5.2.1), to develop a series of pre-projects. The design team followed the design approach suggested by the guidelines (cf. Section 6.1: A. Case Study Reworking).

• • Component Identification: The concept of a component may encompass spatial, functional, material, aesthetic, or other aspects (cf. Section 6.1: A. Case Study Reworking, 1). In ATMosfera, due to space limitations and the need for optimization, function and space are closely intertwined, with each determining the other (“one function, one space”). This observation led to the identification of the following spatial–functional components (Figure 6):
    • Technical Area: The space for the driver and on-board assistant.
    • Service Area: An area comprising the kitchen and a vestibule (filter) space.
    • Common Area: A system consisting of a welcoming space (i.e., the customer reception area) and a permanency zone (i.e., the dining area).
    • Toilet: Toilet facilities.
  • Component Analysis: Components were analyzed in terms of their function, dimensions, technical equipment, materials, quantitative data, and contribution to the design. The analysis revealed a hierarchy among components, with the common area as the central “served” space, the service and toilet areas as “servant” spaces, and the technical area as the “brain” of the system. Composed of two strongly interconnected and inseparable sub-components (welcoming and permanency), the common area was recognized as the spatially central and leading component. This is the space from which the project starts and around which the project is organized.
  • Component Reorganization: The team was subsequently divided into groups of two or three to develop independent design proposals. The groups reconfigured the components to explore how their rearrangement could create the spaces outlined in the Objectives Report, namely, Catering, Classroom, Work (Office/Co-Working), Conference Room, and Multifunctional Use (see Section 5.2.1: C. Definition of Project Objectives, 2). While it is not feasible to detail all outcomes of this phase in this paper, two significant pre-projects are worth further attention.
    • Pre-Project 1 (Figure 6, bottom): This solution suggested reassembling the components of ATMosfera on the original Serie 1500 vehicle. In this design, the permanency zone in the common area serves as a flexible, dimensionally adjustable space hosting the central function, which varies with the tram’s main activity (e.g., working area in Office, etc.). The diagrams in Figure 6 illustrate various layouts achieved by recombining the components: a restaurant (original), office, classroom, conference, and multifunctional space. The technical area and the toilet contract or expand depending on needs. The kitchen can be reduced to a mini-bar or omitted as necessary. In the multifunctional setup, the welcoming space merges with the permanency area, incorporating an autonomous driving solution. This solution includes an additional public storage area (i.e., not originally part of ATMosfera) in the office and classroom layouts.
    • Pre-Project 2 (Figure 7): This solution adapted the same components to a more recent model, the Serie 4900, which was introduced into the Milanese network in 1979. This vehicle shares the same wheelbase width as ATMosfera’s Serie 1500 (1445 mm) but is significantly longer and consists of three wagons. Figure 7 shows the restaurant configuration. Although the toilet facilities and the welcoming area are doubled, all components maintain their original size and thus their functionality and spatial ergonomics. The common area is an exception, as it is allowed to expand along the vehicle’s axis, effectively increasing the available space.

B.

Documentation and Outputs

Both pre-projects were illustrated using sketches, 2D and 3D digital models, physical models, and reports. The design process utilized the tools outlined in Table 3. Note that Figure 6 and Figure 7 only present samples of this material, as this project is currently under development and thus largely confidential.

6.2. Focus

In the Focus phase, the groups of designers working independently in the previous phase should reconverge into a single design team. As their first task, the team should collectively refine (A) the pre-projects developed in the previous phase. They should then analyze and assess the refined pre-projects to identify those with the greatest potential (B). Finally, the design team should extract one or more design principles or concepts from the projects considered to have the most potential (C). These principles, illustrated by a Key Design Principles Index (D), are the final output of the Define stage and provide the framework for the elaboration of the final design.

Collaborating as a single group on both their own pre-projects and those of other team members allows participants to adopt a neutral perspective, facilitating an impartial review of the work produced.

A.

Pre-Project Refinement

This step should ideally be carried out through charrettes, that is, high-intensity collective design sessions. This collaborative method allows for cross-feedback on pre-projects and the integration of different perspectives to enhance them.

B.

Refined Pre-Project Assessment

The assessment of the pre-projects should be based on predefined criteria, with the basic criterion being the satisfaction of the Objectives Report, and conducted using the analysis methods and tools deemed most appropriate by the design team. A checklist of criteria and analytical methods may include the following:

• • Adaptability: Flexibility to accommodate future changes or different uses. This can be investigated through scenario planning and analysis. Integration of Digital Tools lists applicable tools assessing adaptability, as well as the other criteria and analytical methods listed here.
  • User Experience: Level of functionality and comfort from the end-user’s perspective in terms of factors like accessibility, usability, and aesthetic appeal. This can be analyzed through user journey mapping and usability testing.
  • Sustainability: Environmental impact of the design, including energy efficiency and the use of sustainable materials. This can be determined through Life Cycle Assessment (LCA).
  • Dimensional Adequacy: Appropriateness of the sizes of the key functional areas to address spatial constraints and functional requirements. This can be determined through measurement and comparison to references.
  • Materials: The suitability, durability, and aesthetic value of the envisioned materials. To this end, specialized databases can be consulted to analyze and compare materials.
  • Technology: Impact of construction techniques on streamlining the building process and reducing costs and time. This can be estimated by constructing simulations and evaluating techniques.

C.

Key Design Principles Extraction

Once the assessment has identified the pre-projects with the greatest potential, the design team should extract design principles from them based on comparative analysis. This approach may include the following steps:

• • Component Identification and Analysis: Break pre-projects down into their fundamental components (e.g., spatial units, functional elements, materials) and compare these components across different designs to identify recurring themes and strategies.
  • Principle Extraction: Extract the core concepts and strategies from these patterns. These concepts should be broad enough to be adapted to the various aspects of the final design, but detailed enough to offer clear guidance. Like any architectural concept, the principles can focus on different aspects of the project, including space, function, techniques, materials, and historical–cultural values.

As in the Explore phase, the linearity of the process can be interrupted when necessary in order to adopt transversal directions and iterative loops, such as feedback with the client and stakeholders, brainstorming sessions, reassessment, and further refinement.

D.

Documentation and Outputs

Together with some intermediate outputs, detailed in

Table 4. Outline of the Focus phase.

ACTIVITY	DESCRIPTION	METHODS/TOOLS	OUTPUT
Pre-Project Refinement	Refinement of pre-projects developed in the Explore phase	Charrettes/(1), (3), (5)	Refined Design Documents
Refined Pre-Project Assessment
Adaptability Assessment	Evaluation of design flexibility	Scenario planning and analysis/(3), (5)	Adaptability Analysis Report
User Experience Assessment	Evaluation of functionality and comfort from the end-user’s perspective	User Journey mapping and Usability testing/(3), (6)	User Experience Analysis Report
Sustainability Assessment	Evaluation of environmental impact	LCA/(3), (7)	Sustainability Report
Dimensional Adequacy Assessment	Evaluation of the appropriateness of the size of key functional areas	Spatial analysis/(1), (3)	Dimensional Adequacy Report
Materials Assessment	Evaluation of materials’ suitability, durability, and aesthetic value	Materials analysis and comparison/(3), (8)	Materials Analysis Report
Technology Assessment	Evaluation of the impact of the construction techniques on building process, cost, and time	Construction simulations and technique evaluations/(3), (4)	Technology Analysis Report
General Assessment	Comparison of outputs from previous assessments	Comparative analysis/(2), (3)	High-Potential Pre-Project Selection
Key Design Principles Extraction
High-Potential Pre-Projects Component Identification and Analysis	Breakdown of pre-projects into fundamental components and cross-design comparison	Comparative analysis/(2), (3)	Recurring Themes and Strategies Report
Principles Extraction	Core concepts and strategies acquisition from identified patterns	Synthesis/(1), (2), (3)	Key Design Principles Index
Integration of Digital Tools
(1) Modeling and Visualization Software	Development and communication of spatial ideas	AutoCAD, Illustrator, Rhino	2D and 3D Models
(2) Data Analytics Software	Comparison and analysis of data	Alteryx, Tableau	Analytical Reports
(3) Sharing Platforms	Information collection and sharing	Google Drive, Dropbox	Accessible Data
(4) BIM Software	Construction simulations, construction techniques evaluation	Revit, Navisworks	Detailed 3D models, Construction Issues Models
(5) Collaboration Software	Tasks management and tracking of project progress; Scenarios planning and analysis	Asana, Trello, Microsoft Team	Scenario Models
(6) User Experience Software	User journey mapping and usability testing	Figma, Maze	Users’ Needs and Reaction Models
(7) Sustainability Software	LCA	SimaPro, GaBi	LCA Report
(8) Material Databases	Materials analysis and comparison	Material ConneXion, CES Selector	Materials Maps

, the main output of the Focus phase is a Key Design Principles Index.

• • Key Design Principles Index: A comprehensive document illustrating the design principles. The Key Design Principles Index should include graphic materials (e.g., diagrams and drawings), narrative descriptions, a detailed explanation of the analysis process, and practical guidelines for applying the principles in the final design. Concluding the Define stage, the Key Design Principles Index will be the second document formally delivered to the client and, together with the Objectives Report, will serve as the major reference for the final steps of the project.

E.

Integration of Digital Tools

The work of the design team can be aided by tools already utilized in the previous phases.

• • Modeling and Visualization Software, such as AutoCAD, Illustrator, and Rhino, can be used to develop and communicate spatial ideas.
  • Data Analytics Software, such as Alteryx and Tableau, can be used to process, compare, and analyze data.
  • Sharing Platforms, such as Google Drive and Dropbox, enable information collection and sharing.

That said, the analyses that need to be conducted during the pre-project assessment process should employ more specialized software or familiar software in a highly specific way:

• • BIM Software, such as Revit and Navisworks, can be used to perform construction simulations and evaluate construction techniques.
  • Collaboration Software, such as Asana, Trello, and Microsoft Teams, can be used for scenario planning and analysis.
  • User Experience Software, such as Figma and Maze, can be employed for user journey mapping and usability testing.
  • Sustainability Software, such as SimaPro and GaBi, can be used to perform LCA.
  • Material Databases: Materials can be analyzed and compared using material databases, such as Material ConneXion and CES Selector, and their analytical tools.

F.

Alternatives

The goal of this phase is to ensure an unbiased evaluation of the pre-projects. This can also be accomplished by assigning the assessment of the alternatives to an external jury. Similar to an architectural competition, the selected projects can progress and serve as the basis for defining the design principles.

Table 4 summarizes the Focus phase, including an overview of the activities, tools, and expected outputs (for further reference, see [72,73]).

6.2.1. Applicative Example: The Focus Phase in the Gwangmyeong Project

A, B.

Pre-Project Refinement and Assessment

In this phase, the design team regrouped and collaborated to refine the pre-projects developed in the previous phase. The refined pre-projects were then analyzed according to the methods and criteria outlined in the guidelines (cf. Section 6.2: B. Refined Pre-Projects Assessment). For the sake of brevity, a detailed account of the refinement process is omitted from this paper. In short, the assessment identified the two pre-projects outlined in Section 6.1.1 (Figure 6 and Figure 7) as having the most potential, and as fully satisfying all assessment criteria and the requirements of the Objectives Report. These pre-projects demonstrated their strength in two key areas (refer to numbering in Section 6.1.1):

• • Adaptability: Both pre-projects utilized modules (“spatial/functional components,” cf. Section 6.1.1) with fixed transverse dimension compatible with the world wheelbase standard established since the inception of the tram. Consequently, these modules can be adapted to trams of almost any geographical origin or era (Figure 8). Additionally, they can be “stretched” or “contracted” along the vehicle’s axis, allowing them to adjust to different functions (e.g., the permanency zone of the common area in Figure 6) or accommodate trams of varying lengths (e.g., Pre-Project 2 involves a much longer tram, Figure 7). This provides significant design advantages because longitudinal adaptation is less challenging than transverse adaptation, where the space efficiency is a matter of centimeters.
  • Technology: The modularity of the two pre-projects supported design and construction techniques based on the prefabrication and mass production of functional modules and their parts (furnishings, finishes, and technical equipment). This approach enhances the proposals in terms of implementation time and cost, positively impacting other parameters such as project sustainability.

In respect to the other assessment criteria, the envisioned materials maintain the vehicle’s original atmosphere while incorporating a sustainable approach using recyclable, recycled, or upcycled components where possible. The user experience is enhanced through smart technologies that improve the interface between the vehicle and users. Moreover, the modules’ dimensions are adequate and expandable, meeting the requirements of different layouts.

The details of these analyses were condensed in the relevant reports per the guidelines, but are excluded from this paper. As noted, the sections on the Gwangmyeong project are intended to illustrate the application of the guidelines rather than provide a detailed project report.

C.

Key Design Principle Extraction

After identifying the two most promising pre-projects, the team proceeded to the final step of the Focus phase by extracting the key design principles. The extraction process, the details of which have been omitted here, followed the comparative analysis approach suggested by the guidelines (cf. Section 6.2: C. Extraction of Key Design Principles).

After a thorough investigation, the team agreed on the use of a single key design principle: “Flexible Modularity.” This concept summarizes the major features and strengths identified in the pre-projects. The final project will adhere to this principle by proposing a space that comprises clearly defined spatial and functional modules that are (a) universally adaptable to fit different vehicles, and (b) repositionable and dimensionally adjustable to accommodate different functions.

This theme is specific enough to unify all project aspects, but flexible enough to allow the designer a sufficient degree of creative freedom. For instance, modularity can be more or less visually expressed, allowing it to become a formal element. “Flexible Modularity” is particularly suitable for a project like that of Gwangmyeong New Town, where the tram model to be redesigned has yet to be selected (cf. Section 5.2.1: C. Definition of Project Objectives, 1).

7. Materialize

Materialize is the last of the three stages comprising the design process envisioned by the guidelines (Figure 3). In this stage, the design team creates a final project proposal based on the outputs of the two previous stages—that is, the design principles identified in the Define stage, and the project objectives articulated in the Understand phase. The Materialize stage comprises two phases: Verify and Implement. In the Verify phase, the design should be defined in its general lines and tested. In the Implement phase, the technical specifications should be added to finalize the project. The features of the finalized design are condensed in the Final Dossier, which concludes the design process and prepares for the subsequent phases—which are not included in these guidelines—where the project will be developed to the stage of construction documentation, tendered, and built.

7.1. Verify

In the Verify phase, the design team should refer to the design principles outlined in the Key Design Principles Index and develop a design solution that is no longer a case study rework but the project on the actual vehicle that will be remodeled. The solution must comply with the contents of the Objectives Report. A step-by-step design development process that allows for verification phases is recommended. In this respect, the project can first be elaborated in the form of a prototype (A), which should be tested to assess its potential (B). If the test results are positive, the prototype can be further developed to bring it to the stage of schematic design (C).

A step-by-step approach with progressive deepening enables analytical monitoring of each project phase. For instance, if prototype testing produces negative results, this incremental method simplifies retracing the steps leading to the final outcome, allowing for the identification and correction of problematic elements.

A.

Project Elaboration

This step can be carried out according to the designers’ personal philosophy and design customs. As a creative phase, methods and tools cannot be overly generalized. However, we recommend following an approach similar to that suggested in the Explore and Focus phases of the guidelines: namely, sharing information and real-time collaboration among team members, obtaining feedback from clients and stakeholders, and maintaining an iterative design process aimed at continuously refining the partial solutions achieved.

In this design step—the results of which can be condensed into a prototype—designers should clearly demonstrate how the design principles have been applied. They should also provide basic practical information, such as dimensions, material choices, and details of the basic technical systems and equipment. Importantly, the prototype—comprising sketches, drawings, digital material, and physical models—should not be perceived merely as a simple mockup solely focused on form.

B.

Project Test

The prototype can be tested in several ways, depending on the specific focus of the project (e.g., mainly qualitative or quantitative). Metrics can be analyzed using the appropriate tools (see E. Integration of Digital Tools, 4). Possible qualitative testing methods include:

• • User Opinions: Gathering opinions from potential users of the vehicle, identified according to the project’s scope and representative of sufficiently large segments of the population.
  • Feedback from Clients and Stakeholders: Collecting feedback from clients and stakeholders using more formal methods than usual meetings (e.g., written surveys) for greater accountability of opinions.
  • Comparison with case studies: Comparison with similar existing cases to identify and remedy any shortcomings.

The results of these tests should be compiled into a Test Report.

C.

In-Depth Project Elaboration

If the test yields positive results, the design team should proceed by further developing the prototype. This involves detailing the functions, materials, and technological issues as outlined in the Objectives Report. In this step, the design should be elevated to the level of schematic design. The output of this step—that is, the resulting documents—concludes the Verify phase.

D.

Documentation and Outputs

Together with some intermediate outputs detailed in

Table 5. Outline of the Verify phase.

ACTIVITY	DESCRIPTION	METHODS/TOOLS	OUTPUT
Project Elaboration	Development of initial project ideas	Design/(1), (2), (3), (5)	Prototype
Project Test	Verification of the prototype	Gathering of opinions and feedback, comparison with case studies, metrics comparison/(3), (4), (5)	Test Report
In-Depth Project Elaboration	Development of the prototype	Design/(1), (2), (3), (5)	Schematic Design
Integration of Digital Tools
(1) Modeling and Visualization Software	development and communication of spatial ideas	AutoCAD, Illustrator, Rhino	2D and 3D Models
(2) BIM Software	Generation, analysis, modification, and development of spatial ideas	Revit, Navisworks	Detailed 3D Models
(3) Collaboration Software	Task management and tracking of project progress	Asana, Trello, Microsoft Team	Design Progress Sharing
(4) Data Analytics Software	Comparison and analysis of data	Alteryx, Tableau	Analytical Reports
(5) Sharing Platforms	Information collection and sharing	Google Drive, Dropbox	Accessible Data

, the main output of the Verify phase is a schematic design.

• • Schematic Design: As a comprehensive set of documents describing the conceptual and practical aspects of the design, the schematic design should comprise drawings, diagrams, 2D and 3D visualizations, physical models, and preliminary cost estimates. These topics cover preliminary space arrangements, including dimensions and furniture layouts, preliminary material choices, and preliminary technical systems and equipment. These documents should be integrated into a report, which should also provide an overview of the previous prototype and testing stages, illustrate the logic behind the design choices, and include relevant quantitative and technical data.

E.

Integration of Digital Tools

The recommended digital tools are the same as those employed in the other creative phases of the project:

• • Modeling and Visualization Software, such as AutoCAD, Illustrator, and Rhino, can be used to develop and communicate spatial ideas.
  • BIM (Building Information Modeling) Software, such as Revit and Navisworks, can be used to generate, analyze, modify, and develop spatial ideas.
  • Collaboration Software, such as Asana, Trello, and Microsoft Teams, can be used to manage tasks and track the design progress.
  • Data Analytics Software such as Alteryx and Tableau, can be used to process, compare, and analyze data.
  • Sharing Platforms, such as Google Drive and Dropbox, enable information collection and sharing.

F.

Alternatives

The design team may decide to skip the step of developing the project to the schematic design level, moving directly to the next phase, Implement (cf. Section 7.2), where the design is taken to the design development level. This decision depends on the contractual agreements between the client and the designers.

Table 5 presents an outline of the Verify phase, including an overview of the activities, tools, and expected outputs (for further reference, see [74,75,76,77]).

7.1.1. Applicative Example: The Verify Phase in the Gwangmyeong Project

A.

Project Elaboration

In the Verify phase, the design team developed a proposal based on the concept of “Flexible Modularity” (cf. Section 6.2.1: C. Key Design Principle Extraction). The project followed the step-by-step process outlined in the guidelines: Project Elaboration (prototype), Project Test, and In-Depth Project Elaboration (see Section 7.1). As the Verify phase involves developing a design for the vehicle to be implemented, the primary challenge was the uncertainty of the specific tram model to be purchased for Gwangmyeong (cf. Section 5.2.1: C. Definition of Project Objectives, 1). The concept of “Flexible Modularity” was conceived to address this issue. Following the principles of universal adaptability and the repositionability/adjustability of modules, the design team envisioned modules similar to those in the pre-projects (Section 6.1.1, Figure 6 and Figure 7): namely, transversally sized to the world-standard wheelbase and horizontally adjustable. This will make them suitable for the width of almost all existing tram models [61] and adaptable with slight modifications to the length of the chosen tram.

This strategy made numerous models available as a base for the project. The design team chose to work on the Serie 1500 from Milan, the same model as ATMosfera, for two reasons. First, in the Explore phase, valuable pre-projects were developed using this model, so selecting this model would allow the team to capitalize on pre-project experience. Second, the Serie 1500 is one of the smallest and oldest trams in circulation [78]. Designing within such space limitations would train the team to solve challenging problems and provide valuable experience for future work on the selected model. This approach would ensure that, regardless of the model ultimately purchased, the team would work in similar or more favorable spatial conditions, making future adaptations easier.

The project was developed as a 2D and 3D digital prototype, omitting physical modeling. Each significant development received feedback from the client, stakeholders, and technicians. The prototype was iteratively revised multiple times before finalizing its characteristics. Details on the output are provided in the discussion of the last phase (see C. In-Depth Project Elaboration).

B.

Project Test

Once finalized, the prototype was tested according to the guidelines (cf. Section 7.1: B. Project Test). Specifically, its qualitative features were tested using the following methods:

• • User Opinions: A sample group of potential users was selected from Seoul residents of different age groups and social backgrounds and asked to complete a questionnaire.
  • Feedback from Clients and Stakeholders: Additional feedback from the client, stakeholders, and technicians was formally collected through a written questionnaire.
  • Comparison with Case Studies: A comparison with selected cases was conducted, namely, the Fondue Tram in Zürich [79] and Hoftramm in The Hague [80].

The test results were positive, with only the case study comparison suggesting the need for changes in the food preparation area. Consequently, the team moved from the prototype to in-depth project elaboration phase, with focus shifting to achieving a schematic design stage level of completeness.

C.

In-Depth Project Elaboration

The project was named Smart Trams, a palindromic expression signifying how a vehicle invented two centuries ago can become a sustainable and modern means of transport. The following notes illustrate the schematic design results:

• • Spatial Features. Since the prototype phase (not included in this paper), the design team decided to confirm the spatial/functional components identified by the pre-projects (Section 6.1.1, Figure 6) as basic design modules: Technical Area (the space for the driver and on-board assistant), Service Area (kitchen and vestibule filter space), Common Area (welcoming space and permanency zone), and Toilet.
    The modules were recombined within the space of the Serie 1500 to achieve the functions outlined in the Project Objectives. In the schematic design stage, the space was detailed with a furniture layout defining the following configurations (Figure 9): Restaurant, Classroom, Study/Work Café, Public Hall (conference room or small library).
    In Configuration 1, the restaurant tram is almost a precise ATMosfera copy. This configuration pays homage to the project’s matrix, although several aspects may change if the purchased model has different characteristics to those of the Serie 1500.
    Configuration 3, originally planned as a generic working space, was specified as a “Study/Work Cafe.” This addresses a popular Korean concept: work coffee shops, or “study cafes,” where customers can spend most of the day with a single order, working or studying with their digital tools [81].
    Given the limited availability of space, all interiors were designed according to ergonomic principles, with careful consideration of the dimensions of objects and people and analysis of their movement paths (Figure 10).
    To integrate this set of alternatives, the team examined a variant that can be applied to each, namely, an autonomously driving tram (Figure 11). In this solution, the driver space is reduced in favor of the common space, which hosts the main function. Staff are still expected to be on board, but their role shifts from driving to ensuring that the tram proceeds safely and providing assistance (e.g., service assistance in the restaurant or teaching assistance in the classroom).
  • Material Features. In this phase, the project involved developing a preliminary definition of the materials used in each functional area. The Objectives Report prescribed materials that respected the original atmosphere of the tram to be renovated (see Section 5.2.1: C. Definition of Project Objectives, 3). As the specific model for Gwangmyeong had not yet been identified, the team drew inspiration from the examined case studies, including ATMosfera, which selected materials typical of the second industrial era, when the tram was invented. Wood was chosen for the furniture, finishing, and floors; metal for furniture and finishing; and linoleum for the floors. All materials would feature neutral colors, which would be highlighted by warm-colored light. For sustainability, reclaimed wood (possibly from the original vehicle) is recommended, as are metals with high recycled content or that are fully recyclable. The interior will be illuminated by low-temperature light-emitting diode (LED) lights, which will mimic incandescent bulbs.
  • Technological Features. From a constructive perspective, each module was envisioned as prefabricated and based on a fixed platform where furniture, decorative elements, and necessary technical equipment could be mounted. The furnishings were designed to be standardized and mass-produced, allowing for cross-utilization in various configurations. For example, restaurants and study/work cafés will use the same tables with slight variations in the arrangement.

All of these design solutions were illustrated with graphic and narrative documents appropriate to the schematic design stage (cf. Section 7.1: D. Documentation and Outputs, 1) and approved by the client.

7.2. Implement

The Implement phase concludes the tram redesign process. During this phase, the design team should finalize the design by detailing and quantifying all of its spatial, material, and technological aspects (A). This phase can proceed by developing the contents of the schematic design elaborated in the previous phase. Alternatively, it may start directly from the prototype if the design team decides to skip the schematic design phase (see Section 7.1: F. Alternatives). The final output will be reviewed by the client. Upon approval, the team should elucidate the entire design history in a Final Dossier (B).

A.

Project Finalization

The methods and organizational approaches for finalizing the design are left to the designers’ discretion and customs. Project finalization is subject to the iterative principle that characterizes the entire process—that is, the proposed solutions can be reviewed and revised at any time.

To maintain consistency with previous project phases, the level of detail in the project documents should correspond to that of the design development. To this end, the design team must ensure that the documents detail the spatial organization of the vehicle, its material characteristics (both internal and external), and technological equipment. All of these components should be measured and accompanied by technical specifications. Although not final, both code compliance verification and the overall cost of the project must be evaluated.

B.

Project Description

Once the design development has been completed and approved by the client, the design team should summarize all project content in a Final Dossier. The Final Dossier should not only include the final output, but also outline the entire history of the project, starting from the definition of the initial objectives. This comprehensive summary is important for maintaining professional transparency with the client as it provides a complete overview of the project they have funded. It also equips the design team with a detailed case study and methodological reminder for similar projects in the future.

C.

Documentation and Outputs

The entire design process is summated in two final complementary documents, Design Development and the Final Dossier:

• • Design Development: A comprehensive set of documents describing the conceptual and practical aspects of design, Design Development should include the following: (a) technical drawings (plans, sections, elevations, details); (b) 3D visualizations; (c) technical diagrams regarding structures, systems, and equipment; (d) general data sheet; (e) the bill of materials (BOM); (f) technical specifications of components and materials; (g) diagrams verifying code compliance; (h) a general cost estimate; and (i) a plan/manual for the management and maintenance of the project post-implementation.

A report should integrate these documents, illustrate the logic behind the design choices, and provide the relevant quantitative and technical data.

• 2.

  Final Dossier: A comprehensive collection of all main documents produced during the design process, the Final Dossier documents the project’s history and should include the following elements: (a) an introduction illustrating the genesis of the project, (b) the Objectives Report, (c) an overview of the pre-projects, (d) the Key Design Principles Index, (e) overview of the prototype, (f) the Schematic Design, and (g) the Design Development.

The Final Dossier is the final and definitive document of the project and is delivered to the client at the end of the process. Together with project development, it forms the basis for subsequent steps, including the construction documents and preparation of bidding documentation.

D.

Integration of Digital Tools

The recommended digital tools are the same as those employed in the other phases of the project, including:

• • Modeling and Visualization Software such as AutoCAD, Illustrator, and Rhino, can be used to develop and communicate spatial ideas.
  • BIM (Building Information Modeling) Software, such as Revit and Navisworks, can be used to generate, analyze, modify, and develop spatial ideas.
  • Collaboration Software, such as Asana, Trello, and Microsoft Teams, can be used to manage tasks and track the design progress.
  • Sharing Platforms, such as Google Drive and Dropbox, enable information collection and sharing.
  Additional tools can be used to create and manage tram maintenance schedules:

  5.

  Enterprise Asset Management (EAM) Software, such as IBM Maximo and SAP EAM, can be used to create a maintenance schedule for different parts of the tram at varying degrees of obsolescence.

E.

Alternatives

Although this phase concludes the work at the design development stage, leaving the construction documentation phase outside the scope of the guidelines, the Implement phase could also be approached at a more detailed technical level, serving as a preparatory step for the construction phase. To achieve this, the design team should involve professionals and specialized technicians, not yet part of the process, to contribute to the preliminary resolution of critical technical and mechanical elements. This approach enables the design team to oversee the technical development from the outset, ensuring it aligns with the spatial and architectural objectives of the project, which might otherwise be compromised if handled entirely by a separate team.

Table 6. Outline of the Implement phase.

ACTIVITY	DESCRIPTION	METHODS/TOOLS	OUTPUT
Project Finalization	Final definition of spatial, material, and technological aspects	Design/(1), (2), (3), (4), (5)	Design Development
Project Description	Comprehensive summarization of the documents produced throughout the design process	Data collection, synthesis/(1), (4)	Final Dossier
Integration of Digital Tools
(1) Modeling and Visualization Software	Development and communication of spatial ideas	AutoCAD, Illustrator, Rhino	2D and 3D Models
(2) BIM Software	Generation, analysis, modification, and development of spatial ideas	Revit, Navisworks	Detailed 3D Models
(3) Collaboration Software	Task management and tracking of project progress	Asana, Trello, Microsoft Team	Design Progress Sharing
(4) Sharing Platforms	Information collection and sharing	Google Drive, Dropbox	Accessible Data
(5) EAM Software	Creation and management of maintenance schedule	IBM Maximo, SAP EAM	Maintenance Schedule management

presents an outline of the Implement phase, including an overview of the activities, tools, and expected outputs (for further reference, see [82,83]).

7.2.1. Applicative Example: The Implement Phase in the Gwangmyeong Project

A.

Project Finalization

In the Implement phase, the design team expanded the schematic design to the design development level. Although details on the organization and development of this task are omitted from this paper, the following key outputs are worth elaborating.

• • Material Features. Following the schematic design’s preliminary selection of wood, metal, and linoleum for the main internal finishes (see Section 7.1.1: 2. Material Features), the nature of these materials was further specified and mapped. Materials included solid and laminated wood (new or reused), cast iron and steel (with varying degrees of recyclability), and medium- and high-resistance linoleum. Each functional component was initially associated with a dominant material (e.g., steel in the toilets and kitchen, solid wood in permanency spaces). This distribution was then refined through a parametric study involving color intensity and permanence time, with higher-intensity values assigned to environments with shorter permanence, and vice versa. Figure 12 presents a sample of this study.
  • Maintenance Plan. The design team defined all technical equipment and systems for the Smart Trams, including software for controlling main functions, security, and customer communication. A notable result was the identification of the different obsolescence rates of “hard” (mechanical parts) and “soft” components. Hardware generally has a slower obsolescence rate than software, which is frequently updated due to technical progress or customer expectations. Therefore, a plan was outlined to map the obsolescence rate of each component and schedule maintenance interventions over time. This plan was condensed into a Report/Manual, an extract of which is presented in Figure 13.
  • Exterior Features. The original tram livery will be preserved, as per the Objectives Report (see Section 5.2.1: C. Definition of Project Objectives, 3). However, modern graphic elements—such as macro-graphics of different colors around the closed doors (see Figure 14)—will be used to differentiate the tram’s functions while maintaining its original identity. To define this concept, studies were conducted on different tram models in anticipation of the adaptation of the solutions to the purchased model.

B.

Project Description

At the end of the design development process, the documents were integrated with materials from the preceding phases and condensed into a Final Dossier. This document was delivered to the client and constituted the final act of the design team in fulfilling their assignments.

8. Discussion: Potential Validation of the Guidelines

As noted in Section 2.4, this paper presents the guidelines for tram redesign as a project proposal, situating the focus of this study within the research method known as research through design. Section 2.4 also highlighted key issues related to this approach, particularly the challenges involved in validating its outcomes. Section 8 seeks to address this validation challenge by offering initial insights, with the hope of sparking a discussion that may encourage broader dialogue on the topic. In particular, the discussion will assess the material in relation to its hypothetical recoverability and theoretical sensitivity, two validation methods proposed in the literature (cf. Section 2.4).

The recoverability of the guidelines, in our opinion, must be evaluated on two levels: first, by assessing the rigor of the design process that produced them as a design product, and second, by evaluating the intrinsic rigor of the guidelines themselves, as they essentially represent a design process.

The process and methods used to draft the guidelines have been carefully outlined in Section 2, where we believe sufficient elements are provided for a critic to affirm that the logic followed was rigorous—grounded in research, guided by professional experience and contributions from the academic literature, and structured through steps of progressive, in-depth analysis (see Section 2.1, Section 2.2 and Section 2.3). According to the principle of recoverability, if the logic of the process is transparent and recognized as rigorous, the validity of its outcomes can be affirmed.

Regarding the second point, we believe that a careful review of the material presented in Section 5, Section 6 and Section 7 enables critics to assess how it has been structured within a logical and coherent framework.

Specifically, the design thinking approach informed the overall organization of the guidelines, serving as a methodological reference that acted as an “umbrella” for the drafting of the individual steps. Focusing on these steps, each section of the guidelines, including those describing the project, was structured following principles recommended in the relevant literature to ensure coherence and clarity (cf. [42] (p. 8)):

Chronology: “Describe work in the same sequence that it occurred, ideally as bullet points” [69] (p. 473).

Clarity: “Keep entries intelligible, insightful, and honest” [84] (p. 473).

Focus: “Keep entries succinct; they should not be a crafted essay” [84] (p. 473).

Additionally, as also recommended [42] (p. 8), thoughtful documentation of outcomes—through images and diaries—was included in Section 5.1.1, Section 6.1.1 and 7.1.1, which describe the project.

The principle of theoretical sensitivity, on the other hand, guided the entire design process, drawing on two primary references: Zappia’s contribution to the academic literature and the professional experience of ATMosfera (cf. Section 2.1). In the following notes, these references will be reviewed and compared with the study’s results to evaluate their theoretical potential and, consequently, their validity as a research proposal.

• Comparison with Academic Literature

Developed by Zappia [38], the guidelines for yacht restoration that inspired this study provide a valid case for comparison, particularly insofar as both sets of guidelines focus on the intervention of traditional vehicles and are inspired by design-thinking principles. The guidelines for yacht restoration define a series of steps and sub-steps: namely, Start, Project, Intervention, and Post-Restoration. Unlike the guidelines for tram redesign, they include the construction and post-construction phases of the vessel (Intervention and Post-Restoration), which were omitted from this study for the reasons indicated in Section 2.2.

However, although the steps identified in Zappia’s study are logical and clear, they lack practical elucidation of how to execute them. In this respect, suggestions on work organization, tools to be used, or expected outputs are omitted and left to the discretion of the designer; as Zappia notes, “we leave to the designer the option to choose” [38] (p. 269). Zappia’s guidelines essentially propose a logical rather than methodological process for approaching a project. In contrast, the guidelines for tram redesign presented in this study define both a logical design process and a methodology based on the precise identification of relevant roles, tools, and results. As working habits vary from one designer to another, these issues can only be suggested, rather than prescribed. Nonetheless, we contend that concrete indications can provide more solid assistance to professionals tackling this topic for the first time.

As such, while the validity of the tram redesign guidelines and yacht restoration guidelines is comparable in terms of the general structure, the tram redesign guidelines illustrated in this study go a step further by proposing a more complete design method.

2.

Comparison with Professional Experience

The development of the proposed guidelines was greatly influenced by the case study of the ATMosfera Restaurant Tram in Milan. As noted in Section 2.1 and demonstrated throughout this study, the design team drew heavily from the ATMosfera case, borrowing its methodologies and processes. Indeed, the guidelines proposed in this study are a systematization of the ATMosfera experience, integrated with insights from references, enriched by theoretical and field research for the Gwangmyeon project, and updated using the latest software tools (cf. Section 2.1, Section 2.2 and Section 2.3).

The Milanese project has achieved considerable success in recent years. Approximately 20,000 customers use ATMosfera annually, and its presence has become a notable feature of the city’s identity [56]. Therefore, it is appropriate to consider the success of this project as a retrospective validation of the guidelines inspired by the method that led to its creation.

Nevertheless, we recognize that the above may not be sufficient validation on its own. This research requires further discussion by the scientific community, and it is our hope that this study can contribute to stimulating such debate.

9. Conclusions and Limitations

This study emerged from renewed interest in trams as a sustainable means of transport, particularly in respect to the trend of remodeling historical vehicles for functions beyond passenger transport, such as catering, education, and work. However, these projects lacked theoretical and methodological references, such as design guidelines, technical instructions, handbooks, and analytical case studies, resulting in interventions being solely reliant on designers’ creativity or specific contextual conditions. To address this methodological gap, we proposed a set of guidelines for redesigning trams for alternative purposes. These guidelines comprise a series of design steps, each detailed by roles, procedures, technical tools, and expected outputs and exemplified step-by-step through a concrete project. The guidelines were designed during a project for the new town of Gwangmyeong in South Korea, and based on the design team’s research and direct experience with ATMosfera, a restaurant tram in Milan.

The proposed guidelines represent a novel contribution insofar as they are the first to address this topic. This comprehensive study provided a design process with a solid practical framework, but versatile enough to be used in different contexts and adapted to the needs of stakeholders with varying structures and work habits.

The guidelines are proposed as an exemplary case study for designers and interested parties intending to undertake tram redesign projects. However, given the significant research and study behind their development, they will likely be discussed as methodological tools in their own right and opened to scientific debate. This study contributes to such debate by outlining their effectiveness. Positive feedback can make this and similar work the basis for developing a shared methodology, strengthening its influence on project development as well as technical and economic evaluation.

These results notwithstanding, this study has several limitations. First, the research-through-design approach upon which the study is based has been criticized for its limited generalizability, inherent subjectivity, and replication challenges. At present, despite the proposals for a validation methodology outlined in Section 2.4 and developed in Section 8, there is no universal consensus on the scientific validity of this type of approach [42] (p. 2); cf. [85,86].

Second, the guidelines stop at the threshold of the executive stage as they do not go beyond the design development phase. As explained in Section 2.2, this decision was made to maintain methodological coherence, particularly insofar as the phases from construction documentation onwards require a different organization of work and the contribution of different specialists. As addressed later, this is an area where the guidelines can be further developed.

Third, defining design phases in relation to their formal, universally accepted subdivisions, such as those followed by the AIA [82,83], presents a challenge. It is difficult for a methodology that deals with an object such as a tram, which is halfway between an industrial product and architectural space, to organize the project in such a way that the steps satisfy the customs of both sectors. This study attempted to overcome this difficulty by subdividing the process into phases that seemed logically appropriate to the task, while indicating among the outputs of these phases the official documentation of an architectural project (i.e., Pre-Project, Schematic Design, and Design Development; see Section 4, Section 5, Section 6 and Section 7). However, we recognize that alternative solutions can be explored, as this question is crucial in the drawing up of contracts among various other tasks.

These limitations underscore the need for further research and development to enhance the applicability and robustness of these guidelines. First, future studies should validate these guidelines using tangible outputs. In this regard, conducting pilot projects in different cities and contexts can aid the assessment of the practicality and adaptability of the proposed phases and documentation. For example, once built, the Gwangmyeong project will serve as an important testbed.

Second, because the scope of this study is limited to the design development phase, future work should extend the guidelines to cover the construction documentation and execution stages. This will require a different work structure and collaboration with specialists in construction management and industrial design to ensure comprehensive coverage from ideation to final realization. Doing so can also provide guidelines in different formats. As this study introduced these novel guidelines, a discursive approach was adopted to ensure maximum clarity. Going forward, articulating the guidelines in a more technical style, such as that of an instruction manual, may prove beneficial.

Finally, the guidelines should be periodically reviewed and updated to incorporate feedback from practitioners and lessons learned from real-world applications. Establishing a feedback loop with continuous improvements will ensure that the guidelines remain relevant and effective in addressing the evolving challenges and opportunities of tram redesign projects.

We hope that the material presented in this study will be helpful to stakeholders in this discipline, stimulate debate, enhance collaboration, and inspire new ideas. This may lead to the establishment of shared and more sophisticated methodological principles, similar to those in other design and product design fields. Given the growing significance of the field of tram redesign, it may soon be recognized as a classic area of redesign and refurbishment. Such recognition will establish it as a complex multidisciplinary field involving multiple areas of expertise, ranging from spatial design to mobility, mechanics, marketing, and economics.