Exploring the Key Elements of Sustainable Design from a Social Responsibility Perspective: A Case Study of Fast Fashion Consumers’ Evaluation of Green Projects

: With the growing global awareness of sustainable development, the impact of “fast fashion” on the environment has drawn much attention. This study investigated 365 fast fashion consumers with higher-than-average spending on fast fashion garments in Taiwan and analyzed the data with the analytic network process. From the perspective of social responsibility theory, the triple bottom line framework, and the concept of cradle-to-cradle, this study conducted in-depth interviews with 10 experts in the ﬁeld of clothing. Based on the results, this study constructed a model with 4 core dimensions and 12 key criteria of sustainable clothing design, with the enterprise, design, and consumer sides as the decision-making options. Moreover, it was found that consumers believe that the ﬁrst decision-making key that affects sustainable design is the enterprise side, and the most important green item that affects sustainable design is “cherishing”. The ﬁndings of this study can provide an important reference standard for sustainable design in the apparel industry.


Introduction
Excessive consumption is one of the negative effects of "fast fashion" [1].Over 80 billion pieces of clothing are produced globally each year, three-quarters of which end up in landfills or incinerators after their short, useful life; only one-quarter is recycled [2].With fashion bloggers, celebrity endorsements, and online shopping, retailers of leading "fast fashion" brands have grown by 9.7 percent per year, surpassing the 6.8 percent annual growth of traditional apparel brands [3].According to economist Juliet B. Schor's Plenitude: The New Economics of True Wealth in 2010 [4], Americans have three times the spending power they did fifty years ago, and their total amount of purchased apparel is double what it was twenty years ago.In 2017, Nike generated more than USD 34 billion in revenue with a market capitalization of USD 34 to 100 billion [5].By consensus, a company with high turnover sells more goods but also generates more waste at the same time [6].
With people's growing demand for material goods and services, environmental degradation is no longer a mere population issue; rather, it is a direct and indirect expression of people's excessive consumption of resources and the pollution of the rich [7].This phenomenon indicates that people will need land and ocean resources equivalent to two Earth sizes in the future.In a severe state of "human versus nature," the fashion industry is widely considered the second most disruptive industry after oil.The problem of dealing with textile waste worldwide is of increasing concern [8,9].In 2019, an EU initiative called the European Apparel Action Plan was launched to improve the sustainability of textiles throughout their life cycle, from design to end-of-use [10].A large amount of textile waste and piles of out-of-season clothes end up in landfills and various corners of the Earth.It has become a major global concern.Every year, up to 95% of textiles are buried; however, most of them can be recycled [11].As consumers become more concerned about the environmental impact of the products they purchase, businesses are beginning to understand the benefits and economic potential of (re)using waste efficiently [12].
In the global fashion-driven textile and apparel market industry, innovative thinking and efforts are required at the supply and demand levels [13,14].The sustainability challenge, in particular, requires an interaction between the supply and demand sides, bringing sustainability practices into focus more directly [15].Sustainability impacts and measures are positive and should be distributed among them [16].Over the years, people's growing demands for material goods and services have ignored protecting the planet and maintaining biodiversity [17].We need to realize and take effective actions for this, as we are pushing the limit of the planet [18,19].We must recognize the need for sustainability and make changes immediately.In "Perspectives on Barriers and Enablers for Implementing Sustainable Supply Chains in the Textile Industry", it is evident that business collaboration can lead to sustainable policy implementation and reduce barriers [20].
A report published by the Ellen MacArthur Foundation, "A New Textiles Economy: Redesigning fashion's future," revealed that from 2000 to 2015 the total amount of global clothing has tripled, and clothing utilization has fallen by 36% [21].Although there are many second-hand and charity shops worldwide, they cannot keep up with the vast clothing waste [22].Ecofibra, founded in 2018 by engineer Franklin Zepeda, recycles and transforms textiles in Chile; they found that many clothes now contain chemicals that prevent them from biodegrading, so they cannot be buried.Furthermore, the toxic fumes from burning clothes will cause severe pollution in the air and land [23].Fast fashion brands are more well known, with new designs every week that are affordable and have a variety of styles [24].How can we deal with the problems caused by "fast fashion"?If a fast supply chain is necessary, it will also become a normal and irreversible trend; then, how do we equate fast fashion with sustainability?It is worth thinking about [25,26].People have long ignored protecting the Earth and maintaining biodiversity [27].The main motivation of this study is recognizing the importance of realizing this and taking effective action to this end.
Sustainable fashion is a broad topic.However, the lack of an empirical rationale for developing sustainable approaches has resulted in a rarity of actionable indices.Recently, scholars have supported this view, pointing out that global sustainability assessments are primarily based on subjective or professional judgments rather than quantitative methods [28].To date, there has been no agreed-upon methodology for assessing the development of sustainability or achieving sustainability at the spatial scale of planning [29].Therefore, policymakers encourage researchers to innovatively integrate various technologies into new sustainable development plans [30,31].This study adopted the social responsibility theory to examine the issues concerning fashion sustainability in the clothing industry [32][33][34].
Making progress in sustainability is like going to a destination we have never been to, with geographic awareness and navigational principles but no map or compass [35].While sustainability issues are related to economic welfare, social equity, and environmental quality, they may never be evenly distributed in the norm [36].The lack of progress in achieving sustainability primarily comes from the acceptance and application of development indicators and the unawareness that the damage we are doing to the planet has reached its limit; fashion sustainability is now a "must" and an "immediate" task to address this problem [37].In response to the magnitude of global issues and the need to rapidly improve socioecological and public well-being, many development indicators have been proposed in the scientific field of sustainability [38].Unfortunately, our proficiency with these measurement tools has been limited to theoretical and methodological design studies [39].Through continual effort, sustainable development progress in applied research and practices has continued to draw attention to its importance [40].While studies have investigated interrelationships with respect to interpreting sustainability indicators, Sustainability 2023, 15, 995 3 of 20 few have directly attempted to reduce a set of development measures to a few normative variables to understand sustainability further [41].This finding prompted us to investigate whether any decisions could enhance the pervasiveness of sustainable design and, if so, how we might address such issues.The findings of this study expand our understanding of consumer attitudes toward the conflicting values of "sustainability" and "fashion."This awareness is urgently needed to drive the green movement in the fashion industry [42].Therefore, this study aims to explore and define the key elements of sustainable clothing design through expert opinions in the clothing industry chain for the following research purposes: (1) to understand high-spending fast fashion consumers, (2) to examine their cognitive position on sustainable design, and (3) to determine the best decision-making plan to facilitate the practice of sustainable fashion as the primary development goal.

Literature Review
Fast fashion is the number one killer of sustainable fashion [43,44].Enterprises strengthen the concept of the fast fashion economy, which makes the entire fashion industry face a difficult choice, that is, how to balance sustainability and fashion [45].Sustainable design is a way to meet economic and social needs.Referring to a design approach based on sustainable management and ecological principles, this study explains this issue in the introduction and echoes the cradle-to-cradle argument in the literature review.Whether it is the enterprise side that attaches great importance to the economy or the design side responsible for product design and planning, consumers who love fast fashion can use the core value of social responsibility theory to jointly realize the goal of sustainable clothing design [46].

The Impact of Fast Fashion on the Apparel Industry
Fast fashion refers to trendy clothing that can be produced within a week, created according to big data based on styles launched in fashion weeks; it is a business model that sells quickly and makes a profit for the purpose of profit.Consumers can buy trendy clothing at low prices in a short period of time [47].Fast fashion brands are known for their efficient supply chains [8].By investigating consumer needs based on big data and using the fixed process of the traditional supply chain-planning, design, proofing, production, and logistics to shelf-a product development cycle that would normally take at least 3-6 months is shortened to 14 days [48].This study hypothesizes that consumers who love fast fashion can affect the sustainable development of clothing by retaining the concept of social responsibility.Based on the introduction and literature review, this study proposes cradle-to-cradle, triple bottom line architecture theory, and social responsibility theory to discuss the concept of sustainable fashion with the goal of sustainable clothing practices and sustainable design [49][50][51][52][53].

Cradle-to-Cradle: The Future of Zero Waste
In 1970, Walter R. Stahel, who is considered the father of sustainable industry, suggested that commodities become more expensive as the demand for raw materials and the cost of mining increase [54].This finding triggered research into possible solutions.Stahel later worked with the Product-Life Institute to develop a closed-loop commodity process based on the concept of cradle-to-cradle.In 2002, Professor Braungart and William McDonough, both architects, published a book titled Cradle to Cradle: Remaking the Way We Make Things, which is considered the manifesto of cradle-to-cradle design [55].It provides specific details on how to implement the model.The premise is that people need to learn from nature, where everything is nourished and can be returned to nature.Therefore, the cradle-to-cradle manufacturing concept is to design products to produce zero waste, and all products made can be returned to the ecosystem.Simply put, the products can decompose naturally without causing a burden to the Earth.To initiate cradle-to-cradle manufacturing, a vision that we can and should do, it becomes evident that we can implement this process, from shoes to clothes and from factories to cities, in the production of any product [56].
In response to the problems mentioned in the introduction, cradle-to-cradle is the main development goal and the core concept of sustainable clothing design.

Triple Bottom Line Architecture Theory: Economic, Social, and Environmental
In 1998, John Elkington developed the triple bottom line (TBL) framework, which consists of three sustainability pillars: profit (economy), people (society), and planet (environment) [57].This framework reflects corporate performance, using a TBL approach, to deliver a vision of corporate social responsibility (CSR), which positively impacts the world in economic, environmental, and social terms.Only when a business begins to measure its social and environmental impact can it be called a socially and environmentally responsible organization.
Caradonna, J. and Ebrary, Inc. (2014) found that human domination in the ecosystem must enhance the concept of sustainability and the TBL [5,35].There have been studies utilizing the TBL to evaluate design criteria and compare the performance of the proposed architecture with other multi-criteria decision-making methods in order to develop a green supplier evaluation method and selection method architecture.The TBL principle and fuzzy multi-criteria decision-making (MCDM) model architecture have been applied to address global apparel green supplier evaluation and selection issues in manufacturing [58].A study on organizational sustainability performance also used a TBL framework to examine managers' or the top management's perceptions of organizational sustainability performance [59].
Studies on the social dimension of the TBL in supply chain management (SCM) indicate that the internal orientation of a company is a major auxiliary factor for SCM practices [36].More research has analyzed the key factors in achieving sustainable fashion based on the TBL framework.A sustainable product development process matrix has been developed to guide fashion supply chain members to operate sustainably [14].
In business fields, companies are eager to adjust their business strategies to enable them to develop sustainably [60].Consumers are concerned about the environment and society and take a more pragmatic approach to the economic dimension of sustainable development [61].
The decision-making plan of this study was to distribute questionnaires to consumers who love fast fashion on the enterprise, design, and consumer sides and to determine the indicators that affect the key elements of sustainable clothing design.The triple bottom line framework is based on economic, environmental, and social factors that must be given equal attention, which is also the key goal of clothing sustainability pursued by this research.

Social Responsibility Theory
The theory of social responsibility is the most popular theory in the capitalist world.It originated from theories in liberal newspapers and is a moral or ideological theory.
Since 1992, Business for Social Responsibility (BSR) has provided socially responsible business solutions to many of the world's leading companies.It leverages its environmental, human rights, economic development, governance, and social responsibility expertise to guide global companies in creating a just and sustainable world through advisory services, conferences, and research [62].Business in the Community is the oldest and largest businessled membership organization dedicated to responsible business practices, founded 40 years ago by His Royal Highness, the Prince of Wales, to advocate for responsible business [63].A media platform called 3BL CSRwire, respected and trusted by journalists, bloggers, business leaders, and academics worldwide, has been the dedicated, real-time source for major news and updates in corporate social responsibility (CSR) and sustainability since 1999.It provides breaking news from corporations and nonprofits, including press releases, videos, podcasts, blogs, and more, all detailing CSR reports [64].
In January 2022, the Fashion Sustainability and Social Accountability Act was introduced by the New York State Assembly [65].The main promoter of this bill was the New Standard Institute, an American think tank that is dedicated to sustainable fashion.
The bill contains the following: (1) The impact of the production chain on the environment and society (such as suppliers' labor wages, the source of raw materials used by brands, and the total amount of materials) should be disclosed; this is consistent with the core values of the TBL.(2) The sustainable development goals should be set by the brand itself in accordance with international standards; among them, the main appeal is the cradle-to-cradle concept.
Enterprises with unsustainable production practices need to bear their due social responsibility and corporate fines, but this method is negative [66].For companies that regard economic profit as their primary goal, fines are only a formality.However, if consumer awareness of sustainable fashion increases, the attitude of enterprises must change.The question of whether retailers should sell green products first is critical in the era of big data [67].Retailers can collect massive amounts of consumer demand data and instantly update demand forecasts for new products to improve their retail business performance and services [68].If a company sells green products first, it will incur lower environmental costs.However, such big data must be supported by consumer practice.Green products have not entirely replaced traditional nongreen products.Many retailers sell green and nongreen products to consumers [67,69].If such a method is implemented in the fashion industry, the damage caused by the fashion industry to the environment will gradually encourage the development of sustainable fashion [70].

Research Design and Data
According to the Ministry of Finance statistics, Taiwan's apparel retail industry reached NTD 108.3 billion in 2018.In 2019, Kantar Insights Taiwan conduct a survey questionnaire [71].The results found that Taiwanese consumers buy an average of 11 pieces of clothing per year.The results also show that there is not much difference between the current spending habits in Taiwan compared with three years ago.Thus, in this study, we took consumers who consume 11 pieces of clothing per year as the research object.The survey questionnaire adopted the cluster random sampling method, which divided the entire matrix into several clusters with similar properties according to relationships among themselves and convenience sampling.Each group could be regarded as a reduction of the whole matrix.In the first step, 502 questionnaires were randomly distributed.Second, a comprehensive survey was conducted with random groups selected to meet the conditions.This research focused on "are you a fast fashion-loving consumer" as the main cluster and collected 365 consumer questionnaires with an average annual consumption rate of more than 11 pieces as the subject.The subjects' information is as follows: (1) Biological sex: 65.2% female, 34.7% male.(2) Age: 12-18 years old accounted for 1%, 19-30 years old accounted for 23.2%, 31-44 years old accounted for 62.1%, 45-64 years old accounted for 13.6%.(3) The average number of pieces consumed per month: 1-2 pieces accounted for 51.2%, 3-4 pieces accounted for 30.6%, 5-6 pieces accounted for 11.7%.(4) Annual average number of purchases: 0-5 pieces accounted for 10.6%, 6-10 pieces accounted for 30.6%, 11-15 pieces accounted for 31.5%,16-20 pieces accounted for 13.4%, 21 pieces or more accounted for 13.6%.
This study interviewed 10 experts from a government-industry-university-institute alliance in the apparel industry; as such, an expert group was established.Experts discussed and structured the key elements of sustainable design, referring to the expert interview steps of the Delphi method and adding a semi-structured questionnaire (see Appendix A This study explored the key factors of sustainable design and the practices of sustainable fashion.Therefore, we used the analytic network process to analyze the research method, which can better meet the relevant needs of this paper.To achieve the purpose of this research, the overall research plan is discussed below.The following description represents the planning "research process" of the research design (flowchart in Figure 1), the Delphi method, the establishment of an expert group, in-depth interviews with experts, survey questionnaire subjects and questionnaire types, ANP concepts, and analysis steps to be explained.
cussed and structured the key elements of sustainable design, referring to the expert interview steps of the Delphi method and adding a semi-structured questionnaire (see Appendix A This study explored the key factors of sustainable design and the practices of sustainable fashion.Therefore, we used the analytic network process to analyze the research method, which can better meet the relevant needs of this paper.To achieve the purpose of this research, the overall research plan is discussed below.The following description represents the planning "research process" of the research design (flowchart in Figure 1), the Delphi method, the establishment of an expert group, in-depth interviews with experts, survey questionnaire subjects and questionnaire types, ANP concepts, and analysis steps to be explained.

Delphi Method
The Delphi method is a group decision-making method that emphasizes how each participating decisionmaker can fully understand the opinions of others in the discussion.

Delphi Method
The Delphi method is a group decision-making method that emphasizes how each participating decisionmaker can fully understand the opinions of others in the discussion.However, each participant is blind to who the other party is.This method relies on the following characteristics: (1) Using the professional knowledge of scholars and experts to judge or predict the development trend of events.(2) Effective information gathered by experts will be more accurate than information provided by other groups.(3) A group's judgment is superior to an individual's judgment.
The purpose of forming the clothing industry expert group was to formulate the key elements of sustainable fashion, analyze the factors affecting sustainable fashion, and learn from the experience of experts.The list of experts enhanced the reliability and validity of this study with a government-industry-university-institute alliance.This study complied with the characteristics of the Delphi method.The experts do not know each other, and interviews were all conducted when participants were anonymous to each other.
Semi-structured interviews were used to investigate the research questions.First, an interview outline was developed, and online interviews were conducted in a one-to-one manner.The interviews included different forms of open-ended questions, which led the experts to put forward their opinions on the topics.This research regarded the interview processes as conversational events, emphasizing the process of sensemaking by both the interviewer and the interviewee.
The list of expert groups is shown in Table 1.

In-Depth Interviews with Experts
The procedures for this research arrangement are as follows: Pre-interview preparation: draw up interview outlines for decision-making issues, invite interviewees, and schedule interviews.
(1) Conducting the interview: Introduce literature and inform the interviewee of the interview's content, purpose, and motivation and explain that the interviewee's privacy is respected.The interview content is for academic research only and will be treated confidentially.(2) Exploratory processing in interviews: Jointly construct the topic concept of sustainable fashion and adopt a neutral exploratory approach, provide the relevant literature, and discuss with experts as the principle.(3) End the interview: Adopt two principles-first, stop when it is enough, and second, it is normal to take one to two hours and sincerely thank the interviewee.(4) Organize the interview content: Keep detailed interview materials and records for subsequent analyses.(5) Write an interview report: Sort out the new key factors that affect sustainable fashion in the clothing industry.
After sorting out the report, the experts were asked whether there were any objections to the content of the sorted data.After many revisions and confirmations, the experts reached a consensus and made new core dimensions and 12 key criteria for sustainable clothing design.Table 2 lists the opinions given by the experts in the first pretest.This study displayed the following four characteristics: (1) A questionnaire for fast fashion consumers was randomly distributed and targeted at specific groups.(2) It described the general characteristics of the group, not the individual characteristics.
(3) It paid attention to the presentation of the status quo and facts and did not analyze the reasons.(4) Most of the research results were used as a reference for decision-making; this is decision-oriented research.
In a paired comparison scale, subjects were asked to compare a series of objects in pairs, choosing between the two being compared according to a specific criterion.The paired comparison scale is an attitude measurement.This particular rating scale asks one to sort only two objects.Survey questionnaires provide researchers with a reliable and valid measurement tool.The questionnaire type is a paired comparison, as shown in Table 3.

Extreme Importance 9
Very Strong Importance 7 Strong Importance 5

Moderate Importance 3
Equal Importance 1

ANP Concept and Analysis Steps
ANP is an advanced decision-making model derived from AHP, closer to real people's decision-making processes.Saaty proposed it in 1999.In ANP, a method of dependence and feedback among the elements is the main vehicle for solving decision-making problems.This network-level analysis method is a mathematical theory that can systematically address the issues of dependence and feedback.At the same time, it can more accurately express the complex influence of interactions in human society through feedback.ANP uses the following steps: (1) Structure and systematize complex decision-making issues, and list relevant evaluation criteria to establish a network structure as a decision-making evaluation.(2) Establish each evaluation criterion cluster according to the relevant evaluation factors and establish the element nodes in the cluster according to the criterion cluster.(3) Establish links according to the relationships between criteria and the relationships between nodes.(4) Establish its own dedicated network cluster in each criterion.(5) Calculate the relative weight between the criteria and each evaluation scheme's relative value.In this step, in addition to calculating the weight value, each evaluation factor must be sorted according to the size of the weight value.( 6) Inconsistency (C.R. < 0.1).( 7) Propose comprehensive evaluation results according to the criteria and the evaluation results under the criteria.

Pretest Questionnaire Results and Analysis
An expert questionnaire standard pretest was distributed to 10 experts with an average of 26 years of experience (see Appendix A).After three rounds of questionnaire analysis for a total of six times, the questionnaire recovery rate was 100%.A new research dimension was established, as shown in Table 3.The four-dimensional and twelve-item criteria changed.The new criteria are shown in Figure 2, and the definitions are shown in Table 3.The 10 experts' definitions of the 4 core dimensions and 12 key criteria of sustainable apparel are shown in Table 4.

Inconsistency Analysis
The ANP of this research has 4 core dimensions and 12 key criteria.Each pairwise comparison matrix is a synthesis of 365 fast-fashion-loving consumers, and their opinions were synthesized into each pairwise comparison matrix.Excel software was used to calculate the geometric mean, λmax, CI, number of variables, RI, and CR values, as shown in Table 5.All CRs 0.1 indicated that the pairwise comparison data were consistent.Table 6 is a summary of consumer questionnaires (unit: person).Super Decisions is a powerful decision-making program mainly used in the related research of ANP.Thomas L. Saaty developed ANP in 1996, incorporating dependencies and feedback effects, including interactions within and between clusters and feedback effects.Super Decisions uses a supermatrix to calculate the degree of interdependence.This breakthrough brings ANP closer to the human way of thinking, which creates the best tool for Super Decisions to understand the complex relationship caused by this method.There is a good relationship between this software and Microsoft's operating system.Regarding compatibility, the results can be exported to Excel for subsequent analysis.The overall geometric mean can be calculated and directly filled into the software to obtain a weighted supermatrix.This effectively saves the time required for calculation and statistical analysis, meaning research personnel can balance the quality of the research results with the mastery of the time course of the study."Super Decisions" is a decision-support program that implements AHP and ANP-making it possible to include intangible assets in decisionmaking-which combines judgment data to effectively rank options and predict outcomes, all of which make good contributions.
In this study, 365 fast-fashion-loving consumers and the pairwise comparison data between each criterion and each plan were used to calculate the geometric mean with Excel.The matrix and comprehensive results were obtained using the Super Decisions program for calculation and analysis.The results are presented in Table 7.

Creating a Supermatrix: Unweighted Matrix, Weighted Matrix, and Limit Matrix
The sum of the fields in the supermatrix may be greater than one, but it has no random effect.This matrix is an unweighted matrix, while the weighted matrix is a supermatrix that has a sum of one and a random effect.Saaty (1996) suggested that by providing the relative importance of each column element of the supermatrix, each column element of the matrix can be proportionally converted into data with standardized characteristics according to the significance of each element that is affected or controlled by it.The limiting matrix makes the weighting matrix show the relationship between the elements of convergence, stability, and consistency under long-term equilibrium.Since the limit matrix evolved from the weight matrix, its form is the same.However, the limit matrix has the same weight value in each column corresponding to a particular element.The sum of the element weight values in each column is equal to one; all the element weights and the evaluation values of the evaluation scheme can obtain a convergence effect.Table 8 shows the unweighted supermatrix.As can be seen, the priority order of the evaluation factors after the pairwise comparison of the research data, when the research data are not weighted, indicates the relationship between the evaluation criteria.After calculating the weight of each factor, it is assigned to a weighted supermatrix, as shown in Table 9. Multiplying the unweighted supermatrix multiple times will obtain a stable and unchangeable convergence value, which is the limiting supermatrix.The limiting matrix will converge to a specific value, so this value can be used as an alternative basis for timing, as shown in Table 10.

Discussion
Based on the experts' opinions, this study constructed a sustainable design model with 4 core dimensions and 12 key standards [72].The proposed model can be used as the basis for follow-up research and further discussion and practice with respect to the 12 key criteria.According to the survey results on fast fashion consumers, this study ranked the importance of the 12 key criteria for sustainable clothing design.The ranking can allow clothing companies to know consumers' views on sustainable issues and their degree of emphasis; help designers understand the changes in consumer demand; and show consumers that they have a clear and urgent connection with sustainability issues [73,74].
The issue of sustainable development has attracted the attention of the general public.This study coincides with the 2030 Sustainable Development Goals (SDGs) [75][76][77][78].The findings of this study can also be considered the goal of the sustainable development of the apparel industry [79].Using the conceptual behaviors of recognition and implementation, this study discusses "sustainable design" as the goal of the clothing industry; the research target is concentrated on subjects who love fast fashion so as to facilitate research and development conduct.However, the subjects of this study are only Taiwanese consumers; the average annual consumption rate of Taiwanese consumers is not based on academic research but rather based on private consulting companies, and this is a limitation of this study.Different from the discussion of general sustainable issues, this study adopted cradle-to-cradle, TBL theory, and social responsibility theory to strengthen the importance of the core concept of sustainable fashion.Clothing companies, designers, and consumers should find their best feasible solution for a better environment, economy, and society in the 4 core dimensions and 12 key criteria of the sustainable clothing model.
This study conducted expert interviews.The experts discussed the key elements of sustainable design with respect to the practice of sustainable fashion.As for the development of sustainable fashion, there is less discussion.In future research, answering the question of how to strengthen the involvement of consumers who love fast fashion in sustainable fashion is an important goal [80,81].

Conclusions
From the perspective of social responsibility theory and using the Delphi method, combined with in-depth interviews with 10 experts, the experts calibrated the customer value attributes into the three levels of goal-criteria-plan and confirmed that the four criterion levels are ideological awareness, use awareness, product awareness, and recycling awareness, and the sub-criteria are the key elements of sustainable clothing design: "reflection", "creativity", "awareness", "durability", "consumption reduction", "environmental protection", "cherishing", and "transfer".There are 12 key standards, including "modification", "recycling", "transformation", and "disassembly".With the help of the experts, the 4 core dimensions and 12 key standards of sustainable clothing design were discussed and constructed.
Survey questionnaire data from 365 consumers who consume more than 11 pieces per year and like fast fashion comprised the research subjects.ANP was employed to obtain the importance of each weight value after the convergence of the limiting matrix in order to improve and promote the development of a sustainable design while also providing the order of importance for reference.The corporate responsibility side, the design product side, and the consumer side were considered for the order of importance in sustainable design decision-making.Based on the results, this study concluded that consumers think that the first key element of sustainable design is corporate responsibility.The second is the consumers themselves, and the third is the design side.In this study, "cherishing" was considered the most important key factor for sustainable development.The results of this study reflect the evaluation and views of fast-fashion-loving consumers regarding green projects.The results of the study are detailed in Table 11.

Research Highlights
The clothing industry is a high-value industry worldwide.It is also the second largest source of pollution in the world.As such, many studies have proved that fast fashion is one of the factors affecting sustainable development.However, research on consumers who love fast fashion is limited.This research reflected the evaluation of such people regarding their views on green projects.In 2019, the average number of fast fashion garments purchased by Taiwanese people was 11.This study enrolled consumers who consume more than 11 pieces per year and consider themselves fast-fashion-loving consumers.Through expert interviews, this research identified key factors for the sustainable development of the clothing industry and tried to understand the fast fashion consumers' views on sustainable design through this research.Attributes that ultimately improve the service content, of course, can be more in line with the needs of consumers and form the most practical improvements for the problems and the root causes of things.Consumers can put forward their views on sustainable design more consciously so that we can make the ideal allocation under the Earth's limited resources.This can facilitate the sustainable development of all aspects, not only in the clothing industry but in all fields.

Management Implications
Companies produce products for consumers to buy and use.However, it is not just a product but a belief, as indicated by this study.A love of fast fashion does not mean that consumers who love fast fashion do not love the Earth or do not care about the issue of sustainability.Future research should explore whether we have been representing "fast fashion" and "sustainability" as contradictory factors while ignoring the essence of the problem to propose a fundamental solution.Many studies point out how to take care of the environment and reduce consumption.These studies make a valuable contribution.However, from the results of this study, it is evident that research lacks a focus on educating users in terms of awareness.This study assumed that the choice of fast-fashion-loving consumers can promote the development of sustainable design and improve decision-making efficiency.Awareness of "cherishing the use" was the participants' number one key element of sustainable design.This research result is consistent with the research hypothesis.

Research Contributions
According to the meanings mentioned in the theory of social responsibility, this study consisted of four dimensions of awareness: ideological, product, use, and circulation.It attempted to let more people realize that their own awareness has a high impact on sustainable design, even for fast-fashion-loving consumers.This study did not conduct a decision analysis regarding expert opinion; rather, it chose to issue questionnaires for consumers who like fast fashion and took the decision analysis results of the questionnaires as the final value.The reason behind this decision is that the issue of sustainable design covers a global scope.We used professional knowledge and theory to add transparency to this issue.However, customers are the key protagonists of sustainable design and ultimately drive consumer behaviors.In other words, the choice and decisions of consumers are the core of the problem of sustainability.Customers' consumption feelings are challenging to identify.Through the research design of this study, we aimed to inspire deeper thinking: the issue of sustainable design starts with ourselves.

Subsequent Research
The issue of fast fashion is leading companies to realize that they can no longer be the scapegoat for destroying the environment and ecology.Everyone is avoiding this problem, but researchers are afraid that everyone will be blinded by such "outer packaging," thinking that the company itself has done something wrong.A "kind" response is equivalent to solving this problem.It is similar to how politicians who evade taxes always show kindness and donate the most.Researchers can continue to track annual consumption rates and consumer status regarding the issue of sustainable design to lead to more in-depth research and discussion.1.1.First of all, according to the degree of importance you attach to the sustainable design of clothing products in your ideological consciousness: A. Reflection (responsibility to the earth) B. Creativity (changeable clothes), C. Awareness (reasonable purchase), from big (important) to small (not important).
For example, A > B > C, please fill in your personal opinion.Your answer is: 1.2.Please tick "v" in the following pairwise comparisons.(Questionnaire begins) 1.1.First of all, according to the degree of importance you attach to the sustainable design of clothing products in your ideological consciousness: A. Reflection (responsibility to the earth) B. Creativity (changeable clothes), C. Awareness (reasonable purchase), from big (important) to small (not important).
For example, A > B > C, please fill in your personal opinion.Your answer is: 1.2.Please tick "v" in the following pairwise comparisons.

Sustainability 2023 , 21 Figure 2 .
Figure 2. The 4 core dimensions and 12 key criteria of sustainable clothing design.

Figure 2 .
Figure 2. The 4 core dimensions and 12 key criteria of sustainable clothing design.

Table 1 .
List of experts.

Table 2 .
The first answer of the expert interview pre-test.

Table 4 .
The of definitions of the 4 cores and 12 key criteria of sustainable apparel.Four Cores Criteria Definition 1.Ideology 1.1Reflection Responsibility to the Earth

Table 4 .
The of definitions of the 4 cores and 12 key criteria of sustainable apparel.

Table 5 .
The of consistency test results of relevance questionnaire.

Table 7 .
The of matrix and comprehensive results computational analysis.

Table 8 .
The of unweighted matrix.

Table 9 .
The of weighted matrix.

Table 10 .
The of limit matrix.

Table 11 .
The of priorities.