Sustainable Tourism Product Development: An Application of Product Design Concepts

: This study examines sustainable tourism products in tourism destinations. Based on concepts of sustainable product design, our study proposes a framework for sustainable tourism products by adapting an existing Design for Sustainability Framework to consider and analyze the characteristics and themes of sustainable (tourism) products as well as their impact and scope. Using a pragmatic qualitative approach, 15 semi-structured interviews with destination managers from the German-speaking Alpine region formed the empirical basis of the study. The results emphasize key themes and multiple characteristics associated with sustainable tourism products in tourist destinations, addressing all sustainability components and design innovation levels. This study is the ﬁrst to apply existing sustainable product design concepts to destination contexts and discuss their applicability for sustainable tourism products. For practitioners, this study provides support for the development of sustainable tourism products and contributes to a better understanding of the effects and levels of these products as well as sustainability marketing.


Introduction
The tourism industry is an important part of the world economy [1,2] and contributes significantly to economic development in all kinds of areas [3][4][5]. As a result, tourism exerts strong pressures on ecosystems and communities [6], causing numerous challenges for tourism destinations [7]. Hence, the importance of sustainability and sustainable tourism is continuously increasing [8] and remains the subject of ongoing debates in practice and academia (e.g., [9,10]). Sustainable tourism is essentially a multifunctional set of processes that has evolved with views of protecting the environment, preserving culture(s), and promoting social justice, while offering opportunities for responsible economic development, increasing employment and quality of life, and developing local infrastructure [11][12][13]. Therefore, the promotion and support of sustainable tourism and, if necessary, the establishment of appropriate legal frameworks is seen as particularly important and is being facilitated by different institutions (e.g., World Tourism Organization [14]). Primary and secondary tourism products are decisive motivational factors for tourists' travel decisions and thus of central importance for tourism destinations as key components of sustainable tourism [15].
Previous work on sustainable tourism includes discussion on the perception and definition of sustainability in destinations [16,17], its implementation [18,19], the empowerment of sustainable tourism [9,20], and the evaluation of respective initiatives [21]. Sustainable products in tourism have been addressed in terms of product design and communication [22], customer values [23], and competitiveness and diversification [15,24]. However, there is limited research on destination managers' views on what products a sustainable destination should offer and how these fit in with overall destination offerings. Based on sustainable product design concepts such as the Development for Sustainability (D4S), our study addresses this gap and the following research questions: Which characteristics and themes of sustainable tourism products are considered important by destination managers?
Based on an application of the Design for Sustainability Framework, are tourism products associated with these themes conducive to achieving sustainability in the destination?
In our study, we focused on destination managers as key influencers of the overall destination offerings.
The contribution of the study is threefold: First, to the authors' knowledge, this paper is the first in applying product design frameworks to destination contexts to demonstrate and discuss its applicability for (sustainable) tourism products. Second, it explores the characteristics and themes of sustainable tourism products in destinations. Third, in addressing product development for sustainability, we contribute to the understanding of sustainability marketing, a branch of marketing that is "arguably less developed, [and which] considers how marketers have a responsibility to design products that are more sustainable, but that are sold to consumers based on other decision-making attributes" ( [25], p. 875). The results of this study add to the field by providing insights into the perception, (possible) categorization, and current practices of sustainable tourism products.
The remainder of the paper is structured as follows: Section 2 contextualizes our argument using relevant literature and provides the theoretical and conceptual background of this study. Section 3 describes the methodology, method, and sample. The results are presented in Section 4. Section 5 contains the discussion of the results followed by the conclusions in Section 6.

Sustainability and Sustainable Tourism
Sustainability was defined in the well-known Brundtland Report [26] as development that meets the needs of the present without compromising the needs and opportunities of the future generations [27]. Sustainability addresses economic, social, and environmental aspects, as well as further supplemented aspects that are primarily combinations or connections of the above-mentioned areas [26,28]. According to Machado [29] and McIntyre et al. [30], sustainable tourism meets the current needs of tourists, the tourism industry, and host communities without compromising or even destroying the resources on which future tourism depends.
Nevertheless, a clear, detailed definition or description of sustainability is lacking both in research and in (tourism) practice [16,31]. The lack of clarity of the concept of sustainability causes many challenges and problems [31][32][33] as the resulting contradictions and ambiguities impede its application [32]. Studies have tried to understand the meaning of the concept from different contexts [34] or from the analysis of how scholars or practitioners use sustainability [31]. Albrecht et al. [16] thereby focused on destination managers and found that they use the term to indicate a perception (with the aim of communicating, ideally uniformly), a vision or goal (which reflects priorities and actions), or an approach (which determines sustainability strategies).
As the perceptions and attitudes of destination managers determine their priorities in destination development [35], it can have far-reaching effects on the sustainable design of destinations and thus tourism products.

Sustainable Tourism Products and Sustainability Marketing
In their generic form, tourism products fulfill the function of enabling people to travel and engage in activities outside their usual environment [36]. They can be divided into primary tourism products that attract and motivate tourists to visit the destination, and secondary tourism products that are less likely to have a specific attraction such as accommodation or catering [15]. The former are characterized by a complex interplay of tangible and intangible elements, and are geographically and thematically much more far-reaching than secondary tourism products [15,36].
Sustainable tourism products are built in accordance with the environment, community, and cultures in a way to provide certain benefits rather than threats to tourism development [14,29]. In this regard, Eckert and Pechlaner [37] propose strategic product development which goes beyond traditional resource-based approaches by incorporating destination-specific values and core competencies in order to achieve sustainability in the destination. Another promising approach to introducing more sustainable tourism products at the destination level lies in adaptations to supply chains and distribution channels with a view of introducing sustainability requirements. Schwartz et al. [38] suggest that what has been successfully introduced to supply chains for products such as coffee, chocolate, and so on now needs to be implemented in tourism contexts. The increasing demand for "green" products promotes approaches to product development and, moreover, approaches to sustainability marketing and market development [25].
Sustainability marketing aims to raise awareness and increase demand for sustainable products, thereby promoting more sustainable consumer behavior [39][40][41]. Authentic sustainability activities of organizations that are reflected in the products increase consumer trust, satisfaction, and loyalty [39,42]. As an important factor in consumer decision-making, sustainability in (destination) marketing can therefore be a competitive advantage and success factor in tourism [43,44]. Moreover, sustainability marketing has the potential to encourage suppliers to adopt sustainable practices and offers, and encourage tourists to adopt sustainable behavior and consumption [45].
Especially in the marketing context, digital media significantly influences customer behavior [46]. Digitization offers many opportunities and applications for tourism destinations not only in marketing but also in visitor research, sustainable visitor, and capacity management by collecting and analyzing digital data [43,[47][48][49]. These applications are very conducive to sustainable tourism development for all destinations, especially those with protected and vulnerable areas, as media-based data are beneficial for careful planning of access, necessary infrastructure, regulation, and monitoring, thus helping to conserve essential resources [47,50].

Sustainable Product Design and Development
Design concepts for sustainable products have substantially broadened their scope and focus over time [51]. Starting with comparatively modest interventions such as the selection of environmentally sound resources, which were featured in the Green Design [52,53], concepts have increasingly embraced aspects of the entire product life cycle, services, and crucially the environments and contexts of products [54]. Such holistic approaches to sustainable design and product development that consider the three pillars of sustainability including people (social sustainability), profit (economic sustainability), and planet (environmental sustainability) [55,56] implicitly aim to incorporate aspects of social equity and cohesion [51,57]. As such, they are closely linked to the concepts of circular economy and regenerative systems [58,59].
In this paper, we use Ceschin et al.'s ( [54], p. 143) Design for Sustainability Evolutionary Framework ( Figure 1) as a conceptual basis. Its x-axis illustrates design and development approaches ranging from isolated, insular interventions to increasingly integrated and systemic approaches. To more specifically identify, categorize, and map the types of tourism product development for sustainability in the destination, we overlay the three components of sustainability on the y-axis.

Methodology
We follow a pragmatic qualitative research approach. According to Patton [60,61], methodological appropriateness is the primary criterion for assessing methodological quality in pragmatic research. The selection of the methods based on the research problem; the detailed assessment; explanation of why and how these methods are appropriate, comprehensive, and defensible; and the assessment of their impact on the results are central to achieving academic rigor [60]. Hence, researchers must "do what makes sense, report fully on what was done, why it was done, and what the implications are for findings" ( [60], p. 72).
To investigate which characteristics and themes are considered important for sustainable tourism products, we follow a qualitative, phenomenological approach that is particularly suitable for analyzing complex contexts and meanings [62]. Phenomenology enables the study of individuals' lived experiences and perceptions [63] and thus is useful in management and process-oriented research.

Materials and Methods
For the data collection, semi-structured interviews were conducted with high-ranking destination managers as they play a crucial role in the development and design of (tourism) products. Semi-structured interviews have an exploratory nature and enable substantial interaction with interviewees to obtain insights into their attitudes, opinions, values, and to understand behaviors [64,65].
Interviewees were selected utilizing a qualitative sampling plan with selective sampling [66][67][68] using the following criteria: destination manager of (1) a destination in the German-speaking Alpine region that (2) offers both summer and winter tourism. The first criterion was used because destinations in the German-speaking Alpine region have numerous similarities such as landscape, tourism opportunities, weather conditions, topography, and thus similar conditions and prerequisites for product development and

Methodology
We follow a pragmatic qualitative research approach. According to Patton [60,61], methodological appropriateness is the primary criterion for assessing methodological quality in pragmatic research. The selection of the methods based on the research problem; the detailed assessment; explanation of why and how these methods are appropriate, comprehensive, and defensible; and the assessment of their impact on the results are central to achieving academic rigor [60]. Hence, researchers must "do what makes sense, report fully on what was done, why it was done, and what the implications are for findings" ( [60], p. 72).
To investigate which characteristics and themes are considered important for sustainable tourism products, we follow a qualitative, phenomenological approach that is particularly suitable for analyzing complex contexts and meanings [62]. Phenomenology enables the study of individuals' lived experiences and perceptions [63] and thus is useful in management and process-oriented research.

Materials and Methods
For the data collection, semi-structured interviews were conducted with high-ranking destination managers as they play a crucial role in the development and design of (tourism) products. Semi-structured interviews have an exploratory nature and enable substantial interaction with interviewees to obtain insights into their attitudes, opinions, values, and to understand behaviors [64,65].
Interviewees were selected utilizing a qualitative sampling plan with selective sampling [66][67][68] using the following criteria: destination manager of (1) a destination in the German-speaking Alpine region that (2) offers both summer and winter tourism. The first criterion was used because destinations in the German-speaking Alpine region have numerous similarities such as landscape, tourism opportunities, weather conditions, topography, and thus similar conditions and prerequisites for product development and design. The second criterion was chosen because destinations offering both summer and winter tourism provide more holistic and comparable insights with regard to sustainable products. In order to best represent the population and obtain a variety of opinions and perspectives [69], regional and destination-specific differences such as seasonal occupancy, scale, and regulatory framework were also considered in the selection process. Based on these criteria and considerations, destination managers were selected, contacted via email and phone, and invited for an interview. A total of 15 destination managers from 15 destinations including 2 in southern Bavaria, 9 in Tyrol, and 4 in eastern/southern Austria accepted the invitation and participated. The final sample size was determined by the theoretical saturation, whereby as many interviews are conducted until there are enough usable data and no new insights to be gained [70,71]. The theoretical saturation was reached with 15 interviews, thus no further destination managers were invited.
The interviews were conducted in person or via online conference tools (Zoom and Skype) and lasted between 25 and 55 min. Prior to the interviews, the purpose of the study and the handling and processing of the data was explained. After obtaining informed consent from the participants, the following questions were asked:

1.
What is your role and which responsibilities and tasks are associated with it? 2.
In your view, what is sustainability and what constitutes sustainability in destinations? 3.
Do you consider your destination sustainable? What has to be maintained and what has to be improved? 4.
What is your vision for a sustainable destination and how will you achieve it? 5.
What do you consider to be sustainable products? 6.
Which sustainable products are already offered in your destination and what is planned for the future?
All interviews were recorded and transcribed with 2 independent audio recording devices to minimize the risk of data loss. In the case of interviews via online conference tools, the respective recording options of Zoom and Skype were used in addition to a conventional recording device. Using Focused Coding [72], we coded the transcripts guided by 2 thematic issues: (1) themes and (2) characteristics of sustainable tourism products. The results of the coding are shown in Table 1. To ensure reliability and validity, an ongoing reflection process and peer debriefing (i.e., an external person critically reviews the research project [73,74]) were implemented. The person selected for this purpose holds a Ph.D. in management and conducts ongoing research in the field. Each milestone was intensively discussed by the 2 authors and was critically debated and reflected upon with an external person not involved in the study. In addition, the data analysis was only conducted by one author to ensure the second author could evaluate the entire process and the categories derived from it as objectively as possible as an "external auditor" [75]. This review process led to minor adaptations of the categories. The data interpretation took into consideration the relevant literature, the empirical data, the characteristics of the regions studied, and sustainable product design frameworks.

Overview
The focused coding resulted in six categories for "Themes for sustainable tourism products" and in 13 categories for "Characteristics of sustainable tourism products". Table 1 presents the results of the focused coding.
The next two sections present the individual categories. In order to depict the results in terms of the research objective, the quotes of the individual categories were carefully selected to highlight which themes and characteristics seemed to be crucial for sustainable tourism products amongst the interviewees.

Regionality
For the majority of the interviewees (9 out of 15), regionality was a central theme in product development in that they expected "tourism partners predominantly use regionally produced products" (I1) and that "regional products [...] are also processed" (I11). With a "Regionality Day" (I8), the topic is introduced to a broader public to draw attention to and institutionalize the quality and availability of regional products and produce. The institutionalization of measures to promote regionality is addressed by another interviewee: "We try to have as much as possible from the valley [...] there is an agricultural hub [...], which is in the start-up stage, where they try to bring the product from the farmer to the population and to the hotelier" (I10).

Mobility
Another set of observations relates to mobility. This concerned both the arrival and departure of the guests related to the fact that "one tries to get people away from travelling by car and towards the train with cheap travel packages" (I2) and related to the mobility onsite; as one interviewee states: "And inside [the destination], one could only allow electric mobility in the future" (I9). Travelling by train as opposed to by car is often promoted by public transport associations (I11, I14). Another interviewee considered guest guidance to be another issue of mobility: "The issue of mobility and dealing with guest guidance in the city, in the inner city, is very important" (I3).

Community Engagement/Collaboration
There was consensus among the interviewees about the importance "that the inhabitants have a voice, that they have a say, that they are involved in tourism, strategic planning and also planning concerning the destination" (I1). The locals should be "participants" (I5) in tourism with the aim that "added value is generated for the locals and they benefit from it" (I6). The inclusion of the needs of the locals in the product design is associated with a higher acceptance of tourism: Some of the interviewees (5 out of 15) considered the lack of involvement of local peoples' needs in the design and development as a factor for out-migration and low resilience: "And if all of a sudden the local community [...] has nothing left from tourism, then they say I don't want to live here, because hotel chains, external large corporations actually profit from it and I have nothing left' [...]. And that's where I think we have to be careful. As long as tourism is rooted in the local population, we can withstand and solve a lot" (I7) The importance of exchange among and with the locals was also emphasized: "care is taken to ensure that the flow of communication [...], that a campus effect occurs and is maintained, that the exchange [...] also happens" (I3).

Digitization
Digitization emerged as an important topic especially with regard to sales and marketing: "...one of our main tasks is to support the accommodation providers in the area of digitization, that they get into online marketing, that they also maintain their rooms, that we simply support them in every respect" (I11). Digital elements were also directly included in existing products and offers: "Now we are trying [...] to offer an 'Insta-Hike' next year, thus with a photographer and a hiking guide, that we go through nature and take Instagram photos" (I11). Another interviewee considered digitization as important in the development of overall concepts and regional measures: "The topic of smart city, the area of digitization, of course, the topic also plays a role here" (I3).

Sport
Most interviewees (9 out of 15) perceived sports-related products as sustainable products (I3, I6, I7, I8, I9, I10, I13, I14, and I15). In this context, one interviewee emphasized the importance of "interconnected thinking in the area of culture, sport and even urban planning" (I3). Sports in the destinations ranged from extreme types "that attract freaks" (I8) to less extreme forms of exercise such as "pilgrimage" (I6) or "leisurely cycling" (I8). The sport products and offers often require planning and the establishing of necessary infrastructure: "[...] we spend a lot of money [...] for the construction of the cycle path [...] this is also a big sustainability issue for me because more and more people, especially in summer, move between our places by bike, but also in winter with cross-country skis [note: in winter this path is used for cross-country skiing]" (I14).

Employee Satisfaction
Several respondents (6 out of 15) indicated that they "find enough guests, but [...] no employees" (I9). One interviewee noted: "And now we are struggling with the problem of the next generation; with staff problems" (I12). Employee satisfaction was therefore considered essential in design considerations. In addition to "paying employees accordingly" (I1), other measures were taken: "We set accents [...] we make an employee club [...] We want to inform people via new media, Facebook, Whatsapp, in printed form, that they can do a lot in our region independent of work because quite a lot of people don't know that." (I14).

Quality
There was agreement among the interviewees that "the product [...] must be of high quality, and the service behind it must also be of high quality" (I10). It is considered important "to increase quality [...] to regularly improve quality" (I9). Quality is often discussed in an economic context: "It is about qualitative offers with the highest possible added value locally" (I4).

Price-Performance Ratio
Another observation pertained to the relationship between price and value of services: "If I think ten years ahead now, my goal [...] would be to be able to enforce a better price-performance ratio. A fair price-performance ratio means that I am worth the price. It doesn't mean cheap, but the price I pay is worth it" (I7). In this context, another interviewee addressed the effect of sustainability on the price in terms of reducing occupancy: "Sustainability is high-priced for me, which means that if you are sustainable and have fewer guests, then you have to achieve a higher price for it; otherwise it doesn't pay off at some point..." (I10).

Longevity
The majority of the interviewees (10 out of 15) mentioned the topic of longevity: "Product range that lasts in the long term [...] because there are simply things that are now maybe a trend that flares up for a short time [...] and then we have the problem that maybe the trend is really short term and then I have spent a lot of money on something that is not sustainable." (I8).
The interviewees agreed that it is crucial "to plan for the long term and to achieve high quality" (I14). To achieve this, the right indicators are important as one interviewee stated: "What was quite dangerous in tourism management over many years, [was that] the only indicators that counted were overnight stays and turnover. Then it was often not profitable with a really long-term and thus sustainable development." (I4).

Future-Oriented
Future orientation was raised in several interviews. The majority (11 out of 15) understood this to mean "that we not only live in the present but also take care of the next generation and our planet and simply do not rob our livelihood" (I2). In sum, "the tourism that is practiced now should not be harmful to the future" (I4) in order to "preserve the basis of life for the future" (I13). In this context, the future generations are often addressed (8 out of 15): "But you always have to do something from the point of view of not blocking development opportunities for the future generation" (I7).

Utilization-Balanced
Capacity utilization was also a factor in the development considerations of the interviewees. A too-high occupancy rate was seen as a problem by several (5 out of 15) interviewees "because the population can't stand it" (I4) and leads to the situation that "people don't want to live there [note: the destination] anymore [...] the locals leave because they can't stand it anymore" (I7).

Promoting Collaboration
For the interviewees, it was important to "involve the locals" (I13) and to "inspire the young population for tourism" (I14). Involving and gathering all stakeholders to discuss opportunities, goals, and approaches is essential as one interviewee stated: "

Close to Nature
Many of the interviewees linked sustainable products with nature: "But also when we develop something, whether we develop a cycle path, whether we develop hiking trails [...] it all has to do with nature" (I9). Or, as another interviewee notes: "...the nature park [...] has shown us that the topic of nature has a lot to offer and that it is also a sustainable story" (I15). There was agreement among the interviewees that it is vital "to develop the tourist offer in harmony with nature because [...] nature is one of the central, if not the most central topic for a holiday decision" (I9).

Behavior Changing/Educating
The interviewees considered the behavior-changing educational characteristics to be essential for sustainable product development. While some viewed education as a necessity for guests ("I'm thinking of the topic of guided tours for guests. That one should see that the topic of sustainability is even better anchored in the themed tours and thus make people [...] aware of it" (I2)), others emphasized behavior-changing education with regard to the local population: "...we have nature park schools, [...] nature park kindergarten [...] so we try to make the local population [...] feel that nature is important to us, and, yes, these are the points where you have to address the local people or the hotelier" (I10).

Resource-Efficient
For most interviewees (8 out of 15), sustainable product development was also "...the resource-conserving use of what we have available" (I14). Another interviewee noted that production should be conducted "with resource-saving materials" (I2). The resource-saving management is referred to many aspects: "Energy resource-saving accommodation [...] up to resource-saving handling of washing powder and so on" (I6).

Authentic
Authenticity is frequently mentioned as another characteristic of sustainable tourism products: "it is actually the main theme that the guest who consumes there [note: in the destination] has an experience that is [...] authentic and sustainable" (I9). Products and tourism as a whole "simply have to remain real and authentic" (I11). For one interviewee, this meant "bringing history into the modern age" (I13).

Promote Regionality
There was agreement that regionality is an important topic (refer to 4.1.1) and its promotion is central to product development and design. Product examples mentioned include souvenirs (I2), drinks (I8), food (I14), or building measures: "[...] the use of local trees; the region should be reflected in the architecture" (I3). In addition to culinary delights and (tangible) products, the use of regional raw and building materials was also addressed: "...we said we would make it out of pine, out of local wood, when we make platforms and bridges like this [...] it will be made out of local wood with local companies, we try to have everything from the valley as much as possible" (I10).

Attracting Guests
For the majority of the interviewees (8 out of 15), it was crucial "to create a product which attracts guests" (I8). One interviewee considers it essential to "design products and the destination as a whole [...] to stage the potentials that are already here so that it becomes interesting for people" (I5).

Strategically Anchored
For the majority of interviewees (10 out of 15), sustainable goals were (formally or informally) strategically anchored and developments followed a (more or less detailed and formal) strategic plan: "In the provincial strategy, we [...] have the topic of sustainability [...] I think the topic is firmly anchored" (I6). One interviewee mentioned a concrete project that addressed a variety of topics: "the 2030 strategy [...] with eight main topics [...] that we will organize events in 2030 [...] that we will have electric cars, and that travel [...] will perhaps increasingly take place by train again..." (I13).

Discussion
The themes and characteristics identified are wide-ranging and concern many different areas and dimensions. This points to the lack of a clear, detailed definition or description of the concept of sustainability that has been addressed in previous studies [16,[31][32][33][34]. Although there are similarities and consistent approaches in the use of sustainability, there are significant differences especially in the operationalization of sustainability [16]. Similarly, differences, especially different focal points, could be observed in the context of sustainable product development and design. Consistent with previous studies [32], the resulting contradictions and ambiguities seem to impede the implementation of sustainable products and thereby the overall sustainability in destinations.
The themes for and characteristics of sustainable tourism products that we have identified cover primary and secondary products [15] as well as tangible and intangible products in the destination [36]. There was no evidence of destinations adapting their supply chains and/or producing distribution channels to increase the provision of sustainable products in the destination as posited by Schwartz et al. [38].
In considering Regionality, respondents adopted a broad view, wishing to see regionality reflected in primary and secondary products such as souvenirs and in the more complex service-based products or buildings such as hotels. As regionality has the potential to provide benefits to the environment, community, and cultures, it is an important theme for sustainable tourism products, in line with previous work [14,29]. While Mobility did emerge as a theme, respondents' ideas regarding possible related product development remained at a superficial level, merely considering an increased use of electric vehicles (this is evident in the fact that although mobility has emerged as a theme of concern to destination managers, this was not followed up with concrete product characteristics.) As a theme, Digitization was considered in a somewhat unidimensional way as interviewees focused on promotion opportunities and largely disregarded opportunities of the digitization of the products and its potential to influence customer behavior [46]. This focus may be a result of our sample of destination managers who are likely more concerned with digitization in the form of, for example, data-based planning and management of infrastructure, visitors, and capacities [47][48][49][50], and less related with augmented reality [76] or gamification in the destination [77]. The emergence of the theme of sport was somewhat unsurprising given the product base of the destinations in question. Considering sport and related products as core competencies of most studied destinations, strategic product development to this end holds great potential for achieving sustainability in destinations according to Eckert and Pechlander [37]. Possibly most encouraging was the emergence of the themes Community Engagement/Collaboration and Employee Satisfaction. A collaborative, supportive relationship with both (sometimes overlapping) groups is an absolute requirement of sustainability in the destination [78] and although there was little evidence of high-level integration of the stakeholder groups, awareness of their respective needs is an important start especially for more integrated and systemic approaches in terms of sustainable product development [54]. As the theme of employee satisfaction also arose in relation to recruitment difficulties, it must be interpreted in a more nuanced way. Recruitment challenges in tourism can arise because of low pay, seasonality, or the perceived reputation of employment in tourism or hospitality, or among other reasons [79,80] but in the case of the destinations included in this study, the low population base of some of the destinations combined with high living costs are important factors.
While the aforementioned themes provide a useful introduction to destination managers' overall thinking regarding sustainable tourism product development, an assessment of the characteristics of actual and planned products is the appropriate unit of analysis in the context of our adapted of the Design for Sustainability Framework (Figure 2). In the composition of our framework, we have used the innovation level categories posited in Ceschin et al.'s ( [54], p. 143) Design for Sustainability Evolutionary Framework as the x-axis and we have used the sustainability components as the y-axis. This framework has proven to be a useful tool for classifying, considering, and analyzing characteristics, concrete examples, and further considerations of sustainable products as it combines the sustainability components [55,56] and innovation levels [54] with the perspective of offering more holistic and comprehensive insights.
Destination managers report that sustainable products in the destination must demonstrate Quality (Section 5.3.1) and it is tempting to interpret this statement in relation to anticipated increases in destination product prices (refer to Section 5.3.2, Price-performance ratio, that indicates a proportionate price increase that reflects high-quality products). While conceptually the characteristics of Section 5.3.3, Section 5.3.4 and Section 5.3.5 (Longevity, Future-oriented, and Utilization-balanced) are clearly associated with sustainability, they address all three pillars of sustainability [55,56] separately (refer to Figure 2). While this confirms at least some progress towards overall sustainability at the destination level, it also indicates that these measures are isolated and not well integrated across the stakeholders involved and the products offered.
work has proven to be a useful tool for classifying, considering, and analyzing characteristics, concrete examples, and further considerations of sustainable products as it combines the sustainability components [55,56] and innovation levels [54] with the perspective of offering more holistic and comprehensive insights. Destination managers report that sustainable products in the destination must demonstrate Quality (Section 5.3.1) and it is tempting to interpret this statement in relation to anticipated increases in destination product prices (refer to Section 5.3.2, Price-performance ratio, that indicates a proportionate price increase that reflects high-quality products). While conceptually the characteristics of Sections 5.3.3-5.3.5 (Longevity, Future-oriented, and Utilization-balanced) are clearly associated with sustainability, they address all three pillars of sustainability [55,56] separately (refer to Figure 2). While this confirms at least some progress towards overall sustainability at the destination level, it also indicates that these measures are isolated and not well integrated across the stakeholders involved and the products offered.
As Community Engagement/Collaboration has already emerged as an overarching theme for product development, Promoting collaboration (Section 5.3.6) in product development was a logical consequence and an indication of a possible development from isolated, insular interventions to increasingly integrated and systemic approaches in sustainable product design [54]. The characteristic Close to nature (Section 5.3.7) is a reflection of tourism in the German-speaking European Alpine region rather than as an effort in the context of product development for sustainability. Indeed, respondents' mindfulness that nature-based tourism can be just as damaging as any other form of tourism [81] is evident in the behavior changing/educating characteristic that emphasizes the need to manage visitors, visitor impacts, and to an extent the Resource-efficient characteristic. In extension to previous studies [39][40][41]45], behavioral change towards and education on sustainable products (and marketing) are not only addressed to tourists and providers (especially through developments in Regionalityregionality, refer to Section As Community Engagement/Collaboration has already emerged as an overarching theme for product development, Promoting collaboration (Section 5.3.6) in product development was a logical consequence and an indication of a possible development from isolated, insular interventions to increasingly integrated and systemic approaches in sustainable product design [54]. The characteristic Close to nature (Section 5.3.7) is a reflection of tourism in the German-speaking European Alpine region rather than as an effort in the context of product development for sustainability. Indeed, respondents' mindfulness that nature-based tourism can be just as damaging as any other form of tourism [81] is evident in the behavior changing/educating characteristic that emphasizes the need to manage visitors, visitor impacts, and to an extent the Resource-efficient characteristic. In extension to previous studies [39][40][41]45], behavioral change towards and education on sustainable products (and marketing) are not only addressed to tourists and providers (especially through developments in Regionalityregionality, refer to Section 5.2.1) but also to the local population, which offers immense potential for comprehensive sustainable development in destinations.
It is interesting to note that the characteristics Authenticity (Section 5.3.10) and Promote regionality (Section 5.3.11) have emerged in the focused coding as separate categories. Product characteristics related to regionality refer to primary products that can be both tangible products in the conventional sense (such as souvenirs) and more integrated, complex products that have a service component and tangible and/or intangible features [15,36]. Conversely, the term/characteristic of authenticity was used by respondents in a much narrower sense, indicating a realness grounded in tradition rather than localness. However, this has not been explicitly linked to social cohesion [51,57] but can be classified under social sustainability (people) in terms of the sustainability pillars [55,56].
The destinations represented in this study thus employ one of the two components of strategic product development [37]. The foci on regionality, authenticity, nature, and community suggest an existing and growing awareness of local core values but there is little to no evidence of utilizing local core competencies in the development or delivery of destination products. In this context, Strategical Anchoring (Section 5.3.13) can have great potential in drawing separate efforts and initiatives together to achieve an overall successful set of destination products for sustainability [37]. The need to streamline current efforts is further evident in the overrepresentation of economic and environmental concerns in sustainable tourism product development. While this coincides with the current literature [16,82], it also demonstrates that concerns for destination host communities are as relevant and necessary as ever.

Conclusions
The purpose of this paper is to identify and contextualize tourism products for sustainability in destinations. By applying our adapted Design for Sustainability Framework (Figure 2 above) to our findings, we demonstrate that destinations are not as advanced in developing and offering sustainable products as industries where the concepts that we apply originate from are. There are several reasons for this: First, tourism (and hospitality) products are by their very nature more integrated than typical manufacturing products. This can partly be explained both by tourism being a service industry where products can often feature multiple components and by the partial industrialization of tourism [83]. Indeed, the presence of a service element often means that such products are comparatively less sustainable [84]. Second, tourism's relationship with the destination community can be challenging. While true sustainability in the destination requires a positive relationship with the host community, tensions occur where a small local population is (newly) exposed to disproportionally high visitor numbers [85], where there is little regulated mass visitation [86], where the relative economic importance of tourism is high, and/or when the community's sense of control over its extent and development is low [87], among other factors. Several of these factors apply to many destinations and whether these are therefore by definition unable to achieve sustainability regardless of the type of products that they develop and offer is open to debate. Third, destination managers prioritize economic sustainability [16] which exemplifies the importance of a supportive governance context for sustainable destinations [88] and related conducive tourism product development.
The abovementioned lack of definition and clarity of the concept of sustainability [16,[31][32][33][34] is also apparent in sustainable (tourism) product designs. The wide range of topics and characteristics considered important, as well as different foci, can cause barriers to sustainable product and destination development [16,32]. Further clarification, more precise descriptions, and strategic alignment to this end are therefore recommended.
Much like the theme of Mobility, the theme of Digitization was rarely strengthened with concrete product characteristics. Considering its immense potential not only in terms of promotion but in more holistic marketing in response to the increased demand for products for sustainability [25], we recommend that destination managers educate themselves and their stakeholders of the potential of digitization for tourism product development for sustainability; this may include the potential to influence customers to engage in more sustainable behaviors or data-based planning of access, necessary infrastructure, regulation, and monitoring in order to support the conservation of essential resources [47,50].
Overall, products that demonstrate higher levels of innovation tend to incorporate or address more or even all sustainability components (Figure 2). The following practical recommendations arise: As these products thus facilitate more holistic sustainability development through collaborative and systematic innovations, we recommend (1) to promote the participation and involvement of the local community in sustainable products and sustainable product design [54], and (2) to anchor product design strategically and plan it holistically and systematically [37,54]. Furthermore, the potential sustainability of service-intensive products may require particular consideration in practice and research.
Our contributions through this paper thus lie in demonstrating the applicability of the Design for Sustainability Framework in destination contexts; identifying the characteristics and themes of sustainable tourism products; demonstrating the importance of sustainability marketing in tourism; and deriving the relevant practical implications.
The limitations of this paper are those normally associated with qualitative and interview-based research. The method section explains how the method we have employed during data collection and analysis is both reliable and valid. By limiting our research participant base to destination managers representing destinations in the German-speaking European Alpine region, we sought to involve destinations that operate on a comparable product base, although at multiple at different scales. The results are thus specific to the region studied and generalization to other regions with different characteristics and conditions should therefore be considered critically. As this research has not incorporated any business owners or operators, we consider future research that explores their aspirations and actions towards sustainable tourism product development worthwhile. Additional valuable future studies would address tourism product development for sustainability in other geographical contexts (e.g., outside of Europe or island tourism), for particular types of tourism products (e.g., for children or specific origin markets), or in different governance settings (e.g., in national parks, for theme parks, or urban tourism). Furthermore, non-tourism product development processes and product characteristics for sustainability will evolve and it will be worthwhile to continue to assess their potential applicability and usefulness to improve tourism product development for sustainability at the product, business, and destination levels.