Organisational Strategies for Implementing Education for Sustainable Development in the UK Primary Schools: A Service Innovation Perspective

: Education for sustainable development (ESD) in schools requires a whole-school approach to ensure that all stakeholders, including students, value sustainability and express this value in an active engagement in the ongoing development process. Such inclusivity however is rarely achieved, with beneﬁts of ESD in schools usually recognised only by a select few. School strategies that continue to dominate research focus on management of the ﬁnite resources or give emphasis to a particular pedagogical agenda, whereas approaches that emphasise whole-school ESD engagement are scarce. This paper aims to address this gap. To do so, we propose to frame schools as service organisations and use service logic approach and service innovation theory to review how ﬁve primary schools in England deﬁne and implement ESD. The ﬁndings from our comparative case study discuss three strategies that schools as service organisations need to consider: deﬁning sustainable student experience as a core service concept, developing an organisational culture of sustainability-driven innovation, and engaging in a value co-creation process with external stakeholders in order to facilitate the concept. Our results suggest that by placing “sustainable student experience” as the core service concept, schools can align their external and internal organisational activities to enable sustainable education for all stakeholders.


Introduction
In the context of unsustainable development, the need to reorient formal education towards sustainable development prevails on the international level [1,2], with the agreement that this will require a shift in thinking, learning, and teaching [2,3]. However, what such a shift presupposes continues to be debatable. In addition to the expansion of the curriculum content, more current discourse in education for sustainable development (ESD) is being influenced by ecological and systems thinking and the need for education to create change for long-term sustainability, meaning changes within the mindsets, values, and lifestyles of individuals, organisations, and society [2,4,5]. Ecological and systems thinking informs an alternative educational paradigm that is different to the current dominant 'mechanistic' one [3], which is informed by dualistic view of the world, rationality, determinism, and linearity. Instead, the proposed new paradigm is relational, integrated, and joined up [5]. It includes a set of alternative values such as social/ecological responsibility, cooperation, and interconnectedness [6]. Finally, it presupposes new educational practices that are inclusive and integrative, participatory and cooperative [7].
Educational systems around the world have been engaging with ESD in different ways [8]. One of the leading approaches for implementing ESD in schools is a 'whole-school approach' [7] that draws on organisational change theory and describes a desired state for ESD [9] where sustainable development is considered in a holistic way [10]. Within such schools, all stakeholders, including pupils and the organisation, value sustainability and express this value through active engagement in the ongoing development process [3]. For example, the whole-school approach was linked to developing activity competencies in students [11], explorations of local sustainable solutions within the curriculum that lead to whole-school participation in critical reflection of school culture [12], day-to-day school practices, school operations, and stakeholder and community involvement [13]. This approach highlights the participatory nature of the schools' ESD pedagogy and describes a strong relationship between the curriculum towards ESD and the rest of the organisation, both on individual and organisational levels. However, despite being a key approach within ESD, evidence of whole-school approach implementation continues to suggest its incomplete nature with limited impact on schools, students, and staff.
Few studies have conceptualised the implementation of ESD at an organisational level, an area of research that continues to be poorly investigated [14,15]. For example, Mogren and Gericke [16] discuss ESD implementation through a metaphor of anchoring to either an organisational structure (e.g., vision) or individuals within an organisation [16,17], arguing that the former embeds ESD and leads it to a more transformational change, whilst the latter promotes an isolated set of activities. Bosevska and Kriewaldt [18] identify a school community as a complex adaptive socio-ecological system that is becoming sustainable, rather than is sustainable, drawing attention to the importance of not only having a vision and an image of what that should look like, but also the design and taking action to realise it. Yet despite recognition of the need to embrace the whole-school in an ongoing process of innovation towards sustainability, research on how to drive such change continues to focus on either student-centred pedagogy [19] or resource management [20][21][22], leaving the discussion on the school-wide engagement out.
This paper provides an opportunity to undertake further research on the implementation of a whole-school approach, through consideration of schools as service providers and change towards education for sustainable development as a service innovation process that is driven by schools as service organisations. The following sections will address the conceptualisation of schools as service organisations and draw on service innovation and service logic literature to position schools within that literature.

Schools as Service Organisations
This paper positions schools as service providers and students as service users [23,24]. This view on schools and students draws on service logic, which has been defined as a logic for managing service organisations and evolved in contrast to the goods-dominant logic, proposing 'service' as a unit of exchange [25,26]. Service logic does not see value to be embedded in goods and services to be destroyed by the users; instead, it defines value as being co-created [27]. This emerging view on schools and education is referred to in studies that address a re-design of the student learning experience in educational institutions [28], using participatory approaches of a 'student journey' to study student experience [29][30][31][32]. The aim of the service is to help users to undertake processes that support 'his or her goal achievement in a way that is valuable to them' [33]. This means placing service users at the centre and exploring how the service and service organisation facilitate the co-creation of value by service users [34]. Such 'servant' perspectives on the service are in line with how this research perceives the aims of education for sustainable development and schools, being service organisations. However, there is also recognition of the complexity that is presupposed by helping service users to achieve their goal. For example, in education both individual citizens and the public may be considered users, whilst their goals may be similar or dissonant [34], resulting in the need to question the extent to which the school as service provider should balance the goals of both these users.
Further, schools encounter multiple users, some who may be using service involuntarily, and yet there is a need to enable value for all. This is of particular importance in a whole-school approach that aims to create value for the whole organisation and its wider set of stakeholders. Yet, so far literature does not link value creation to a whole-school approach and innovation in schools as service organisations. This paper aims to address this gap.

Sustainability as Srategy for Service Innovation
Sustainability presupposes change, and a few service innovation studies ouside of education have begun to explore a transition towards sustainability, notably in hotels [35,36] and banks [37]. These studies begin to link sustainability to new value configurations where service organisations move beyond 'optimization' to 'transformational' and 'system builder' levels [38], which requires service organisations to acquire logic of service innovation. Service innovation is a multi-dimensional concept [39][40][41] that describes change to take place in four major domains of the service including service concept, user interaction, organisational delivery system, and technological system [42].
The first two dimensions may be defined as 'interactive' or user-facing dimensions that aim to develop a discerning user experience, creating sustainable advantage for the service provider [43]. This is the space where organisations are strategically spending more time innovating [39]. The experiential aspect of service innovation [44] proposes an experience of the user as a starting point for innovation. Following service logic, this view recognises that service providers do not deliver value directly to the users. Instead, they innovate value propositions, with which users interact. The value-in-use is subjectively determined by service users whilst they co-create it. Research in service design has been particularly instrumental in promoting and enabling experience-centred, co-creative ways of service innovation through design-led, user-centred approaches [45,46].
On the other hand, the latter two dimensions, organisational and technological delivery systems, are defined as 'supportive' and internal-facing [43], focusing on organisational arrangements and use of technology. Such back-end activities [47] are seen as generating value indirectly by providing configuration of resources to support value proposition for the user [48]. Thus, these systems are key to the delivery of the value through strategic alignment of service concept with service structure (e.g., facilities) and infrastructure (e.g., skills, policies) [49]. Hertog [42] particularly puts emphasis on the 'infrastructure' element, and the employees within it, as key facilitators of service provision, and requirement to find means to empower them to deliver new service proposition. This calls for an integrated approach to service innovation where people, policies, processes, structures, and technology are considered. Studies on organisational change portray the level of resistance to adapting new systems and processes as a result of the social context of organisations and individuals in it [50,51]. This, however, is linked to the level of innovation in the service, with most radical innovation requiring change at the deepest level of organisations [52] or development of new organisational forms that support new skills, capabilities [42], and even individual beliefs.
A whole-school approach in education for sustainable development presupposes the creation of value for the whole organisation, including students and its wider set of stakeholders. This section drew on literature from service innovation and sustainability to explore multifaceted approach that schools as service organisations need to engage with in order to facilitate such value co-creation at a whole-school level. Yet there is lack of empirical research that considers a whole-school approach to sustainability from a service innovation perspective. To address this, this paper explores how the implementation of sustainability supports value creation in schools as service organisations.

Methods
As the aim of the empirical study was to understand how sustainability is understood and implemented within schools, as service organisations, it aimed to develop and build an understanding of complexities of real life rather than test theories [53]. It looked at how five primary schools in England define and implement ESD. In this respect, case study as a flexible research methodology was deemed appropriate. Robson [54] notes that a particular strategy does not have a strong link between the research methods and research strategy, yet most authors agree that flexible, exploratory research tends to use qualitative methods of inquiry [54,55]. A multiple, rather than a single, case study approach with its focus on analytical instead of statistical generalisation was chosen as a method that is sensitive to the unique approaches of the schools, while developing an understanding that is generalised [56].

Case Selection and Sampling Strategy
The case study strategy for selecting units of analysis followed purposive rather than statistical logic [57]. Amongst various types of case studies, a study of organisation(s) undergoing a change process may be carried out [54]. School, as an organisational entity, was selected as the unit of analysis for the purposes of this research. Further, in this research, an interest lay with a change that is being carried out by a school, a change towards sustainability. Thus, the number of case studies had to be large enough to establish analytical generalisation, yet be manageable for the duration of research. Five primary schools with a variety of knowledge and involvement with sustainability concepts were recruited for the purpose of this research. All were mixed community primary schools maintained by the local authority in England. Three schools self-identified as leading in the sustainability agenda and implementing whole-school approaches (Cases 1-3), one school as interested in the agenda (Case 5), and one as not involved (Case 4).

Data Collection
During the research study, three types of methods were used to provide breadth and depth to the investigation and to provide validity through triangulation [58]: in-depth, contextual interviews (with headteachers), questionnaires (staff), and analysis of documents and materials online. The aim of the initial interviews was to gain a holistic overview of the school's organisational approach to sustainability. The advantage of interviews as a method to provide such in-depth, detailed, and holistic information meant that they were the chosen method for the first stage of data collection. At the same time, interviews have a disadvantage, in that they are time consuming [59], which led to a premeditated selection of interviewees, head teachers. A head teacher's role is both strategic and operational; thus, interviews with them provided an overview of each schools' approach to sustainability and touched upon elements of organisational operations, strategies, vision, projects, and leadership.
Organisational vision and strategies are facilitated by individual employees who constitute the supportive element of service provision. The aim of the next data collection stage therefore was to engage with as many school staff as possible at all levels of the school to further understand organisational practices in each school. To do so, a questionnaire was chosen as a method to capture people's values, perceptions, and interests (ibid.). The chosen format was a semi-structured questionnaire, which set the agenda based on the analysis of the interviews with head teachers, but did not presuppose the nature of the responses, keeping in line with the exploratory nature of the research [60]. To increase participation, questionnaires were distributed by two means: Bristol Online Survey (BOS) and paper based. Reminders through the head teachers also were sent to encourage staff to take part. The percentage of the respondents was high, ranging from 8-12 members of staff, which constitute 30-50% of the school (based on the size of the school), which allowed for some cross referencing of the responses.
For the purposes of this research, documents were used as supplementary evidence [61] to enrich understanding of each case. These included online and offline documents such as individual school websites, Ofsted reports, newsletters, online news articles, project records, planning permissions, evaluation documents, and awards submissions. A selection of documents that spanned over time were available for all schools. These episodic records (ibid.) allowed for tracking the development process of each school. This partial documentation of the school's processes and facts were produced either by the school itself or an official, making these documents both authentic and credible for the purposes of the research [62].

Data Analysis
Data analysis followed both within and cross-case analysis. "Within-case analysis" in this research was developed to draw conclusions about the phenomenon of transition towards sustainability in a bounded context of a school [63]. Data analysis followed an inductive, flexible, and data-driven methodology, where concepts and themes emerged from the data [64]. For every data set (interviews, questionnaires and documents), data was reduced to a manageable format, organised, and validated [63]. NVivo software was used throughout the analysis, for its key features of coding, storage, organisation, and retrieval capabilities.
Thus, the line-by-line analysis of the interviews with the head teachers led to the development of 200 open codes, while axial coding allowed for higher level of abstraction and led to development of 11 core categories [65]. This produced a preliminary structure, which was used to display the initial data for each case through a preliminary interim summary [54] and guide future research. Data from questionnaires was analysed to compare and contrast initial findings and existing categories developed through the interviews and weight evidence between two sets of responses. Interim summaries for each school were also performed to further build understanding of individual case and make sense of the data. Evidence from other sources [56] including school documents were collected, annotated, and memoed, focusing on organisational-level patterns and themes rather than individual-level. Using conceptually clustered matrices [63], comparative analysis, and counting, the evidence from all sources has been converged for individual cases. It was then transformed into a formalised descriptive set of variables that has been written into within-case analysis narratives. Each case was understood holistically before cases were compared to each other.
Cross-case analysis was performed to increase generalisability of the research (ibid.) and to develop an understanding of sustainability as change at the organisational level across schools rather than within one single case. In this process, an analytical approach of 'stacking comparable cases' and looking for alternative evidence [54] was used to get a richer understanding and explanation of conditions under which the identified phenomenon happens. Overall approaches, patterns, and general concepts across cases were defined and are presented below in the findings.

Results
The following empirical findings present three broad themes: (1) sustainability as core value proposition in student experience; (2) practices of value creation; and (3) organisational culture, leadership, and operations. These themes also frame the discussion through which cases are compared and contrasted in their approaches towards sustainability transition.

Sustainability as Core Value Proposition in Student Experience
Cross-case analysis showed that a move towards a more sustainable service organisation required schools to expand their service offering to include sustainability values as part of the core value proposition to student experience. All schools acknowledge that they provide a core service offering to all students through formal and informal curriculum. Formal curriculum emphasises the teaching-learning nexus, whereas informal curriculum emphasises pastoral care. In both Cases, 1 and 4 (Table 1), students enter education with 'exceptionally low standards in all areas of their learning' (Ofsted, 2009). For both schools, it is important to engage students in the process of learning in order to have a positive impact and support the core value proposition of education. In Case 4, the service offer and value proposition are rooted in the needs of the students. There are 26 cultures in the school, and 76% of the students have English as their additional language. The school seeks to provide student experience where diversity of students is preserved while engaging all students in learning and developing as 'rounded and independent individuals' (Staff Questionnaire, 4). To do so, the school innovates its service offering, from 'lecture type of teaching' to 'visual, kinaesthetic, multisensory type of learning' (Head teacher, 4), based on the student's immediate need of 'English as a second language'. At the same time, the school sets up multicultural events and brings local community to the schools' grounds for classes in English. This promotes local integration of its students and seeks to address some issues of the emotional and physical well-being in students. Students in Case 1 come 'from the most deprived estate in the area' (online report, 2004) with students having 'a raft of experiences' (deputy head teacher, 1). The percentage of special educational needs and pupils eligible for free meals is 'well above national average' (Ofsted, 4). Case 1 also adapted service offering to the needs of the students; however, it was done by integrating values of care for environment, energy, resources, and healthy living as part of value proposition for the student experience. In particular, 'children (are) to discover how they as individuals, groups and communities can improve quality of life now without damaging the planet in the future' (staff questionnaire, 1). To support this student experience, the school had to innovate its service offering to 'real life (and) experiential learning', which is viewed as contributing to the enrichment of the curriculum (formal and informal) and helping 'children to learn, above and beyond' (head teacher, 1). For example, value of care and healthy living is embedded in the curriculum where students learn about healthy eating and its benefits. Children undergo experiential learning in their school year garden, as all classes 'must have some time in the school garden' (deputy head teacher, 1). The harvest from the garden goes into the kitchen and into the children's school dinners. The garden is thus seen both as an educational resource and as a source of nourishment and emotional wellbeing. This is particularly important for the higher than national average number of learners whose emotional and social development needs are high at the school and whose needs are at the core of the service offering. Cases 2, 3, and 5 also define their student experience in relation to sustainability values and the future of the planet. However, in Case 5, only half of the service offer supports that student experience. For example, both schools place value on care for the environment, care for the community, and local resources (Table 1). For Case 5, this is defined through helping students to be aware of their role in sustainability with the focus on sustainable lifestyle (staff questionnaire, 5). The service offer of Case 5 integrates some experiential learning, yet mostly within the informal curriculum, engaging students and the wider community in sustainable behaviours such as recycling water, paper, etc. This is done on a small and practical level, reflecting the needs of the children.
On the other hand, Case 3, defined student experience as becoming 'eco warriors' (TA interview, 3) with sustainability values and behaviours instilled in them for the rest of their lives (staff questionnaire, 3). The main value of care is between students and their immediate community and local resources in the school, including its allotments, a farm and beehive. As in Case 1, Case 3 s service offering is an integrated formal and informal curriculum where 'work on (local resources) and other work relevant to the school are incorporated into planning of the curriculum' (head teacher, 3). Case 3 uses outdoor resources as learning platforms, to inspire learning activities across different subject areas. For example, stories are acted out in the woods and animals are used to perform basic numeracy lessons. In addition, inquiry-based activities are planned to encourage discovery about local and global environments. Students explore hedgerows and woodlands to learn about natural habitat and local history. Finally, as with other schools, Case 3 s service offer considers children's needs, which are partly dictated by their age. For example, sustainable issues may be too complex for young children. School therefore seeks to balance how to explore issues with children without overwhelming them and at the same time without making issues too simple and redundant.

Practices of Value Creation
While the core value proposition is defined to be student-oriented for all schools, there are variations in how schools view and practice value creation (Table 2). In Case 4, the process is seen to be driven by the service provider for the student with some engagement from the external stakeholders. For example, one school's value proposition to the students is that of diversity while providing equal opportunity to education, and the head teacher sees his role and the role of the school as to develop resources and create innovative solutions that enable this value proposition. School's main value proposition is mostly defined by the head teacher with school developing an acceptance culture for the process: 'it's one of my crazy ideas we'll go with that, that's fine' (head teacher, 4). For example, the head teacher supported professional development for teachers to acquire skills to implement innovative ways of teaching that are not restricted by language fluency. Here, the value of diversity and equal opportunity was embedded in the style of teaching that teachers implement in the classroom. The head teacher also initiated the school's involvement in bringing the local community to the schools' grounds for classes in English to help foreign pupils in the local community including those going to the school to learn English and to promote local integration. The community is defined as an important partner in enabling local integration, yet the school still approaches it as a stakeholder to whom they deliver English language services. Finally, the school has created a mutual relationship with an architect in residence. The architect receives free office space from the school and in return he advises the headteacher on how to refurbish the grounds of the school, including advice on creating spaces for different tools of inquiry that the child may want to use independently. In this case, the stakeholder and service provider established a collaborative partnership around value of resources, which also results in solutions that link to value of diversity and equal opportunity to education. Overall, Case 4 exhibits practices of value proposition being defined by the service provider and delivered to the student. External stakeholders are perceived as school partners, helping school to create solutions for value delivery. While the relationship between school and students is mostly unidirectional, school does exhibit a variety of relationships it is able to create with its other stakeholders, including reciprocal processes of value proposition and resource co-creation. In other cases, Cases 1, 2, 3, and 5, the rhetoric of students and their involvement with service development is different. In all these cases, students are perceived to be primary co-creators of the service and thus active partners in service offer development and delivery. For example, the head teacher in Case 5 describes the relationship between the school and the students as: 'The children actually own the school...we encourage them to own the school' (head teacher, 5). This view resonates with other schools, where students' voice and action are integral to sustainable value co-creation.
For example, students' ideas and opinions are listened to and incorporated into the decision-making about change at operational levels: 'We got offered some apple trees, we got a school map, we did a little bit of orienteering, we went all around school grounds...and we looked . . . what sizes of the tree we want' (TA Interview, 1). In these schools, students are also involved in the practices of environmental evaluation, which may lead to innovative proposition. In Case 5, students looked at and monitored water usage and proposed a way to decrease the amount of water the school uses: 'Can we get the smaller systems, and a double presser, so we don't use as much water . . . so those were all their ideas, which we did over the summer' (head teacher, 5).
In addition to consulting and listening to students (which is the main practice in Case 5 in relation to sustainability), some schools also promote student's active contribution to the school's physical resource design, development, and management (Cases 1, 2, and 3). For example, in Case 1, students were involved in the research and development stages of an Eco Building that the school aimed to build. The new Eco Build project was embedded into the curriculum across all subjects: 'The whole curriculum was taken over by the build, which gave children real life learning experiences in literacy, numeracy, art, science and many other subject areas' (New Building Information, 2008). Students were involved in the design stages from researching and discussing eco credentials of the building materials to be used, to making models of the classrooms, all the way through visiting and experiencing the site during the construction stage (ibid.).
In Case 3, all children in the year 5/6 cohort have an opportunity to look after the animals at the farm. Students are paired up to work with a friend on a weekly rota. Spending a whole week with the animals allows each child to develop knowledge on animal husbandry, skills, and respect for diversity and at the same time to take care of the resource that the whole school engages with through formal and informal curriculum. Students are thus contributing to development of the resources that form part of value proposition to other students and stakeholders who use these resources. Thus, students may be described as service co-producers as well as service users, co-creating value with the service provider and for the service provider.

Value Creation with Immediate and Wider Sets of Stakeholders
In addition to students, these schools perceive external stakeholders as important sustainability value co-creators within the service ecosystem. All schools build partnerships with the most immediate stakeholders in their local communities, including parents, governors, parish councils, and local organizations. These partners are active in developing value propositions with the schools leading to projects that are based on gaining knowledge, co-creation of resources or experiences, and funding. In Cases 2, 3, and 5, local stakeholders already exhibited values that relate to sustainable development and coincide with values of the school. For example, in Case 2, the local council has an ongoing relationship with the school, sharing information on sustainable projects, sustainability-related competitions, and updates on certain operations (e.g., recycling). In Case 3, the school partners with parents, in their professional capacity. For example, a parent who is a veterinarian passes on knowledge to the staff member on how to take care of animals, helping the school to stay independent and save some money: 'We also got a parent who is a veterinary nurse . . . she showed me how to inject so I can do all that now. Now I can buy the medicine . . . but then I am not actually billed for them physically giving medicine, because I can do it as well' (TA interview, 3). Another example includes family homes used in the curriculum for students to investigate a new technology, such as solar panels or electric units (Case 2). However, in Case 1, the immediate stakeholders were less engaged with the issues of sustainability than in other cases, whilst being very much affected by them. For example, half of the families in Case 1 were experiencing fuel poverty. In order to co-create value with its stakeholders in the long term, the school took the initiative to educate its stakeholders on the topic first. It developed an eco-literacy programme for the families and set up Low Carbon Days that demonstrated low carbon behaviours to the parents. Consequently, the school was able to involve its local community in a renewable energy initiative, based on a 'community investment model'. The local community funded the school to have photovoltaic panels to produce electricity by buying its shares and continued to receive a return on their investment when surplus electricity was sold by the school to the national grid (school case study, 1).
Finally, some schools broadened their value creation ecosystem by proactively partnering with the organisations who are working in the field of sustainability. These partners can support schools in determining what is of value to the school. For example, in Case 1, global organizations such as WWF and more local NGOs such as Sustainability and Environmental education (SEEd) are instrumental in helping schools to explore larger themes and definitions of sustainable development: 'we looked at WWF, it was 10 or 12 different behaviours for sustainability' (deputy head teacher, 1).

Culture
Cases 1, 2, and 3 had a clear vision to embed sustainability as part of their school ethos: 'If you cut us in half, the eco school is right in the middle of us' (head teacher, 2). This approach endorses support of the whole school, building a proactive culture of sustainable education. Unlike Case 5, where the school had one dedicated staff member 'to do something' about the sustainability agenda, most staff, including teaching assistant and lunch ladies, in Cases 1, 2, and 3 view their role as keepers of the ethos and were motivated to look after it and to make it stronger. In these cases, schools took time to evaluate the existing values related to sustainability and the needs and interests of their staff members and to develop activities that enhanced them. For example, in Case 1, where gardening is part of the curriculum, the school draws on its internal expertise: 'we have some fantastic gardeners, and an amazing experience in this school' (TA interview, 1). A teacher in Case 3 notes, 'I have always recycled and reused things . . . it is a lifestyle choice that has become part of everything I do' (staff questionnaire, 3). This member of staff is responsible for looking after the food waste that comes from the kitchen and the garden and is recycled in the farm and composted. In addition to drawing on personal values, Cases 1 and 3 also makes sustainability part of the performance management as well as the continuous professional development: 'The CPD of the staff . . . we have elements of sustainability within that, in any given year' (head teacher, 1). Finally, Case 3 demonstrates the importance of personal values in the driving main service offer by placing them as a requirement in the hiring process: 'So you are not going to get a job here unless you espouse those (sustainable) values and actually do something' (head teacher, 3).

Leadership
Further, leadership played an important role in driving sustainability value proposition and creation in the schools. For example, in Case 5, a leadership role was created for one senior teaching assistant (TA): 'Steff now does it, I don't really get involved anymore' (head teacher, 5). The TA communicates with the rest of the staff, parents, and children, accumulating ideas and interests, and then proposes them to the head teacher for approval. Thus, for Case 5, most sustainability activity is governed by one member of staff, who relies on developing her sustainable value propositions as a result of the informal input from others. In Cases 1, 2, and 3, sustainable leadership has developed from being in the hands of the few passionate ambassadors, including head teachers, to being distributed amongst various stakeholders as well as institutionalised through leadership positions and clubs: 'I am trying to spread the leadership in terms of development in this area' (head teacher, 1). Ofsted (2007) has mentioned that leaders of Case 1 have strong commitment to ESD amongst other priorities. The school therefore has leadership positions that have responsibilities relating to ESD such as eco club coordinator, ethical procurement for budget manager, coordinator of nurture group, teacher managing year group plot, and outside learning coordinator. While these positions are ongoing, there are other responsibilities that are distributed on needs basis, for example, a teacher being sent to London to get an eco-school award. Further, in Case 3, a large eco-team was created for students around sustainability issues. The eco team is comprised of a gardening group, animal group, farm group, woodlands group, travel plan group, energy team, water team, light team, and recycling team. Each team is a platform through which students get involved with a specific task, but also a platform for raising issues, ideas, and suggestions for value creation. The role of the eco team is further institutionalised through having a permanent place to voice its work and suggestions in the assemblies and at governor's meetings. Finally, in Case 2, external stakeholders play a vital role in shaping how the school engages with sustainability. The school is open to receive and act upon the incoming support from outside the immediate school community for example from local council on available funding for recycling. Thus, in most schools, sustainability leadership is distributed within the organisation and between the service providers and the students rather than residing in the hands of one or two individuals.

Operations
Most schools (1, 2, 3, and 5) manage their operations in line with sustainable values. For example, the Travel Plans of Cases 1 and 5 focus on the benefits walking and cycling can bring to the local community. As a result, both schools invested money in bike sheds, and Case 5 constructed a sheltered area for parents to encourage them to walk to school. Further, most schools have recycling embedded in their waste management plans. For example, Case 1 seeks to recycle its waste from all aspects of its work; it includes a wide selection of materials including from any construction process it is involved in. Case 2 expanded its scope of recycling material from paper and metal to include clothes. Case 3 focuses on animal and garden waste as an important component of the school with the farm and allotments. Finally, Cases 1 and 3 have also considered the procurement policy, aiming for the schools to become an 'ethical consumer'. Schools began with their food purchasing 'to source locally where possible, especially local and organic food' (staff questionnaire, 1), and slowly expanded their scope, establishing a regional supply chain for their materials. Lastly, Case 1 established a fair trade shop in the school and Case 3 runs trade fairs, selling produce made by the school.

Discussion
The above findings were clustered to develop strategies for implementing whole-school approach in schools from the service innovation perspective. These strategies include (1) re-defining sustainable service concept from quantifiable measure to 'sustainable student experience', (2) approaching 'sustainable student experience' as a reciprocal value co-creation process; (3) and aligning organisational culture, leadership, and operations towards 'sustainable student experience'. The strategies are discussed below with the suggestion to align all three in order to have an integrated approach to implementation of sustainability across the whole school.

Re-Defining the Sustainable Service Concept: From Quantifiable Measure to Sustainable Student Experience
The findings of the research show that schools define and approach sustainability in two ways. For some, sustainability is defined as managing finite resources, such as carbon reduction or energy use. For these schools (Cases 4 and 5), changes to operations and individual behaviours that improve performance of the organisation (e.g., increased recycling rates) are a key measure of sustainability success. Such a 'managerial' approach to sustainability however is limiting [66,67]. For example, whilst schools may engage with activities that seem to deliver immediate value to themselves and to their community, they usually overlook the main user of the service, the student.
Schools that engaged in ecologically-driven pedagogy [68], however, defined sustainability as a shift in the human-nature relationship, to be addressed through student's learning experience. This 'sustainable student experience' approach places student's learning at the centre of their service offer. It focuses on the development of the whole child through participation, transformation, and engagement with the local environment and ecology. Some schools approach it as a voluntary activity, where students 'willingly participate' [34] in the sustainable projects with the school, usually designed outside of the main curriculum. This leads to sustainable student experience being an exclusive service offer, available to a few interested 'service users'. Yet other schools view sustainable student experience as a core service offer of their organisation, arguing for it to be a public service that needs to be facilitated to all students. The latter approach means schools cannot propose an 'off the shelf service' with a buy in from a few students; instead, they have to innovate to deliver 'sustainable student experience' across complex service system delivery [69]. This means integrating core curriculum and supplementary activities within a school, engaging with the broad set of stakeholders including parents, and addressing a diverse set of student needs.

Approaching 'Sustainable Student Experience' as a Reciprocal Value Co-Creation Process
The findings also show that schools need to approach 'sustainable student experience' as a reciprocal value co-creation process. For schools, this means creating new or re-designing existing relationships with their stakeholders, such as sustainability-oriented charities, local government, suppliers, and local community, including parents. Sustainable value co-creation has been particularly challenging for schools where the requirement was to change the relationship with the local community and parents in the context of social innovation. The emergence of such relationships can be a complex process [70], including the need for local community to see the value of the new relationship in accomplishing their own needs, goals, and motivations [71].
Further, schools have to coordinate and institutionalise [72] value co-creation for sustainable development across their whole service ecosystem for the students to experience an integrated sustainable service offer, whilst navigating a set of very different relationships. Undertaking sustainable value co-creation with one or two stakeholders only might lead to a partial resource integration for sustainable value creation, yet create no direct value for the student or other immediate stakeholders.

Developing Culture of Sustainability-Oriented Innovation
Our research shows that in addition to being key actors at institutionalising sustainable value co-creation within their wider ecosystem, schools also institutionalise it as a norm at the organisational level. This is supported by key cultural and organisational foundations [73,74]. For example, findings show the development of a culture of sustainability-oriented innovation, where school staff are not only engaged with practicing sustainable value co-creation, but express consensus and intensity of feeling [75] and willingness towards engaging with new opportunities. Findings showed that a key process that supports development of such culture is hiring and recruitment [73,76]. This approach evidences recognition that maintaining sustainability-oriented innovation as organisational culture long term requires organisations to not only address extrinsic motivations of their staff, but also cater to the intrinsic needs [77], supporting co-creation of self-actualisation (ibid.) value for the staff during service privision.
Further, sustainability-oriented innovation culture needs to be enabled within a service organisation through leadership [78]. Whilst externally, schools practice "linking leadership" [79], developing relationships that promote social innovation for sustainable value co-creation, internally, schools practice shared principles of leadership [80] alongside hierarchical practices [81] to support a culture of sustainability-oriented innovation [82]. For example, findings show the formation of formal and informal groups, which encourage staff and student leadership to address an aspect of sustainability at the organisational level and promote the agenda of sustainability within the organisation, making it part of the service offer. Such an interactive approach that is based on competencies of individuals and a sense of responsibility [83] further supports a culture that is proactive and engaged.
The notion of shared leadership is in line with employee and user involvement [84][85][86] in service innovation. However, the findings of this research show that the aim of employee involvement in shared leadership for sustainable service innovation is not to serve as proxy for service users; instead, it is about developing and leading individual or community practices around a sustainability issue that become integrated as part of the service offer. Further, student involvement in shared leadership shows a shift away from engagement for 'information sharing' to engagement for both design and implementation of new value propositions [87]. This approach necessitates adjustments to organisational structure and development of new platforms for participation [87].
Finally, the research shows that schools need to institutionalise sustainability strategy in relation to their operations. Sustainable operations management (OM) is needed, including environmental and social policies [88], ethical procurement [89], closed-loop supply chain [90], and others.

Theoretical Implications
This paper takes a different view on how schools can implement sustainability at a whole-school level. The traditional, 'managerial' approach promotes an assumption that schools deliver sustainable value through their performance [34]. This view places emphasis on the needs of the school, rather than the student and wider set of stakeholders, where students and other stakeholders are either unaware of, or marginally contributing to, the school's sustainable activities. The view proposed in this paper draws on service logic and suggests that the role of the sustainable school is to facilitate 'sustainable student experience' through co-creation activities with the user and integration of the local resources, including knowledge and expertise of the local stakeholders. Such a localised approach occurs through service providers' developing what Dumay et al. [67] call 'one's own sustainability narrative' that is informed by the local resources and needs rather than based on the set of generic performative indicators.

Practical Implications
Beyond theoretical implications, this research has practical implications for the management of schools. In particular, schools need to consider how 'sustainable student experience' is facilitated and how it engages with a reciprocal process of value creation both externally and internally to their organisation. The findings of the research show that schools need to engage with an ecosystem perspective and support initiation of sustainable value co-creation across all stakeholders, rather than keeping it in the hands of the few, reflecting the dynamic view of actor interactions in a service system [91,92].
Further, the educational context highlights the embeddedness of actors in the system that can be disengaged [34], but who could be key actors in supporting facilitation of 'sustainable student experience'. Thus, research shows schools have to take a leading role within the social innovation initiatives where they need to understand the needs of their communities, generate value propositions, and implement support structures that enhance the public value [93] whilst also enabling the core 'sustainable student experience'.
In addition, schools need to internalise both service logic and sustainability-driven innovation as part of the organisational culture, with implications on its leadership and operations management. Shared leadership for facilitating 'sustainable student experience' draws attention not only to the idea of service employee's integral role in designing and facilitating interactions with service users, but also to the intrinsic motivation required to support such process. In addition, shared leadership also includes students' involvement in co-design, co-development, co-manufacturing, and co-delivery of some of the resources that facilitate 'sustainable student experience' and that also constitute the 'sustainable student experience' itself. Finally, schools need to consider sustainable operations management. Whilst the value of the sustainable operations management in the manufacturing service provision is well documented [89], in non-manufacturing services it continues to be perceived as an add-on [94]. This research proposes for schools to view sustainable operations management as an enabler of the 'sustainable student experience', enabling and supporting students' and staff's engagement in its development, thus promoting learning within individuals and organisations.

Limitations and Future Research
This paper is not without its limitations, which present avenues for future research. First, five primary schools were selected, allowing for some level of analytical generalisation, yet ensuring manageable levels of data for the duration of research. The small sampling size is mitigated somewhat through the qualitative deep approach of case study and the use of cross case analysis to allow generalisation. Future research is required to expand the selection of case studies, engage with alternative sets of participants, including students, and attend to alternative units of analysis, for example studying sustainable value creation at the level of service encounters for different educational stakeholders or as a socio-material configuration [95]. Second, the paper presents three strategies for sustainability-driven service innovation that need to be tested, evaluated, and revised. The experience-based and co-creation nature of these service strategies highlights the potential to explore service design [45,52,96] as an approach to innovation. Finally, this research focuses on the public sector and education, opening opportunities for research into other public service organisations engaging with or wanting to engage with sustainability-driven service innovation.
Author Contributions: Conceptualization: K.K., R.T. and T.B.; methodology: K.K.; formal analysis: K.K.; investigation: K.K.; writing-original draft preparation: K.K. and R.T.; writing-review and editing: R.T. and T.B.; supervision: R.T. and T.B. All authors have read and agreed to the published version of the manuscript.