Hadi Kandjani
email: h.kandjani@griffith.edu.au

Peter Bernus
email: p.bernus@griffith.edu.au

Cybernetics of the Collaborative Networks Discipline

Keywords: Collaborative Networks, Cybernetics, Unified Developing Theory, Evolving Discipline

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

'Cybernetics of the Collaborative Networks (C2N)' was previously proposed as a field of research intended to address complexity management and control problems in CNs [START_REF] Kandjani | Towards a Cybernetic Theory and Reference Model of Self designing Complex Collaborative Networks[END_REF]. C2N can be thought of a field on its own, which re-interprets old and new theories, and point at the need for genuinely new results for designing / creating and managing complex CNs. The aim of this previous research was to understand how various theories contribute to the management of CNs, so that the Network evolves and remains viable in the long term. As part of this endeavor, the authors developed a model (called the co-evolution path model), discussing the evolution of a CN in light of the evolution of the Network's environment, so as the Network can remain relevant, competitive, and viable.

The idea of this paper is to look at the evolution of the discipline itself, i.e., how the discipline of CNs evolves? After all, a discipline can also be considered a system (of concepts, axioms, theories, scope definitions, paradigms, etc.), and it is relevant to ask: how does discipline development ensure that it remains relevant on the long term? What we set out to discuss, is a theory of the evolution of the CN body of knowledge. This theory is to describe the evolution mechanisms of the CN body of knowledge, but is open for further development by CN practitioners and researchers.

The or interdisciplinary aspect of CNs manifests when researchers not only apply models, methods and theories of management and control, engineering, linguistics, cognitive science, environmental science, biology, social science, artificial intelligence, systems thinking and cybernetics, but also create a synthesis of these. Such a synthesis would be the source of a new, unified theory, giving rise to more powerful theories, methodologies and reference models than available today.

For the study of Collaborative Networks, previous work has developed a roadmap to facilitate the invocation and integration of previous results into a theoretical foundation, including terminology, axioms, models, and methodologies [START_REF]Collaborative Networked Organizations In[END_REF][START_REF] Camarinha-Matos | A roadmap for strategic research on virtual organizations[END_REF][START_REF] Camarinha-Matos | The emerging discipline of collaborative networks[END_REF][START_REF] Camarinha-Matos | Collaborative networks: A new scientific discipline[END_REF][START_REF] Camarinha-Matos | On reference models for collaborative networked organizations[END_REF][START_REF] Camarinha-Matos | Towards a reference model for collaborative networked organizations[END_REF][START_REF] Camarinha-Matos | Motivation for a theoretical foundation for collaborative networks In[END_REF][START_REF] Camarinha-Matos | ECOLEAD: A holistic approach to creation and management of dynamic virtual organizations[END_REF].

The critical question in the present paper is: is it possible to develop a theory of how the CN Body of Knowledge is developing as a discipline?

Kandjani and Bernus [START_REF] Kandjani | Towards a Cybernetic Theory and Reference Model of Self designing Complex Collaborative Networks[END_REF] argue that Cybernetics [START_REF] Wiener | Cybernetics or Control and Communication in the Animal and the Machine[END_REF][START_REF] Ashby | An introduction to cybernetics[END_REF], Management Cybernetics [START_REF] Beer | Decision and Control: The Meaning of Operational Research and Management Cybernetics[END_REF][START_REF] Beer | Diagnosing the system for organizations[END_REF] and General Systems Theory (GST) [START_REF] Boulding | General systems theory-the skeleton of science[END_REF][START_REF] Bertalanffy | General System Theory-Foundations and Developments[END_REF] have previously tackled these types of problems at the same, or similar, level of abstraction and generality, therefore, to describe discipline evolution we use a similar approach to the cybernetics-inspired discussion of how CNs develop.

Viability of the CN Discipline and Effective CN Practice

In this section we propose a viable model of the CN body of knowledge, as an interdisciplinary discipline of designing, creating and maintaining CNs.

Beer's Viable System Model

Beer [START_REF] Beer | The Heart of Enterprise: the Managerial Cybernetics of Organization[END_REF] describes every system as consisting of three main interacting components: Management, Operation and Environment. Every system of interest has a metasystem as its management and operates in an environment, where each component could be further decomposed into more detailed elements. There are communication channels to keep the Operation in homeostasis, these channels are called variety attenuators and -amplifiers [START_REF] Beer | The Heart of Enterprise: the Managerial Cybernetics of Organization[END_REF][START_REF] Beer | Brain of the Firm, 2nd Ed[END_REF][START_REF] Beer | Diagnosing the system for organizations[END_REF], to ensure that the variety what the Operations can provide meets the variety of the demands of the environment.

According to Beer [START_REF] Beer | The Heart of Enterprise: the Managerial Cybernetics of Organization[END_REF] the 'variety' of the operations is always less than that of the Environment, and the 'variety of Management' is always less than the variety of Operations. In contrast, based on Ashby's law of requisite variety (1956), in order to achieve dynamic stability under change, the variety of Operations should be equal to that of its relevant environment, and the variety of Management should be at least equal to that of Operations. In fact variety attenuation and amplification mechanisms need to be designed in order to keep the system of interest viable ('evolvable') in its environment.

The CN Discipline as a Viable System

One can map the three components of Beer's VSM to the CN Discipline itself, and to its surrounding Environment (Fig. 1). We consider CN-related disciplines as 'Operations' shown as a circle, and the CN discipline as its integrating and interdisciplinary meta-system ('Management') shown as a square, with CN's task being to observe and cross-fertilise problem domains, and observe the 'Environment'.

The CN discipline acts as a meta-system, investigates the CN problem domains and using attenuation mechanism, invokes the relevant terminology, models and theories from CN-related disciplines (e.g. industrial engineering, management science, control engineering, information and communication technology,…) to respond to new issues arising in these domains.

Fig. 2 Three components of a Viable CN Discipline

Changes in the problem domains mandate the evolution of individual CN related disciplines, so as to respond to the new requirements of the evolving environment.

In order to harmonise this co-evolution, we need to understand what the relevant mechanisms to guarantee an effective evolution of the CN discipline itself are.

If we consider the CN discipline as 'problem solving', then the step-by-step stages of co-evolution would be: 1) diagnose a significant problem in the CN problem domain, 2) invoke one or more relevant disciplines studying the CN problem domain and decide if such multi-disciplinary combined action is adequate, and if not, then 3) provide solutions for CN problems by harmonising and integrating multiple theories, models, techniques and methods from relevant disciplines in a synthesis (new or extended theory), and 4) adopt any 'new' case records of relevant disciplines and integrate them into the CN Body of Knowledge.

The need for a unifying theory clarifies the role of the CN discipline as a metasystem (as in Beer's VSM) answering a) what CN problem domains would be addressed in specific CN practices?, b) what would be the invoked disciplines targeting the problem domains in combined use?, c) how to formalise and harmonise other disciplines' contributions and apply them in a CN practice?

As the invoked disciples are continuously progressing and evolving in their specific domain and field of application, a more effective CN practice could be guaranteed if the evolution of these disciplines were influenced or monitored by the CN discipline and the findings reflected in CN theory and practice when necessary.

Co-Evolution Mechanisms for an Evolving CN Discipline

We discussed three of a viable CN discipline in Section 2, now the question arises: what are the mechanisms to keep the requisite variety of the CN discipline as a viable system?

Co-Evolution Path Model, Dynamic Homeostasis vs. Dynamic Hetereostasis

Beer [START_REF] Beer | Decision and Control: The Meaning of Operational Research and Management Cybernetics[END_REF] argues that a key property of a viable system and a "measure of its submission to the control mechanism" is its ability to maintain its equilibrium or homeostasis, which he defines as "constancy of some critical variables (outputs)". In our model of co-evolution, we define the dynamic sustenance of requisite variety based on Ashby's law: "only variety can destroy variety" [START_REF] Ashby | An introduction to cybernetics[END_REF], paraphrased by Beer [START_REF] Beer | The Heart of Enterprise: the Managerial Cybernetics of Organization[END_REF] as "variety absorbs variety". Here, 'variety' is the number of possible states of a system [START_REF] Beer | Brain of the Firm, 2nd Ed[END_REF], or as recently re-interpreted and refined by Kandjani and Bernus [START_REF] Kandjani | Engineering Self-Designing Enterprises as Complex Systems Using Extended Axiomatic Design Theory[END_REF], the number of relevant states of a system.

Considering the system and its environment as two coupled entities, if one component is perturbed, the effect of that perturbation on the other component is either amplified through positive feedback, or may be reversed (attenuated) through negative feedback. These channels serve as self-perpetuating mechanisms of the system. (Note that what we call here a 'system' includes the system's controller.)

The role of the negative feedback loop is to reverse the effect of the initial perturbation and restore the system's homeostasis (in which critical variables are stable), while positive feedback can create unstable states [START_REF] Ashby | Adaptiveness and equilibrium[END_REF].

As both the system and its environment (including systems in that environment) evolve, change can create imbalance between the requisite variety of our system of interest and the variety that would be required for it to maintain homeostasis. In other words, systems that want to live long must co-evolve with their environment.

More formally: we consider the environment an entity with a possible set of observable states and if two such states require different response from the system then the system must be able to differentiate between them (thus they are two different relevant states). Consequently in Fig. 3, for this purpose, the complexity of a system (CS) is defined to be the complexity of the model that the controller of the system maintains (appears to be maintaining) in order to manage the system's operations, so as to maintain adequate interaction with the environment.

The complexity of the system's environment (CE) is a relative notion and is defined to be the complexity of the model of the environment that the controller of the system would need to maintain the in system's homeostasis. Specifically, such an 'environment model' must have predictive capability, so that the system, while interoperating with the environment, could maintain a homeostatic trajectory.. These models are needed to be able to represent and predict the states of signals and resources among the system, the external systems and the rest of the environment. This because based on the theorem of the 'Good Regulator' [START_REF] Conant | Every Good Regulator of a System Must be a Model of That System[END_REF], a good controller of a system must have a model of that system with an equal complexity at its disposal as the system to be controlled has. If the complexity of the system (CS) equals to that of its environment (CE), then the system has the requisite variety and is in static equilibrium. However, any change in the complexity of the environment should be sensed by the system's selfperpetuating mechanism to restore the system to its initial state or to create a new equilibrium state.

2) If the complexity of the environment is greater than that of the system, then the system should attenuate the effects of this complexity, i.e., change and co-evolve with its environment (in other words, the environment produced, or is recognised to have the potential to produce, some states in which the system cannot function adequately).

3) If the complexity of the system is greater than that of its environment, then the system can potentially create a set of different states and perform behaviours, which are not differentiated by its environment. The system can identify this extra complexity as undesired, or use an amplification mechanism to create new differentiations in the environment.

Any system has a number of variables characterizing its essential survival properties. Ashby refers to these as 'essential variables', and defines survival as: "a line of behaviour [that] takes no essential variable outside given limits" [START_REF] Ashby | Design for a brain; the origin of adaptive behavior[END_REF][START_REF] Geoghegan | Design for a self-regenerating organisation[END_REF] . Therefore, by definition, any line of behaviour outside limits of essential variables is on the non-viable system path and is fatal to the system.

For a system to be regarded as adaptive, and therefore viable, Ashby introduces two necessary feedback loops [START_REF] Ashby | Design for a brain; the origin of adaptive behavior[END_REF][START_REF] Geoghegan | Design for a self-regenerating organisation[END_REF][START_REF] Umpleby | Ross Ashby's general theory of adaptive systems[END_REF]. The first loop makes small modifications and corrections to the system. As opposed to this, the second loop changes the structure or architecture of the system and operates if essential variables are predicted to fall outside the limits of survival. If the system's second feedback loop does not respond to the changes in complexity of the environment, then the system will be on a non-viable path.

Based on Ashby's theory of adaptation [START_REF] Ashby | Design for a brain; the origin of adaptive behavior[END_REF], according to Umpleby [START_REF] Umpleby | Ross Ashby's general theory of adaptive systems[END_REF], the first feedback loop is necessary for a system to learn a pattern of behaviour necessary for a specific environment, while the second feedback loop is required for a system to identify the changes in the environment and design/create new patterns of behaviour. If there is a dramatic increase in environment complexity and the system is not prepared to act, then the lack of functioning of the second feedback loop makes the system non-viable and the system is doomed to fail.

Co-Evolution Path Model of the CN Discipline

Looking at the CN discipline as a system ( 'discipline-as-a-system') the co-evolution model of Section 3.1 applies to that system too (see Fig. 5), therefore the question is: what are the co-evolution mechanisms through which the CN discipline can maintain requisite variety and remain relevant in light of changes to problem domain changes?

The CN discipline as an integrating discipline invokes models, theories, and methods of related disciplines, and effective co-evolution is only guaranteed by: a) invoking the right theories, models, and methods from CN-related Disciplines (CNRD) to address new and emerging CN Problem Domains (CNPD) in a combined use (attenuation mechanism), and b) promoting new synthesised CN terminologies, reference models, and methods to provide solutions in CN problem domains using a holistic approach (amplification mechanism).

Thus, if at any one time the variety of the unified theory of CN discipline is less than the variety of the CN problem domains, then the CN discipline cannot respond to the needs of the environment problem domain) and must increase its variety by attenuating the relevant variety (e.g. adopt new elements from relevant CN related disciplines).On the other hand, a CN researcher or practitioner should also formulate and execute a 'promotion' mechanism if the variety of CN models, methods and frameworks is more than the variety of the CN problem domains. In this case, system managers, users, and stakeholders would not be able to comprehend these complex CN models, methods and etc. and would probably avoid using them, therefore one should decrease the variety of these models, or promote the use of more complex models by inventing new applications in the problem domain. The CN discipline as an integrating discipline invokes models, theories, and methods of related disciplines, and effective co-evolution is only guaranteed by: a) invoking the right theories, models, and methods from CN-related Disciplines (CNRD) to address new and emerging CN Problem Domains (CNPD) in a combined use (attenuation mechanism), and b) promoting new synthesised CN terminologies, reference models, and methods to provide solutions in CN problem domains using a holistic approach (amplification mechanism).

Thus, if at any one time the variety of the unified theory of CN discipline is less than the variety of the CN problem domains, then the CN discipline cannot respond to the needs of the environment problem domain) and must increase its variety by attenuating the relevant variety (e.g. adopt new elements from relevant CN related disciplines).On the other hand, a CN researcher or practitioner should also formulate and execute a 'promotion' mechanism if the variety of CN models, methods and frameworks is more than the variety of the CN problem domains. In this case, system managers, users, and stakeholders would not be able to comprehend these complex CN models, methods and etc. and would probably avoid using them, therefore one should decrease the variety of these models, or promote the use of more complex models by inventing new applications in the problem domain.

The evolution of problem domains must therefore be closely monitored (including strategic forecasts) so as to be able to perform the mentioned 'invocation' and 'promotion' to provide the CN problem domains with relevant combined disciplinecontributions in practice.

Conclusions

To develop a theory of evolution of the CN Body of Knowledge, we focused on the viability of the CN discipline as a system, discussed it using Beer's Viable System Model (VSM), and introduced its three components using VSM. We also proposed the concept co-evolution mechanisms concept for the evolving CN discipline based on VSM and a companion theory, Ashby's law of requisite variety, but used a new complexity measure, that takes the relativity of this term into account.

Our cybernetic model of the evolution of the CN discipline enriches Anderton and Checkland's model of developing disciplines, who previously demonstrated the cyclic interaction between theory development and formulation for a problem, and theory testing [START_REF] Anderton | On learning our lessons[END_REF][START_REF] Checkland | Systems Thinking, Systems Practice[END_REF], warning about the need for theories to remain 'relevant' (viable). Our model which is based on the Co-evolution Path Model [START_REF] Kandjani | Co-evolution path model: how enterprises as complex systems survive on the edge of chaos[END_REF][START_REF] Kandjani | Enterprise Architecture Cybernetics and the Edge of Chaos: Sustaining Enterprises as Complex Systems in Complex Business Environments[END_REF] now illustrates the mechanisms of theory development from this point of view.

A relevant field of study called 'Enterprise Architecture Cybernetics (EAC)' [START_REF] Kandjani | Capability Maturity Model for Collaborative Networks based on Extended Axiomatic Design Theory[END_REF][START_REF] Kandjani | Evolution of the Enterprise Architecture Discipline: Towards a Unified Developing Theory of EA[END_REF][START_REF] Kandjani | Enterprise Architecture Cybernetics for Collaborative Networks: Reducing the Structural Complexity and Transaction Cost via Virtual Brokerage[END_REF] has a similar purpose and level of abstraction to this intended theory, however EAC has a different scope and genericity (namely its scope encompasses all socio-technical systems of systems in the broadest sense, including social, economic and ecological systems, and aggregates thereof).

Future work will concentrate on applying this model, whereupon testing and validation of this theoretical model of discipline development is to be performed by illustrating the above effects through concrete cases from the development of the CN body of knowledge-hopefully also discovering new, open problems in this domain.

  of the System and its Environment through First and Second Feedback loops

Fig. 4

 4 Fig.[START_REF] Camarinha-Matos | The emerging discipline of collaborative networks[END_REF] Co-evolution Path Model 1) If the complexity of the system (CS) equals to that of its environment (CE), then the system has the requisite variety and is in static equilibrium. However, any change in the complexity of the environment should be sensed by the system's selfperpetuating mechanism to restore the system to its initial state or to create a new equilibrium state.2) If the complexity of the environment is greater than that of the system, then the system should attenuate the effects of this complexity, i.e., change and co-evolve with its environment (in other words, the environment produced, or is recognised to have the potential to produce, some states in which the system cannot function adequately).

Fig. 6

 6 Fig. 6 Co-evolution Path Model of the Collaborative Networks Discipline


Antonio P Volpentesta
email: antonio.volpentesta@unical.it

Marco Della Gala
email: marco.dellagala@unical.it

Analyzing Mobile Services in Alternative Agrifood Networks

Keywords: agribusiness, Alternative Agrifood Networks, mobile services, mobile applications

Recently, Alternative Agrifood Networks (AAFNs) represent a form of collaborative agrifood networks characterized by a re-connection and close communication among producers and consumers in order to overcome the limits of dominant capital-intensive agribusiness system. In this paper, we propose a framework to analyze and explore the value of the use of mobile information services in an AAFN. The applicability of the framework is shown by presenting some results obtained from an analysis of different types of case studies referring to the use of mobile services in real-world AAFNs.

Introduction

Over recent years, the industrialization of mainstream food systems has resulted into a concentrated control of product markets, with a small number of dominant organizations. Big organizations monitor every transaction among millions of disconnected producers and consumers, leading both to the loss of decisional power for farmers and producers and to the crisis of confidence in mass-produced, 'placeless and faceless' food products, as well as the 'crisis of trust' among consumers [START_REF] Watts | Making reconnections in agro-food geography: alternative systems of food provision[END_REF], [START_REF] Sánchez Hernández | Alternative Food Networks: concept, typology and adaptation to the spanish context[END_REF]. In addition to that, rural SMEs are subjected to a continuous imbalance of their bargaining power; they suffer cost-price squeeze, unfair contractual agreement, rising production costs and declining commodity prices that reduce their profitability [START_REF] Watts | Making reconnections in agro-food geography: alternative systems of food provision[END_REF], [START_REF] Sánchez Hernández | Alternative Food Networks: concept, typology and adaptation to the spanish context[END_REF] [3], [START_REF] Slee | Exploring hybridity in food supply chains[END_REF].

All the above mentioned factors have induced farmers, and other people or organizations dealing with agricultural and rural issues, to organize themselves spontaneously in order to solve their problems and those of rural communities. This has led to new and alternative business models to guarantee competitive advantages, to improve farm revenue streams, to return in taking an active role in the agrifood 1system, and to develop new consumer market niches, [START_REF] Chiffoleau | From Politics to Co-operation: The Dynamics of Embeddedness in Alternative Food Supply Chains[END_REF], [START_REF] Slee | Exploring hybridity in food supply chains[END_REF], [START_REF] Goodman | Editorial the quality ''turn'' and alternative food practices: reflections and agenda[END_REF], [START_REF] Renting | Understanding alternative food network: exploring the role of short food supply chains in rural development[END_REF], [START_REF] Volpentesta | A Collaborative Network Model for Agrifood Transactions on Regional Base[END_REF], [START_REF] Volpentesta | Networking farmers clusters and consumers groups in local agribusiness, in Pervasive Collaborative Networks[END_REF].

With this aim, different forms of collaborative networks have been introduced in the agrifood sector as characterized by a re-connection or close communication among producers and consumers, allowing the development of new forms of relationship and governance of the actors' network and also enhancing a redistribution of value for primary producers [START_REF] Watts | Making reconnections in agro-food geography: alternative systems of food provision[END_REF], [START_REF] Sánchez Hernández | Alternative Food Networks: concept, typology and adaptation to the spanish context[END_REF], [START_REF] Ammirato | Alternative Agri-Food Networks as learning communities: some issues for a classification model[END_REF], [START_REF] Volpentesta | Alternative Agrifood Networks in a regional area: a case study[END_REF].

According to Goodman [START_REF] Goodman | Editorial the quality ''turn'' and alternative food practices: reflections and agenda[END_REF], alternative agrifood networks (AAFNs) is an umbrella term that is used to indicate all these new forms of collaborative development. AAFNs are alternative to the logic and organizational arrangements of the dominant agrifood system which is based on long and multinational supply chains in the direction of shortening the distance (physical, social, cultural, and economic) between world production and world consumption [START_REF] Jarosz | The city in the country: Growing alternative foodnetworks in Metropolitan areas[END_REF], [START_REF] Sánchez Hernández | Alternative Food Networks: concept, typology and adaptation to the spanish context[END_REF].

AAFNs can be shaped into different organizational forms (Direct on Farm Sales, Farmers Markets, Box Schema, CSA, Collective Kitchens) in relation to the socioeconomic context of the reference territories and to the peculiarities of the many grassroots initiatives promoted both by producers and consumers, see [START_REF] Volpentesta | Knowledge exchange and social learning opportunities in direct agri-food chains[END_REF] for a descriptions of these forms.

However, no matter of organizational issues, in any AAFN the agrifood is regarded as 'embedded' with value-laden information, concerning the mode of production, provenance and distinctive quality assets of the product, when it reaches the consumer. An AAFN provides a sort of liminal space that subverts the normal experience of food shopping [START_REF] Holloway | Possible Food Economies: a Methodological Framework for Exploring Food Production-Consumption Relationships[END_REF] and where a variety of information and knowledge related to agriculture, rural economy, the environment, food production, healthy eating and consumer values, may be exchanged [START_REF] Fonte | Knowledge, Food and Place. A Way of Producing, a Way of Knowing[END_REF].

Nowadays, such information/knowledge exchange may be supported by new types of services based on recent technology developments. In particular, mobile services can provide information offerings regardless of temporal and spatial constraints, in an AAFN, they make easy to share detailed agrifood and agrifood source information, bringing AAFN people closer to each other. On one hand, agrifood producers can give consumers insight into sourcing and production methods, monitor their customer base, and make transparency a competitive advantage; on the other hand, consumers may be empowered with more timely and accurate information to make better buying decisions based on their personal values. In essence, the use of mobile services may contribute to the growth of AAFNs through supporting grass-roots and up approaches aimed to connect local citizens, restaurants, and produce distributors directly to the local farmers in their communities.

In this paper, we propose an AAFN mobile service analysis framework for eliciting key components that concur to generate value for AAFN people. In our opinion, such a framework constitutes a valid basis to develop an evaluation model of AAFN mobile information services under a user-centric perspective. Its applicability is primary processed products that are consumed in the original state, as they are produced with no value additions being made, or are processed and refined as little as possible, before being consumed; secondary processed products that require basic level of processing (grading, sorting, cleaning, cutting, etc.) before they are consumed;

tertiary processed products that result in the output being in a different form, shape and with a higher value as compared to the original production.

showed by presenting some results obtained from an analysis of different types of case studies referring to the use of mobile services in real-world AAFNs.

AAFN Mobile Information Services

The term mobile service is used to describe all services that can be used independently of temporal and spatial restraints, and that are accessed through a mobile handset (mobile phone, PDA, PC tablets , smartphone, etc.). They differ "from traditional interpersonal services that are delivered face-to-face, or from other types of e-services, such as wireless online services, where the service delivery is linked to a specific fixed local area network or specific location", [START_REF] Heinonen | Classifying mobile services[END_REF]. In general, benefits of mobile services are mainly due to four factors: ubiquity, convenience, localization and personalization that differentiate mobile services from online services [START_REF] Clarke | Mobile Portals: The Development of M-Commerce Gateways[END_REF].

In an AAFN, mobile services can provide new opportunities for serving awareness and transparency needs of consumers as well as request of information of producers on their business processes. For example, they may provide farm site or agrifood product information (processing methods, provenance of the produce, agrifood physiological and health aspects, etc.) in digital format (labels, pictures, videos, geo position, and graphics) on a user's individual display or through headphones for audio content. Moreover, the integration of new technologies, such as object recognition, feature tracking, RFIDs, Near Field Communication (NFC), geotagging, and web services, in mobile devices has enabled to conceive new mobile services that enrich the relations between AAFN actors and better support their activities.

AAFN mobile services can be grouped in five major classes [START_REF] Volpentesta | Investigating augmented learning opportunities in Direct Agri-Food[END_REF]: Virtual visits services: most of them provide an interactive virtual farm tour. They aim to create an opportunity for consumers to know the countryside and to facilitate a wider understanding of the environmental, economic and social issues linked to an AAFN. Moreover, they improve consumers' confidence in offered products allowing consumers to find out how agrifood is grown and produced and discover what happens on a farm. For instance, in a virtual egg farm tour consumers can get information about where eggs come from and how hens are raised (in cages or in barns with or without access to outdoors run).

Traceability and product related information services: they deliver tailor made information (including physiological and health aspects, origin, recipes, conserving methods, etc.) according to individually determined criteria selected by a consumer [START_REF] Sebők | Food Awareness and Transparency: Current Practices and Future Tools[END_REF]. Traceability data can be provided by a code. Product information can be got through scanning the related code by using a smartphone camera. For instance, these services enable consumers to read product descriptions, view photos and availability, compare prices, read recipes and access to information such as origin of the product, presence or absence of GMO, absence of pesticides, fat content, food miles, etc.. Location-based services and geospatial services: based on geotagging technology, they make searching for in season agrifood products and places where AAFN activities may occur. For instance, through GPS routing and getting turn-byturn directions, they may enable a consumer to easily find farmers markets near his/her current location or within a state/city, and to get market information (hours/dates of operation, parking places, prices of products for sale, etc.).

Dietary and health services: exploiting location-based services or object recognition applications, they essentially provide a consumer with agrifood nutritional information (e.g. what vitamins a fruit or a vegetable have, and what diseases they are good at protecting against) and dietary advices (e.g. daily healthy-eating tips and how many calories, vitamins, and minerals are in a certain meal). Some of them are customized services that provide personal dietary and health advices (e.g. explanations and warnings about agrifood's nutrients and ingredients) on the base of the consumer's profile (body mass index, intolerances, special diets, alimentary restrictions, etc.).

Social Networking services: they allow interactive learning experiences through uploading of photos, tagging of photos and presenting of feedback or recommendations. They represent a mean for consumers to get information about their past behavior, or actions of other consumers in similar positions [START_REF] Parikh | A survey of information systems reaching small producers in global agricultural value chains[END_REF]. For instance, consumers, farmers, distributors, and food producers can submit pictures of their products and add information about which farmers' market, restaurant, or grocer the agrifood is bound for; this helps people to know where agrifood comes from, who produces it, and who handles it as it travels from its source to plate.

The overall value of these mobile services is influenced by four main factors: 1. Consumption motivation: this factor refers to the relative importance of the learning, social and utilitarian value generated for service users. Learning value refers to intrinsic motivation that is associated with needs of experiential learning about AAFN agrifood products, people, organization, and environment [12] [20]. Social value is also referred to intrinsic motivation, but the associated needs are more communicative and relational (e.g. sharing downloaded digital content and received messages for AAFN social belongingness). The utilitarian value refers to extrinsic motivation that exists in goal directed service use and is associated with effectiveness/efficiency information needs (e.g. saving time and easily finding vendor or producer location, time table of operations, etc.) in performing a task [START_REF] Heinonen | Classifying mobile services[END_REF]. 2. Use context criticality: the time when and place where the service is used affect the value generated for service users. Temporal criticality points out how urgently the user needs the service. Spatial criticality indicates if the service can be used anywhere, i.e. non-location-based service, or if the service should be used at a specific AAFN place (e.g. a farm site), i.e. location based service. 3. User's role: this factor refers to the relative importance of the role played in the AAFN by a service user. The service can be oriented to specific AAFN roles (e.g. consumer, producer, organization operator, etc.) in order to increase the value gained by its users. 4. Information source: any mobile service utilizes a variety of knowledge and information sources that can be valuable in terms of their extension (or coverage), their intension (or density), and their trustworthiness. Such source qualities naturally affect the value generated by the service for its users. The above-described factors are further expanded in the next section and have been used as the base in developing our framework for analysing mobile information services in an AAFN.

A Mobile Service Analysis Framework

In this section, we propose an AAFN service analysis framework for eliciting key components that concur to generate value for AAFN people. The value segmentation, introduced in the previous section and such a framework constitute a useful basis to develop an evaluation model of AAFN mobile information services under a usercentric perspective. In order to analyze the overall value generated by an AAFN mobile service, three main components are considered: a. the human-service system interaction (HSSI); b. the knowledge and information source (KIS); c. the information content domain (ICD). Such components are interrelated, as depicted in Figure 1, in the following sense: HSSI-ICD: the information exchanged in the interaction regards some ICD elements. For instance, a mobile service may provide information about agrifood products (e.g. seasonality or shelf life) or AAFN organization culture (e.g. norms or values).

HSSI-KIS: in the interaction, some KISs are made accessible by the service system. For instance, a mobile application can make it possible to access an organizational database containing data about the sale, movement, and distribution of produce along the AAFN.

KIS-ICD: any KIS of the service system is related to a subset of ICD that constitutes its information content domain. For instance, a research center, as an AAFN external source, may be involved in service management by providing scientific knowledge that can be lately exploited by farmers to learn how to grow better quality, higher-yielding crops.

Let us discuss now the structure of each single component.

Human-Service System Interaction (HSSI)

By taking into account a user-centric perspective, we group interaction characteristics into dimensions as follows:

a.1 User's role: it specifies the role of the user in the AAFN, when acting in the interaction with the service system. Such role is typed as consumer, producer, or organization operator.

a.2 Scope: it specifies the type of motivation for the participation to AAFN activities. Participation is seen in terms of expressing and discussing ideas,

KIS ICD

Exchanged Information Source Accessibility Information Source Domain HSSI Figure 1 developing plans, evaluating actions, and decision-making. Motivation types are social (e.g. tighter relationship with others, social belonging), ecological (e.g. lower environmental impact), economical (e.g. available income/budget impact), and personal wellbeing (e.g. physical and mental health, pleasant time).

a.3 Timing: it specifies the moment in the agrifood chain of the AAFN when the interaction occurs: "production", "distribution", "consumption", and "waste management" turn out to be the values along this dimension. Synchronicity and asynchronicity can be also considered in this group interaction characteristics, especially when the use situation is time critical.

a.4 Place: it specifies the place where the interaction occurs; this place is typed as "farm site", where the agrifood product is coming from, "agrifood terroir", i.e. the land bestowed upon the agrifood, "proximate area", i.e. an area (e.g. urban area) that is close to the agrifood terroir. Such a dimension is particular important in locationbased services in which a mobile application uses the user's location interaction place. a.5 Flow type: it specifies both the type and the direction of the information flow in the interaction; it is typed as "informational", i.e. information is only pushed from a mobile application to the user, "reporting", i.e. information is only pulled by the mobile application from the user, and "interactional", i.e. a bidirectional flow between the user and the mobile application occurs.

Knowledge and Information Source (KIS)

A service system makes use of many KISs that can be grouped in the following categories:

b.1 Participants: AAFN people (e.g. consumers, producers, FM operators, regarded as individuals) constitute KISs, since they possess interesting information and individual knowledge, independent of an organizational entity's existence, which can be exchanged in a user interaction with the service system. For instance, producers could provide information and knowledge about the farm origin of agrifood, including the environmental and social conditions of its production, as well as the cultural significance behind agrifood tied to a specific method or place of production; consumers could provide information and knowledge about taste, culinary uses and sales responsiveness of agrifood products.

b.2 Organization: any organizational entity (e.g. a consumers group, a group leader, a farmer-driven board of directors, a vendor-consumer advisory committee, a FM operator) in an AAFN is a source of organizational information and knowledge that is embedded within the behaviours that manifests in the overall AAFN organization through its culture (values, principles, norms, traditions, unwritten rules, and informal procedures), its structure (roles, relationships, and regulations that govern their use), and its business function (activities or tasks, such as planning, production, sales, performed together to obtain a defined set of results). For instance, a FM operator could provide information and knowledge about market prices and even latest agricultural practices that are essential in creating opportunities for small producers to know their economic performance.

b.3 Environment: external entities (e.g. input providers, certifying and extension agencies, NGOs, governments, financial service providers, research centers and other agrifood organizations) operating in an AAFN surrounding (socio-political, economical, bio-ecological) environments constitute a KIS. For instance, input retailers often serve as a de-facto source of expert information for small farmers who can learn about the application and use of nutrients and pesticides.

Information Content Domain (ICD)

In analyzing the component ICD, we distinguish two main dimensions: c.1 Content exposure: it refers to what extent the ICD (or a part of it) is accessible to service users. In public exposure the domain is publicly accessible by anyone at any time. In private exposure the domain can only be accessed by a pre-selected (by a third party) group of users.

c.2 Content orientation: it refers to semantic aspects of the ICD. An ICD of an AAFN service may be related with the following categories: c.2.1 agrifood product, i.e. content items regarding attributes (e.g. price, seasonality, varieties, taste shapes, textures and aromas of agrifood) of products exchanged in an AAFN; c.2.2 people: content items that are useful to know a person (e.g. trustworthiness, loyalty, integrity, wishes and needs) involved in AAFN activities; c.2.3 organization functions: content issues about activities (e.g., agricultural practices, processing methods, food preparation) at any stage (production, distribution, consumption, and waste management) of the agrifood chain in an AAFN; c.2.4 organization structure: content items that are useful to know roles, relationships, and regulations that govern their use in an AAFN; c.2.5 organization culture: content items that are useful to know norms, values, experiences, and history of an AAFN; c.2.6 environment: content items regarding social, economic and natural aspects of the environment surrounding an AAFN.

Selected Case Studies

In order to demonstrate the applicability of our service analysis framework, we have selected and analysed 10 real world cases of AAFN services that have been considered relevant in the mobile service classes described in section 2.

For each of them, the analysis has been carried out by examining relative web sites, combining qualitative information from relative professional literature, and, when possible, downloading and using relative supporting mobile applications.

Analysis results are synthetized in Table 1, where rows correspond to mobile service classes and columns correspond to analysis dimensions (including organizational forms of an AAFN as a further dimension). Mobile service examples mentioned in the table may be placed in several classes depending on the use situation and the individual user's preferences.

Conclusions

AAFNs can benefit of the use of mobile information services in several different ways. Under a user perspective, the overall value of a service is based on consumption motivations, use context criticalities, user's role in the AAFN, and information sources of the service. According to this value segmentation, we have proposed an analysis framework that represents a meaningful tool for both AAFN managers and service providers. Specifically, the first ones can benefit of using the framework to evaluate AAFN people reactions to specific mobile services and to understand which types of mobile service are likely to be tried and used in an AAFN. The second ones can benefit of using the framework to segment their customers, to assess critical success factors of their services from a customer-centric viewpoint, and to develop strategies to create value for AAFNs.

Real world cases of AAFN mobile services have been taken into account as exemplifications of our analysis scheme. However, because the focus is on general characteristics of mobile services, the framework can be used to explore or create new types of services for AAFNs.

Table 1 .

 1

			ICD	KIS		Users Interactions				Org. Form
		Private CO	Public CO		ur	s	t	p	ft
	Virtual visits 1	Consumers shopping list	Agrifood products: prices, descriptions, photos and availability; Organizational functions: Producers practices, hours, dates of operation Organizational Structure: FM map: producers at the market; Market	Producers, FM steering committee; Other Organization	Producers: managing information on own profile and products Consumers: search information about market and products, sourced by producers	Producers: grow their customer base by providing detailed information to consumers. Consumers: shop with confidence, save time and discover new products with	Asynchronous Distrib.	Non based location	Informational: to consumers from producers	FM
			what's new at the market,			information sourced directly from
			hours, and parking info			the producers themselves
			Agrifood products: descriptions,
	traceability and product related informations 2 ,3,4		about food provenance, source and traceability Organizational functions: agricultural practices; Productions methods Organizational structure:	Producers input providers Other Organization	Producers: managing information on own profile and expose QR-codes Consumers: Scan QR-codes to get information about food source;	Producers: grow their customer base by making traceability a competitive advantage. Consumers: searching for food provenance and food source	Asynchronous Prod./ distrib.	location based FM or farm site/	Informational: from producers to consumers	FM DoFS
			Producers relationships
			Organization culture: Farmers history 3
	location-based services 5,6,7	GPS coupons for those in the area	Agrifood products: fruit and vegetables in season, nearest to consumers ,5 Organizational functions: production methods; Organizational structure: FM or vendors location on map (and GPS routing) , hours/dates of operation Organization culture: Farmers history 6	Government Consumers 7 Other Organization 4 Producers 6 , FM steering committee 6	Producers: managing information on own profile 5 Consumers: search information on market location and product availability; reporting information about listed AAFNs or add new one , 7	Producers: providing information about places where AAFN activities may occur. Consumers: searching for in-season, local food by pinpointing nearest DoFSs, FMs, and CSAs	Asynchronous Distrib	location based farm site/proxim ate area	interactional from producers, or Other Organization to consumers and vice versa	CSA; BS, FM DoFS
	dietary and	nutrition	Agrifood products: nutritional information, preparation guide, recipes,	Government,
	health	calculator for	storing advices and pesticide information	Research centers
	services 8, 9	consumers 8	buy organic or healthy products Organizational structure: FM where to	Other Organization

Table 1 . Reference urls of mobile services

 1 1. Edibly Pike Place Market (itunes.apple.com/us/app/edibly/id553296441?mt=8) 2. shopSavvy (shopsavvy.mobi/2011/03/08/food-traceability-on-shopsavvy; top10produce.com) 3. localsqr (localsqr.com) 4. HarvestMark Food Traceability (harvestmark.com) 5. locavore (getlocavore.com) 6. Atlantic Highlands Farmer's Ma (itunes.apple.com/us/app/atlantic-highlandsfarmers/id521136603?mt=8) 7. NRDC Eat Local (simplesteps.org/eat-local) 8. Smart Foods-Organic Diet Buddy (saagara.com/apps/organic-diet-buddy-app) 9. Seasonal and simple (seasonalandsimple.info) 10. foodtree (foodtree.com/you);

Agrifood is a generalized term for mostly farm-originated products that are intended for human consumption. Of course, this definition is a fuzzy definition, since it depends on how much a product is farm-originated. A deep discussion on farm-originated food is beyond the scope of this paper. However, it is useful to distinguish:

Acknowledgement. This research work was supported by AGROMATER LAB, and DIRECT-FOOD, two projects funded by the EU and the Italian Government, both aimed to support marketing of typical agrifood products in Calabria (Italy).

Consumers: search nutritional and health information food products

Consumers:

Wellbeing: searching for health aspects related to fruits and veggies


Antonio P Volpentesta
email: antonio.volpentesta@unical.it

Nicola Frega
email: nicola.frega@unical.it

Giuseppe Filice
email: giuseppe.filice@unical.it

Interactions Patterns in NFC Interfaces for Applications and Services

Keywords: NFC, interaction pattern, mobile service, human-system interaction

Near Field Communication (NFC) technologies are normally used to establish radio communication between two NFC compatible devices by touching them together or bringing them together less than four centimeters. Nowadays, the interface of a large range of business and consumer applications are based on such technologies. In this paper, we propose a model to identify human-system interaction patterns that occur when NFC enabled devices are employed. Moreover, we show the applicability of such a model through an analysis of a relevant number of real world cases of applications and services which have currently arisen in many business streams. The study is aimed to categorize current NFC interfaces and to explore their underneath value..

Introduction

The term "Near Field Communication" (shortly, NFC) is used to refer to a short range wireless communication technology that is derived from Radio Frequency Identification (RFID) and enables communication between two NFC enabled devices within few centimeters. It is based on an integrated circuit chip in a card, or any other form factor device. More precisely, NFC devices (e.g. a contactless card and a mobile phone) can communicate with each other when they are less than four centimeters nearby. NFC technology is usually employed to provide applications with NFC interfaces (shortly, NFC apps) that are:

• RFID compatible. They ensure interaction with existing RFID infrastructures;

• Usable. They can be easily used to make an application run, without requiring any particular technical knowledge of NFC devices (a communication starts by bringing two devices together, and it is cut by separating two devices), [START_REF] Csapodi | New applications for NFC devices[END_REF]; • Secure. Security measures can be built into NFC technology in order to establish a NFC secure channel for confidentiality, integrity and authenticity of the data transferred between devices. This would protect against eavesdropping, data corruption, data modification, and man-in-middle attacks, [START_REF] Haselsteiner | Security in Near Field Communication (NFC): Strengths and Weaknesses[END_REF]; • Convenient. They can advantageously assist people to perform every day actions, especially in searching for information . Many useful information (e.g. location-relevant map, transport timetables, special discounted product/service offers, etc.) can be more easily accessed through an NFC interface rather than using conventional human computer interface. Nowadays, NFC interfaces have been developed for a large range of business/consumer applications and services in various industry sectors. Nevertheless, many researchers continue to propose application scenarios or use cases in order to explore new opportunities of NFC apps that can generate significant business value through the provision of more accurate and timely information, [START_REF] Haselsteiner | Security in Near Field Communication (NFC): Strengths and Weaknesses[END_REF]. However, a characterization of NFC interfaces is still needed in order to provide both a common understanding of capabilities and features of NFC apps and a support to the design, development and deployment of novel services. In this paper, we propose a general model to identify human-system interaction patterns that occur when NFC enabled devices are employed in services and applications. The resulting classification provides definitions and distinctions that constitute a primary benefit at a general level of communication among all NFC ecosystem stakeholders. Many services that are currently available in different business sectors, exhibit the same interaction patterns and make use of NFC apps with considerably overlapping interface requirements. Another motivation of our work is to provide an aide for the interface design of NFC apps with a generic applicability. Moreover, in order to show the applicability of our model, we present results obtained by an analysis of a relevant number of real world cases of applications and services in many target service industries (e.g. marketing, transportation, education, etc.).

Backgrounds

NFC is a subclass of RFID technology which uses similar working principles. NFCenabled devices can both extract information from an RFID transponders and imitate them. NFC technology supports two main communication modes:

• the communication between two active devices, powered and equipped with data processing capability; • the communication between active devices and passive NFC tags. In general, when two devices interacts thru NFC, we can have three different communication configurations [START_REF] Haselsteiner | Security in Near Field Communication (NFC): Strengths and Weaknesses[END_REF] as in Table 1. In addition to the active/passive mode definition, two different roles can be played by a device in NFC interactions [START_REF] Haselsteiner | Security in Near Field Communication (NFC): Strengths and Weaknesses[END_REF]. The role of the device which triggers the data exchange is called initiator, the role of the other device is called target. So, an active NFC device can be both initiator or target; a passive device can only work as a target. NFC is becoming a significant rival of Bluetooth for proximity communication where a Wi-Fi connection is unavailable or not trusted. For example when two active NFC devices interact we have some advantages over Bluetooth:

• Simpler and easier gestures for communication start (touch or tap);

• Lower-latency for effective data transfer start (hundredths vs. seconds);

• NFC power consumption in active devices is significant less than Bluetooth (passive NFC tags are powerless);

• NFC technology is cheaper and less complex;

• Shorter field range ensures more security against man-in-middle attacks.

In last years, many scientific work has been devoted to study the NFC world. Scientific papers have essentially regarded four major NFC topics: theory and development, applications and services, infrastructure, ecosystem. In particular, many surveys have been proposed in order to cover a large number of implemented and prototype applications in many economic fields such as transportation, retailing, banking, security, social networking, entertainment. Most of these surveys have tried to put in strict relation NFC operation modes with benefits and future scenarios in the NFC ecosystem [START_REF] Özdenizci | Current Benefits and Future Directions of NFC Services[END_REF]. These typical modes are mainly identified as:

• "Reader/Writer Mode Applications": let NFC devices to read and write content data stored in NFC passive (i.e. without battery powering) tag; • "Card Emulation Mode Applications": let NFC devices to act like a standard smartcard (ex: for payment and ticketing); • "Peer-To-Peer Mode Applications": allows two NFC devices to create a device to device connection to exchange any kind of data (ex: pictures, contacts) . Such NFC modes are considered as "essential characteristics for examining NFC applications", since they can provide different benefits to users and can suggest different future usage scenarios [START_REF] Özdenizci | Exploring Underlying Values of NFC Applications[END_REF]. Other surveys are focused on a single business stream, like mobile contactless payments, examining advantages and obstacles of NFC technology adoption. However, all these investigations essentially adopt a designer perspective by taking into account technical features of NFC interfaces, e.g. NFC operation modes. A usercentric perspective would be more effective both in identifying common solution for common problems in human-system interactions and in explaining usability aspects of NFC apps supporting a service.

Interaction Patterns in NFC Interfaces

In software engineering, a pattern is generally defined as "a common solution that can be applied to a common problem in a given context" [START_REF] Issa | Using use case patterns to estimate reusability in software systems[END_REF]. In particular, much research work has been devoted to interaction patterns in user interfaces, i.e. patterns that are focused on solutions to problems that end-users have when interacting with systems. Such studies essentially take into account a designer perspective and are aimed to improve both communication within and across software development teams (programmers, managers and end-users of a software system) and productivity of software engineers, [START_REF] Larsen | Designing Component-Based Frameworks Using Patterns in the UML[END_REF]. Restricting our attention to NFC interfaces, we take into account a user perspective by focusing on those patterns that really benefit the user, and explain usability aspects of NFC apps. Of course, patterns that are identified under a user perspective are also usable for designers, but not vice versa.

In this section, we categorize NFC interface patterns according to the kind of usage problems they address in different application domains. Our categorization is based on a survey of real-world NFC applications that are described in professional and academic literature or commercial web sites.

The rationale is to specify attributes and properties of the different pattern types to facilitate their understanding and reuse. In this sense, it should be noted that the link between patterns is as important as the pattern itself: in most real world NFC applications, an interface pattern are applied in conjunction with other patterns that might be used alternatively or as complementary ones.

In [START_REF] Alexander | The timeless way of building[END_REF], it is stated that "Each pattern is a three-part rule, which expresses a relation between a certain context, a problem, and a solution". Applying this concept to an NFC interface pattern, we may say that pattern attributes are:

1. the pattern name, or a pattern identifier, which is used to capture the meaning and intent of the pattern in a way that facilitates communication and describes the offered service. 2. the problem, which explains the user need to be satisfied when the user interacts with the system; 3. the context, which describes the situation where the pattern is relevant and when to apply the pattern; 4. the solution, which describes how to solve, as far as possible, the problem. The description deals with the adopted user and system NFC devices, their communication configuration and NFC operation mode; Since an NFC basic pattern essentially concerns with the transmission of a unit of information in a human-system interaction trough an NFC protocol, we may analyze it with respect to three fundamental dimensions:

• content entirety: the information content may be either self-contained (SC) , i.e. it can be useful and understood if viewed alone with no other supporting data, or containing external references (ER), e.g. a link, an identification key; • content domain orientation: the information content may regard either the human (H), i.e. personal data, or the system (S), i.e. system data. Personal data include data about the person interacting with the system, data about his/her interaction NFC device, or data collected for personal use. System data include data for its functioning, management, or comprehension; • content use side: the unit of information generated in the NFC interaction may be either used (scanned/read/viewed/processed) at the system's side (SS), i.e. the system is the end-user, or at the human's side (HS), i.e. the human (or client) is the end-user. According to these dimensions, we may group NFC basic interface patterns in eight classes that are described as follows:

1. Pattern P(SC,H,SS) Problem: a person is required to provide his/her own personal data in a way understandable to a system's component (personnel or device) that has to make a decision or take an action depending on such information; the person should be relieved of searching for data and performing data entry; Context: any human-system interaction where a person needs to give his/her personal data to the system through a quick one-step interaction; the person may be not familiar with the data, he/she may not know the exact required syntax, he/she is temporary unable to provide such data. Solution: provide the person with a passive NFC tag that contains his/her own personal data readable by the system NFC active device, eventually used by the system personnel. Example scenarios: A user can bring a passive NFC tag (i.e. embedded in a lace or wrist band) containing basic medical information to be read in case of first medical aid when unable to communicate with medical operators (user can be unconscious or affected by a social disorder disease). Another scenario can be simply related to the need of printing a photo contained on user device directly on an NFC-enabled printer like FujiiFilm SmartPix Kiosks in UK [u20].

Pattern P(ER,H,SS)

Problem: a person is required to provide his/her own personal data in a way understandable to a system's component (personnel or device) that has to make a decision or take an action depending on such information; the person should be assisted in searching for data and performing data entry; Context: any human-system interaction where a system's component (personnel or device) is required to perform an action depending on the person's data that are stored at an external source (another component at system side or third-party archive); Solution: provide the person with an NFC tag that contains a reference to his/her own personal data stored at an external source (another component at system side or thirdparty archive); the reference is in a format readable by the system NFC active device that can perform a query to obtain the complete information. Example scenarios: digital personal ID (smart ID) Future Personal ID or passport can be issued with NFC technology, embedding an encrypted NFC tag, with owner personal information, into physical card (rubber or plastic) or directly into SIM phone card (for example [u21])

Pattern P(ER,S,SS)

Problem: a person should be relieved of providing the system with a complete and truthful information (license, certificate, token, permit, etc.) that is needed to be validated by the system before taking an action; Context: any human-system interaction where the person needs to access and/or redeem a service and he/she could be provided with a reference to secure and acceptable data stored at an external source (another module at system side or thirdparty archive), no matter of the location of the system device charged to check it out; Solution: provide the person with an NFC device that contain a reference to truthful information (license, certificate, token, permit, etc.) necessary to access the service; the system is in charge to get the reference and validate the license/token/certificate to let the person access to the service. Example Scenarios: smart boarding pass: an airline company can allow members of its frequent flyer programme to use their mobile phone as their smart boarding pass. These members attach an NFC sticker to their mobile phone and this will then act as a wireless transmitter across the airport at self-service kiosks, security, fast track lanes, lounges, and gate facilities. In this way, the tags not only replace their boarding passes, but also allow them to access the priority security check, and even enter the VIP-style lounge. (see [u14]) SAS Airlines introduced a "Smart Pass" pilot program; others can be found in [u15][u19].

Pattern P(SC,S,SS)

Problem: a person should provide the system with some parameter values through a quick one-step interaction; such values are needed by the system in order to perform an action; Context: any human-system interaction where the person needs to provide the system with setting configuration values based on situation profiles; Solution: provide the person with an NFC tag that has been programmed to efficiently adjust a series of system settings based on situation profiles , e.g. settings based on the arrival or departure of commonly visited locations. Example scenarios: Auto-start timers: an NFC tag is put on a home appliance (e.g. washing machine, oven, or vacuum cleaner) so that, when tapped, it fires up a timer.

Pattern P(ER,S,HS)

Problem: a person needs to quickly get enriched information about a system entity (product, person, digital object, space area) located in a physical/virtual space; the person wants to enhance his/her comprehension of such an entity and should be assisted in searching for appropriate information; Context: Any circumstance where enriched information of system entities are available to be accessed by a person, through using external reference to information contained in an external source (another component at system side or third-party archive); the person is not required to strive for data entry necessary to retrieve system entities information on the external source. Solution: provide any physical entity (a system component) with a passive NFC tag that contains external references; the person is provided with an active NFC device (e.g. a mobile phone with an appropriate app) able to get the referenced content on this device.

Example scenario: smart poster. A poster promoting some kind of new product or service, or an event, could be provided with an NFC tag; a person could touch his/ her device against the tag embedded in the poster, and he/she will receive the URL for a web site containing further information [p1].

Pattern P(SC,S,HS)

Problem: a person needs to quickly get enriched information about a system entity (product, person, digital object, space area) located in a physical/virtual space; the person wants to enhance his/her comprehension of such an entity and should be relieved of searching for information; Context: Any circumstance where several physical entities are presented and arranged spatially on a limited area. A non-expert person needs to perform an infrequent task consisting of getting entity few basic information about a physical entity (or physical objects grouped conceptually), by a simple action (touch/tap); Solution: provide any physical entity (a system component) with a passive NFC tag and the person with an active NFC device (e.g. a mobile phone with an appropriate app) able to read and display the tag information on it (such device can be owned by the user or system can make it available to the user); the tag information may regard location or content information about the physical entity; Example scenario: In a store, merchant can embed an NFC passive tag on products, containing valuable ready-to-use information; any user can read the content of the product tag by using a NFC-enabled phone. Another scenario can be outfitted for visual impaired people, sticking an NFC tag on "everyday " objects, including food products, to aid them to get memo-text ready to be synthetized by specific TTS-enabled app. The user can even record him/herself the memo-text using speech-recognition app (ASR) to transform speech to text before writing it in NFC tag [p5].

Pattern P(SC,U, HS)

Problem: a person should provide its own device with some parameter values in a quick one-step interaction in order to let it perform a frequent preferred task in a certain location; Context: Any circumstance where the person needs to provide its own device with preferred settings configuration values depending on the location where he/she is; Solution: provide a physical entity in the person's environment with a passive NFC tag and the person with an active NFC device (e.g. a mobile phone with an appropriate app) able to interact with system components; the tag information may regard location or content information about the physical entity; Example scenario: At home, an NFC tag can be put near the door and can be settled to do things like: enable Wi-Fi, decrease brightness, disable Bluetooth, and auto-sync. The tag has been previously programmed (e.g. by using NFC Task Launcher [u24]) to "switch," so that when the person exits his/her house and taps the tag for the second time, it changes those settings (ex: enabling Bluetooth for in-car use) 8. Pattern P(ER,U, HS) Problem: a person needs to quickly get personal information (text, audio, images, video) stored on his/her own device; the person should be assisted or relieved of searching such information; Context: any situation where a person in a certain place frequently needs to know the location of a file on his/her own device; Solution: provide user with a set of NFC passive tag (i.e. stickers) to be formatted and written by the user him/herself with reference to personal information on his/her device; the user can later read the NFC tag to retrieve referred content.; user can use his/her personal device (smartphone) for both write and read the NFC tag via a specific app. Example scenario: Getting shortcuts to specific personal notes: an NFC tag can be programmed to link directly to specific notes on an NFC mobile phone. For instance, a tag can be put on a desk so that when tapped, it opens a to-do list (or a checked-in contacts view) on the mobile phone, or it can be placed near a tech product so that when tapped, it links to a note with personal remarks on how to use it [u22].

Selected Case Studies

Since June 2006, when the NFC standardized technology architecture has been introduced, higher-volume NFC deployments have become common in many devices (mobile handsets, PCs, set-top boxes, cameras, printers, cash machines, posters, street signs, bus stops, parking meters, door openers, and product packaging). This has pushed software developers to conceive and implement a lot of NFC-enabled applications that, currently support several hundreds of NFC services in different business areas. In order to demonstrate the applicability of our classification model, we have selected and analyzed 26 real world cases of services and projects that have been considered relevant in main target industries (transport, hospitality, banking, retail, medical, logistic, educational, office automation, government, and amusement). For each of them, we have identified the underneath NFC-enabled application and patterns that occur in a human-system interaction mediated by NFC devices to execute a service function. Results obtained from the analysis of these case studies are reported in Table 2, where we have deliberately omit technical features (NFC embedded modules, external peripheral devices, etc.) not useful to our purpose.

Conclusions and Future Work

The rationale of our investigation was to identify human-system interaction patterns (mediated by NFC devices) in services and applications. In our opinion, these patterns constitute a base to classify NFC services that are currently available in different business sectors, providing a primary benefit at a general level of communication among all NFC ecosystem stakeholders. Moreover, they can be used in most cases as an aid to design appropriate NFC interfaces to apps supporting services. In order to test the applicability of our model, we have selected and analyzed a set of real world cases of services and projects that have been considered relevant in main target industries. In future works, we plan to apply the model for the analysis of NFC interfaces of mobile services in agrifood systems [8] [9].

Table 1 .

 1 Communication Configurations

	Device 1	Device 2	Explanation
	Active	Active	The RF field is alternately generated by Device 1 and 2
	Active	Passive	The RF field is generated by Device 1 only
	Passive	Active	The RF field is generated by Device 2 only


Christopher Durugbo
email: christopher.durugbo@bristol.ac.uk

Managing Partnership Uncertainty for Sustainable Services: A Conceptual Model

Keywords: collaborative networked organisation, sustainability, supply chains, virtual enterprise, product-services systems

The paper presents the findings of a qualitative analysis that makes use of literature to determine the nature of uncertainties that characterises industrial collaborations for providing sustainable services. It aims to propose a conceptual model of partnership uncertainty management for sustainable services. The analysis finds that managing partnerships uncertainty for sustainable services requires foci that reflect governance structure and relationships climate priorities. These priorities are life-cycle control, resource governance, capability focus and integrative operations with regards to self uncertainty, participative decisions, intervention mechanisms, idea linkage, consumption patterns, communicative structure, clear representations and relationship incentivisation in terms of relationship /behavioural uncertainty, and creativity leveraging, environmental profiling, systemic measuring and process learning as they relate to partner uncertainty. The paper concludes by highlighting research limitations and potential future research directions.

Introduction

Forecasts by organisations such as the United Nations suggest an increasing global population which is estimated to reach 8.9 billion by 2050 [START_REF]The World at Six Billion (ESA/P/WP.154)[END_REF]. This trend underscores constraints and limitations on the availability of natural resources. The increased level of production and energy consumption due to the rising population also causes concerns due to the earth's inability to accept industrially generated waste. With this in mind, research has intensified into theories and philosophies that concomitantly deliver high quality services, efficiently apply resources, and minimise waste from production and consumption. A sustainable service (e.g. [START_REF] Halme | Sustainable homeservices? Toward household services that enhance ecological, social and economic sustainability[END_REF] and [START_REF] Heiskanen | Can services lead to radical eco-efficiency improvements? -A review of the debate and evidence[END_REF]) is an approach designed to capture this philosophy.

Sustainable services (also known as a 'sustainable product-service systems' [START_REF] Roy | Sustainable product-service systems[END_REF] or 'eco-efficient product-service systems' [START_REF] Manzini | A strategic design approach to develop sustainable product service systems: Examples taken from the 'environmentally friendly innovation' Italian prize[END_REF], [START_REF] Ceschin | Critical factors for implementing and diffusing sustainable product-Service systems: insights from innovation studies and companies' experiences[END_REF]), strategise the provision of results or functions and motivates firms to form partnerships and make decisions, under uncertainties, to creatively generate ideas that reduce the environmental impact of companies by factors between 4 and 20 [START_REF] Roy | Sustainable product-service systems[END_REF]. These partnerships coincide and align with widely acknowledged notions that companies are increasingly competing as part of supply chains and partnerships to deliver customer solutions. In spite of this, to date, there has been limited coverage in the literature on the uncertainties that plague partnerships to provide sustainable services. This paper seeks to confront this gap.

The aim of this paper is to propose a conceptual model of partnership uncertainty management for sustainable services. Uncertainty is used in this context, as "the difference in the amount of information that is required to perform a task and the amount of information already possessed by the firm" [START_REF] Galbraith | Designing Complex Organizations[END_REF]. Uncertainty is typically associated with production in collaborations such as supply chains [START_REF] Davis | Effective supply chain management[END_REF] and with how sustainability policies are adopted and partners are chosen to deliver sustainable product-service mixes [START_REF] Mont | Clarifying the concept of product-service system[END_REF]. Consequently, the research is guided by the following research question: What is the nature of uncertainties that characterises industrial collaborations for providing sustainable services?

Background

In the provision of sustainable services, stakeholder participation is achieved through solution-oriented partnerships (SOPs) i.e. strategic partnerships that share common visions of delivery systems for sustainable services (e.g. [START_REF] Krucken | Building stakeholder networks to develop and deliver productservice-systems: practical experiences on elaborating pro-active materials for communication[END_REF], [START_REF] Vogtländer | Communicating the eco-efficiency of products and services by means of the eco-costs/value model[END_REF], [START_REF] Wang | Analysing network uncertainty for industrial product-service delivery: a hybrid fuzzy approach[END_REF] and [START_REF] Evans | Industrialization as a key element of sustainable product-service solutions[END_REF]). These partnerships focus on multi-level communications and complex relationships among platform providers, other providers that are needed to complete the system, as well as intermediate-and end-users of the system. Communication and relationships among stakeholders encourages positive attitudes towards selecting products, combining products and services, and formulating regulations that promote lower environmental burden [START_REF] Vogtländer | Communicating the eco-efficiency of products and services by means of the eco-costs/value model[END_REF], [START_REF] Evans | Industrialization as a key element of sustainable product-service solutions[END_REF]. SOPs -in view of uncertainties of partnershipsalso fundamentally change producer-consumer relationships towards new notions of sale, ownerships and consumption in which functions are delivered and potentially leads to customer loyalty and innovation that causes behavioural and system-level changes [START_REF] Manzini | A strategic design approach to develop sustainable product service systems: Examples taken from the 'environmentally friendly innovation' Italian prize[END_REF], [START_REF] Ceschin | Critical factors for implementing and diffusing sustainable product-Service systems: insights from innovation studies and companies' experiences[END_REF].

Uncertainty associated with partnerships is reflected in the variability of governance structure and climate of relationships [START_REF] Wang | Analysing network uncertainty for industrial product-service delivery: a hybrid fuzzy approach[END_REF], and researchers have used several terms to characterise this variability, as shown in Fig. 1. For instance, using uncertainty reduction theory, partnership uncertainty has been split into self uncertainty (individual's involvement in relationships), partner uncertainty (variance in partners involvement in a relationship), and relationship uncertainty (variance in the relationship itself) [START_REF] Berger | Language and Social Knowledge: Uncertainty in Interpersonal Relationships[END_REF]. Relationship uncertainty (also termed behavioural uncertainty) refers to how adaptability partners are to specification changes at short notice and an awareness of partner's resources and goals [START_REF] Eriksson | Modeling uncertainty in buyer-seller cooperation[END_REF]. Behavioural uncertainty, i.e. the variability of a partner's behaviour or the partner's changes in external environments, is also reflected in performance variations of partners during transactions [START_REF] Wang | Analysing network uncertainty for industrial product-service delivery: a hybrid fuzzy approach[END_REF]. While there is a common theme in the literature supporting the need to identify and mitigate uncertainty, these are predominantly studied in relation to manufacturing and product delivery processes [START_REF] Mason-Jones | Shrinking the supply chain uncertainty circle[END_REF]. In this article, current research is enhanced through the introduction of a conceptual framework that not only captures the forms of uncertainties that characterise SOPs but also identifies key factors for realising collaborations that provide sustainable services.

Self uncertainty

Partner uncertainty

Relationship climates

XXXXX XXXXX Uncertainty Contribute to Key:

Behavioural uncertainty

Relationship uncertainty

Partnership uncertainty

Governance structures

Stakeholders

Method

In attempt to offer insights into the nature of uncertainties that characterises industrial collaborations for providing sustainable services, this research is driven by the multicase study logic [START_REF] Yin | Applications of Case Study Research[END_REF] and relies on literature as secondary cases [START_REF] Stewart | Secondary Research: Information Sources and Methods[END_REF]. This logic was chosen because an assessment of the literature suggests limited studies to provide insights into partnership uncertainties for sustainable services. This motivation stirred the research towards case studies in an exploratory approach that captures the 'what's and 'how's of partnership uncertainty for sustainable services. Also, the use of multiple secondary sources was geared towards a holistic view with potentials to unearth uncertainties across discovery, design, development, delivery and disposal phases of service operations. Holistic in used in this context to mean connectedness among characteristics and phenomena, and is required for the integration of sustainable service elements such as goods, equipment, services, information or infrastructure. For this study, 17 research articles were selected based on a search for publications within SCOPUS, ABI/INFORM (ProQuest), Academic Search Premier (EBSCO Host), and ACM Digital Library. Selection involved an initial search and screening process using keywords: "sustainable product-service systems", "ecoefficient product-service systems", and "sustainable service". Next, using the conceptual framework from Fig. 1, the main findings and discussions of the cases were analysed to shed light on key factors for realising collaborations that provide sustainable services and to refine the research model. This research is therefore positioned within an interpretive epistemology to make sense of partnership uncertainty for sustainable services. By applying the multiple-case logic, a C. Durugbo range of management factors was explored and the study generalises at a level of theory as opposed to statistical representativeness or significance.

Findings

An analysis of the data showed several challenges faced by partnerships for sustainable service provisions, as described in Table 1. These challenges span several individual-, organisational-and institutional-levels of concern and range from humanrelated questions on the consumption patterns of consumers (e.g. [START_REF] Tukker | Eight types of product-service system: Eight ways to sustainability? Experiences from suspronet[END_REF] and [START_REF] Briceno | The role of social processes for sustainable consumption[END_REF]) to innovation-related problems of diffusion and idea generation (e.g. [START_REF] Roy | Sustainable product-service systems[END_REF], [START_REF] Ceschin | Critical factors for implementing and diffusing sustainable product-Service systems: insights from innovation studies and companies' experiences[END_REF] and [START_REF] Anttonen | Greening from the front to the back door? A typology of chemical and resource management services[END_REF]).

Case

Challenges for sustainable service partnerships Halme, Jasch and Scharp [START_REF] Halme | Sustainable homeservices? Toward household services that enhance ecological, social and economic sustainability[END_REF] Governance of resources to ease service accessibility Heiskanen and Jalas [START_REF] Heiskanen | Can services lead to radical eco-efficiency improvements? -A review of the debate and evidence[END_REF] Trajectory of eco-efficient service to establish necessary intervention mechanisms and to improve design practices Roy [START_REF] Roy | Sustainable product-service systems[END_REF] Radical process ideas to consolidate waste reduction practices Manzini and Vezzoli [START_REF] Manzini | A strategic design approach to develop sustainable product service systems: Examples taken from the 'environmentally friendly innovation' Italian prize[END_REF] The development of business ideas that link sustainability to structural and behavioural changes Ceschin [START_REF] Ceschin | Critical factors for implementing and diffusing sustainable product-Service systems: insights from innovation studies and companies' experiences[END_REF] Socio-technical experiments and societal embedding process for which actor networks, project visions and learning processes are critical factors for the diffusion of system innovation Mont [START_REF] Mont | Clarifying the concept of product-service system[END_REF] Readiness to adopt and accept sustainable service strategies Krucken and Meroni [START_REF] Krucken | Building stakeholder networks to develop and deliver productservice-systems: practical experiences on elaborating pro-active materials for communication[END_REF] Pro-active and participative attitude for customer solutions Vogtländer, Bijma and Brezet [START_REF] Vogtländer | Communicating the eco-efficiency of products and services by means of the eco-costs/value model[END_REF] Availability and use of information by stakeholders to make decisions. Evans, Partidário and Lambert [START_REF] Evans | Industrialization as a key element of sustainable product-service solutions[END_REF] Realising solutions that incentivise organisations to be sustainable Tukker [START_REF] Tukker | Eight types of product-service system: Eight ways to sustainability? Experiences from suspronet[END_REF] Incentives for stakeholders to be sustainable Briceno and Stagl [START_REF] Briceno | The role of social processes for sustainable consumption[END_REF] Alternate consumptions patterns that reflect social strategies Anttonen [START_REF] Anttonen | Greening from the front to the back door? A typology of chemical and resource management services[END_REF] Management to integrate innovation and environmental policies Maxwell, Sheate and van der Vorst [START_REF] Maxwell | Functional and systems aspects of the sustainable product and service development approach for industry[END_REF] Targeting companies for effective management of supply chains Mont [START_REF] Mont | Institutionalisation of sustainable consumption patterns based on shared use[END_REF] Consumption behaviour mainly in terms of institutional factors Hu, Chen, Hsu, Wang, and Wu [START_REF] Geum | Designing the sustainable product-service integration: A productservice blueprint approach[END_REF] Overcoming barriers to implementing new business models Geum and Park [START_REF] Hu | Development of sustainability evaluation model for implementing product service systems[END_REF] Clear representations for effective sustainable service design Lee, Geum, Lee and Park [START_REF] Lee | Dynamic and multidimensional measurement of product-service system (PSS) sustainability: A triple bottom line (TBL)-based system dynamics approach[END_REF] Systematic approach to measuring sustainability Based on the research model in Fig. 1 and findings from the case studies, a conceptual model of partnership uncertainty management was developed, as illustrated in Fig. 2. The figure attempts to map the various management factors (4 for self uncertainty, 7 for relationship /behavioural uncertainty, and 4 for partner uncertainty) analysed from the cases according to governance structure and relationships climate management priorities. These next sub-sections present the findings from the analysis under three headings that correspond to the main concepts from the research model in Fig. 1.

Self uncertainty

Partner uncertainty

Behavioural uncertainty

Relationship uncertainty

Life-cycle Control

Self Uncertainty

Self uncertainty in the cases was reflected in four main management factors: life cycle control, resource governance, capability focus and integrative operations. Life-cycle control is motivated by the need to target companies for the effective management of supply chains for sustainable services. It challenges firms to maintain levels of control (irrespective of size) over key life cycle stages. Resource governance stems from challenges for maintaining effective governance of resources. This factor enables and enhances how stakeholder access services but also heightens the need for institutional arrangements to deliver services directed to households. Capability focus recognises the need to overcome barriers to implementing new business models and stresses the importance of organisational factors relating to management capability and external factors. Integrative operations concentrate on orientations that combine innovation and environmental policies to create service profiles.

Relationship and Behavioural Uncertainty

Seven main management factors were extracted from the cases relating to relationship and behavioural uncertainty. The first, participative decisions, is concerned with how information is made available and used by stakeholders to make decisions. In this regard, stakeholder (consumers, business managers and governmental representatives) participation to influence eco-efficiency decisions is crucial. The second, intervention mechanisms, is motivated by potential variations in the trajectory of providing ecoefficient service and the influence of company activities on stakeholders. This makes it necessary for interventions, particularly guided by environmental potentials, to be in place to guide and improve service design and delivery practices. The third, idea linkage, prioritises the development of business ideas that link sustainability to structural and behavioural changes and this can be achieved through the involvement of stakeholders along value chains and life cycles. The fourth, consumption patterns, is driven by the need to improve consumption behaviours and emphasises business-toconsumer relationships to deal with unsustainable consumption patterns. Along these lines, alternate consumptions patterns can be formulated with new shared norms, attitudes, and social frameworks that aid in transitions to more sustainable practices.

Communicative structure is the fifth factor for operations management and stakeholder empowerment that stresses a combination of pro-active and participative attitudes for effective and efficient delivery of customer solutions. Closely related to communicative structures are clear representations, the sixth factor, that are needed to effectively design sustainable services and to map the behaviour of actors and spatial relationships within delivery networks. The seventh factor, relationship incentivisation, concentrates on fundamentally changing the relationship between stakeholders by offering incentives to be sustainable. Incentives also act as relationship building avenues with clients to enhance customer loyalty.

Partner Uncertainty

With regards to partner uncertainty, four main management factors were captured from the cases: creativity leveraging, environmental profiling, systemic measuring and process learning. Creativity leveraging requires partners to understand and take advantage of creativity within their locus of control for generating radical ideas that promote cleaner processes and consolidate waste reduction practices. Environmental profiling encapsulates how firms are involved and are working closely with different stakeholders to improve product life span and efficiency of resource consumption. This profiling is also important for determining the readiness of a partner to adopt and accept sustainable service strategies. Systemic measuring of sustainability variables is a challenge for firms to develop approaches that measure their sustainability levels and to factor these levels into relationships and communication among stakeholders.

Process learning centres on (re)discovering the scientific, social, economic, politic and cultural linkages within the network of actor for delivering sustainable services. It also promotes the use of socio-technical experiments for learning and improving partner's involvement in providing sustainable services.

Conclusions

Working at the right time, using the right resources and delivering the right results, is a major challenge for partnerships that requires multiple actors and joint effort. As mentioned earlier, when partnerships are forged for providing sustainable services, these partnerships tend to be plagued by uncertainties that make it difficult to extrapolate from past sustainable service operations -to make forecasts for future sustainable service projects. This is due to differences in variances and variability that create levels of fuzziness for collaboration among partners. Along these lines, this paper has attempted to shed light on "What is the nature of uncertainties that characterises industrial collaborations for providing sustainable services?" Using a research model grounded on literature and findings from secondary case studies, a conceptual model of partnership uncertainty management was developed according to governance structure and relationships climate management priorities. The paper makes two useful contributions. First, it investigates the nature of partnership uncertainty within operations. Second, the paper analyses orientations for managing partnership uncertainties during the provision of sustainable services. It is however important to stress that practices and policies for uncertainty management should be treated on a case-by-case basis and with respect to leveraging the knowledge of domain experts to better understand uncertainties of transitions to more sustainable and service-oriented operations.

The study is however limited to a qualitative analysis that makes use of 17 secondary case sources and there is a need to widen the scope of the literature investigation. The management model also needs to be applied in real case-studies and quantitative studies to validate the hypothesis. Future cross-sector analyses that investigate trends across industrial sectors are also suggested. While factors of partnership uncertainty management for sustainable services have been highlighted in this study, their significance in short-, medium-and long-structures and behavior has not been ascertained. Future work is therefore needed to study these dynamics and their influences on service encounters, negotiations and innovations. Further research could also use the conceptual model of partnership uncertainty management in studies based on mathematical reasoning, expert systems and decision support systems for generating frameworks, tools and techniques that enhance decisions to join, leave, or remain in solution-oriented partnerships.

Fig. 1 .

 1 Fig. 1. Research model.

Fig. 2 .

 2 Fig. 2. The management factors model of partnership uncertainty for sustainable services.

Table 1 .

 1 Salient partnership uncertainty challenges for providing sustainable services.