Ovidiu Noran
email: o.noran@griffith.edu.au

David Romero
email: david.romero.diaz@gmail.com

Milan Zdravkovic
email: milan.zdravkovic@gmail.com

The Sensing Enterprise: Towards the Next Generation Dynamic Virtual Organisations

Keywords: Virtual Organisations, Breeding Environments, Sensing Enterprise, Internet of Things, Collaborative Networks, Disaster Management

In today's dynamic and volatile global environment, established legacy concepts such as Virtual Organisations (VOs) need to be evolved to enhance their agility in order to promptly adapt to changes. This paper proposes the use of the Sensing Enterprise concept and properties, supported by the paradigms of the Internet of Things, Cyber-Physical Systems and Future Internet Enterprise Systems, as an essential enabler towards the advancement of the current 'dynamically created' VO concept towards a Next Generation of agile and genuinely Dynamic Virtual Organisations (DVOs), displaying awareness, perceptivity, intelligence and extroversion. The properties and benefits of the Next Generation 'sensing' DVO are defined and then illustrated in a scenario that typically requires utmost agility and dynamism.

Introduction

In the context of increasingly competitive global environments in market and society, enterprises and organisations are often compelled to take on project opportunities requiring competencies beyond their individual resources and knowledge. As a result, organisations become so-called Collaborative Networked Organisations (CNOs) that act as 'breeding environments' (BEs) for Virtual Organisations (VOs) [START_REF] Camarinha-Matos | Collaborative networked organizations -Concepts &practice in manufacturing enterprises[END_REF]. VOs are temporary associations between BE members, created in order to bid for, win and complete projects requiring resources and know-how above those available in any BE member alone. However, in an increasingly volatile market and society environment, successful VOs are required to become dynamic and agile, i.e. to constantly perceive changes and adapt to them in a timely manner.

In this paper, the authors argue that the new 'Sensing Enterprise' (SE) concept, supported by the paradigms of the Internet of Things [START_REF] Ashton | That 'Internet of Things' Thing, in the real world things matter more than ideas[END_REF], Cyber-Physical Systems, [START_REF] Lee | Cyber Physical Systems: Design Challenges[END_REF] and Future Internet Enterprise Systems [START_REF] Man-Sze | Future Internet Enterprise Systems (FInES) Cluster[END_REF], is able to assist in the evolution of current VOs and dynamically created VOs within a VO Breeding Environment (VBE) [START_REF] Romero | Virtual Organisation Breeding Environments Toolkit: Reference Model Management Framework and Instantiation Methodology[END_REF], towards a next generation of genuinely Dynamic and agile VOs, hereafter referred to as 'Dynamic VOs' (DVOs). As a result, DVOs will be able to sense and promptly adapt to changes in their environment during their entire lifecycle.

A brief review of current research in the SE area is followed by defining the capabilities of the future SE. Next, the SE paradigm is applied to the current VO concept so as to transform it into a genuine DVO. Finally, the practical application of the new DVO concept is exemplified through a case study in disaster managementan environment that would greatly benefit from higher levels of dynamism and agility, present in the next generation DVOs.

The Sensing Enterprise

As the economy and society is becoming increasingly networked and digital, there seems to be a need to redefine the notion of enterprise1 , especially as new social and technology tools are provided by recent advances in new research paradigms, such as Internet of Things [START_REF] Ashton | That 'Internet of Things' Thing, in the real world things matter more than ideas[END_REF], Cyber-Physical Systems [START_REF] Lee | Cyber Physical Systems: Design Challenges[END_REF], Future Internet Enterprise Systems [START_REF] Man-Sze | Future Internet Enterprise Systems (FInES) Cluster[END_REF] and others. Such paradigms facilitate the pervasiveness of the enterprise, blurring its traditional boundaries to the point where internal and external stimuli (coming from within and outside of the enterprise) cannot be distinguished. As pervasiveness implies a federation of processing capabilities and knowledge resources, the new paradigms will also make collective intelligence more accessible and coordinated.

In an attempt to reconsider the notion of the enterprise, the FInES cluster [START_REF]FInES Future INternet Enterprise Systems -Research Roadmap[END_REF] has identified so-called Qualities of Being as properties of the future enterprise as being humanistic, community-oriented, cognizant, people-centred, inventive, agile, environmentally aware, and 'glocal' (with local and global perspective). An enterprise displaying the above properties becomes a so-called Sensing Enterprise (SE).

The SE is also described as "an enterprise anticipating future decisions by using multi-dimensional information captured through physical and virtual objects and providing added value information to enhance its global context awareness" [START_REF]FInES Cluster Position Paper on Orientations for FP8: A European Innovation Partnership for Catalysing the Competitiveness of European Enterprises[END_REF]. In fact, it is not characterised only by awareness (as the term implies), but also by decentralised intelligence. This does not only concern collaboration in decision making, but also purposefulness evaluated in its environment. Thus, an SE is in fact a social enterprise, sometimes also described as 'liquid' to suggest its pervasiveness.

The 'liquid' character of the SE is supported by the anticipation that sensors will become a commodity in the future [START_REF] Santucci | Câlcic The Sensing Enterprise[END_REF]. Thus, the ownership of an enterprise on the sensors will not necessarily restrict other organisations to provide value-added services, based on observations of these sensors. Santucci et al. [ibid.] point out that "the Sensing Enterprise will be a sort of radar in perfect osmosis with an ecosystem of 'objects' supported by several private area networks and delivering in real time a wealth of unstructured data, not only more data but also new data".

Presently, the main technical obstacle for 'de-solidification' of the conventional enterprises is the 'verticalisation' of the existing technical solutions, e.g. Cyber Physical Networks -the trend of manufacturing devices initially customized to the specific applications. This leads to application silos with fragmented architectures, incoherent unifying concepts, and as a result, a lack of interoperability.

The Sensing Enterprise Capabilities

In terms of technical architecture, the SE is considered as a system-of-Cyber Physical Systems (CPS) where these CPSs do not necessarily operate within the boundaries of the enterprise, nor even in its domain of interest or operation. The SE will also encompass the CPSs owned and governed by the other enterprises.

In order to access, combine, use and act upon the extensive, multi-dimensional, multi-modal data (now at the disposal of the enterprise), an SE needs to maintain the capabilities to seamlessly sense this data, perceive its meaning, make decisions and articulate a response (whether this articulation refers to acting (actuating), requesting the additional data, transferring an information to another enterprise, etc.). The stimulus for this cycle may originate from within or outside the enterprise and within or outside its domain of interest.

The cycle above can be explained in terms of semantic interoperation of two enterprises. Note that hereby, the term 'enterprise' is used in this explanation only to illustrate the ownership on the specific CPS, which one enterprise could exploit. In order to illustrate this cycle, we extend Sowa's [START_REF] Sowa | Knowledge Representation: Logical, Philosophical, and Computational Foundations[END_REF] formal definition of semantic interoperability of systems; thus, an enterprise S is semantically interoperable with enterprise R, if and only if the following condition holds for any stimulus p that is articulated by S and sensed by R: For every statement q that is implied by p in the enterprise S, there is a perception of p, namely q', in the enterprise R that: (1) is implied by p in the enterprise R, and ( 2) is logically equivalent to q (see Fig. 1.).

Fig. 1. Illustration of the interoperable SE

Based on the assumptions above, we identify awareness, perceptivity, intelligence and extroversion as the key capabilities of the Sensing Enterprise [START_REF] Zdravković | Enabling Interoperability as a Property of Ubiquitous Systems: Towards the Theory of Interoperability-of-Everything[END_REF].

Although the core concept of SE does not distinguish between the internal and external stimuli, there is a need to separately consider the self-awareness and environmental awareness of one SE. While the latter is crucial for exploiting the pervasiveness of one SE, the former is relevant for maintaining its multiple identities (e.g. towards suppliers and customers, but also on web or a social network). The pervasiveness of an SE extends the conventional domains of interest of an enterprise (e.g. typical channels for detecting new business opportunities). Hence, now one has to consider not only the functional environmental awareness, but also the universal one concerning observations of any stimuli, even from unknown and unanticipated sources. When arbitrary stimuli are taken into account, it becomes important for the enterprise to achieve the capability to perceive any stimulus, be it multi-modal, multi-dimensional, discrete or continuous. Perceptivity is a capability of an SE to assign a meaning to the observation from its environment or from within itself. Then, based on the perception, the SE should be able to decide on the consequent action. This decision is a result of a cognitive process, which consists of identification, analysis and synthesis of the possible actions to perform in response to the "understood" observation. The intelligence also encompasses assertion, storing and acquisition of the behaviour patterns, based on the post-agreements on the purposefulness of the performed actions.

The last desired attribute of an SE, extroversion, is related to the willingness and capability of the SE to articulate the above action/s and demonstrates the SE's business motivation and/or a concern about its physical and social environment.

Towards Next Generation Dynamic Virtual Organisations

Virtual Organisation Evolution

The development of VO and VBE management models, methods, systems and tools [START_REF] Camarinha-Matos | Methods and Tools for Collaborative Networked Organizations[END_REF] addressing challenges in CNOs management, supported by the progress in Information and Communication Technologies (ICT) [START_REF] Camarinha-Matos | Dynamic Virtual Organizations, or not so Dynamic?[END_REF], is on-going given the dynamic environments in which organisations exist. Thus, 'first generation' VOs were created from an 'open universe' of organisations considering a number of important factors in the process so as to quickly and reliably establish an interoperable environment between trusted partners. This approach was limited by the possibility of rapidly finding a set of suitable partners that best fit a collaboration opportunity and quickly configure them into a VO. 'Second generation' VOs called for a more effective VO creation process [START_REF] Camarinha-Matos | A Framework for VO Creation in a Breeding Environment[END_REF] to enable having dynamically created VOs in response to the requirement to capture short-time windows of collaboration opportunity. Therefore, VBEs (as 'nesting' environments) emerged in order to increase the preparedness of organisations towards rapid configuration and creation of VOs by negotiating in advance a set of cooperation agreements and common operation principles, interoperable systems and ontologies [START_REF] Camarinha-Matos | A Framework for VO Creation in a Breeding Environment[END_REF].

Nevertheless, market dynamics have made collaboration opportunities not only short-time windows, but also collaborative projects with evolving features induced by the fluctuations in the continuously changing environments that may surround a VO collaborative project operation. This calls for a 'third (next) generation' VO type, with an emphasis not only on a dynamic VO creation process, but also on VO's 'agile' behaviour during its lifecycle. A third generation, truly dynamic VO (DVO) would be capable to recognise and promptly react to changes in the environment during its operation, and therefore survive and even thrive on change. This organisational behaviour matches that of what has been described above as the 'Sensing Enterprise' [START_REF]FInES Cluster Position Paper on Orientations for FP8: A European Innovation Partnership for Catalysing the Competitiveness of European Enterprises[END_REF], on which authors believe DVOs should be based on.

Next Generation Dynamic Virtual Organisation Properties

During the last years, advances in ICT have been facilitating more effective, agile, flexible and trustworthy collaborative environments and networks, enabling organisations to collaborate and negotiate, systems/services to adapt and interoperate, information to be exchanged and retrieved, and resources to be discovered and shared [START_REF] Rabelo | Advanced Collaborative Business ICT Infrastructures, in Methods and Tools for Collaborative Networked Organizations[END_REF]. In this context, organisations need to acquire new Qualities of Being [START_REF]FInES Future INternet Enterprise Systems -Research Roadmap[END_REF] (see Section 2) which are strongly related to the properties that define an SE: aware, perceptive, intelligent, and extroversive. Authors propose the adoption of these properties for the next generation VOs (DVOs).

Thus, a genuine DVO must display self-awareness and environmental awareness capabilities in order to cope with dynamic and sometimes turbulent market conditions. Self-awareness is related to the capability of the DVO or DVO partner to sense a phenomenon or event within itself; for example, the DVO should be able to forecast, based on its own internal performance a possible need for re-engineering during its operation and proactively react with the required changes/adaptations to maintain the time-, cost-and quality frames constraining its mission/goal. Environmental awareness is related to the capability of the DVO or DVO partner to sense a phenomenon or an event from its environment, extended by the capability to receive messages from its environment; for example, to detect an external driver or inhibitor in the market and/or society that may trigger an internal DVO change process to take advantage of the driver or mitigate the risk of the inhibitor.

A second important Next Generation DVO property would be perceptivity as the capability to assign a meaning to an observation internally or in its environment and decide on possible action -for example, real-time continuous monitoring, assessment and adjustment aiming to sustain DVO efficiency.

The third property of a Next Generation DVO would be intelligence, as a capability encompassing assertion, storing and acquisition of behaviour patterns (best practices), based on post-mortem analyses in regards to the purposefulness of the past performed actions; for example the use of past DVOs heritage (experience and other assets) for improving future or current DVOs operation performance.

Fourth and last property that a Next Generation DVO would need to exhibit is extroversion, related to the willingness and capability of the DVO or DVO partner to articulate its actions in case of a request or need for change (e.g. VO evolution); for example, a DVO partner willing and capable to change its position in the DVO topology or modify the initial role, rights and responsibilities assigned to it, or a DVO capable of reconfiguring, rescheduling, reallocating or optimising the resources involved in its operational plan.

Case Study: Dynamic VOs in Disaster Management

The increasing rate and intensity of natural and man-made disasters demands more than ever effective prevention, preparation, prompt response and recovery from catastrophic events. Governments worldwide respond to this challenge by putting in place various disaster management policies, departments, agencies and organisations providing emergency management and services. Typically however, such organisations display a high organisational diversity due to their complex historic, traditional, geographical, cultural and political environments. In addition, there is a plethora of other participants (e.g. non-governmental organisations, volunteers etc.) that need to be included in the disaster relief effort. These factors significantly increase the complexity involved in cooperation. The collaborative operation of emergency services is often promulgated at state, national and international levels (e.g. [START_REF]Emergency Management Act[END_REF][START_REF]Attorney's General's Office -Emergency Management in Australia[END_REF][START_REF]National Response Framework[END_REF][START_REF]Hyogo Framework for Action 2005-2015: Building resilience nations & communities to disasters[END_REF]). However, such directives alone have proven insufficient, bringing about increased response times, sub-optimal cooperation on the ground and even dispute as to who, where and when is 'in charge' [START_REF] Waugh | Collaboration and Leadership for Effective Emergency Management[END_REF].

In order to address these issues, previous research has argued for and modelled the establishment of so-called 'Disaster Management Collaborative Networks' (DMCN) as strategic alliances of governmental and non-governmental organisations which are aimed to act as BEs facilitating the prompt establishment of Disaster Management Task Forces (DMTF) and Disaster Response Teams (DRT) in order to handle complex search, rescue and/or relief mission [START_REF] Noran | Towards Improving Information Systems Interoperability in Disaster Management[END_REF].

The models previously proposed relied on the dynamically created, second generation VO paradigm; while this approach improves response times and cooperation, it does not address well the degree of autonomy and interoperability required of the DMTFs and DRTs during operation on the ground. Independence and resilience are crucial in emergency situations where some response teams may fail, with the rest of the teams having to promptly reorganise or find replacements (with or without BE/DMCN assistance) in order to recover missing functionality; this would require prompt, ad-hoc interoperation with potentially new partners [START_REF] Noran | Interoperability as a Property: Enabling an Agile Disaster Management Approach[END_REF]. Response teams should also be able to perceive and promptly adapt to changes to their operating environment, to ensure the safety and efficiency of their partners and of other teams.

Sensing, Agile Disaster Management Task Forces and Response Teams

It is hereby argued that the previously defined DVO concept featuring 'Sensing Enterprise' properties could address the shortcomings of the previous models.

Thus, self-awareness (perceiving a phenomenon or event within itself) would help DMTFs and DRTs to continuously monitor the status and performance of their human, software and hardware components (e.g. monitoring the vital signs of team members, functionality of equipment etc.). Environmental awareness would enable the task forces and response teams to sense events and receive information from other sources in the operating environment -e.g. data from wireless sensor networks (WSNs) or other teams and compensate for fluctuations, within pre-determined limits. This capability, currently restricted to a functional aspect (i.e. matching predetermined interests of the team) could be subsequently evolved to ubiquitous (universal) awareness, enabling the team to receive and interpret messages beyond agreed interests and formats. This would allow a heterogeneous set of response teams to interoperate seamlessly and share data essential to their mission and safety.

The perceptivity of the Next Generation DVO concept employed in disaster management would allow the DMTF or DRT to assign a meaning to an internal or environmental observation and decide on possible action; for example, location information provided by an internal GPS sensor combined with radiation, temperature etc. readings from the environment (e.g. via a WSN) would create a percept that may lead to certain action (proceed, evade, etc.). Should the envisaged action be beyond predetermined autonomy level, contact the DMCN or BE for mission reconfiguration.

In disaster management, a timely, suitable response is crucial in saving lives and property. Therefore, the DMTF/DRT decision to act based on a percept must be based on a cognitive process, consisting of identification, analysis and synthesis of the possible actions to perform in response to the understood observation (i.e. the percept). Therefore, the DVO-based agile response teams must also possess intelligence, possibly in the form of a knowledge management/expert system that would provide possible actions based on rules established by using disaster management best-practice, previous disaster response actions and outcomes and importantly, by externalising relevant human tacit knowledge. The DMTF/DRT would become a learning organisation that constantly learns, stores, and improves its response to external challenges in an agile manner.

The social effect of extrovert DMTFs and DRTs, materialised by transparency towards other teams, disaster relief participants (e.g. community, non-governmental and faith groups, etc.) and general public would bring significant benefits. In large scale catastrophic events, trust and communication are paramount in an effective response and minimising negative effects [START_REF] Waugh | Collaboration and Leadership for Effective Emergency Management[END_REF][START_REF] Wray | Public Perceptions About Trust in Emergency Risk Communication: Qualitative Research Findings[END_REF]. Often, in a disaster situation, the population self-organises in novel and efficient ways; response teams must tap into this resource and use it to optimize their operations; for this to happen however, in addition to gaining community trust, the response teams must also be able to interoperate at short notice and without previous preparation and negotiationin effect, displaying interoperability as a unilateral property [START_REF] Noran | Interoperability as a Property: Enabling an Agile Disaster Management Approach[END_REF].

Conclusions and Further Research

The aware, perceptive, intelligent and extrovert Sensing Enterprise holds the promise to revolutionise all areas of the current market and society landscape.

Following a brief review of the SE research state of the art and the description of the typical SE capabilities, the paper has described the evolution of the VO concept from its origins up to the current, dynamically created VO. Next, the SE capabilities have been applied to the current VO concept in order to enhance its agility and evolve it into a next generation, genuinely real-time Dynamic Virtual Organisation (DVO).

Furthermore, it has been exemplified how the DVO concept could be employed in an area demanding extreme agility and dynamism, namely disaster management. A brief review of the current problems in disaster management and shortcomings of the previous models based on the legacy VO concept was performed. This was followed by the application of the new DVO paradigm to disaster management task forces and response teams in order to improve collaboration, safety, response time and efficiency.

The SE and VO areas are continuously evolving. Therefore, further research is necessary in order to update and refine the Next Generation DVOs SE-related attributes and to test them in various case studies.

The terms 'enterprise' and 'organisation' are used interchangeably throughout this paper.


David Romero
email: david.romero.diaz@gmail.com

Arturo Molina
email: armolina@itesm.mx

Forward -Green Virtual Enterprises and Their Breeding Environments: Sustainable Manufacturing, Logistics and Consumption

Keywords: Collaborative Networked Organisations, Green Virtual Enterprises, Breeding Environments, Industrial Ecology, Sustainable Manufacturing, Sustainable Logistics, Sustainable Consumption, Circular Economy

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

Introduction

Circular Economy (CE) is a generic term for a new and more sustainable industrial economy in which material, energy and waste (MEW) flows are closed-loop [START_REF] Graedel | Industrial Ecology: Definition and Implementation[END_REF] [START_REF] Romero | Green Virtual Enterprise Breeding Environments: A Sustainable Industrial Development Model for a Circular Economy[END_REF]. In a CE, two types of cyclic flows can be identified: a) quasi-cyclic flows in where there is a certain degree of cycling in resources circulation through an industrial system, which reduces the need for external resources input and waste output, and b) cyclic flows which have the highest degree of cycling (self-sufficiency) with closed-loop circulation of resources within an industrial system [START_REF] Graedel | Industrial Ecology: Definition and Implementation[END_REF] [START_REF] Despeisse | Industrial Ecology at Factory Level -A Conceptual Model[END_REF]. Developing a CE is about optimising industrial systems, and eco-industrial chain models are the prerequisite and basis for running eco-industrial systems [START_REF] Romero | Towards a Sustainable Development Maturity Model for Green Virtual Enterprise Breeding Environments[END_REF] [START_REF] Guo | Research on the Stability of Eco-Industry Chains[END_REF].

An Eco-Industrial Chain (EIC) refers to a closed-loop model of economic activities creating feedback cycles of resources products renewable resources, following the '3R' principles of the CE (Reduce, Reuse, Recycle) in the processes of production, logistics and consumption in order to achieve eco-industrial systems with improved economic activities and environmental benefits [START_REF] Romero | Towards a Sustainable Development Maturity Model for Green Virtual Enterprise Breeding Environments[END_REF] [START_REF] Guo | Research on the Stability of Eco-Industry Chains[END_REF].

The '3R' principles are at the core of the CE development strategy: Reduce refers to the input of resources usage, aiming at reducing the input materials and energy in the production and consumption processes; Reuse is concerned with processing, and promotes a higher utilisation rate of resources by reusing raw materials, by-products and used-products, so products' lifecycle can be extended and the waste created in production processes can be minimised; finally, Recycle is concerned with output, which requires that waste be turned into secondary resources replacing virgin resources input [START_REF] Shi | Strategy and Mechanism for Promotion of Circular Economy in China[END_REF]. Nevertheless, building a CE in the industrial landscape is not enough, since consumerism can have a big impact on the environment and consume large amounts of energy. As a result, consumers in the marketplace play a crucial role to achieve a sustainable economy, since "CE is not just about sustainable production models and products, but also about sustainable lifestyles and societies sustaining them" [START_REF] Holemans | Cities as Eco-Factories of the Future[END_REF]. This research will explore Forward -Green Virtual Enterprises and their breeding environments [8] [9] within the 'build-to-order supply chain management' paradigm [START_REF] Gunasekarana | Build-to-Order Supply Chain Management: A Literature Review and Framework for Development[END_REF] in order to support the creation and operation of goal-oriented supply networks capable of responding to the two-sided market demands of the CE, sustainable offers by industry and sustainable demand by society.

Green Virtual Enterprises and their Breeding Environments

A Green Virtual Enterprise Breeding Environment (GVBE) is a long-term strategic alliance of green enterprises 1 and their related support institutions aimed at offering the necessary conditions (human, financial, social infrastructural and organisational) to support the rapid and fluid configuration of GVEs. From a 'socio-economic and technical' point of view, GVBEs support the creation of an adequate environment for the establishment of cooperation agreements, common operation principles, common interoperable infrastructures, common ontologies, and mutual trust among others, with the objective of preparing their members to collaborate in potential GVEs that will be established when a green business opportunity arises (e.g. identified by a GVBE member acting as a broker). From an 'ecological' perspective, GVBEs promote the sharing and recycling of resources such as information, materials, water, energy and/or infrastructure with the intention of achieving sustainable development in a collaborative way (e.g. industrial symbiosis 2 ) [8] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

Green Virtual Enterprises (GVEs) are short-term and dynamic coalitions of green enterprises that may be tailored within a GVBE to respond to a single cooperation opportunity, through integrating the green technology (skills or core-competences and resources) required to meet or exceed the quality, time and cost frames expected by the customer with a low ecological footprint, and that dissolve once their mission/goal has been accomplished, as whose cooperation is supported by computer networks [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF]. Depending on its delivery or recovery goal, a GVE can be tailored to become a dynamic forward supply network for delivering new green products (virgin or used/ recovered) to the market, or a dynamic reverse supply network [START_REF] Romero | Reverse -Green Virtual Enterprises and their Breeding Environments: Closed-Loop Networks[END_REF] for recovering the products sold under the GVBE brand (product stewardship) for service provisioning, product recovering or for safe disposal [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

GVEs as dynamic reverse supply networks (R-GVEs) 3 are temporary alliances of green enterprises that come together in order to better respond to a business opportunity 1 A Green Enterprise is an enterprise that strives to meet the triple bottom line by ensuring that all products, processes, manufacturing and logistics activities in its business operation address the sustainability principles [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [9]. 2 Industrial Symbiosis can be defined as an industrial ecology strategy based on collaboration and synergetic possibilities, aimed at sharing/exchanging information, materials, water, energy and/or infrastructure (e.g. services) among industrial actors in order to increase economic gains and achieve sustainable development in an eco-industrial network [2] [11]. 3 For additional information on R-GVEs please refer to [START_REF] Romero | Reverse -Green Virtual Enterprises and their Breeding Environments: Closed-Loop Networks[END_REF].

based on a sustainable reverse logistics and end-of-life manufacturing approach for recovering products, parts, subassemblies and/or scrap through the most efficient use of their complementary skills or core-competences and shared resources for their direct-use (re-use), repair, refurbishment, re-manufacture, recycle or safe disposalwithin a GVBE. In this research work, authors will focus on the case of GVEs as dynamic forward supply networks (F-GVEs) operating as temporary alliances of green enterprises that come together in order to better respond to the market demands through the most efficient use of their complementary skills or core-competences and shared resources, for developing and delivering in a sustainable way new products (goods and services) to the customer with a minimal environmental impact (see Fig. 1) [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] Furthermore, F-GVEs can be sub-tailored to become Green Virtual Manufacturing Enterprises compromising different kinds of resources, manufacturing processes and knowledge needed for designing, engineering and manufacturing sustainable goods for the customer; Green Virtual Service Enterprises sharing knowledge and skills to fulfil different customer requests in after-sales services in a sustainable way; and Green Virtual Product-Service Enterprises integrating manufacturers and service providers in order to support a sustainable customer lifecycle based on a combination of sustainable goods and their related value added services (see Fig. 2).

Green Virtual Manufacturing Enterprise

Green Virtual Service Enterprise

Green Virtual Product-Service Enterprise GVE Typology

Fig.2. Forward Green Virtual Enterprise Typology

Sustainable Manufacturing & Logistics: Build-to-Order

When judging the rationality of economic development in the past and looking into the future, if a sustainable economy is the goal, it is important to understand that the industry of the 21 st century will not be the same as the mass-production model throwaway economy of the 20st century [START_REF] Holemans | Cities as Eco-Factories of the Future[END_REF]. The emerging CE will rely on new sustainable (mass-) customised products (goods and services) [START_REF] Osorio | Design for Sustainable Mass-Customization -Design Guidelines for Sustainable Mass-Customized Products[END_REF] and production and service provision models [START_REF] Bettoni | Integrated Product and Supply Chain Design: Bridging the Gap towards Networked Environment for Effective Implementation of a Sustainable Mass-Customized Solution[END_REF], as well as their related sustainable business models [START_REF] Short | Business Model Innovation for Embedding Sustainability -A Practice-Based Approach Introducing Business Model Archetypes[END_REF], to support (mass-) customisation, sustainable production and logistics and ondemand manufacturing/service provision as enablers of a sustainable industry: 'Delivering not what the market wants, but what specific customers want'… 'Producing green products just when the customer needs them and only in the quantity they are needed'.

Sustainable Manufacturing is defined as "a systems approach for the creation and distribution (supply chain) of innovative products (goods and services) that minimises resources utilisation (inputs such as: materials, energy, water, and land), eliminates toxic substances, and produces zero waste that in effect reduces greenhouse gases (carbon intensity), across the entire lifecycle of products" [START_REF]Sustainable Manufacturing: Metrics, Standards, and Infrastructure -Workshop Report[END_REF]. F-GVEs aim to bring forward an emerging sustainable manufacturing and logistics mode of operation focused on compromising high levels of customisation, high customer-driven design, volume flexibility (not quantity restricted), short-cycle time, zero-inventory costs, minimal total cost and high supply chain integration for offering and delivering green products to the market in a sustainable way [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF].

F-GVEs focus on implementing mass-customisation and personalisation in a sustainable manufacturing and logistics paradigm empowering sustainability through eco-friendly and high flexible product designs (goods and/or services), production and/or service systems, and supply chains/networks.

The Build-to-Order (BTO) operation model [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF] aims to incorporate the key advantages of different operation models to become an attractive sustainable strategy for manufacturing and service enterprises. The BTO model takes the characteristics of 'high level customisation' and 'customer driven design' of the Engineer-to-Order (ETO) model, the 'volume flexibility' of Make-to-Order (MTO) model, the 'shortcycle time' of the MTO and Assembly-to-Order (ATO) models, the 'zero-inventory costs' of the ETO model, the 'minimal total cost' of the Make-to-Stock (MTS) model, and the 'supply chain integration' of the Configure-to-Order (CTO) model towards more sustainable supply networks operations [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF]. Nevertheless, the BTO model implementation challenges the capacity and capability of a single enterprise calling for a 'network of enterprises' to gain access to its sustainable benefits and competitive advantage. Therefore, F-GVEs and their breeding environments represent a wellsuited model to guarantee the agility, leanness, greenness, flexibility, collaboration and specialisation levels [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF] needed to deploy the BTO model successfully (see Fig. 3).

A high level of customisation can be achieved by means of the F-GVE partners' green capabilities and capacities integration, thus avoiding design, engineering, manufacturing and/or logistics competence and/or resource restrictions to develop sustainable (mass-) customised products (goods and/or services) 4 [17] [START_REF] Romero | Next Generation Manufacturing Systems and the Virtual Enterprise[END_REF]. F-GVEs will be always created with the most suitable GVBE members for fulfilling any special request of a green customer or for guaranteeing the requirements of a given green business opportunity [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF]. Moreover, (mass-) customisation offers the opportunity to develop true sustainable products (goods and services) with a high performance when it comes to meet the customer needs and being environmental-friendly within an affordable price [START_REF] Osorio | Design for Sustainable Mass-Customization -Design Guidelines for Sustainable Mass-Customized Products[END_REF].

High customer-driven design is in the nature of F-GVEs, being 'goal-oriented supply networks' driven by the aim of grasping a single green customer request or green business opportunity [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF] [START_REF] Romero | Next Generation Manufacturing Systems and the Virtual Enterprise[END_REF]. F-GVEs are customer-oriented entities where a 'network of enterprises' focuses on a 'customer-centric collaboration' to co-create a green product (whether of the goods or services type) [START_REF] Romero | Collaborative Networked Organisations and Customer Communities: Value Co-creation and Co-innovation in the Networking Era[END_REF]. By avoiding or reducing the risks involved in forecasting the right production mix, F-GVEs can save a great number of resources (e.g. raw materials, energy, water, etc.) related to unsold products, and conserve also such input resources for a longer time till the moment they are truly needed (e.g. just-in-time) [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

Volume flexibility is satisfied by adding/aggregating F-GVE partners' production capacities and accommodating the proper volume of work accordingly to the task to their production capacity availability [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF] [START_REF] Romero | Next Generation Manufacturing Systems and the Virtual Enterprise[END_REF]. Such flexibility allows a sustainable manufacturing where the required amount of products will be produced, and any waste related to unsold products be avoided (resources conservation) [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

Short-cycle time, or shortest-cycle time possible, is attained by the analysis of different F-GVE partners topologies and work-breakdown-structure configurations during the F-GVE creation in order to create the right partnership and schedule (critical path) to meet or exceed the time-frame (lead time) expected by the green customer [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF] [START_REF] Romero | Next Generation Manufacturing Systems and the Virtual Enterprise[END_REF]. F-GVE partners' search and selection process [START_REF] Baldo | An Ontology-based Approach for Selecting Performance Indicators for Partners Suggestion[END_REF] [21] will guarantee always the best possible forward supply network configuration in terms of cost-efficiency, flexibility, responsiveness and lowest ecological footprint to manufacture and deliver a product [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

Zero-inventory costs are realised since F-GVEs don't need to have an inventory before any manufacturing order is launched [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF] [START_REF] Romero | Next Generation Manufacturing Systems and the Virtual Enterprise[END_REF]; F-GVEs operate under an on-demand manufacturing/service provision paradigm which can be considered a resources conservation strategy [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

Minimal total cost is accomplished due to the cost savings gained throughout the forward supply network [17] [18] by means of selecting the most cost-effective F-GVE partners for the manufacturing and logistics value added activities needed to be performed and efficient F-GVE operation [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

A high supply chain integration is reached thanks to the GVBE role as long-term strategic network [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF] concerned with facilitating the adoption of common operation principles and interoperable infrastructures in advance to improve communication, cooperation and coordination between GVBE members; when members are selected to become GVE partners, they will behave as an integrated whole, therefore enhancing their overall agility, flexibility and productivity to collaborate in a F-GVE [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

Fig.3. Forward Green Virtual Enterprise Vision-based Framework

Sustainable Consumption: Customer Communities

Sustainable Consumption is defined as "the consumption of goods and services that have a minimal impact upon the environment, are socially equitable and economically viable whilst meeting the basic needs of their target customers, without jeopardising the needs of future generations" [START_REF]GDRC): Sustainable Consumption Definition[END_REF].

Customers and, customer communities, play a vital role in contributing to a sustainable production and consumption in the industrial landscape and marketplace, being the ultimate target of a 'sustainable supply network'. Their involvement and empowerment in sustainable supply networks is of key importance for driving the demand for sustainable products (goods and services), since customers are those who initiate the creation of any given product. First, customers influence what goods and services are being produced and offered (e.g. green products), and partially how products are being produced, delivered and disposed (e.g. green manufacturing and logistics). Second, how products are being consumed, which drives or constrains any product lifecycle extension strategies (e.g. products with recycled materials, secondhand products, refurbished/ upgradable products, repaired products). Third, customers influence each other in their consumer decisions of what, how and how many products are consumed (e.g. green purchasing and usage recommendations).

Customers' role in sustainable production and consumption will continue growing in the coming years, as advances of the 'social' Internet empower green consumers to actively participate in different sustainable practices (e.g. recycling) [START_REF] Romero | Collaborative Networked Organisations and Customer Communities: Value Co-creation and Co-innovation in the Networking Era[END_REF] [START_REF] Sigala | Customer Involvement in Sustainable Supply Chain Management: A Research Framework and Implications in Tourism[END_REF]. BTO supply networks [START_REF] Molina | Virtual Enterprise Brokerage: A Structure-Driven Strategy to Achieve Build to Order Supply Chains[END_REF] (e.g. GVEs and their breeding environments [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF]) offer the opportunity to meet green customers' demands and to manage their involvement in the co-creation/co-innovation [START_REF] Romero | Collaborative Networked Organisations and Customer Communities: Value Co-creation and Co-innovation in the Networking Era[END_REF] of sustainable (mass-) customised products [START_REF] Osorio | Design for Sustainable Mass-Customization -Design Guidelines for Sustainable Mass-Customized Products[END_REF] [14] and sustainable business models [START_REF] Short | Business Model Innovation for Embedding Sustainability -A Practice-Based Approach Introducing Business Model Archetypes[END_REF]. Sustainable (mass-) customisation may trade-off lead time for environmental-friendliness, but pays back the customer with a certain level of personalisation/customisation of his/her goods or services and a truly sustainable product lifecycle [START_REF] Osorio | Design for Sustainable Mass-Customization -Design Guidelines for Sustainable Mass-Customized Products[END_REF] [START_REF] Bettoni | Integrated Product and Supply Chain Design: Bridging the Gap towards Networked Environment for Effective Implementation of a Sustainable Mass-Customized Solution[END_REF].

In order to explore customers' role in achieving sustainable supply networks, authors have chosen Sarkis [START_REF] Sarkis | Strategic Decision Framework for Green Supply Chain Management[END_REF] framework for outlining the operational processes of a sustainable supply network with the customer involvement [adapted from 23]: Starting with green designing, customers education and awareness in (co-) designing and demanding sustainable products can incentivise manufacturing and service enterprises to look into more sustainable designs for their value propositions. This effect is also magnified by green (virtual) customer communities that collect, share and disseminate information about the sustainable performance of products, and customers increased interest to co-create/co-innovate sustainable products and business models [START_REF] Romero | Collaborative Networked Organisations and Customer Communities: Value Co-creation and Co-innovation in the Networking Era[END_REF]. Green procurement is the most obvious customer influence in a sustainable supply network since customers can choose their own goods manufacturers and service providers according to their sustainable performance (e.g. eco-certifications and environmental standards). Also, customers can influence procurement by eliminating and/or attenuating resources use by providing their own resources (e.g. self-service) and/or by helping to reuse or share resources (e.g. reuse programs) [START_REF] Sigala | Customer Involvement in Sustainable Supply Chain Management: A Research Framework and Implications in Tourism[END_REF]. Green production and Green logistics are influenced by the customer consumption behaviour, which challenges manufacturing and service enterprises demand management, considering now the expected lead time by the customer in order to support sustainable production (e.g. dematerialisation, slow fashion, on-demand manufacturing/service provisioning, packaging reduction, product longevity) [START_REF] Sheth | Mindful Consumption: A Customer-centric Approach to Sustainability[END_REF] and (collaborative) logistics practices (e.g. route planning, intermodal solutions, smart distribution, cargo consolidation, shared warehousing) [START_REF] Langley | 7 Immutable Laws of Collaborative Logistics[END_REF]. Green purchasing, consumption and marketing, as the three main relationships of the firm with its customers, drives manufacturing and service enterprises to ethically promote their products (goods and/or services) by reinforcing customers' sustainable lifestyles using different sustainable marketing practices (e.g. rewards, discounts, eco-labels, demarketing, remarketing) in order to develop a mindful consumption mind-set [START_REF] Sheth | Mindful Consumption: A Customer-centric Approach to Sustainability[END_REF]. Lastly, there is the green recycling achieved through different product recovery opportunities [START_REF] Romero | Reverse -Green Virtual Enterprises and their Breeding Environments: Closed-Loop Networks[END_REF] that involve bringing back customers who have already purchased a product to restart a new supply network cycle presumably with greater efficiency and lower resources use (e.g. reuse, repair, refurbish, re-manufacture, recycle) [START_REF] Sigala | Customer Involvement in Sustainable Supply Chain Management: A Research Framework and Implications in Tourism[END_REF] [25] (see Fig. 4).

Sustainable Consumption

Buy Less Share Swap Giveaway

Fig.4. Green Customers Sustainable Consumption Profile

Increasingly, the sustainable production and consumption of products (goods and services) in the industrial landscape and marketplace will involve a mix of long-and short-term collaborative networks, strategic and goal-oriented networks [START_REF] Camarinha-Matos | Interplay of Collaborative Networks in Product Servicing[END_REF], and networked enterprises and customers communities [START_REF] Romero | Collaborative Networked Organisations and Customer Communities: Value Co-creation and Co-innovation in the Networking Era[END_REF], making GVEs and their breeding environments [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [9] a suitable collaborative environment and sustainable development model for customers' involvement and other stakeholders in the process of collaboratively creating new products in a sustainable way and meeting customers' needs and preferences.

Sustainable Business Models: Interplay Networks

A Sustainable Business Model is defined as "a business logic that seeks to create balanced social, environmental and economic value through integrating sustainability more fully into its business model and value proposition(s)" [START_REF] Lüdeke-Freund | Towards a Conceptual Framework of Business Models for Sustainability[END_REF]. The development of sustainable business models architectures [START_REF] Short | Business Model Innovation for Embedding Sustainability -A Practice-Based Approach Introducing Business Model Archetypes[END_REF] is fundamental for the adoption of new sustainable production and consumption paradigms. In this sense, nowadays we can find some practical examples from an industrial perspective such as different product-service systems (PSS) variants aiming to deliver functionality rather than ownership through: 'product oriented approaches' based on maintenance and extended warranties; 'use-oriented approaches' based on rentals, leasing or sharing; and 'result-oriented approaches' based on pay per use or functional use; and various product recovery networks variants aiming to create new forms of value and/or capture the value missed in a product lifecycle based on reuse, repair, refurbish, remanufacture and/or recycle strategies. From a customer perspective there are examples such as: self-service, do-it-yourself, co-design, co-creation and coinnovation. In both cases, these existing business models have further development opportunities for creating more sustainable industrial ecosystems and consumer markets. Understanding and supporting the growth of green networked enterprises and green customers' communities' interactions is a current challenge but a need towards a sustainable production and consumption [START_REF] Romero | Green Virtual Enterprise Broker: Enabling Build-to-Order Supply Chains for Sustainable Customer-Driven Small Series Production[END_REF] and a Circular Economy (see Table 1, Fig. 5, and [START_REF] Romero | Collaborative Networked Organisations and Customer Communities: Value Co-creation and Co-innovation in the Networking Era[END_REF]).

Conclusions & Further Research

Dynamic F-GVEs represent an intelligent integration of green enterprises' competences, best practices and technologies for creating and managing sustainable BTO supply networks in response to the development of sustainable (mass-) customised products.

GVEs and their breeding environments [START_REF] Romero | Green Virtual Enterprises and their Breeding Environments[END_REF] [9] represent a promising collaborative environment for enhancing green enterprises and green-minded customers' readiness for collaboration in more sustainable industrial ecosystems and consumer markets needed for a true sustainable development [START_REF] Romero | Green Virtual Enterprise Breeding Environments: A Sustainable Industrial Development Model for a Circular Economy[END_REF]. A multitude of options exist for the development of more sustainable industrial ecosystems and consumer markets, but sustainability of such strategic options needs to be based on new sustainable business models in order to guarantee their success [15] [28], nevertheless this is a research are currently in a maturing stage.

Future research aims to refine the F-GVE -dynamic forward supply networkmodel introduced, and the study, development and validation of its related business models for sustainable production and consumption.

Fig. 1 .

 1 Fig.1. Forward Green Virtual Enterprise Lifecycle: Dynamic Forward Supply Network

Fig. 5 .

 5 Fig.5. Interplay Networks as a base for Sustainable Production and Consumption

  [START_REF] Romero | Green Virtual Enterprises Breeding Environment Reference Framework[END_REF].

		F-GVE Creation Stage
	Input	CO Identification	CO Characterization & F-GVE Rough Planning	Partners Search & Selection	Negotiation	Detailed R-GVE Planning	Contracting
	New Product Development	Green Business Opportunity [identification]		Green Design Green Materials Green Processes [selection]	Green Partners [green degree] Selection	Negotiation	Planning Logistics Green Production & Forward	Contracting
		Business Opportunity:	Green Practices:	Green Capabilities:	Triple Top Line:	Clean Production:	Environmental:
		+ Green Good		+ DFX	+ Design	+ Economic		+ Lean Manufacturing	+ Regulations
		+ Green Service		+ Lifecycle Analysis	+ Materials	+ Environmental	+ Lean Services	+ Laws / Trades
				+ TQEM	+ Processes	+ Social		Clean Logistics:	+ Taxes
				+ EMS	+ Technologies			+ Forward Logistics	+ Fines
				+ G-SCM	+ Logistics
				+ ISO14000 series
	F-GVE Operation and Dissolution Stages		Output
		Operation Green Production		Dissolution Green Delivery	GVE Customer	GVE Product
	[green manufacturing]	[green packaging, green logistics,	GVBE	Surplus and/or
		[green services]		green labeling]	Bag of Assets	Abandoned Resources

Table 1 .

 1 A Business Model Framework for Sustainable Production & Consumption Green Products • Green Services • Green Product-Service(s) Customer Segments • Green Customers • Green Consumers • Green Communities Customer Relationships • Green Purchasing • Green After-Sales Services Channels • Green e-Marketplace • Green Brokers Key Partners • Green Manufacturers • Green Service Providers • Green Brokers Key Activities & Resources • GVBE Management Systems • GVE Management Systems Cost Structure • Green Costing Models (e.g. Green Loans, Green Taxes) Revenue Streams • Green Profit Models (e.g. Green Market Share)

	Building Blocks	Description
	Value Proposition(s)
		Networked Enterprises	Customers Community
		Interplay
		Network

•

Sustainable (mass-) customised products can be defined as goods or services capable of fulfilling engineering and customers' requirements including environmental, economic and social constrains[START_REF] Osorio | Design for Sustainable Mass-Customization -Design Guidelines for Sustainable Mass-Customized Products[END_REF].

Acknowledgments. The research presented in this document is a contribution for the ECOLEAD Project (FP6 IP 506958), for the S-MC-S Project (FP7 NMP-ICT-FoF 260090), and for the ITESM, Campus MTY & CCM, Research Chairs.

Green Virtual Enterprise Themes Social Economic Technological Ecological Green Virtual Enterprise Environmental Factors Green Virtual Enterprise Targets Green Virtual Enterprise Value Proposition Design Technologies Green Procurement Green Materials Green Designs Green Processes Green Virtual Enterprise Operational Technologies Green Manufacturing Green Logistics Green Packaging Green Recycling Green Virtual Enterprise Effects Low Energy Footprint Low Water Footprint Low Emissions Footprint Low Waste Footprint Green Systems Agility Leanness Greenness Flexibility Collaboration Specialisation Green Products Green Customers (Environmentally-Conscious) Environmental Laws & Regulations Depletion of Resources (Scarcity and Cost) Social and Environmental Responsibility Green Competences Green Drivers & Constraints Green Innovation Opportunities Green Reputation Green Market Share Green Certifications Green Consumption Green Improvement Opportunities


Arturo Molina
email: armolina@itesm.mx

Pedro Ponce
email: pedro.ponce@itesm.mx

Miguel Ramirez
email: miguel.ramirez@itesm.mx

Gildardo Sanchez-Ante
email: gildardo@itesm.mx

Designing a S 2 -Enterprise (Smart x Sensing) Reference Model

Keywords: Sensing Enterprise, Smart Enterprise, reference model, RM-ODP

The definition of the concept of S 2 -Enterprise (Smart x Sensing) reference model is presented. The S 2 Reference Model (S 2 -RM) is targeted to assist in the system specification and development of future computer based systems, which support the creation of this concept. It is a hybrid reference model that includes Enterprise Integration Engineering Concepts and Interoperability models. The Reference Model for Open Distributed Processing or RM-ODP is used as the basis to define S 2 -RM because it allows the definition of the structure and characteristic of the Smart and Sensing systems in terms of five different views (enterprise, information, computational, engineering and technology). The importance of using reference models for the definition, design and implementation of S 2 -Enterprise systems is outlined. A pilot system has been developed using a micro-factory concept and a collaborative networked organization.

Introduction

Research that is currently being undertaken by several research laboratories to address issues of Enterprise integration and interoperability has been reported in [START_REF] Panneto | Enterprise Integration and Interoperability in Manufacturing Systems: trends and issues[END_REF]. The aim of all these research is to move from highly data-driven environments to a more cooperative information and knowledge-driven environment in order to design and create the concept of an enterprise, which is smart and sensing [START_REF] Panetto | Enterprise Integration and Networking: Theory and practice[END_REF].

Sensing Enterprise is described as "an enterprise making use of the sensing possibilities provided by interconnected 'environments', anticipating future decisions by using multi-dimensional information captured through physical and virtual objects, and providing added value information to enhance its global context awareness" [START_REF]Position Paper on Orientations for FP8: A European Innovation Partnership for Catalysing the Competitiveness of European Enterprises[END_REF].

A Smart Organisation is defined by [START_REF] Filos | Smart Organizations in the Digital Age. Integration of ICT in Smart Organizations[END_REF]: "A smart organization is understood to be both, internetworked and knowledge-driven, therefore able to adapt to new organizational challenges rapidly, and sufficiently agile to create and exploit knowledge in response to opportunities of the digital age."

Smart and Sensing systems are highly complex and the activity of coordinating and structuring their design and development necessitates the use of formal methods for their representation. The development of complex integrated and networked environments, such as a Smart and Sensing Enterprise, requires that system developers and the users are able to hold meaningful discussions and share a common understanding of underlying goals and ideas. The use of reference models in such complex tasks has been proven successful [START_REF] Williams | Architectures for Integrating Manufacturing Activities and Enterprises[END_REF].

A key issue in the research presented here is the development of a S 2 -Enterprise (Smart x Sensing) reference model to provide a framework to support the development of new integrated enterprise concepts and hence the implementation and interoperability of networked enterprises by establishing a generic set of viewpoints. Methodologies and tools are recommended to assist in the specification, development and analysis of each view (e.g. UML, Petri-nets, Artificial Hydrocarbon Networks). This will ensure that certain key issues are considered during the design of a system, and that standardized methods are used for the design and documentation of the system. In the S 2 -Reference Model (S 2 -RM), a combination of reference models, methodologies and computer tools have been defined, to enable to address the complexity and interoperability of such systems.

In this paper, the next section offers a general overview of reference models and their major characteristics. Section 3 describe the issues involved in the definition of the S 2 -RM. Section 4 describes a pilot system that has been develop using the S 2 -RM to design and create a micro-factory. Finally conclusions are proffered about the authors' experiences on the use of reference models.

Reference Models, Frameworks and Architectures

Reference models provide general representations of different aspects (views) of a system, for example [START_REF] Chen | Architectures for enterprise integration and interoperability: Past, present and future[END_REF]: Function, Information, Resources and Organization (CIMOSA); Safety, Environment, Compatibility, Performance, Operability, Maintainability, Reliability, Qualifications and Description (ISO/TR 101314-1: 1990); Enterprise, Information, Computational, Engineering and Technology (RM-ODP). These representations can be referenced to assist in the development of a system during various stages of its life cycle (e.g. requirements, design, implementation, operation, decommission).

A reference model must be [START_REF] Molina | Reference Models for the Computer Aided Support of Simultaneous Engineering[END_REF]:

1. Structured: based on readily available and acceptable terminology, methodologies or standards. 2. Flexible: able to be applied to wide range of systems within its domain of applicability and at different stages of the system life cycle. 3. Generic: independent of any existing implementation. [START_REF] Filos | Smart Organizations in the Digital Age. Integration of ICT in Smart Organizations[END_REF]. Modular: open-ended in its ability to be extended in order to incorporate new concepts and technologies. In Manufacturing, reference frameworks and architectures used for developing information systems have been based on concepts delineated above. The terms framework and architecture have been used ambiguously within the manufacturing domain to denote reference models that assist in the development of an information system during different phases of, or throughout, the complete life cycle.

The Reference Model for S 2 -Enterprise presented in this paper is based on the framework concept defined by [START_REF] Molina | Reference Models for the Computer Aided Support of Simultaneous Engineering[END_REF] which describes a representation of characterized situation types that occur during an information system life cycle for enterprise integration. Enterprise in the context of this research is also a Collaborative Networked Organization (CNO) as described by [START_REF] Camarinha-Matos | Collaborative Networked Organizations -Concepts and practice in Manufacturing Enterprises[END_REF]. Therefore the reference model could be used and applied in the creation of Smart and Sensing Collaborative Networked Organizations.

A Reference Model for S 2 -Enterprise (Smart x Sensing)

The authors believe that a Reference Model for S 2 -Enterprise (Smart x Sensing) should assist the users and developers in the following three tasks:

1. Identify the Enterprise requirements to support the concepts of Smart an Sensing Enterprise 2. Guide the design and implementation of the enterprise system itself. 3. Organize the process of implementation (people, methods and tools) to evolve the Smart and Sensing system towards the desired level of integration and automation. The research into the development of a reference model for S 2 -Enterprise has embraced issues related to distribution and sharing of information, integration of application by means of networking and multimedia environments, incorporation of new paradigms (Smart and Sensing), use of standards languages and modelling techniques, and the provision of services for co-ordination and collaboration. These systems are open in nature to allow the incorporation of a wide range of technologies, and distributed, to enable the interaction among remotely located people.

The rationale of S 2 -RM based on RM-ODP

A well-documented standard related to these issues is the one concerned with open distributed systems, known as the Reference Model for Open Distributed Processing or RM-ODP [START_REF] Linington | Introduction to the Open Distributed Processing Basic Reference Model[END_REF]. This reference model was chosen to describe, design and implement the S 2 -Enterprise concepts, due to the fact that the RM-ODP allows to represent an open and distributed information system from different viewpoints: Enterprise, Information, Computation, Engineering and Technology. Each viewpoint represents a specific aspect of the S 2 -Enterprise and system at any required level of detail. Therefore the use of the RM-ODP views allows a complex system to be described from a number of perspectives (see Figure 1). The S 2 -Enterprise Reference Model (S 2 -RM) enables the successful support the tasks defined above i.e. identification of requirements and guidelines for system development. However, the organization and management of the timely incorporation of people, methods and tools to evolve a Smart and Sensing environment towards the desired level of integration and automation requires further definitions at the different levels of integration, therefore models such as Petri Nets [START_REF] Gomes | Structuring and composability issues in Petri nets modeling[END_REF], Interoperability systems and control systems such as SaaS [START_REF] Espadas | A tenant-based resource allocation model for scaling Software-as-a-Service applications over cloud computing infrastructures[END_REF] are used.

The S 2 -RM aims to support the development of existing and new systems by establishing a generic set of viewpoints that should be used to analyse any such system. Each viewpoint is represented by a view in the reference model. A view depicts the system from a known perspective. Methodologies and tools are recommended to assist in the specification, development and analysis of each view. This will ensure that certain key issues are considered during the design of a system and that standardised methods are used for the design and documentation of the system, hence enabling the comparison of different integrated and interoperable systems at different levels of abstraction.

The use of S 2 -RM enables the generic structures and characteristics of systems to be compared. The reference model facilitates comparison by providing a standard representation format for system structure and characteristics. The measures against which the systems are compared are still in the domain of the comparator and have not been included in the reference model structure. This is because each user group will have a different specification for a Smart and Sensing system that best suits their needs and priorities e.g. a requirements definition model. Using this model as a driver the S 2 -RM allows a system designer to select from a range of concepts the ones that most adequately fulfil their need and then for the system developer to be guided to the tools and methodologies that will most helpfully assist the integration of elements that realise the concepts.

The S 2 -RM has been used to represent two distinct levels of system design i.e. concept and implementation. At the conceptual level the generic building blocks of systems are defined using UML [START_REF] Costa | The application of UML and an open distributed process framework to information system design[END_REF]. It is possible that, depending on the requirements made of it; a given system may not require all the concepts that are modelled. This is perfectly reasonable as one of the key aims of the model is to provide a comprehensible representation that aids the description, understanding and discussion of system solutions with developers and users. It is also possible that a viewpoint may exist that is not adequately reflected in the current structure of the reference model. The modular nature of the reference model enables different viewpoints to be included as and when they become appropriate. At present the viewpoints are treated as distinct elements that can be considered independently. The reference model needs to be extended to map the relationships between the viewpoints more completely. This will improve the clarity of the reference model concept and its use.

At the implementation stage of a system the S 2 -RM is useful because it defines the boundaries between software and hardware interfaces, the relationships between them, and it specifies the tools that should be used for the modelling of these elements. Wherever possible international standards have been followed in order to promote standardisation.

The reference model that is under development is designed to be applicable to smart and sensing systems. Many of the concepts can be applied to a reference model for any open, distributed computing system, however, the incorporation of the conceptual building blocks defines the specialisation e.g. product model, manufacturing model, integration environment, etc. By altering these building blocks the reference model could be adapted to suit a wide range of domains.

The definition of the S 2 -RM is independent of vendor software and hardware systems. The reference model is a general description, which is acceptable to both users and developers. It is based on the principal that the whole function of Smart and Sensing systems can be represented in totality by a series of models, each representing one particular viewpoint. Instances of the S 2 -RM would represent real systems.

Therefore the Reference Model can be used to define, design and create a Smart and Sensing Enterprise by defining the different levels for Enterprise requirements (UML), information/knowledge models (UML), computational interactions among all process and systems Petri Nets, infrastructure required to support distribution (Interoperation, Integration, communication protocols -SaaS platform) and Technology -RFID, WSN -Wireless Sensors Networks/Mobile Devices/Virtual Technologies.

The S 2 -RM : models, methodologies and tools

The S2-RM is a five level model that is intended to represent open distributed systems (Figure 2). To achieve this, the following five levels have been defined based on the RM-ODP: Enterprise, Information, Computation, Engineering, and Technology.

The Enterprise Viewpoint is associated with the specification of requirements for ODP systems. Nevertheless, the scope of the information described, and the level of detail contained in the Enterprise View remains a point of debate. There are two main schools of thought regarding what the Enterprise viewpoint should represent. These are to:

1. Represent a model of the organisational environment, in terms of engineering functions and the relationships between them, in which Smart and Sensing systems could be used 2. Represent the functional capability of Smart and Sensing system concepts In order to define a more flexible S 2 -RM, the authors have agreed, to represent at the Enterprise Viewpoint the functionality that Smart and Sensing Enterprise is intended to achieve. In this research Enterprise also means a Virtual Networked Organization. Therefore, the Enterprise View is modelled using the EIE Framework and toolbox defined in [START_REF] Vallejo | Enterprise Integration Engineering Reference Framework & Toolbox[END_REF] to describe strategies (competitive, value-chain, production/service), extended/virtual enterprises models and business performance measures. For the case of Collaborative Networked Organizations the concept of the Virtual Enterprise Broker is used at this level to design the type of CNO to be designed and created [START_REF] Molina | Virtual Enterprise Brokerage: A Structure Driven Strategy to Achieve Build to Order Supply Chains[END_REF]. Also UML modelling is used to support a formal representation: User case diagrams, Package Diagrams, and Sequence Diagrams (Packages).

Fig. 2. S 2 -reference model: Models, methodologies and tools

The Information Viewpoint focuses on describing the semantics of information and information processing functions in the system. Three information models are required in an Enterprise to describe all information and knowledge namely: Product, Manufacturing and Knowledge models [START_REF] Molina | A Manufacturing Model Representation of a Flexible Manufacturing Facility[END_REF]. In the S 2 -RM this viewpoint is defined via a combination of UML descriptions of class diagrams and activity diagrams. This combination of models allows description of the information flows together with the structure of the information elements, their relationships and quality attributes.

The Computational Viewpoint focuses on the representation of the functional decomposition of the system into objects, the activities that occur within those objects and the interactions between the objects. This level represents the Core Business Process (New Product Development, Obtaining Customer Commitment, Order Processing, Customer Service). Therefore UML (Sequence Diagram Classes, Activity Diagrams) and Petri Nets are used to model this this view.

The Engineering Viewpoint focuses on the infrastructure required to support distribution and interoperability. This view enables the specification of the processing, storage and communication functions required to implement the system PyME CREATIVA (Software as a Service Platform -Cloud Computing Infrastructure) and Software tools (Java based SaaS Platform and Private cloud platform), for more detail [START_REF] Molina | The HUB as an enabling IT strategy to achieve Smart Organizations, Chapter III in Integration of ICT in Smart Organizations[END_REF][START_REF] Nogueira | Leveraging the Zachman Framework Implementation Using Action-Research Methodology -A Case Study: Aligning the Enterprise Architecture and the Business Goals[END_REF].

Finally, the Technological Viewpoint focuses on the selection of the necessary technology to support the system. In this research the technologies for sensing resources used are RFID, WSN and Real-time networked systems [START_REF] Delgado | Wireless Technology for Next Generation of Manufacturign Systems[END_REF]. For smart resources: Machines, AGVs, Robots, PLCs, CNCs with Intelligent Control systems based on Fuzzy logic and Artificial Organic Networks [START_REF] Ponce-Espinosa | Artificial Organic Networks Artificial Intelligence Based on Carbon Networks[END_REF][START_REF] Pérez | An Integrated View to Design Reconfigurable Micro/Meso-Scale CNC Machine Tools[END_REF].

The top levels of the reference model (enterprise, information and computation) are non-software specific and so they provide a base level description for system development. Although the S 2 -RM allows the thorough description of a Smart and Sensing system from different views.

Pilot Demonstrations

Pilot demonstrations of a S2 -Micro Factory / S2 -Collaborative Networked Organization (CNO) have been developed using the S2-RM to corroborate how the reference model can guide the design and implementation of a Smart and Sensing systems (Figure 3). The micro factory may be used to produce work parts based on machining parts. The CNO for manufacturing additional to machining process capacities, it has an entity (Virtual Enterprise Broker) which executes the process of Marketing, Product Development and Logistics.

Scenario 1: Micro -Factory (Make to Order)

A MTO Micro-Factory has been designed to produce machining components that are produced based on a product catalogue. The strategy for this facility is Operation Excellence where manufacturing should be executed in minimum time and cost. It also is organized as a Strategic Business Unit with all its operations embedded in one business entity and factory. Information models used to operate the Micro-Factory are Product, Manufacturing and Knowledge Model.

The product model is a catalogue of products that can be manufactured in this facility. Descriptions of all the products that can be manufactured in the catalogue are presented in e-marketing page.

The Manufacturing Model includes manufacturing resources and processes that can be performed with these resources. The detailed list of micro factory resources is: two mechanical kit (RmMT assembly); two storage spaces (store raw materials and finished products); two spindle (NAKANISHI AM-300 R); two air pressure regulator (NSK Air Line Kit AL-0201); two air control (NAKANISHI E2530); two linear actuator clamp (Firgelli PQ-12. 25 mm); six lineal actuator axes (PI M-111.2DG); two assembly toolkit (screwdrivers, wrenches, hoses, cables); one compressor (Truper 21/2 hp); one work station (UNC); three cutting toolkit (drills, cutters, polishers); one robotic arm with two metal gear motors, three servo motors, two kit encoder, one proto-board; and one acquisition card (PIO-D48U). Wireless sensors networks are used to sense vibration/noise/movement in the Micro-Factory, also RFID to track products has been implemented.

The Knowledge model includes strategies, procedures and rules to operate the facility. Also Fuzzy Logic and Artificial Organic Networks are used to implement intelligent control and automation algorithms. The core process to be executed at this factory is Order Processing that allows the customer to order any product in the catalogue.

PyME CREATIVA software enables the operation of the facility with the following e-services: e-marketing, e-brokerage, e-supply and e-productivity. PyME CREATIVA runs on the SaaS platform [START_REF] Concha | The e-HUB Evolution: From a Custom Software Architecture to a Software-as-a-Service Implementation[END_REF].

Scenario 2: Collaborative Networked Organization (Build to Order)

The manufacturing CNO has been implemented to satisfy the Build to Order paradigm with a mass customization strategy. Key performance measures for this model are time to respond and customer satisfaction. A pilot case of multiple sites of manufacturing facilities has been created to demonstrate the concept of a Virtual Enterprise Broker and Manufacturing Collaborative Network of manufacturing competencies. The CNO is configured of three manufacturing facilities (drilling, turning, milling), and a Virtual Enterprise Broker to execute product development, logistics, assembly and quality assurance processes [START_REF] Molina | Virtual Enterprise Brokerage: A Structure Driven Strategy to Achieve Build to Order Supply Chains[END_REF]. The level of customization is implied in terms of time to deliver, volume, and configuration options. The Broker model works in a collaborative way with the customer; the customization will be measured as the capacity to respond to customer requests i.e. Customer Satisfaction.

The Virtual Enterprise Broker (Broker) is responsible for searching business opportunities and enabling the creation of Virtual Enterprises. In this scenario a Virtual Enterprise is the network of manufacturing facilities that will be required to produce a customized product. The Virtual Enterprise Broker performs the processes of partner search and partner selection, and configures suitable infrastructures for Virtual Enterprise formation/commitment i.e. physical, legal, social/cultural, and information. To achieve its goal the Virtual Enterprise Broker is supported by the services provided by the manufacturing facilities. The Broker model allows achieving Build To Order (BTO) strategies through the aggregation the manufacturing capacities and capabilities of each of the different facilities in the network. This aggregation of capabilities together with the core process of the Broker as an entity reaches the BTO flexibility required, and makes an adaptable model that can be applied to different kinds of companies and industries.

The activities of the broker include searching and selecting business opportunities and partners, developing products, logistics, and quality assurance to ensure that the final product is delivery to the customer. While on the other hand, the activities of the facilities are related to the manufacturing capabilities necessary for the manufacturing of the final product.

The core processes of the Broker are supported by the use of PyME CREATIVA in terms of e-services. Some of the e-services that support the operations are [START_REF] Molina | The HUB as an enabling IT strategy to achieve Smart Organizations, Chapter III in Integration of ICT in Smart Organizations[END_REF][START_REF] Concha | The e-HUB Evolution: From a Custom Software Architecture to a Software-as-a-Service Implementation[END_REF]:

• e-Marketing intelligent web-portals for promotion of products and services of each member of the CNO and integrates a unique catalogue of products. • e-Brokerage integrates software to enable the selection, evaluation and configuration of manufacturing facilities to produce an specific product. • e-Supply integrates services related to e-factory, e-logistics for importing/exporting materials and products, ERPs, supply chain management and manufacturing execution systems. • e-Productivity integrates technologies for the diagnosis, planning, evaluation and monitoring of manufacturing facilities.

All these e-services support the collaboration activities among all the facilities in the manufacturing network.

Fig. 1 .

 1 Fig. 1. S 2 -Enterprise Reference Model (Smart x Sensing)

Fig. 3 .

 3 Fig. 3. S 2 -Scenarios: Micro-Factory and Collaborative Networked Organization

Acknowledgments. The research is part of a Research Chair in Mechatronics products of Tecnologico de Monterrey