Elena Pessot
email: elena.pessot@stiima.cnr.it

Andrea Zangiacomi
email: andrea.zangiacomi@stiima.cnr.it

Frank Berkers
email: frank.berkers@tno.nl

David Hidalgo-Carvajal

Ron Weerdmeester
email: ron.weerdmeester@pnoconsultants.com

Rosanna Fornasiero
email: rosanna.fornasiero@stiima.cnr.it

Investigating Supply Chains Models and Enabling Technologies towards Collaborative Networks

Keywords: Business models, Collaborative practice, Value Chain, Digitalization, Supply chain

This research employs an extensive multiple case studies analysis to identify the most important business models affecting supply chain configurations and related enabling technologies towards the creation of collaborative networks. The results obtained from the investigation of 24 companies of manufacturing and process industry, informed by literature, identify four 'design principles' of business models, i.e. Personalized production, Servitization, Decentralized and modular production, and Recycle, Re-use and Sustainability. Each model is further described and discussed at the interplay between digitalization and collaborative network practices at supply chain level, showing that adopting one or the combination of the four design principles allows to actuate some of the most important features of collaboration like Vertical integration or networking of smart production systems, Horizontal integration through global value chain networks, Through-engineering across the entire value chain, Acceleration of manufacturing and Digitalization of products and services.

Introduction

Companies need to promote an efficient and sustainable production of high added value goods to remain competitive in global markets and respond to the demanding requirements of consumers [START_REF] Ben-Daya | Internet of things and supply chain management: a literature review[END_REF]. The market dynamics require companies to adapt their business and links within the existing supply chains towards new reconfigured network collaborations and business models that shift from cost competitiveness to cooperative efforts for a higher added value and competitiveness of the supply chain as a whole [START_REF] Camarinha-Matos | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF][START_REF] Fornasiero | Implementation of customisation strategies in collaborative networks through an innovative Reference Framework[END_REF]. Along with this line, a greater vertical and horizontal integration between the involved actors should favor flexible, collaborative and interconnected networks of factories able to manage shorter cycles life of products while maintaining high levels of quality and resource efficiency [START_REF] Büyüközkan | Digital Supply Chain: Literature review and a proposed framework for future research[END_REF]. Within this context, the digital technologies play a key role in enhancing the collaboration at value chain level and the integration of manufacturing and process sectors by improving flexibility and delivery of added value [START_REF] Büyüközkan | Digital Supply Chain: Literature review and a proposed framework for future research[END_REF][START_REF] Ivanov | The impact of digital technology and Industry 4.0 on the ripple effect and supply chain risk analytics[END_REF]. Supply chain models are thus evolving in order to benefit from technological innovation (and digitalization), with advantages in promoting a higher focus on customer requirements, improving efficiency in resource utilization, enhancing modularization of products and services [START_REF] Ben-Daya | Internet of things and supply chain management: a literature review[END_REF], [START_REF] Ivanov | The impact of digital technology and Industry 4.0 on the ripple effect and supply chain risk analytics[END_REF]. Indeed, the mega-trends identified in literature as reshaping the process and manufacturing sectors are digitalization, customization, resources optimization, servitization and modularization. Nevertheless, companies are still struggling to leverage or react to the shifts characterizing the actual competitive landscape and the way they do their business, and further research is required.

According to the depicted context, the aim of this study is to investigate the enabling technologies and main practices fostering collaboration at supply chain level, basing on the exploration of current practices of companies at the intersection of digitalization and collaborative networks (as in [START_REF] Camarinha-Matos | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF]). With this goal, the unit of analysis is represented by the business models emerging from the current trends and consequent opportunities leveraged by companies in their business. Specifically, design principles of business models have been identified and characterized in terms of main features, impacts on supply chain (supply and demand side), technologies and types of collaboration and integration towards digitalization.

Methodology

Aiming to perform an exploratory qualitative research, a multiple case study design [START_REF] Yin | Case Study Research: Design and Methods (Fifth Edition)[END_REF] has been employed. We purposefully selected 24 among leading European companies of high value-added goods demonstrating to leverage on at least one of the main trends identified (i.e. digitalization, customization, resources optimization, servitization and modularization) as the base for the "design principles" to be followed in shaping their business model. A stratified sampling has been adopted in order to have a set of cases including different kinds of value chain partners (i.e. raw material providers, manufacturers, logistics providers, clients), types of manufacturing (process/discrete) and flexibility (e.g. capacity, product, location), sectors, to conduct a cross-sectorial and holistic investigation.

Table 1 provides an overview of cases basing on the integration of these variables. Data collection was based on semi-structured interviews and secondary data (publicly available and internal documentation provide by interviewees), also for triangulation purposes [START_REF] Yin | Case Study Research: Design and Methods (Fifth Edition)[END_REF][START_REF] Voss | Case research in operations management[END_REF]. Interviews have been conducted by the research team at company site or via Skype call and were based on a common protocol. Questions aimed at assessing the emerging supply chain configurations and business models basing on the combination of several dimensions of analysis: enabling technologies (with related readiness and impact on business model change), coordination and collaboration mechanisms along the supply chain, flexibility parameters to optimize flows in the value chain process, key activities involved in the delivery of value offer. Both multiple-choice (e.g. with provision of the list of technologies) and open questions were included, in order to enhance a further exploration of the real industrial cases. One to two respondents per each case were involved in the different interview meetings among the key roles in the digitalization, supply chain flows or strategy of their respective companies, e.g. CEOs, innovation, supply chain and operations managers. The collected data were qualitatively analyzed and coded independently by the researchers to identify common patterns and elements in the supply chain models, practices and enabling technologies. Emerging results were then compared until reaching agreement among researchers, and further presented and discussed in a workshop with experts from academic and industrial fields, aiming to assess their accuracy and significance for literature on collaborative network practices, digitalization and design principles of business models in a supply chain perspective.

Results

Results from pattern-matching and cross-case analysis [START_REF] Yin | Case Study Research: Design and Methods (Fifth Edition)[END_REF][START_REF] Voss | Case research in operations management[END_REF], informed by current literature (e.g. [START_REF] Fornasiero | Implementation of customisation strategies in collaborative networks through an innovative Reference Framework[END_REF], [START_REF] Ivanov | The impact of digital technology and Industry 4.0 on the ripple effect and supply chain risk analytics[END_REF]) allowed to identify four main design principles of business models to frame the investigation: Personalized production, Servitization, Decentralized and modular production, Recycle, Re-use and Sustainability (RR&S). These business models are not completely independent from each other and are able to capture the majority of megatrends considered in the study even if they are addressing one of them in a more significant way than the others. This section includes the description of main features, involved value chain actors, type of collaborations and enabling technologies to activate each design principle of business model emerging from the analysis of the cases and the current trends in manufacturing and process industry.

A further analysis of the results, building on the work by [START_REF] Camarinha-Matos | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF], allowed to identify how the digital technologies adopted in the implementation of the four models enable the key features of collaborative models at the interplay with digitalization, i.e. Vertical integration or networking of smart production systems, Horizontal integration through global value chain networks, Through-engineering across the entire value chain, Acceleration of manufacturing and Digitalization of products and services.

Personalized Production

Customization has emerged over the past two decades as one of the strategies that allows companies to differentiate their offer through innovative products, where added value is given by meeting the specific needs of a customer or a target group of customers thanks to highly flexible manufacturing systems [START_REF] Ivanov | New flexibility drivers for manufacturing, supply chain and service operations[END_REF][START_REF] Montalto | An approach to design reconfigurable manufacturing tools to manage product variability: The mass customisation of eyewear[END_REF]. The shift towards personalization is reinforced by new manufacturing technology developments, e.g. in advanced robotics, additive manufacturing and advanced digital simulation of manufacturing processes, enabling shorter production runs and more one-of-a-kind products [START_REF] Ivanov | The impact of digital technology and Industry 4.0 on the ripple effect and supply chain risk analytics[END_REF]. Supply chains for personalized products enhance consumers to have products with a unique design and style, along with functional and comfort-related aspects, even in the more traditional sectors, and to make a choice in terms of value, functionality and performance [START_REF] Fornasiero | Implementation of customisation strategies in collaborative networks through an innovative Reference Framework[END_REF].

Enabling technologies for personalized production. Enabling technologies include: 3D scanning, additive manufacturing (as 3D printing) and multi-purpose and hybrid processes for the production of customized components or products; virtual and augmented reality for supporting sales processes; modelling and simulation, business intelligence and sensors to enable changes in product and processes and reconfiguration of production networks; big data to optimize data driven manufacturing, better management of the innovation and the definition and analysis of the effects of location of the supply chain.

Collaborative practices for personalized production. In the attempt to rapidly reconfigure to satisfy custom requirements, the manufacturing systems should develop a high level of integration with customers/users, who become the main creators of the solution produced. For example, C2 developed direct customer relations by avoiding intermediaries as retailers and using on-line channels and platform strategy. Some technologies are also changing the relationships between business partners, as smart materials for C2: material suppliers are becoming technology providers, subject to strict selection and performance evaluation. Therefore, companies along the supply chain need to develop new business models and flexible manufacturing systems capable of producing relatively small batches of customized products at competitive costs, as C4, which outsourced both design and production of part of components to reduce complexity.

Basing on the analysis of the enabling technologies and practices, we can argue that the activation of the Personalized production model allows to realize the dimension of Horizontal integration through value chain, especially with customers for collecting their needs and integrate design activities through 3D scanning and big data analytics; the Through-engineering across the entire value chain thanks to collaborative product design and configuration, also with the use of smart materials; the digitalization of products and services through the use of Virtual reality and Internet of Things in supporting sales channels and design process.

Servitization

As more companies and industries in the world are increasingly adding value to their products by including additional services [START_REF] Vandermerwe | Servitization of business: Adding value by adding services[END_REF], the need for a clear business model becomes more relevant. This provides the opportunity for the development of servitization (also known as Product Service System (PSS) [START_REF] Goedkoop | Product Service systems, Ecological and Economic Basics[END_REF]) as a design principle that significantly changes the dynamics in a typical value chain, also in terms of services that could be oriented to the product, user, or result [START_REF] Reim | Product-Service Systems (PSS) business models and tactics -a systematic literature review[END_REF]. Companies are deciding to offer a broader set of products, ranging from mere products, to bundles of product-services and finally experience-based products and services [START_REF] Hassenzahl | Needs, affect, and interactive products -Facets of user experience[END_REF][START_REF] Kimbell | Designing for Service as One Way of Designing Services[END_REF]. Indeed, servitization leads the shift from a traditional linear supply chain centered on the product to a supply chain that increases the relevance of the services around the product, with key differences in terms of risks, responsibilities, ownership shared among the PSS provider and its partners in a value chain.

Enabling technologies for servitization. The technologies that have the largest impact in this model are focused on information sharing, monitoring and diagnostic, prognostic analysis and decision-support and include big data and big data analytics (with descriptive, predictive and prescriptive purposes), cloud computing and mobile platforms for customer communication and data access, IoT to enable automatic monitoring along the overall value chain, 3D printing for refurbishing, telemedicine and 360-degree medical data for the e-health services.

Collaborative practices for servitization. This design principle creates new relationships between a "supplier" and a "user/buyer", transforming the interaction usually based on single transactions into a long-term ongoing relationship, which can include the delivery of services, goods, management and knowledge. For example, C18 developed result-oriented servitization whereby the supplier and buyer collaborate in a form of payment called "paid per service unit", while reducing production costs and environmental impacts, improving expertise of both parts and optimizing processes. Beyond the strategy of the single company, the collaboration along the overall supply chain need to become more flexible and agile to incorporate a reconfiguration of the relationship between the manufacturer and the customer. C5 improved customer intimacy to grow trust, understanding of customer needs and faster achievement of outcomes through virtual communications.

It is possible to infer that the implementation of new technologies in this design principle will lead to develop of new services and complement current product offering, towards the dimension of Digitalization of products and services. Moreover, available technologies (Big data, Artificial intelligence, Automation, etc.) are becoming increasingly useful as they generate valuable information to the provider and generate an opportunity for a closer relationship with customer and for the dimension of Horizontal integration along product life-cycle, proving to be a key component in the introduction of new services.

Decentralized and Modular Production

Companies decentralizing their manufacturing split the production processes into smaller plants to produce in different locations or regions. Decentralized and modular production has effects on the organizational structure of companies, which can be more effective by focusing on their core activity, and on the value chain, which is broken down over more decision-making units that may be outsourced or procured at different locations. This shift leads to supply chains based on economies of scale and customerspecific, from process optimization to agile and distributed processing needs [START_REF] Srai | Distributed Manufacturing: scope, challenges and opportunities[END_REF].

Enabling technologies for decentralized and modular production. Enabling technologies for this design principle need to support modularity, ICT for control, electrification, equipment manufacturing referred to novel inexpensive mass production technologies, process intensification and continuous processing and recovery/work-up. These include electrically powered chemical technologies, 3D printing and automated process control for manufacturing, and big data, skid based designs and plate based equipment for engineering.

Collaborative practices for decentralized and modular production. The business case of small-scale production is mainly focused on locating the production facility closer to the customer. For example, C21 is developing plants consisting of modular building blocks that can be easily extended to address increase in market demand or even adapted to fit in a container, to be easily transportable close to customer location. This changes a pivotal part of the supply chain in the manufacturing and sourcing stages. Also the container-base manufacturing in the value chain of C23 allows for local production and direct use of equipment and produced goods, with transportation discarded from the supply chain and consequent less impact on price volatility. Moreover, the decentralized supply chain is not fixed and can change based on the specific case at hand, with the large scale producer elements that can either be bypassed or integrated in the new supply chain.

Basing on the analysis of the enabling technologies and practices, we can argue that the activation of the Decentralized and modular production model allows to realize the dimension of Vertical integration, with the collaboration among small scale platforms, and the Acceleration of manufacturing, thanks to the increased use of technologies as electrically powered chemical technologies and multilayer disposable plants for small scale production.

Recycle, Re-use and Sustainability (RR&S)

RR&S business model is based on the principle of Circular Economy, where resource input and waste, emission, and energy leakage are reduced by slowing, closing, and narrowing material and energy loops [START_REF] Witjes | Towards a more Circular Economy: Proposing a framework linking sustainable public procurement and sustainable business models[END_REF]. The introduction of such a model has impact on both upstream (changed collaboration with raw material suppliers), downstream (collection of waste) and side stream (industrial symbiosis) value chain partners as well as on the value proposition (e.g. new recycling, extended producer responsibility or industrial symbiosis services), with closed material loops [START_REF] Bocken | Product design and business model strategies for a circular economy[END_REF]. For example, C6 is creating new feedstock types based on waste, contributing to feedstock flexibility as well as environmental benefits with reduced impacts by providing alternative added value.

Enabling technologies for RR&S. Recycling refers to technologies that aim to recover materials from end-of-life products as disassembly and separation techniques. Technologies and solutions for industrial symbiosis represent an important area of development. Optimization of material use will increasingly see a combination of recyclability and biodegradable materials (e.g. in packaging). Novel "repair technologies" for industrial processes, such as 3D printing enable remanufacturing and repair. Key information and telecommunication technologies support the mapping, tracking and matching of materials throughout the supply chain. Moreover, data driven simulation of business model, product-ageing and reverse supply chain support decision making in the development and design of Circular Economy operations and organizations.

Collaborative practices for RR&S. The RR&S supply chain requires significant built of trust and collaboration among partners, from design for recycling up to dismantle for recycling (so called "reverse logistics"), from the planning and coordination of the circular supply chain to decision making in terms of remanufacturing, refurbishing and repair. It hence requires solutions that favor value chain coordination from end-of-life collection, treatment and re-introduction as a resource in the primary production process. For example, C13 is innovating the process to be more efficient, introducing new actors in the value chain, reinforcing relationships with neighboring industries and redefining capacity, location and feedstock flexibility for maximizing sustainability and recycling opportunities.

It is possible to infer that the implementation of an RR&S business model allows to enable more than one dimension of collaborative networks, i.e. Horizontal integration, also thanks the adoption of trusted cloud based platforms, e.g. for waste value chain management, the Vertical integration through product-ageing simulation, and Acceleration of manufacturing through selective separation technologies and automated disassembly.

Discussion and Conclusions

This study performed a broad investigation of 24 companies of manufacturing and process industry to identify the most important business model affecting supply chain configurations and related enabling technologies towards the creation of collaborative networks. Basing on this analysis, we can argue that the four design principles analyzed enable all the characteristics of collaborative networks for the digitalization of the overall value chain, i.e. Vertical integration or networking of smart production systems, Horizontal integration through global value chain networks, Through-engineering across the entire value chain, Acceleration of manufacturing and Digitalization of products and services, and the integration of the manufacturing and process industry. Design principles are addressed to any type of collaborative network described in [START_REF] Camarinha-Matos | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF], i.e. one business model (design principle) does not preclude the implementation of one collaborative network or another. Moreover, the enabling technologies should be targeted for sustaining specific collaborative practices, but also developed in a systemic perspective for enhancing the overall supply chain performance.

Obtained results contribute to advance knowledge in the research on digitalization and collaborative networks by adopting a perspective integrating business model design principles, enabling technologies and collaborative practices implemented at the value chain level. Managers should develop one or a combination of these design principles on the basis of company's competitive priorities, while considering the value chain perspective, in order to foster practices with downstream and upstream actors enabling the digitalization and the implementation of a holistic collaborative network approach. Even if design principles identified in the empirical investigation are not completely new, the originality of the paper consists in providing industry practitioners with examples that can be considered and configured in their own contexts as a sort of 'working ingredients' clustered around the design principles identified. An expected impact is a wider adoption of the business models guiding supply chains configurations towards collaborative networks, in order to improve competitiveness and resilience of European industry in dealing with major industrial challenges.

A recognized limitation of the study concerns the methodology and the sampling adopted that can pre-determine to some extent the emerging patterns of design principles. Nevertheless, the focus is on the exploration of the design principles at the base of supply chains configuration to foster their adoption towards collaborative networks, rather than the identification of the principles themselves.

Table 1 .

 1 Overview of selected case studies.

	Case Brief description of company main activity and industry
	C1	Leather fabrics supplier for customized consumer goods
	C2	Flexible manufacturer of customized shoes
	C3	Provider of rapid / additive manufactured components
	C4	Steel machineries manufacturer for customized small scale batches
	C5	Implantable drug delivery devices manufacturer
	C6	REE logistics provider for industrial symbiosis
	C7	Service provider for recycling tasks in chemicals
	C8	Recyclable packaging manufacturer
	C9	Aluminum printing plates provider, involved in recycle process
	C10	Polymers supplier, focused on sustainability
	C11	Mobile industrial processing of biomass
	C12	Water utilities provider, involved in re-use process
	C13	Processing of biomass flows into bio-based aromatics
	C14	Logistics provider of post-consumer textile waste
	C15	Pipeline transportation provider re-using residual gasses
	C16	Energy-and feedstock intensive company involved in industrial symbiosis
	C17	Metal and textile cleaning service provider
	C18	Provider of chemical leasing for metal cleaning
	C19	Remote chemical production control devices manufacturer
	C20	Provider of data analytics software for integrated plant-wide scheduling and control
	C21	Biopharmaceutical company developing transportable plants
	C22	Food company with flexible modular factory
	C23	Provider of equipment for container-based chemical manufacturing
	C24	Functional molecule production manufacturer with modular factory

Acknowledgments. This research has been conducted as part of the INSPIRE project, which has received funding from the European Union's Horizon 2020 Research and Innovation program under Grant Agreement n°723748. The authors wish to acknowledge their appreciation to the European Commission for their support and to all the project team for their contribution during the development of this research.


Sobah Abbas Petersen

Zohreh Pourzolfaghar
email: zohreh.pourzolfaghar@dcu.ie

Iyas Alloush
email: iyas.alloush@dcu.ie

Dirk Ahlers
email: dirk.ahlers@ntnu.no

John Krogstie
email: krogstie@ntnu.no

Markus Helfert
email: markus.helfert@dcu.ie

Value-Added Services, Virtual Enterprises and Data Spaces inspired Enterprise Architecture for Smart Cities

Keywords: Data Spaces, Enterprise Architecture Framework, Smart Cities, Collaborative Networks, Positive Energy Blocks

As a part of their digital transformation, municipalities across Europe have taken initiatives to support Open Data platforms and provide services leveraging on data. This challenges the traditional business driven IT strategy promoted by several Enterprise Architecture methodologies, which are designed to operate within a single enterprise that has a complete overview of its data and ICT systems. We envisage scenarios where public and private collaborative networks provide value added services to its citizens by leveraging on data. In this paper, we propose an Enterprise Architecture Framework for Cities to support them maneuvre smartly within their data space to create value added services through a variety of collaborative networks or Virtual Enterprises that bridge organisational boundaries. The novel elements of this Enterprise Architecture Framework are a DataxChange, the Value-Added Services and Virtual Enterprise layers. This work has been conducted within the EU H2020 Smart City project +CityxChange.

Introduction

Sustainability and digital transformation and are two of the main driving forces for cities and municipalities today. Current Smart City approaches have advanced from monitoring various aspects of a city through sensor and other data to providing services to its citizens in more collaborative ways [START_REF]4.2 -Definition of Smart City Reference Architecture[END_REF][START_REF] Helfert | Data Model Architecture Implementation[END_REF]. We adopt the view of a smart city that integrates people, technology and information to create a sustainable and resilient infrastructure that provides high quality services for its citizens [START_REF] Villanueva-Rosales | A collaborative, interdisciplinary initiative for a smart cities innovation network[END_REF]. The data that is gathered through sensors and/or other sources are central to developing value added services for the citizens. We envisage scenarios where public and private collaborative networks (CNs) provide value added services to its citizens by leveraging on data and systems that bridge different organisations.

The work reported in this paper is motivated the EU H2020 project +CityxChange, which focuses on Positive Energy Blocks (PEBs) to reduce emissions in cities and communities towards reaching the Paris Climate Goals [START_REF]What is the Paris Agreement?[END_REF]. Taking a broad perspective of cities and communities in the light of UN's Sustainable Development Goals (SDG); in particular SDGs 7, 11 and 13 (Affordable Clean Energy, Sustainable Cities and Societies and Climate action respectively), there is a need to engage citizens and to develop a portfolio of value added services that will enable citizens to increase their awareness about environmental sustainability and to help them make better choices. Furthermore, cities are motivated to engage their private businesses and other stakeholders in novel and innovative partnerships to provide value added services to the citizens.

One of challenges faced by cities and service providers is the lack of access to relevant data or indeed an overview of available data and relevant actors. Enterprise Architecture (EA) used initially in the business world to bridge between the business needs and the ICT strategy of a company has been used in Smart City contexts to bridge the needs of a city with ICT, resulting in a number of Smart City Enterprise Architecture Frameworks (EAFs). Our review of several EAFs from Smart City projects show that while several of them identify the need for services, the emphasis on the role of data is not so evident. We argue that the role of data must be a central component of a Smart City EAF, to support the drive for digital transformation as well as the effective use of available data.

In this paper, we propose a layered EAF for +CityxChange and Smart Cities in general where a DataxChange lies at the heart of the EAF. The DataxChange bridges the technology layers and the higher layers of the architecture, such as the business collaborations and value added services. The proposed architecture builds upon existing work, and complements them by emphasising the novel elements, which are the DataxChange, the Value-Added Services and the Virtual Enterprise (VE) layers to support CNs.

This paper is structured as follows: Section 2 describes the +CityxChange project; Section 3 describes our vision for a Smart City EAF; Section 4 describes the +CityxChange EAF to realise such a vision; Section 5 illustrates how value added services can be supported by EAF; Section 6 gives an overview of related work and Section 7 summarises the paper and provides an outline of the future work.

+CityxChange Project

The background and motivation for this paper is the EU H2020 funded +CityxChange project [START_REF]Positive Energy Blocks[END_REF] that aims to develop PEBs in smart cities and communities as part of emission reductions to reach the Paris Climate Goals [START_REF]What is the Paris Agreement?[END_REF]. It is a Lighthouse project, where Trondheim, Norway, and Limerick, Ireland, are the lighthouse cities, and five follower cities showcase replication. The consortium of 32 partners include universities, municipalities, utility and infrastructure providers and other private entrepreneurs. It follows an integrative approach with a strong focus on city integration, open innovation and replicability. The approach combines:

• Integrated Planning and Design of cities;

• Creation and Enabling of a Common Energy Market;

• A CommunityxChange with all stakeholders of the city to create connected and engaged communities. The project focuses on the technical solutions as well as the interactions and integration between buildings, users, cities and the energy system. It also focuses on the implications and impact on city planning, city systems, energy trading, citizen involvement, policies and regulations, data and digitalisation and socio-economic issues. A Positive Energy Blocks (PEB) is defined by the EU as several buildings that actively manage their energy consumption and the energy flow between them and the wider energy system1 . They achieve an annual positive energy balance through use, optimization and integration of advanced materials, energy reduction, local renewable energy production and storage, smart energy grids, demand-response, energy management of electricity, heating and cooling, user involvement. PEBs or Positive Energy Districts (PEDs) are designed as an integral part of the district energy system. They should be intrinsically scalable up to positive energy districts and cities and are well embedded in the spatial, economic, technical, environmental and social contexts.

New forms of integrated spatial, social, political, economic, regulatory, legal and technological innovations are envisaged to deliver citizen observatories, innovation playgrounds and regulatory sandboxes linked to Urban Living Labs. Municipalities will develop Bold City Visions to engage civil society, local authorities, industry and Research and Technology Organisations to scale up from PEBs to PEDs or Positive Energy Cities, supported by a distributed and modular energy system architecture.

The ICT related challenges faced by the +CityxChange project include the lack of a means or forum for discovering existing and available data and services and indeed accessing and retrieving relevant data from available data sources [START_REF] Ahlers | A Smart City Ecosystem enabling Open Innovation[END_REF], for use in developing value added services. ICT is envisaged to play a central role as an enabler for innovative value added services, stimulating new collaborations and in achieving PEBs and scaling up to the district and city levels. Similarly, ICT will provide support for the replication of solutions from the Lighthouse cities to the follower cities [START_REF]What is the Paris Agreement?[END_REF][START_REF] Ahlers | A Smart City Ecosystem enabling Open Innovation[END_REF].

Vision

Our vision for an EAF to support the +CityxChange project and Smart Cities in general is driven by the need and availability of data and systems and the central role that data plays in today's cities and how the data could be leveraged to provide valueadded services to the citizens. Many Smart City concepts are inherently multidisciplinary and need the collaboration of various stakeholders from different domains, including cities and citizens [START_REF] Ahlers | Understanding Smart Cities as Social Machines[END_REF]. New and innovative value added services could be provided by diverse constellations of CNs or VEs, which are a group of partners that collaborate to achieve a specific goal [START_REF] Petersen | Virtual Enterprise Formation and Partner Selection: An Analysis Using Case Studies[END_REF]. Our vision will address some of the shortcoming of existing EAFs to meet the needs of smart cities. We believe that data can play a central role in bridging the technology aspects to the strategic and business aspects of an enterprise, such as the business collaborations and value added services. The central role of data and its value to an organisation has been discussed in many contexts, such as Industry 4.0 [START_REF] Otto | IDS Reference Architecture Model, Industrial Data Space[END_REF]. The need for supporting collaborative data analysis and processing and enhancing collaboration support among the data owners, data scientists and indeed service providers have received attention [START_REF] Park | Web-based collaborative big data analytics on big data as a service platform[END_REF]. Examples of leveraging on data in the context of smart cities have appeared recently in the literature; in Helsinki, the city has been considered as a Living Lab and the data that is collected has been used to develop services as mobile applications [START_REF] Hielkem | Developing the Helsinki Smart City: The Role of Competitions for Open Data Applications[END_REF]. The need for easy discovery of existing and available data and services and indeed accessing and retrieving relevant data is increasing and is one of the main challenges in the +CityxChange project. Thus, an EAF that supports an overview of data and the meta-data related will be an important asset to the creation and operation of value-added services in a smart city. If the stakeholders of a smart city have an overview of data that is potentially accessible and available for them to leverage on, the potential of value added services for the citizens can be enhanced.

CNs and VEs have long been discussed as means and drivers for value creation [START_REF] Camarinha-Matos | Knowledge Enterprise: Intelligent Strategies in Product Design, Manufacturing, and Management[END_REF]. More recently, they have been discussed as an important mechanism in the context of leveraging on the vast amounts of data that are available in many contexts; e.g. [START_REF] Camarinha-Matos | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF]. Bringing these concepts to the heart of an EAF is essential in supporting the creation of innovative and value added services in the context of smart cities. This can facilitate the integration of services vertically within a city such as technological support, data processing as well as operational services, and connecting them to a clearly identified value to the city and citizens. Similarly, it can ensure the integration of the processes horizontally across the value chain around data, such as the data owners, processors and data consumers. Furthermore, this can support empowerment not only of the citizens, but provide opportunities for project partners to collaborate in new and innovative CNs, VEs and business models.

+CityxChange Enterprise Architecture Framework

Based on the literature and the smart city EAFs developed in relevant EU projects, such as the Smart City project SmartEnCity [START_REF] Helfert | Data Model Architecture Implementation[END_REF] and the standardisation efforts in ESPRESSO [START_REF]4.2 -Definition of Smart City Reference Architecture[END_REF], we propose a layered EAF for the +CityxChange project, as illustrated in Figure 1. The main driver for the EA is the "service-based ecosystem", identified as an objective for the EA in the +CityxChange project [START_REF] Ahlers | A Smart City Ecosystem enabling Open Innovation[END_REF]. The scenarios envisaged for the project span many application domains (or silos) such as energy, transport, IoT, built environment and governance. An example of a value added service considered in the project that spans several application domains is eMobility as a service, across energy, transport and urban planning domain.

Several horizontal layers are defined in the EAF to support value added services, which utilise data and are provided by collaborations among two or more enterprises; i.e. by a VE. The thinking behind the layered approach is that each layer supports the layer above it. Thus, the value-added services are supported by one or more businesses or a VE, which are supported by one or many applications, which use data from the +CityxChange DataxChange layer. The +CityxChange DataxChange is supported by technologies and finally, the data is obtained from data sources.

Figure 1 +CityxChange Enterprise Architecture Framework

The +CityxChange DataxChange is at the heart of the EAF, where this layer provides an overview of all available data and systems and relevant information about the data that is required for creating value added services. Relevant information about the data will include the owner of the data, how the data may be accessed and the conditions and criteria that may be necessary to access or use the data. The DataXchange plays a central role is providing a comprehensive overview of the available data, providing the support that the various service providers need. Indeed, it should provide information about the relevant and potential collaboration partners that could participate in providing value added services to citizens, leveraging the data. The DataXchange provides a means to bridge the lower levels of the EAF, such as supporting technologies, and the higher levels of the EAF, such as value added services. Furthermore, this layer will also serve as a common "platform" for the lower layers to facilitate access to data for the higher layers. Together with the Business Layer, this layer is designed to support concepts such as data markets and data as a commodity in the near future.

The highest layer of the EA is the context layer, which drives the services and the business context. Value added services are created to meet the needs of the citizens or to affect and change their behaviour to meet the strategy of the city or some business actor. The Value added Service layer is below the Context layer, which both offers services to and uses data and applications from the different application domains and involves one or more actors. The Application and Data Processing Layer describes the different applications that support the services. Applications may support processing or analytics of data that are relevant for the service or other purposes such as searching and navigating the information space, visualisation of information or other.

Two layers are defined below the DataXchange: Technologies layer and Data Sources layer. The Technologies layer describes the different technologies that support the DataXchange and the higher layers of the EAF. Technologies include hardware (e.g. servers and sensors, metering devices), applications such as databases and infrastructure, e.g. for micro payments. As data is obtained from a variety of sources such as IoT, sensors or local renewable energy production such solar panels mounted on private property, the origin of the data is essential for data governance; for ensuring the quality of the data, fostering trust among the users of the data, for supporting transparency and integrity of data, and for adhering to regulatory frameworks such as GDPR. Thus the Data sources layer is important to identify the sources that provide the data.

Related to the horizontal layers, we have two perspectives: (i) Stakeholder perspective to highlight the different stakeholders, their roles and perspectives; and (ii) Data perspective to address the specific principles and guidelines that are relevant in data-rich environments. These perspectives apply to all or most levels of the EAF as shown in Figure 1. A number of high level principles were identified for the +CityxChange EAF in [START_REF] Ahlers | A Smart City Ecosystem enabling Open Innovation[END_REF]. These perspectives provide a means of structuring and contextualising guidelines and principles for using the +CityxChange EAF. A detailed description of principles and guidelines are provided in [START_REF] Petersen | +CityxChange -D1.2 Report on the Architecture for the ICT Ecosystem -Initial Version[END_REF].

Stakeholder Perspectives

The +CityxChange project has a citizen focussed approach with several tasks dedicated to citizen engagement. Similarly, the service-based ecosystem and the participation of several public and private entities call for close attention to the diverse stakeholders that are a part of the city-wide or +CityxChange-wide EA space. Stakeholders describe the various entities involved in the city-wide EA space, which include citizens, service providers and consumers, who develop service to create added value. Stakeholders also include data owners, providers, processors and consumers of data, public authorities, private enterprises, researchers and various communities (e.g. a local housing complex).

Privacy and Trust describes the relevant principles and guidelines that need to be followed not only to respect and protect the privacy of individual people and organisations, but also support a network of trust among the various stakeholders of the +CityxChange DataxChange and value added services. Given the focus on stakeholders and the protection of individuals through the recent EU GDRP regulations, we have chosen to separate privacy and trust from data security (although they are dependent on one another). An EAF for a smart city spans beyond organisational boundaries and consequently the potential of sharing privacy-related data among stakeholders and data processors from a number of different prganisations can be envisaged. Thus, the need to increase awareness of privacy-related issues and designing to ensure privacy and trust and compliance to regulations, in particular with respect to the use of stored data for multiple purposes, increases.

Policies and regulations describe the regulatory stakeholders that are involved in the project, the influencers and stakeholders and services that are affected by the specific policies and regulations. Ownership and access describe the relationships between the stakeholders and the entities that will be represented in the layers of the EAF. The scenarios envisaged in the project highlight that the relationships between the data and other entities or the ownership or accessibility models for data elements are not simple, uniform or trivial.

Data Perspectives

The +CityxChange project envisages value added services that leverage on data and system integration that is available through the +CityxChange DataxChange or indeed Open Data. Thus, there is a data perspective related to all layers of the EAF, from the data sources to the value added services. This raises a need to address the data perspectives.

Interoperability addresses how entities, through all the layers in the EAF, could be brought together in a cohesive way to provide the value added services. Interoperability applies to all the levels of the EAF.

Data security and risk assessment apply to all the layers the EAF to ensure that the data is handled in a secure and reliable manner. The security of data is not a static state; i.e. data that is secure at any time may not be secure at a future time, and thus requires regular assessments of risks and threats to the security of the data.

Data Governance ensures proper data management and ownership processes and data quality and encompasses people, organisations and processes. Data governance ensures that data is consistent, available and useable.

Value Added Services

One or more value added services (example services A, B and X) could be created by using the data available from the +CityxChange DataxChange, as shown in Figure 2. Each of the services are likely delivered by collaboration among one or more organisations; any organisation may participate in the delivery of one or more services and participate in one or more VEs. For example, the municipality of a specific city may be a part of a VE that provides both the Services A and B. Similarly, the same municipality may also play a role in Service X, perhaps different to that for the Services A and B. This simple example illustrates that several elements (data/services) from the DataxChange may be used by one or more services.

Based on the scenarios envisaged for the +CityxChange project and the visions of the Lighthouse cities that have been shared and integrated so far, we see the need to support such value added and the need to share data and the ability to incorporate new data that is generated through the value added services. The +CityxChange DataxChange is designed to facilitate such activities.

Related Work

EA concerns the overall ICT landscape and alignment of the business strategy and its ICT implementation. Several EAFs have been proposed for Smart Cities. Based on the leading EAF in the industry [START_REF] Cameron | Analyzing the current trends in Enterprise Architecture Frameworks[END_REF], The Open Group's EA, TOGAF [START_REF]The Open Group Architecture Framework TOGAF Version 9[END_REF], several Smart City EAFs are based on a multi-tier or layered approach proposed; e.g. [START_REF]4.2 -Definition of Smart City Reference Architecture[END_REF][START_REF] Harrison | A Theory of Smart Citie[END_REF][START_REF] Fsp_Org_Id | ISO/IEC JTC 1 Information technology, WG11 on Smart Cities[END_REF][START_REF] Pourzolfaghar | Standardisation of Enterprise Architecture Development for Smart Cities[END_REF][START_REF] Winter | Essential Layers, Artifacts, and Dependencies of Enterprise Architecture[END_REF]. The notion of services is identified explicitly in some of the EAFs [START_REF]4.2 -Definition of Smart City Reference Architecture[END_REF][START_REF] Helfert | Data Model Architecture Implementation[END_REF][START_REF] Pourzolfaghar | Standardisation of Enterprise Architecture Development for Smart Cities[END_REF][START_REF] Ferguson | Open Frameworks for Information Cities[END_REF]. The service layer identifies the business and the stakeholder perspectives, often considered as services offered by municipalities or the cities.

Of particular interest to our work is the Intelligent Data Spaces Reference Architecture Model (IDS-RAM), proposed by the German Fraunhofer Institute and the International Data Spaces Initiative [START_REF] Otto | IDS Reference Architecture Model, Industrial Data Space[END_REF]. They describe an Industrial Data Space as a "virtual data space leveraging existing standards and technologies as well as accepted governance models for the data economy, to facilitate the secure and standardized exchange and easy linkage of data in a trusted business ecosystem". Similar to other EAFs, IDS-RAM also takes a layered approach. However, a few things distinguish it from the other frameworks and methodologies; e.g. it focuses on the Industrial Data Space and it takes a data-centric approach and thus supports both top-down and bottom-up approaches. A framework which describes foundation and principles for Information Technology in smarter cities is proposed in [START_REF] Harrison | Foundations for Smarter cities[END_REF]. It incorporates instrumented data from sensors, Integration of data and intelligent inclusion of complex analytics, modelling and optimization, and visualization in operational business processes.

Summary and Future Work

An EAF to support a service-based ecosystem for the +CitxChange project is proposed, which supports the creation of value added services that leverage available data and services/systems. The novel elements of this Enterprise Architecture are the DataxChange, the Value-Added Services and the Virtual Enterprise layers. A DataxChange is at the heart of this architecture, which we argue is an essential part of a Smart City EAF, and which will bring together all available data and relevant information about the data to support the creation of value added services, by collaborative networks of partners from public private and research sectors. The DataXchange layer provides a bridge between the lower levels of the EAF, such as supporting technologies and data sources, and the higher levels of the EAF, such as the value added services.

The proposed architecture is work in progress and we are working on refining this EAF by applying it to describe the different services that will be developed in the project. Furthermore, this EAF is envisaged as a support in reaching out to the partners who will participate in the VEs providing the value added services, and in driving the dialogue in the iterative definitions of the value added services. As such, it can also support many of the collaborative relationships within a complex project and provide additional technical frameworks and collaboration spaces, based on a joint understanding of the ICT relationships and networks within the project. These should also support easier communication, information access, and knowledge finding and sharing within the project. Our next steps are to describe a few scenarios and services using this EAF and facilitate the service description process, while refining EAF based on the feedback.

Figure 2

 2 Figure 2 Value added Services as an instance in the +CityxChange EAF

https://ec.europa.eu/info/funding-tenders/opportunities/portal/screen/opportunities/topicdetails/lc-sc3-scc-1-2018-2019-2020

Acknowledgements

+CityxChange is a smart city project under the Smart Cities and Communities that is funded by the European Union's Horizon 2020 Research and Innovation programme under Grant Agreement No. 824260. The authors would like to thank the project partners from Trondheim Municipality, Limerick City Council and the participants of work packages 1 and 2 as well as the whole project team.


A Luis Osório

Luis M Camarinha-Matos

Tiago Dias
email: tdias@cc.isel.ipl.pt

José Tavares
email: jose.tavares@fordesi.pt

Adaptive Integration of IoT with Informatics Systems for Collaborative Industry: The SITL-IoT Case

Keywords: Collaborative Networks, Internet of Things, Systems Integration, Cyber-physical systems, Distributed systems

Legacy industrial infrastructures are facing complex challenges to evolve to integrated solutions through the adoption of novel computing and business paradigms. The fast-growing collaborative businesses introduce the additional complexity of managing cooperative interactions among systems of business partners. The SITL-IoT research project aims to develop an open integrated and collaborative systems landscape for the silos agri-food industry. This case considers a silos' operator managing a maritime silos terminal in collaboration with the seaport administration, where trucks transfer bulk products to silos or bulk storages and distribute them to factories. The existing legacy management and supervision solutions are neither integrated nor properly prepared to cope with collaborative processes. Furthermore, the interactions with business partners are complex and follow dedicated integration solutions that pose difficult challenges in terms of management and evolution, since they do not follow open collaborative models or technology implementations. This paper discusses the problem domain and the approach to co-design and implement a technology-agnostic open integration infrastructure to support such collaborative network. The proposed approach considers a multi-supplier strategy for the adaptive integration of things on Internet of Things (IoT), considering the collaborative networks dimension.

Introduction

Industrial companies are facing complex challenges to adapt their sensor/actuator and computing systems to new business models to maintain competitiveness. The fast move towards digital transformation, pulled by retail, social and media companies (e.g., Amazon, Facebook, Netflix), as well as the objectives highlighted by Industry 4.0, put pressure on traditionally conservative industrial systems not only to adhere but also to evolve their technology landscapes to offer advanced management and operations intelligence. However, such trend is complex and difficult to make effective since current approaches still lack a clear systemic structuration. In fact, such traditional approaches consider the incorporation of software parts to improve specific features of a system or the development of independent applications to automate specific processes, without a well-founded systems' engineering approach. Hence, there is an urgent need to evolve towards a systems' thinking paradigm, in order to be able to effectively develop complex composites of collaborative components.

In this paper, we address the challenges faced by a maritime terminal silos operator when deciding about the strategy to integrate multi-supplier things following the Internet of Things (IoT) trends [START_REF] Calado | An Adaptive IoT Management Infrastructure for EcoTransport Networks[END_REF], owing both to the legacy of its current solutions and the expectations of an agri-industry silos concessionaire. Such legacy solutions lack an automatic procedure for the loading of trucks for the transport of bulk products from silos conveyor structures to factories or intermediary logistics infrastructures that is able to smoothly cope with complex collaborative interactions. The challenge is how to structure such cyber-physical components into manageable systems so that they can be part of more complex systems or system of systems (SoS) [START_REF] Vargas | Approaches for Integration in System of Systems: A Systematic Review[END_REF].

The main expectation of this project, named SITL-IoT, is to develop a technology strategy evolve to a higher integration level of legacy and new technical systems. An utmost challenge is how to organize such complex technology systems/elements into integrated vendor agnostic and reliable composites or aggregations. By composites, we mean elements of a system under the same responsibility domain (e.g., from a single vendor or integrator). By aggregation, we mean an agreement between responsibilities under different responsibility domains. Aggregation is important to reduce the governance risks of existing computing related technology landscapes [START_REF] Balalaie | Microservices Architecture Enables DevOps: Migration to a Cloud-Native Architecture[END_REF]. As a contribution to modularity abstractions, we consider the concept of "informatics system" as a composite of computing centric elements, establishing a well-bounded responsibility. We consider a cyber-physical system as a composite of computing and physical interacting elements involving contributions from Informatics Engineering and Electrical Engineering [START_REF] Derler | Modeling Cyber; Physical Systems[END_REF].

In another dimension, the SITL-IoT project addresses the need to coordinate processes involving business stakeholders. The legacy processes involve truck drivers that need to interact with self-service kiosks to operate bulk product transports. These processes are expected to evolve to electronic interactions, making the transport more efficient based on automatic scheduling and authorizations of truck or train operations. The IoT perspective needs to consider a cross border scope, since we need to cope with a diversity of business stakeholders, including telecom operators, vehicle owners and manufacturers, manufacturers of the micro embedded connected devices, etc. On the other side there are organizations like the silos concessionaire, a user organization that needs such things framed to be reliable (responsibility), integrated (in system of systems and collaborative networks), cost-effective (vendor agnostic) and manageable, maintainable, and supported by integrated models. Integration is a complex endeavour, since the interdependence of responsibilities tends to be difficult to manage. In many cases, user organizations have independent 24 hours/7 days support for each critical system even when they are under aggregation mechanisms.

The SITL-IoT is an integrating project joining: (1) an agri-food industry maritime terminal concessionaire SDL, aiming to evolve for integrated and collaborative operations and management of their supervision, control, and business processes; (2) a technology company FORDESI, already a supplier of a silos management system (SIGSIL product), which is committed to offering a vendor agnostic and advanced integrated and collaborative technology system and solutions; and (3) research organizations POLITEC&ID&ISEL and UNINOVA, which provide an open model driven systems engineering (MDEOS) framework.

The paper is organized in five main sections. Section 2 positions the problem and the main research questions. Section 3 summarizes and discusses research and industry contributions to the area. Section 4 presents and discusses the SITL-IoT project case and the proposed approach. The last section draws some conclusions and outlines open questions for further research.

Problem Domain and Main Research Questions

The SITL-IoT project aims to define an approach for agile integration of physical sensors and actuators under an IoT and cloud computing strategy, as depicted in Fig.

1.

Fig. 1. SITL-IoT Systems vision for Logistics Terminal and products flow

The agri-food silos operator company has a terminal concession of the port of Leixões/Porto Portugal, managing a complex network of technological systems and interacting with networked business partners. The aims of the project fit well with the industry 4.0 and digital transformation trends [START_REF] Luis | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF]. The Silo business ecosystem supervises and manages IoT/cyber-physical (mechanical, electrical, automation and computing) artefacts that need to be considered under a unified and single collaborative responsibility.

The agri-food silos ecosystem is under operation, and supported by five main systems (informatics or cyber-physical), as depicted in Fig. 2: i. The Monitoring System, responsible for collecting events from temperature sensors and energy consumption instrumentation; ii. The SCADA, which is a supervision and control system;

iii. The SIGSIL, a product and a central responsibility of FORDESI, which is composed of a customer portal, a mobile portal, and an operations portal, with interoperation to the WS Mobile and OPCS systems; iv. The WS Mobile Portal System for managing the interaction of SDL's operators and truck drivers from ubiquitous user interface devices; v. The OPCS system, which is responsible for the management of the domain processes control.

Fig. 2. The legacy systems at the silos operator

These legacy systems are not integrated under a common technology framework. For instance, the Monitoring System does not process events from the other systems. Moreover, the two systems on the left (Monitoring System, and SCADA) are from two competing suppliers, while the three on the right (SIGSIL, WS Mobile, and OPCS) are from FORDESI. It is interesting to note that no interactions exist between the two systems on the left; they are isolated "islands" [START_REF] Joao | Dynamic Integration of Mould Industry Analytics and Design Forecasting[END_REF].

Technically, suppliers agree on some interaction strategy, e.g., based on an enterprise integration bus. The difficulty lies in the fact that the new system responsible for establishing such an enterprise bus raises additional research questions, since another system needs to be managed. So, the question is if the right strategy to create higher integration levels should be delegating on current suppliers to agree on interoperation mechanisms or to adopt open and vendor-agnostic infrastructures.

To meet this later goal, the challenge is to find an approach for establishing a sustainable multi-supplier technology framework, where systems from different vendors interact under an integrated system-of-systems framework. One key problem is to find the right modularity division of responsibilities, considering that a sustainable technology solution is the one that gets advantage from market competition for each elementary responsibility [START_REF] Osorio | Towards Vendor-Agnostic IT-System of IT-Systems with the CEDE Platform[END_REF], [START_REF] Joao | Dynamic Integration of Mould Industry Analytics and Design Forecasting[END_REF]. Another concern is the design and validation of an appropriate structuration of collaborative responsibilities.

Related Research

The SITL-IoT project is conceptually aligned with Industry 4.0 or smart manufacturing [START_REF] Luis | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF]. It does not involve a manufacturing execution system, but it considers systems responsible for the execution of the SDL processes and, at the base, it involves a distributed cyber-physical system. Such system comprehends multiple embedded devices positioned at different sites that operate as actuators or perform data acquisition through sensors, which we can consider as elements positioned at "Field Level" [START_REF] Bagheri | Cyber-physical Systems Architecture for Self-Aware Machines in Industry 4.0 Environment[END_REF]. One example of such elements is a Truck Weighting physical infrastructure to obtain position and weight of trucks.

The smart city concept and the emergence of sensor data available under open data models have motivated research and industry contributions to make huge amounts of sensor data available through cloud services [START_REF] Ahlgren | Internet of Things for Smart Cities: Interoperability and Open Data[END_REF]. While the idea is interesting for a more "citizen-centric and participatory mobility model" [START_REF] Yadav | The of Open Data in Driving Sustainable Mobility in Nine Smart Cities[END_REF], the authors point for a backbone leveraged by ICT and open data. In fact, in the smartcity concept, the IoT has been the driver for new services offered by computing elements, contributing to data to be analyzed based on cloud systems [START_REF] Nahrstedt | City-Scale Intelligent Systems and Platforms[END_REF]. While emphasizing the value of IoT and cloud computing, the mentioned work adopts an open infrastructure for sharing data sets and understand the interdependencies in such complex dynamic systems. Interdependencies appear as one of the recurrent problems in constructing enhanced intelligent mobility and friendly cities. The Open Data maturity report from the European Commission [START_REF] Cecconi | Open Data Maturity in Europe Report 2018: New horizon for Open Data driven transformation[END_REF] positions cities like Lisbon in a high ranking, as open data is concerned. However, from the presented list of recommendations, it seems that it is lacking a technology strategy in terms of infrastructure responsibilities. The question is whether we need a kind of "city operating system" (what in [START_REF] Marvin | Urban Operating Systems: Diagramming the City[END_REF] is called Urban Operating System) to provide an integrated ICT technology strategy for the coordination and integration of the complex system of systems.

In [START_REF] Marvin | Urban Operating Systems: Diagramming the City[END_REF], the authors establish a parallel with corporate enterprise resource planning (ERP) to question the need for structuring consistent concepts towards the idea of Urban Operating System. The work discusses experiences of smart-city architectures of IBM, Microsoft, and Hitachi, pointing the need to "view the city as an experimental site for the transmutation of corporate integrated information systems into an urban context" [START_REF] Marvin | Urban Operating Systems: Diagramming the City[END_REF]. We find this discussion interesting because it corroborates our hypothesis for the need of a novel technology strategy for answering business requirements under complex evolving ubiquitous computing elements as composites or aggregations of things (IoT), crossing infrastructure elements to business or control process automation systems. As in the SITL-IoT case, the IoT sensors and actuators need to interoperate, not only as sources of open data but also as elements composed or aggregated into cyber-physical or informatics systems. Despite the number of available standards, e.g., internet engineering task force (IETF) CoAp/REST or MQTT messaging protocol on the application layer of a communication stack, the huge number of open and proprietary specifications makes interoperability an unsolved challenge [START_REF] Ahlgren | Internet of Things for Smart Cities: Interoperability and Open Data[END_REF].

The relevance of IoT for SITL-IoT deserves a discussion about relevant IoT platforms like OpenMTC, FIWARE, Site-Where, and Amazon Web Services IoT, as established in [START_REF] Guth | Comparison of IoT Platform Architectures: A Field Study based on a Reference Architecture[END_REF]. In that work, the authors proposed a reference architecture as an abstraction for the discussed platforms, depicted in Fig. 3. Fig. 3. IoT reference architecture (adapted from [START_REF] Guth | Comparison of IoT Platform Architectures: A Field Study based on a Reference Architecture[END_REF])

The proposed reference architecture raises a few questions related to how to frame the approach into a complex system of systems perspective. The Gateway seems to be necessary only if the "things" cannot cope with the proposed communication protocols and related stack layers (HTTP or MQTT, and JSON or XML for payload). It is suggested that IoT Integration Middleware "may comprise all kinds of functionality that are required by a certain cyber-physical system, for instance, a rules engine or graphical dashboards," but the proposed architecture still includes an upper Application layer. Although the approach has some interesting features, we argue that dealing with all existing specific technologies and protocols is not realistic. Hence, in our perspective, an adaptive strategy is needed to plug the elements to the systems and to support the interactions between the systems [START_REF] Calado | An Adaptive IoT Management Infrastructure for EcoTransport Networks[END_REF].

The IoT is being materialized on a diversity of ecosystems (smart-cities, transports, mobility, home automation, healthcare), making possible the mobile ubiquity sensing and computing. The convergence of communication infrastructures, currently evolving fast to the 5G (fifth generation), also raises the need for a novel approach to the fast-upcoming Everything Integrated and Collaborative. The question is whether we need an IoT Manager, as proposed in [START_REF] Calderoni | IoT Manager: an open-source IoT framework for smart cities[END_REF], or a strategy to make IoT things pluggable to (aggregation) or into (composition) higher level constructors (systems and elements of systems), sourced from a diversity of technology and process cultures and under clear administrative boundaries.

The SITL-IoT Approach under ISoS and ECoNet Frameworks

Given the initial problem formulation proposed by FORDESI, a decision was taken to adopt the MDEOS strategy [START_REF] Osorio | Towards Vendor-Agnostic IT-System of IT-Systems with the CEDE Platform[END_REF] as a (co)-development effort based on the CEDE collaborative development environment [START_REF] Osorio | Towards Vendor-Agnostic IT-System of IT-Systems with the CEDE Platform[END_REF] and the ISoS framework [START_REF] Osorio | Agnostic Informatics System of Systems: The Open ISoS Services Framework[END_REF], towards an open technology landscape for SDL. Fig. 4 depicts the ISoS framework and the collaborative business relations of SDL and FORDESI as a technology supplier under the ECoNet framework and platform.

Fig. 4. The vision behind the SITL-IoT project

This research project gives an opportunity to rethink the legacy modularity, since both the Monitoring System and the SCADA functions are supposed not only to be maintained but also to evolve.

The adoption of the right modularity strategy is another issue, not only from the technical perspective but also from the vision and interests of the suppliers of the other legacy systems. The existing "things" and sub-systems provided by competing suppliers must evolve and be adapted to the ISoS framework. From our previous research [START_REF] Osorio | Open Multi-Technology Service Oriented Architecture for ITS Business Models: The ITSIBus Etoll Services[END_REF], [START_REF] Osorio | ITSIBUS Jini and RFID Open Service-Oriented Architecture for Toll Management[END_REF] [START_REF] Osorio | Agnostic Informatics System of Systems: The Open ISoS Services Framework[END_REF], and considering the commitment of the SDL, we believe that other suppliers will adhere to the open specifications model, taking the advantage of being prepared to adopt open solutions.

The Isystem of Isystems (ISoS) and ECoNet Models

As depicted in Fig. 4, the extended SDL ecosystem comprehends warehouses, factories, and transport organizations and involves FORDESI as a supplier and support organization. The interactions flow through the Isystem ECoM [START_REF] Osorio | ECoNet Platform for Collaborative Logistics and Transport[END_REF], specialized in establishing collaborations and responsible for managing the data and coordination exchanges. Specialized collaboration contexts are to be designed and developed to establish short and long term collaboration relations [START_REF] Luis | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF]. Using ECoM to establish an ECoNet collaborative network has the advantage of following a unified technology approach. Based on the simple infrastructural mechanisms, each specific collaboration case, e.g., the exchanges with port authorities to access port community system, needs a specialized collaboration context to be installed [START_REF] Osorio | ECoNet Platform for Collaborative Logistics and Transport[END_REF]. The advantage is that the Isystems from all the organizations interacting in the context of a port community system share the same interchange mechanism.

ECoM is an Isystem integrated with the remaining Isystems of SDL through a new meta-Isystem that is designed and developed as the main entry point for the SDL technology landscape. The Isystem concept is part of the ISoS framework [START_REF] Osorio | Agnostic Informatics System of Systems: The Open ISoS Services Framework[END_REF], where an Isystem0 (the mentioned meta-Isystem) is the entry point to access and introspect about the installed Isystems. This entry point establishes a secure and authenticated access to a self-awareness() web service. It assumes that any Isystem developer can implement the access to the selfAwareness() service, since it follows web services standards. Through the Isystem0 it should be possible to access the other Isystems, under the assumption that any computational responsibility is "wrapped" into an Isystem concept.

One important research item in the SITL-IoT project is the (re)construction of the modularity in SDL considering a revision of business processes, both internal and collaborative, in order to establish the Isystem structuration that better fits activity needs.

An Isystem is structured as a composite of Cooperation Enabled Services (CES) elements [START_REF] Osorio | Cooperation Enabled Systems for Collaborative Networks. In: Adaptation and Value Creating Collaborative Networks[END_REF]. Access to the CES services follows a strategy like the one adopted for an Isystem. A CES is accessed and introspected through the selfAwareness() web service, which is the entry point to obtain the implemented services and the information necessary to access them. A service can be implemented in any legacy or new technology. A Generic Modelling Entity object holds the necessary information encoded/decoded by a predefined MIME tag. This means that no restrictions are imposed to developers of CES elements, since they are free to adopt the technologies considered to be most appropriate. The ISoS approach aims to reduce the risks of having innovation hampered by vendor lock-in situations.

Also, the offered flexibility allows a single CES to answer under different technology implementations. The multi-technology CES approach enables the incorporation of innovative features, making the product competitive without compromising interoperability. In fact, interoperability is adaptive, since any peer can obtain information about the implementation and the necessary elements for each specific implementation, making it possible for peers to access the service.

The SITL-IoT project offers the opportunity to validate the ISoS framework under an open specifications and development initiative. An initial question is how to migrate the existing products supplied by FORDESI, since they were developed using a different technology. Considering the adopted mechanism to cope with technology diversity, the main problem would not be the "wrapping" of legacy implementations but rather the (re)design of the "would-be" architecture.

Integration of Legacy Systems and IoT Things

From our perspective, there are two main structuration lines for the "things". On the one hand, "things" can be in the WAN space, meaning that thing's data needs to be transported by global communication providers. On the other hand, "things" can be local to the bounded infrastructure and therefore the communication is exclusively based on the LAN. Still, there are other application domains, as the example of the vehicle-to-vehicle or vehicle-to-infrastructure communication (V2X), where the communication is hybrid [START_REF] Wang | An Overview of 3GPP Cellular Vehicleto-Everything Standards[END_REF]. The communication can use the cellular or the road operator's G5 infrastructure, depending on availability and on mechanisms to improve reliability. In the SITL-IoT case, it seems that a hybrid approach is appropriate, since trucks, drivers and the SDL's personal can use ubiquitous mobile devices as sensing devices, which contributes for a smarter and agile processes control.

Hence, a hybrid strategy can consider the following association cases: i. The IoT "things" are elements of the organization's ISoS technology landscape, and therefore they are framed under the CES abstraction. ii. The IoT "things" embed mobile elements, like trucks or nomadic devices held by a truck driver or a foreign person (from a different organization), in which case the access to the sensors is through the collaborative partners' Isystems. iii. The IoT "thing" of a foreign person interacts with the physical "things" in the SDL's infrastructure. The smartcard to authenticate a foreign user is an example of such situation that requires a learning interaction phase between the Isystems of both organizations for the sharing of the necessary authentication data. Therefore, an IoT "thing" can be the responsibility of either the ISoS [START_REF] Osorio | Agnostic Informatics System of Systems: The Open ISoS Services Framework[END_REF] of SDL (a Local Thing), or a business partner interacting in the context of an operation (Collaborative Thing), as depicted in Fig. 5.

Fig. 5. The SysML model framing of the IoT "things" to the ISoS framework

The hypothesis of an interaction between a truck and the silos terminal weighing infrastructure to make the weighing operation aware of truck characteristics like its tare can be considered. In this particular case, the Collaborative Thing is modelled as a service playing a surrogate role (digital twin) responsible for managing the interactions with a business partner; the owner of the IoT "thing" modelled by the ISoS service. It can be a truck IoT from different transport companies dynamically detected and associated with making the weighting process accurate. The approach needs further research and validation, owing to the difficulty to guarantee interoperation considering heterogeneous "things" embedded into trucks.

Conclusions and Further Research

This paper presents and discusses the initial approach of the SITL-IoT project aiming at establishing a strategy for an open technology landscape for both the user organization and the associated collaborative network. The initial formulation of the SITL-IoT vision is presented and discussed. While considering the holistic vision for the collaborative network, the paper discusses the framing of IoT elements into the proposed holistic open integration strategy. The preliminary research, based on results from previous projects, suggests the IoT elements need to be under a clear governance model. The proposed approach, while not undervaluing public communication infrastructures (communication and internet service providers), assumes that the IoT devices are elements of cyber-physical or informatics systems. With such approach, we do not discard the access to IoT through public Internet/web services, whilst at the same time we uphold the responsibility integrity led by the system concept.

Nevertheless, the proposed strategy faces many obstacles requiring further research and validation. The so far theoretical CES model needs to be demonstrated in wrapping legacy implementations, and one main question encompasses the cost and the risks of such required changes. Beyond the migration problem, the SITL-IoT faces several other challenges, among which we consider:

• The cost of wrapping legacy systems needs to be clarified. This problem is related to decision making regarding the right Isystem or CES modularity, due to the related market competing issues. In other words, achieving the balance between the market/business interests and the openness strategies. • The strategy to follow making local or just-in-time access to data critical for operation. A practical example can be the case of a planned truck that needs to be replaced after a breakdown, and the new tare weight need to be obtained. • The design and management of both the operational processes and the collaborative processes already established based on long term contract agreements to their execution control and auditing. The collaboration contexts managed by the ECoNet/ECoM seem to be flexible enough to develop higher collaboration models of collaboration processes, but this needs to be verified.

This project is particularly relevant for this study, considering that a supplier, the FORDESI company, decided to invest on an open strategy to rethink the offered products and architecture for the integration of the overall automation solution of the agri-food silos industry.

Acknowledgments. Special thanks to Paulo Borges, as a research fellow leading the development of ISoS in a pre-stage for an open specifications and open source initiative under SOCOLNET scientific network and its ARCON-ACM initiative. This work has been partially supported by the PT2020 project SITL-IoT promoted by FORDESI company, BP Portugal through the research project HORUS, and the A-to-Be (Brisa Innovation and Technology) company with the project MOBICS/CITS. Partial support also from the Center of Technology and Systems -UNINOVA, and the Portuguese FCT-PEST program UID/EEA/00066/2019.