This page has only limited features, please log in for full access.

Mr. Stefan Wiesner
BIBA - Bremer Institut für Produktion und Logistik GmbH

Basic Info


Research Keywords & Expertise

0 Requirements Engineering
0 Industry 4.0
0 product-service system
0 digitalization
0 servitization

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

Stefan A. Wiesner has a diploma in Industrial Engineering and Management (focus on Project Management and Development of Production). He has been working as a research scientist for BIBA in the department of ICT applications for production (IKAP) since 2007. His research interests are in the field of collaborative Requirements Engineering and Business Model innovation for complex Cyber-Physical Systems (CPS) and Product-Service Systems (PSS). Mr. Wiesner has been the responsible manager for several European projects, subprojects and work packages in these areas (ESKALE ERA-NET, MSEE IP, PSYMBIOSYS RIA, inter alia). Contributions and publications include the development and application of a game-based Requirements Engineering framework and a Business Modelling methodology for PSS, supporting the implementation in industrial companies. He is active in the IFIP 5.7 SIG on Smart Manufacturing with the aim to integrate PSS and CPS concepts.

Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 21 January 2021 in Systems
Reads 0
Downloads 0

The evolution towards more customer-centric operations within manufacturing and service industries gave rise to novel ways of value creation and delivery such as Product–Service Systems (PSS). PSS integrate tangible and intangible elements to create new values for both customers and providers. Therefore, a close collaboration is required among various actors in a value network to co-create values towards win–win gains. For companies to keep up with this pace, new decision support tools are needed to accompany PSS engineering and to adjust business models. This need is confronted with the scarcity of PSS-oriented economic assessment models and methods. This paper presents a comprehensive framework for the economic assessment of PSS. The framework relies on a novel combination of system modelling and analysis approaches to enable cost and revenue attribution to different actors in a value network. The applicability and relevance of the framework are demonstrated through a case study in the industrial cleaning sector.

ACS Style

Khaled Medini; Sophie Peillon; Martha Orellano; Stefan Wiesner; Ang Liu. System Modelling and Analysis to Support Economic Assessment of Product-Service Systems. Systems 2021, 9, 6 .

AMA Style

Khaled Medini, Sophie Peillon, Martha Orellano, Stefan Wiesner, Ang Liu. System Modelling and Analysis to Support Economic Assessment of Product-Service Systems. Systems. 2021; 9 (1):6.

Chicago/Turabian Style

Khaled Medini; Sophie Peillon; Martha Orellano; Stefan Wiesner; Ang Liu. 2021. "System Modelling and Analysis to Support Economic Assessment of Product-Service Systems." Systems 9, no. 1: 6.

Journal article
Published: 03 November 2020 in Systems
Reads 0
Downloads 0

Today’s fast-growing demands at the global level for mobile applications (apps) cause customers to call for the customization of their apps to fit their individualized needs and business realms. Customization is a challenge for apps-development companies when they want to satisfy their numerous users in a crowded competitive market. Moreover, pursuing customization involves additional challenges when ramping up app development projects in order to meet demands at a larger scale. To address this challenge, we proposed a framework to systematize and support mobile apps’ development consistently with a customer-driven approach and modular design philosophy. From a practical point of view, the proposed framework integrates quality function deployment (QFD), axiomatic design (AD) principles, and practices from the ITIL (Information Technology Infrastructure Library) framework. The framework supports a systematic process for translating customer needs into design parameters as well as supporting prioritization of ITIL practices for further development. The effectiveness of the framework was explored in practice through a case study about an app supporting relief in the 2020 COVID-19 pandemic, as well as a survey among potential users. The assessment of the framework indicated an average score ranging between 3.58 and 3.92 in a five-point Likert scale for all of the items used in the survey.

ACS Style

Khaled Medini; Stefan Wiesner; Milad Poursoltan; David Romero. Ramping Up Customer-Centric Modular Design Projects: Mobile App Development for Pandemic Relief. Systems 2020, 8, 40 .

AMA Style

Khaled Medini, Stefan Wiesner, Milad Poursoltan, David Romero. Ramping Up Customer-Centric Modular Design Projects: Mobile App Development for Pandemic Relief. Systems. 2020; 8 (4):40.

Chicago/Turabian Style

Khaled Medini; Stefan Wiesner; Milad Poursoltan; David Romero. 2020. "Ramping Up Customer-Centric Modular Design Projects: Mobile App Development for Pandemic Relief." Systems 8, no. 4: 40.

Review article
Published: 04 September 2020 in Computers in Industry
Reads 0
Downloads 0

Digital technologies are encouraging manufacturing companies in their servitization process by accelerating the offer of integrated product and service to create new value and grow relationships with customers in the Industry 4.0 era. In parallel, digitalization and servitization research streams are merging and paving the way for the Smart Product-Service System (Smart PSS). By analyzing the concept of Smart PSS, this paper questions the convergence between digital and service orientations and considers how digital technologies are used to enable decisions along the PSS lifecycle and/or at different planning levels. Applying topic modeling, a semi-systematic literature review on the combination of digital technologies with PSS has highlighted five main research streams: PSS design, digital servitization, assessing tool for PSS decisions, knowledge management along the lifecycle, sustainability business models. The development over time of these research streams has been tracked leading to the definition of a new research agenda on Smart PSS.

ACS Style

Fabiana Pirola; Xavier Boucher; Stefan Wiesner; Giuditta Pezzotta. Digital technologies in product-service systems: a literature review and a research agenda. Computers in Industry 2020, 123, 103301 .

AMA Style

Fabiana Pirola, Xavier Boucher, Stefan Wiesner, Giuditta Pezzotta. Digital technologies in product-service systems: a literature review and a research agenda. Computers in Industry. 2020; 123 ():103301.

Chicago/Turabian Style

Fabiana Pirola; Xavier Boucher; Stefan Wiesner; Giuditta Pezzotta. 2020. "Digital technologies in product-service systems: a literature review and a research agenda." Computers in Industry 123, no. : 103301.

Conference paper
Published: 25 August 2020 in Collaboration in a Hyperconnected World
Reads 0
Downloads 0

Fully dynamic cross-company production networks that adapt to individual customer orders are a core vision in Industry 4.0. For different reasons, like failure of machines of a supplier or a sudden increase of demand, additional production capacities might be required at short notice. However, there are barriers to finding and integrating suppliers with free capacities into existing ordering and logistics processes. A Dynamic Production Network Broker (DPNB), which is an online marketplace that actively connects suppliers and consumers of production resources to dynamic, cross-company production networks, might bridge this gap. New generic service-based business models are required for operation and usage of the DPNB platform. In this paper, such a business model is drafted.

ACS Style

Stefan Wiesner; Larissa Behrens; Jannicke Baalsrud Hauge. Business Model Development for a Dynamic Production Network Platform. Collaboration in a Hyperconnected World 2020, 749 -757.

AMA Style

Stefan Wiesner, Larissa Behrens, Jannicke Baalsrud Hauge. Business Model Development for a Dynamic Production Network Platform. Collaboration in a Hyperconnected World. 2020; ():749-757.

Chicago/Turabian Style

Stefan Wiesner; Larissa Behrens; Jannicke Baalsrud Hauge. 2020. "Business Model Development for a Dynamic Production Network Platform." Collaboration in a Hyperconnected World , no. : 749-757.

Conference paper
Published: 24 August 2019 in Adaptation and Value Creating Collaborative Networks
Reads 0
Downloads 0

Smart Product-Service Systems, i.e. solutions consisting of tangible and intangible components interacting with their environment through information and communication technology, are subject to various dynamic influences along the life cycle. Stakeholders to the solution may change, as well as their needs and technological capabilities. This makes the requirements for the solution volatile, uncertain, complex and ambiguous. The system scope and associated requirements are constantly changing. In this paper, it is discussed how agile methods can help to deal with these influences in the development phase. A literature review and an industrial case study are used for analysing the problem of dynamic requirements, and agile methods are identified that can be applied for Smart Product-Service Systems.

ACS Style

Stefan Wiesner; Jannicke Baalsrud Hauge; Paul Sonntag; Klaus-Dieter Thoben. Applicability of Agile Methods for Dynamic Requirements in Smart PSS Development. Adaptation and Value Creating Collaborative Networks 2019, 666 -673.

AMA Style

Stefan Wiesner, Jannicke Baalsrud Hauge, Paul Sonntag, Klaus-Dieter Thoben. Applicability of Agile Methods for Dynamic Requirements in Smart PSS Development. Adaptation and Value Creating Collaborative Networks. 2019; ():666-673.

Chicago/Turabian Style

Stefan Wiesner; Jannicke Baalsrud Hauge; Paul Sonntag; Klaus-Dieter Thoben. 2019. "Applicability of Agile Methods for Dynamic Requirements in Smart PSS Development." Adaptation and Value Creating Collaborative Networks , no. : 666-673.

Conference paper
Published: 25 August 2018 in IFIP Advances in Information and Communication Technology
Reads 0
Downloads 0

Digitalization is a challenging topic for manufacturing SMEs. Besides improving their technological base, they have to keep the business offer attractive, e.g. by bundling their products with smart services. In addition to limited resources, often the necessary knowledge is missing to select the right technologies and develop attractive services based on their functionality. Due to the resulting high risks, SMEs neglect the chances of digitization and lose competitiveness. To start with, they need a maturity assessment model that can help them understand their level of readiness to implement aspects, such as Industry 4.0. In order to identify and fit such a model for SMEs, already existing assessment methods were analyzed according to a series of selected dimensions linked to SMEs features. The evaluation result illustrates requirements that have to be addressed by a new maturity model suitable for SMEs attempting digitalization.

ACS Style

Stefan Wiesner; Paolo Gaiardelli; Nicola Gritti; Gianluca Oberti. Maturity Models for Digitalization in Manufacturing - Applicability for SMEs. IFIP Advances in Information and Communication Technology 2018, 81 -88.

AMA Style

Stefan Wiesner, Paolo Gaiardelli, Nicola Gritti, Gianluca Oberti. Maturity Models for Digitalization in Manufacturing - Applicability for SMEs. IFIP Advances in Information and Communication Technology. 2018; ():81-88.

Chicago/Turabian Style

Stefan Wiesner; Paolo Gaiardelli; Nicola Gritti; Gianluca Oberti. 2018. "Maturity Models for Digitalization in Manufacturing - Applicability for SMEs." IFIP Advances in Information and Communication Technology , no. : 81-88.

Conference paper
Published: 31 August 2017 in Advances in Production Management Systems. The Path to Intelligent, Collaborative and Sustainable Manufacturing
Reads 0
Downloads 0

With customers demanding more and more holistic answers to their problems, solution providers respond with complex systems, integrating product, service and ICT elements into their offer. These solutions need to be aligned to a high number of requirements, coming not only from the individual customer but also from an environment of network partners, technology providers and other stakeholders. Especially for Product-Service Systems, where the solution provider takes responsibility in the operational phase, this environment is dynamic over the system life cycle. Stakeholders may enter or leave, as well as changing needs and technological capabilities. This makes the requirements towards the solution volatile, demanding a suitable Requirements Engineering approach. In this paper, it is discussed how environmental dynamicity can be monitored for its effect on requirements, with a special focus on organizational issues. Through a literature review and industrial case studies it is analysed, how it can be ensured that environmental changes can be taken into account in Requirements Engineering, leading to an optimal system configuration to address the customer problem.

ACS Style

Stefan Wiesner; Marco Seregni; Mike Freitag; Jannicke Baalsrud Hauge; Annalaura Silvestro; Klaus-Dieter Thoben. Effects of Environmental Dynamicity on Requirements Engineering for Complex Systems. Advances in Production Management Systems. The Path to Intelligent, Collaborative and Sustainable Manufacturing 2017, 255 -262.

AMA Style

Stefan Wiesner, Marco Seregni, Mike Freitag, Jannicke Baalsrud Hauge, Annalaura Silvestro, Klaus-Dieter Thoben. Effects of Environmental Dynamicity on Requirements Engineering for Complex Systems. Advances in Production Management Systems. The Path to Intelligent, Collaborative and Sustainable Manufacturing. 2017; ():255-262.

Chicago/Turabian Style

Stefan Wiesner; Marco Seregni; Mike Freitag; Jannicke Baalsrud Hauge; Annalaura Silvestro; Klaus-Dieter Thoben. 2017. "Effects of Environmental Dynamicity on Requirements Engineering for Complex Systems." Advances in Production Management Systems. The Path to Intelligent, Collaborative and Sustainable Manufacturing , no. : 255-262.

Chapter
Published: 07 May 2017 in Multi-Disciplinary Engineering for Cyber-Physical Production Systems
Reads 0
Downloads 0

Cyber-Physical Production Systems (CPPS) foster new processes and production methods for reducing “time to market”, waste and failures, as well as improving quality and cost effectiveness. However, changes cannot be restricted to the technological side. An increasing share of services is offered with these systems in order to deliver new customized functions and other benefits. This trend has led to the introduction of Product Service Systems (PSS) as a promising framework describing the integrated development, realization and offering of specific product-service bundles as a solution. The integration of both CPPS and PSS concepts is becoming relevant for industry, because data monitoring, storage and processing allow creating a higher service layer able to deliver production systems with new “intelligent” behaviors and communicating capabilities. In this chapter, we use the term Cyber-physical Product-Service Systems (CPSS) for such an integrated approach. It gives a definition of CPS-based PSS and unveils the state-of-the-art for both concepts with major research issues for their integration. The evolution from products to solutions through servitization is shown, as well as the hardware, software, and service elements of CPSS, requiring an alignment of CPPS and service lifecycle models. Based on industrial use cases, this chapter also deals with challenges for engineering CPS-based PSS in terms of complexity, end user involvement with information exchange among stakeholders and linking views of multiple disciplines (mechanical engineering, information systems, service science etc.). This leads to implications for engineering processes, particularly cross-domain Requirements Engineering and design but also servitized Business Models enabled by CPS.

ACS Style

Stefan Wiesner; Klaus-Dieter Thoben. Cyber-Physical Product-Service Systems. Multi-Disciplinary Engineering for Cyber-Physical Production Systems 2017, 63 -88.

AMA Style

Stefan Wiesner, Klaus-Dieter Thoben. Cyber-Physical Product-Service Systems. Multi-Disciplinary Engineering for Cyber-Physical Production Systems. 2017; ():63-88.

Chicago/Turabian Style

Stefan Wiesner; Klaus-Dieter Thoben. 2017. "Cyber-Physical Product-Service Systems." Multi-Disciplinary Engineering for Cyber-Physical Production Systems , no. : 63-88.

Articles
Published: 04 January 2016 in International Journal of Computer Integrated Manufacturing
Reads 0
Downloads 0

In this paper, the requirements for models, methods and tools to support servitisation through collaboration of manufacturing enterprises and service providers are addressed. The Manufacturing SErvice Ecosystem (MSEE) European project has applied a novel approach to elicit these requirements and aims to fulfil them by establishing a manufacturing service ecosystems (MSE) concept. After identifying and specifying the requirements for support, MSEE has developed models, methods and tools to realise products and services in virtual enterprises, established from the MSE and validated them in four European test cases.

ACS Style

Stefan Wiesner; Klaus-Dieter Thoben. Requirements for models, methods and tools supporting servitisation of products in manufacturing service ecosystems. International Journal of Computer Integrated Manufacturing 2016, 1 -11.

AMA Style

Stefan Wiesner, Klaus-Dieter Thoben. Requirements for models, methods and tools supporting servitisation of products in manufacturing service ecosystems. International Journal of Computer Integrated Manufacturing. 2016; ():1-11.

Chicago/Turabian Style

Stefan Wiesner; Klaus-Dieter Thoben. 2016. "Requirements for models, methods and tools supporting servitisation of products in manufacturing service ecosystems." International Journal of Computer Integrated Manufacturing , no. : 1-11.

Conference paper
Published: 01 January 2016 in Collaboration in a Hyperconnected World
Reads 0
Downloads 0

Solutions are offered more and more in the form of Product-Service Systems (PSS), which combine tangible and intangible components into a comprehensive package for the customer. The rise of Internet of Things technology enables new ways of integrating products and services. So-called Cyber-Physical Systems (CPS) include the necessary sensors, actuators and software to provide reconfigurable functionalities for changing demands. However, engineering complexity is increased by the evolutionary aspect, as well as the increased number of stakeholders and system components involved over the whole life cycle. Understanding the underlying requirements is fundamental to establish a common perception of the targeted system among the manufacturer, service providers and the other stakeholders. This paper presents a gamified approach to elicit stakeholder requirements for the development of these complex systems. Four industrial users will use the gamified environment for refining their existing requirements.

ACS Style

Stefan Wiesner; Jannicke Baalsrud Hauge; Florian Haase; Klaus-Dieter Thoben. Supporting the Requirements Elicitation Process for Cyber-Physical Product-Service Systems Through a Gamified Approach. Collaboration in a Hyperconnected World 2016, 687 -694.

AMA Style

Stefan Wiesner, Jannicke Baalsrud Hauge, Florian Haase, Klaus-Dieter Thoben. Supporting the Requirements Elicitation Process for Cyber-Physical Product-Service Systems Through a Gamified Approach. Collaboration in a Hyperconnected World. 2016; ():687-694.

Chicago/Turabian Style

Stefan Wiesner; Jannicke Baalsrud Hauge; Florian Haase; Klaus-Dieter Thoben. 2016. "Supporting the Requirements Elicitation Process for Cyber-Physical Product-Service Systems Through a Gamified Approach." Collaboration in a Hyperconnected World , no. : 687-694.

Conference paper
Published: 18 August 2015 in Security Education and Critical Infrastructures
Reads 0
Downloads 0

The adoption of advanced manufacturing intelligence technologies offers opportunities for new profitable business models. The basis for this is the data that is related to the manufactured product, the physical components used for the manufacturing and the services that are applied in this context. In such a Product-Service System (PSS) there are several interactions and corresponding dependencies between physical products and services that have to be managed to obtain an optimal added value from the PSS. A first step is to make the informational interactions between Product and Service Lifecycle Management (PLM and SLM) transparent and visualize them. The objective of this paper is therefore to identify and visualize the interactions between SLM and PLM in general and as a subsequent step in a use case of a manufacturing enterprise.

ACS Style

Ingo Westphal; Mike Freitag; Klaus-Dieter Thoben. Visualization of Interactions Between Product and Service Lifecycle Management. Security Education and Critical Infrastructures 2015, 575 -582.

AMA Style

Ingo Westphal, Mike Freitag, Klaus-Dieter Thoben. Visualization of Interactions Between Product and Service Lifecycle Management. Security Education and Critical Infrastructures. 2015; ():575-582.

Chicago/Turabian Style

Ingo Westphal; Mike Freitag; Klaus-Dieter Thoben. 2015. "Visualization of Interactions Between Product and Service Lifecycle Management." Security Education and Critical Infrastructures , no. : 575-582.

Conference paper
Published: 18 August 2015 in Advances in Production Management Systems: Innovative Production Management Towards Sustainable Growth
Reads 0
Downloads 0

Engineering of systems is highly influenced by rapid technological changes, such as the emergence of Cyber-Physical Systems (CPS). These are interconnected embedded systems enabled by human-machine interaction. Realisation of CPS require a collaboration between mechanical engineering, electrical engineering, and computer science since different components are delivered and developed by different disciplines. Consequently, the Requirements Engineering (RE) process needs to consider multi-disciplinary perspectives. The objective of this paper is to elaborate the specific challenges of RE for CPS in a distributed environment and to identify knowledge sources and targets in CPS engineering. It describes the relevant types of knowledge and defines appropriate exchange mechanisms and standards.

ACS Style

Stefan Wiesner; Jannicke Baalsrud Hauge; Klaus-Dieter Thoben. Challenges for Requirements Engineering of Cyber-Physical Systems in Distributed Environments. Advances in Production Management Systems: Innovative Production Management Towards Sustainable Growth 2015, 49 -58.

AMA Style

Stefan Wiesner, Jannicke Baalsrud Hauge, Klaus-Dieter Thoben. Challenges for Requirements Engineering of Cyber-Physical Systems in Distributed Environments. Advances in Production Management Systems: Innovative Production Management Towards Sustainable Growth. 2015; ():49-58.

Chicago/Turabian Style

Stefan Wiesner; Jannicke Baalsrud Hauge; Klaus-Dieter Thoben. 2015. "Challenges for Requirements Engineering of Cyber-Physical Systems in Distributed Environments." Advances in Production Management Systems: Innovative Production Management Towards Sustainable Growth , no. : 49-58.

Book chapter
Published: 01 January 2013 in Lecture Notes in Production Engineering
Reads 0
Downloads 0

The growing demand for integrated solutions forces manufacturers of industrial goods to combine their products with service components to Product-Service Systems, or Extended Products (EP). The new value proposition of the EP and the required network of business partners are not included in the traditional business models of manufacturing companies. A business model represents the implementation of an industrial strategy in respect to its specific elements. The purpose of this paper is to investigate classic strategies in manufacturing and new strategic approaches to help manufacturers transform their business models for EP. A special focus is given to value innovation and collaboration in Manufacturing Service Ecosystems (MSE). In an MSE, different organizations and individuals can work together with common or complementary objectives on new value added combinations of manufactured products and product-related services. The approach is exemplified by the transformation of the business model of a machine tool manufacturer.

ACS Style

Stefan Wiesner; Marcus Winkler; Jens Eschenbächer; Klaus-Dieter Thoben. Strategies for Extended Product Business Models in Manufacturing Service Ecosystems. Lecture Notes in Production Engineering 2013, 239 -250.

AMA Style

Stefan Wiesner, Marcus Winkler, Jens Eschenbächer, Klaus-Dieter Thoben. Strategies for Extended Product Business Models in Manufacturing Service Ecosystems. Lecture Notes in Production Engineering. 2013; ():239-250.

Chicago/Turabian Style

Stefan Wiesner; Marcus Winkler; Jens Eschenbächer; Klaus-Dieter Thoben. 2013. "Strategies for Extended Product Business Models in Manufacturing Service Ecosystems." Lecture Notes in Production Engineering , no. : 239-250.

Conference paper
Published: 01 January 2013 in The Philosopher's Stone for Sustainability
Reads 0
Downloads 0

Nowadays, manufacturing enterprises shift to bundle their products with services to satisfy customer needs. This process is called “Servitization”. The European project “Manufacturing SErvice Ecosystem” (MSEE) is developing models supporting Servitization, based on Future Internet architectures and platforms. To allow efficient collaboration for the provision of Product-Service Systems (PSS), the business as well as the ICT environment needs to be adapted. However, stakeholders are typically not aware of all requirements for the transition in the areas of physical resources, organization and IT. This paper presents one of the results of MSEE project: the development of an adequate Requirements Engineering approach.

ACS Style

S. Wiesner; M. Peruzzini; G. Doumeingts; K. -D. Thoben. Requirements Engineering for Servitization in Manufacturing Service Ecosystems (MSEE). The Philosopher's Stone for Sustainability 2013, 291 -296.

AMA Style

S. Wiesner, M. Peruzzini, G. Doumeingts, K. -D. Thoben. Requirements Engineering for Servitization in Manufacturing Service Ecosystems (MSEE). The Philosopher's Stone for Sustainability. 2013; ():291-296.

Chicago/Turabian Style

S. Wiesner; M. Peruzzini; G. Doumeingts; K. -D. Thoben. 2013. "Requirements Engineering for Servitization in Manufacturing Service Ecosystems (MSEE)." The Philosopher's Stone for Sustainability , no. : 291-296.

Book chapter
Published: 01 January 2013 in IFIP Advances in Information and Communication Technology
Reads 0
Downloads 0

The trend for servitization is increasingly affecting manufacturing enterprises. Products are bundled with associated services to so called “Extended Products” (EP). However, the share of services becomes more and more important. This requires on the one hand an evolution of the EP concept towards greater interoperability of the physical product and on the other hand additional competencies in service innovation. Traditional manufacturing enterprises are not able to handle the related challenges by themselves. The paper presents a more open and service-oriented “EP 2.0” concept and introduces the Manufacturing Service Ecosystem as a model to support service innovation by facilitating collaboration.

ACS Style

Stefan Wiesner; Ingo Westphal; Manuel Hirsch; Klaus-Dieter Thoben. Manufacturing Service Ecosystems. IFIP Advances in Information and Communication Technology 2013, 305 -312.

AMA Style

Stefan Wiesner, Ingo Westphal, Manuel Hirsch, Klaus-Dieter Thoben. Manufacturing Service Ecosystems. IFIP Advances in Information and Communication Technology. 2013; ():305-312.

Chicago/Turabian Style

Stefan Wiesner; Ingo Westphal; Manuel Hirsch; Klaus-Dieter Thoben. 2013. "Manufacturing Service Ecosystems." IFIP Advances in Information and Communication Technology , no. : 305-312.