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Publications

Publications by SYSTEM

2005

Virtual enterprise integration: Challenges of a new paradigm

Authors
Putnik, GD; Cunha, MM; Sousa, R; Avila, P;

Publication
Virtual Enterprise Integration: Technological and Organizational Perspectives

Abstract
Virtual enterprise integration (VEI) is virtually the most critical success factor for making virtual enterprise (VE) a real, competitive, and widely implemented organizational and management concept. However, according to many authors, the present solutions for VEI are either insufficient or inexistent. One of the reasons for the situation is the failure of the approach of "traditional" information systems and organizations to dealing with the nowadays turbulent market and organizations' requirements, where actual VEI solutions are mainly sought. This chapter presents a discussion on the VEI issue as a contribution to a better understanding of the VEI phenomenon, and it could be seen as a contribution to an eventual framework for VEI science, engineering, development, and implementation. Also, two metatheoretical structures for VEI research and development are proposed: VEI abstractions hierarchy and VEI semiotics. © 2005, Idea Group Inc.

2005

Analyses of the resources system selection algorithms for agile/virtual enterprises integration through genetic algorithms

Authors
Avila, P; Putnik, GD; Madureira, AM;

Publication
WSEAS Transactions on Information Science and Applications

Abstract
The process of resources systems selection takes an important part in Agile/Virtual Enterprises (A/V E) integration. However, the resources systems selection is a difficult matter to solve in A/VE because: it can be of exponential complexity resolution; it can be a multi criteria problem; and because there are different types of A/V Es with different requisites that have originated the creation of a specific resources selection model for each one of them. In our A/V E project we have made some progress in this matter and identified the principal gaps to be solved. This paper will show one of those gaps in the algorithms area to be applied to the problem. In attention to that gaps we address the necessity to develop new algorithms and with more information disposal, for its selection by the Broker. In this paper we propose a genetic algorithm to deal with a specific case of resources system selection problem when the space solution dimension is high.

2004

Reel and sheet cutting at a paper mill

Authors
Correia, MH; Oliveira, JF; Ferreira, JS;

Publication
COMPUTERS & OPERATIONS RESEARCH

Abstract
This work describes a real-world industrial problem of production planning and cutting optimization of reels and sheets, occurring at a Portuguese paper mill. It will focus on a particular module of the global problem, which is concerned with the determination of the width combinations of the items involved in the planning process: the main goal consists in satisfying an order set of reels and sheets that must be cut from master reels. The width combination process will determine the quantity/weight of the master reels to be produced and their cutting patterns, in order to minimize waste, while satisfying production orders. A two-phase approach has been devised, naturally dependent on the technological process involved. Details of the models and solution methods are presented. Moreover some illustrative computational results are included.

2004

Teaching logistics without formal classes: A case study

Authors
Carravilla, MA; Oliveira, JF;

Publication
European Journal of Engineering Education

Abstract
This paper describes a case study concerning the teaching of logistics in the Computers and Electrical Engineering degree at FEUP. The logistics course is taken in the last semester of the degree and there are no lectures given by the teachers. All the learning strategy is based upon the autonomous learning capacity of the students, following the widespread citation of Confucius, ‘I hear and I forget. I see and I remember. I do and I understand’. The students are organized in groups and their autonomous work is motivated by the presentation that each group leader has to give every other week. A discussion period follows each presentation, and can be used by the teachers to evaluate the involvement of each member of the group and to complement the presentation whenever necessary. All the students are leaders at least once. The leaders are responsible for the group management and must prepare for the ‘leaders’ meeting', where the presentation session is organized. Assessment is based both on the quality of the presentation and on the technical correctness and completeness in the way subjects are treated and on leadership skills. While the teachers evaluate the two first issues, peers evaluate leadership. © 2004, Taylor & Francis Group, LLC.

2004

An advanced agent-based order planning system for dynamic networked enterprises

Authors
Azevedo, AL; Toscano, C; Sousa, JP; Soares, AL;

Publication
PRODUCTION PLANNING & CONTROL

Abstract
There is an increasing interest in exploring the opportunities for competitive advantage that arise from reinforcing core competencies and innovative capabilities of the individual companies, and by forming integrated supply networks. In complex and dynamic environments such as the automotive and semiconductor industries, managing and co-ordinating the procurement of materials, their transformation into intermediate and finished products, and the distribution to the final customers, are very demanding tasks in terms of information systems. In general, current available software packages do not provide the full support needed for networked and distributed organizations, and are clearly insufficient in what concerns the planning and coordination activities needed in these heterogeneous environments. In order to adequately tackle these problems, this work proposes a multi-agent system architecture for real-time customer-order planning in distributed manufacturing enterprises, addressing the requirements of a make-to-order environment. The present research work resulted from the Co-OPERATE European Project. Enhanced visibility of information, early warning of disturbances, synchronized production and collaborative planning in the supply chain are the general goals of the project. In particular, for aggregate planning and order promising, a distributed and decentralized information system, based on an architecture of agents and extensively using the internet, was designed and implemented. This system aims at responding to the basic requirements of cooperativeness, integration and configurability, and at providing new and more powerful decision support.

2004

Modeling the structure of collaborative networks: Some contributions

Authors
Soares, AL; de Sousa, JP; Barbedo, F;

Publication
PROCESSES AND FOUNDATIONS FOR VIRTUAL ORGANIZATIONS

Abstract
Collaborative Networks (CN) and Virtual Organisations (VO) can partially be modelled by using Graph Theory, as a natural framework for describing relationships, interactions and collaboration. Our work aims at extending and integrating results from that theory and other different fields and scientific disciplines, to enable modelling complex and non tangible factors, dynamics, trade-offs between individual and common objectives, arising in the set-up and management of VO. As a way to handle these issues in a holistic way, we present extensions of Social Actors Networks that are able to encompass various, complementary perspectives in dealing with VO, and coping with the different phases of its life cycle. Current results seem promising in the direction of creating a sound frame work for modelling and supporting holistic process management in Collaborative Networks. For illustration purposes a simple case study is briefly sketched and some findings presented. Finally sortie open issues are surveyed and lines for future research identified.

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