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Publications

Publications by CESE

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

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.

2004

Recyclable waste collection planning - a case study

Authors
Teixeira, J; Antunes, AP; de Sousa, JP;

Publication
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH

Abstract
This paper describes a study of planning vehicle routes for the collection of urban recyclable waste. The aim is to create collection routes for every day of the month, to be repeated every month, minimizing the operation cost. Two important features of the problem are the planning of a relatively long period of time and the separate collection of three types of waste. The collection operation was modelled in accordance to the practice of the company that manages the collection system. Heuristic techniques were developed to solve the model in three phases: definition of the geographic zones served by the vehicles, definition of the waste type to collect on each day of the month, definition of the collection routes. Preliminary results suggest that significant economies in collection costs are possible.

2004

Order planning decision support system for customer driven manufacturing: Overview of main system requirements

Authors
Proenca, H; Azevedo, A;

Publication
ICEIS 2004 - Proceedings of the Sixth International Conference on Enterprise Information Systems

Abstract
An important goal in schedule production orders through a manufacturing facility is to assure that the work is completed as close as possible to its due date. Work that is late creates downstream delays, while early completion can be detrimental if storage space is limited. Production planning and control manufacturing is becoming more difficult as family products increase and quantity decreases. This paper presents an ongoing information system development that aims the production planning of special test tables equipment for automobile components manufacturers. The simulated based information system will be used to support planning and schedule activities; to compare and analyze the impact of planning rescheduling; to forecast the production completion date; to detect bottlenecks and to evaluate machines performance.

2004

The Formation and Dissolution of Organizational Networks: A Knowledge Management Perspective

Authors
Simões, D; Soares, AL;

Publication
Virtual Enterprises and Collaborative Networks - IFIP International Federation for Information Processing

Abstract

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