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Publicações

Publicações por CESE

2013

Multimethodology in Metaheuristics

Autores
Ferreira, JS;

Publicação
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY

Abstract
As a combination of different methodologies or parts of methodologies, Multimethodology is becoming more frequent in OR practice. This paper contributes with a new proposal and a new field of application: the employment of Multimethodology in problem solving with Metaheuristics (Mh). A convenient selection of soft and hard methods will be considered, from Soft OR, Creativity and Metaheuristics, such as Strategic Choice Approach, SWOT Analysis and Divergent and Convergent thinking. Formulating the 'right' optimisation problem, choosing a method based on Mh and accomplishing an effective implementation is an imprecise decision-making process, which may require skills and ideas that are beyond the ordinary boundaries of Mh practice. The relevance and success of Mh have been well-known for decades, but some open questions concerning choice and implementation strategies, for instance, still remain. If these questions are not adequately answered, they may lose credibility in the long term. The quality of solutions and computational times are not the only criteria used to analyse Mh, nor are they the most important. Very often, the effectiveness of an approach has to be evaluated from the perspective of modelling and practical problem solving. This paper investigates the advantages of Multimethodology and, furthermore, it sketches a framework for a coherent and comprehensive comparison of Mh and recommends a dynamic guiding tool for their implementation.

2013

Recolha de resíduos sólidos urbanos - otimização de rotas

Autores
Rodrigues, Ana Maria; Soeiro Ferreira, José;

Publicação
Livro de Atas do XVI Congresso da Associação Portuguesa de Investigação Operacional

Abstract
Este trabalho dá a conhecer um novo problema, Problema Capacitado de Rotas em Arcos Misto, com Múltiplos Aterros Limitados. Baseado na situação de recolha/transporte de Resíduos Sólidos Urbanos no concelho de Monção, são apresentadas características que, não sendo únicas em Portugal, nunca foram mencionadas na literatura. Diferencia-se pela existência de diversos pontos de deposição que, especialmente devido às reduzidas dimensões, apresentam restrições relacionadas com o número de visitas recebidas por dia. Um novo modelo de otimização, baseado na formulação do Mixed Ca- pacitated Arc Routing Problem é apresentado. São incluídos resultados computacionais provenientes de instâncias adaptadas da literatura e do problema real descrito.

2013

A Collaborative Planning Approach for Non-hierarchical Production Networks

Autores
Almeida, R; Toscano, C; Azevedo, AL; Carneiro, LM;

Publicação
Intelligent Non-hierarchical Manufacturing Networks

Abstract
This chapter presents an innovative collaborative planning (CP) approach for non-hierarchical production networks that enhances collaboration between partners in two different lifecycle phases of the virtual organizations (VOs). The first phase concerns the first planning iteration for the customer, and it basically defines the operations plan and a quotation for the customer, supported by a negotiation process between partners. The second phase concerns a detailed specification of the manufacturing operation and its planning. The chapter first presents a summary of the main trends and previous work concerning collaborative network (CN), governance models and approaches for CP. Next, it provides the requirements for the CP. The chapter ends with the methodology proposed for CP, considering two planning schemes and the evaluation of the quality of the solutions. © 2013 by John Wiley & Sons, Inc.

2013

Case studies on collaboration, technology and performance factors in business networks

Autores
Carneiro, LM; Soares, AL; Patricio, R; Azevedo, AL; de Sousa, JP;

Publicação
INTERNATIONAL JOURNAL OF COMPUTER INTEGRATED MANUFACTURING

Abstract
This paper presents part of the findings of a research project aiming at characterising high-performance collaborative business networks and at defining the conditions required for their creation and management. The project adopted a multiple case study research strategy and three different business networks are presented in this paper. Empirical studies have been performed in Northern Portugal. The results of the study include operational definitions based on a comprehensive literature review, a conceptual reference framework for the analysis of high-performance collaborative networks and recommendations for the creation and management of such networks.

2013

Flexible and Reconfigurable Layouts in Complex Manufacturing Systems

Autores
Azevedo, MM; Crispim, JA; de Sousa, JP;

Publicação
ADVANCES IN PRODUCTION MANAGEMENT SYSTEMS: COMPETITIVE MANUFACTURING FOR INNOVATIVE PRODUCTS AND SERVICES, AMPS 2012, PT I

Abstract
This paper studies the Facility Layout Problem (FLP) of a first tier supplier in the automotive industry. This complex manufacturing system involves multiple facilities, complex products, and layout reconfiguration constraints. One of the key requirements of this particular system is the need for high levels of flexibility in the reconfiguration of the layouts. This problem is formulated as a mixed-integer programming (MIP), based on a FLP model with multiple objectives and unequal areas. The model allows for two reconfiguration types: small and large changes. We explore the application of optimization methodologies to produce efficient and flexible layouts.

2013

New General Discrete-Time Scheduling Model for Multipurpose Batch Plants

Autores
Moniz, S; Barbosa Povoa, AP; de Sousa, JP;

Publicação
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

Abstract
This work deals with the optimal short-term scheduling of general multipurpose batch plants, considering multiple operational characteristics such as sequence-dependent changeovers, temporary storage in the processing units, lots blending, and material flows traceability. A novel Mixed Integer Linear Programming (MILP) discrete-time formulation based on the State-Task Network (STN) is proposed, with new types of constraints for modeling changeovers and storage. We also propose some model extensions for addressing changeovers start; nonpreemptive lots; lots start and sizes; alternative task-unit and task-unit-layout assignments. Computational tests have shown that the proposed model is more effective than a similar model based on the Resource-Task Network (RTN).

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