Modelagem e projeto de um sistema distribuído de gestão da produção /

Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico

Sistema de apoio à decisão para programação da produção em fundições de mercado Decision support system for production scheduling in steel casting foundries

Este trabalho tem por objetivo propor um sistema de apoio à decisão (SAD) para elaboração da programação da produção em fundições que trabalham com produtos personalizados sob encomenda, também conhecidas como fundições de mercado. Para isto, o ambiente produtivo das fundições de mercado é estruturado por meio do sistema de controle da produção conhecido como PBC, sendo propostas, também, três modelagens decisórias viáveis para o processo de programar a produção: um modelo de programação inteira binária, um modelo heurístico clássico de busca em árvore, conhecido como beam search e um modelo meta-heurístico baseado em algoritmos genéticos. Este trabalho apresenta ainda os resultados experimentais obtidos com a aplicação dos modelos decisórios e a análise da adequação do SAD proposto em fundições de mercado representativas do interior do Estado de São Paulo.This work proposes a Decision Support System (DSS) for production scheduling in steel casting foundries. To this end, the productive environment of these foundries is organized by means of a production control system known as Period Batch Control (PBC). Three viable decision models for production scheduling are proposed: a binary integer programming model, a model based on classical approximation methods, specifically the method known as beam search, and a model based on a meta-heuristic known as genetic algorithm. Also presented here are the experimental results obtained from the application of the three models and an analysis of the fitness of the proposal for eight representative steel casting foundries in the state of São Paulo, Brazil

Problem of assignment cells to switches in a cellular mobile network via beam search method

The problem of assigning cells to switches in a cellular mobile network is an NP-hard optimization problem. So, real size mobile networks could not be solved by using exact methods. The alternative is the use of the heuristic methods, because they allow us to find a good quality solution in a quite satisfactory computational time. This paper proposes a Beam Search method to solve the problem of assignment cell in cellular mobile networks. Some modifications in this algorithm are also presented, which allows its parallel application. Computational results obtained from several tests confirm the effectiveness of this approach to provide good solutions for medium- and large-sized cellular mobile network

Binary integer programming formulations for scheduling in market-driven foundries

This paper describes the development and solution of binary integer formulations for production scheduling problems in market-driven foundries. This industrial sector is comprised of small and mid-sized companies with little or no automation, working with diversified production, involving several different metal alloy specifications in small tailor-made product lots. The characteristics and constraints involved in a typical production environment at these industries challenge the formulation of mathematical programming models that can be computationally solved when considering real applications. However, despite the interest on the part of these industries in counting on effective methods for production scheduling, there are few studies available on the subject. The computational tests prove the robustness and feasibility of proposed models in situations analogous to those found in production scheduling at the analyzed industrial sector. (C) 2010 Elsevier Ltd. All rights reserved