DOI
10.11606/T.55.2007.tde-18062007-112036
Documento
Autor
Nome completo
Kelly Cristina Poldi
E-mail
Área do Conhecimento
Data de Defesa
Imprenta
São Carlos, 2007
Arenales, Marcos Nereu (Presidente)
Castelo Filho, Antonio
França, Paulo Morelato
Morabito Neto, Reinaldo
Moretti, Antonio Carlos
Título em português
O problema de corte de estoque multiperíodo
Palavras-chave em português
Geração de colunas
Otimização linear e inteira
Problema de corte de estoque
Resumo em português
Título em inglês
The multiperiod cutting stock problem
Palavras-chave em inglês
Column generation
Cutting stock problem
Linear and integer optimization
Resumo em inglês
Cutting stock problems consist of cutting a set of available stock objects in order to produce smaller ordered items. Such problems have been intensively researched over the last decades, together with additional characteristics and new methods for solving them. In this thesis, we address the multiperiod cutting stock problem, which arises in the production planning and programming in many industries that have a cutting process as an important stage. Ordered items have different due date over a finite planning horizon. An integer linear optimization model of large scale is proposed. The model makes possible to anticipate or not the production of items. Unused objects in inventory in a period become available to the next period, added to new inventory, which are acquired or produced by the own company. The mathematical model's objective is to minimize the cost of waste in the cutting process and costs for holding objects and fInal items. The simplex method with column generation was specialized to solve its linear relaxation. Computational experiments were carried out to solve one-dimensional and two-dimensional cutting stock problems. Such experiments showed that the multiperiod model could obtain effective gains when compared with the lot-for-lot solution, which is typically used in practice. However, in practical problems, the fractional solution is useless. So, in this thesis, two rounding procedures are developed to determine integer solutions for multiperiod cutting stock problems. Such procedures are based on a rolling horizon scheme, which roughly means, find an integer solution only for the first period, since this is the solution to be, in fact, carried out. Finally, we conclude that the proposed model for multiperiod cutting stock problems allows flexibility on analyzing a solution to be put in practice. The multiperiod cutting problem can be a tool that provides the decision maker a wide view of the problem and it may help him/her on making decisions

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Data de Publicação
2007-06-18

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Centro de Informática de São Carlos