As atividades de planejamento de médio prazo (nível tático) são especialmente importantes em empresas de manufatura, visto que tratam do dimensionamento dos recursos produtivos (recursos humanos, materiais, equipamentos, instalações, etc) , que terá impacto na capacidade de atendimento da demanda e nos resultados operacionais da empresa. Este trabalho apresenta um modelo de Planejamento Agregado da Produção e Distribuição para aplicação em empresas do setor cimenteiro, com múltiplas famílias de produtos, múltiplas localidades (de produção e de demanda) e produção em dois estágios, tendo por objetivo a maximização do resultado operacional. O modelo desenvolvido é baseado em Programação Linear Inteira Mista e considera, além dos custos das operações de produção e de transporte, os gastos com impostos, que variam de acordo com a estratégia de abastecimento dos pontos de demanda, dada a existência de diferenças nas alíquotas do Imposto sobre Circulação de Mercadorias e Serviços entre operações inter e intra-estaduais. Os resultados obtidos demonstraram a importância da abordagem conjunta dos processos de produção e de distribuição, tornando clara a necessidade de integração dos mesmos no planejamento agregado num ambiente produtivo de múltiplas localidades e com mais de um processo de produção. / Middle-term production planning (tactical level) is an important activity in manufacturing companies, once it deals with production resources (work-force and production capacity) and stocks dimensioning, impacting on the company supply capacity and on its operating results. This dissertation presents an Aggregate Production and Distribution Planning model to be applied in multi-site, multi-product cement companies with the purpose of maximize operational results. The developed model is based upon Mixed Integer Linear Programming (MILP), and it considers, besides production and transportation operational costs, taxes expenses, which in the Brazilian context can change considerably depending on the supply strategy adopted, due to taxation differences between inter and intra-state sales operations. The results confirmed the importance of the combined approach of the production and distribution, demonstrating the relevance of integrating these two planning processes in a multi-site two-stage production environment.

Orientador: Ariovaldo Denis Granja / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-13T11:13:19Z (GMT). No. of bitstreams: 1 Branco_TatianaBorges_M.pdf: 1099960 bytes, checksum: c10764476c446e6ace42dcab973f323d (MD5) Previous issue date: 2007 / Resumo: A indústria da construção atravessa uma fase de adequação à realidade financeira do país, onde a melhoria na produção é requisito para reduzir custos e manter a competitividade da empresa. A busca por ritmar a produção e nivelar os recursos, ainda na etapa de planejamento, visa facilitar as tomadas de decisões no canteiro de obras. Este estudo analisa o planejamento de empreendimentos habitacionais repetitivos destacando situações que identificam gargalos futuros de produção no canteiro de obras. Dois estudos de caso foram realizados em condomínios residenciais repetitivos. As medições mensais dos serviços executados no primeiro estudo de caso e os problemas encontrados serviram de embasamento para a elaboração do planejamento do segundo estudo. Analisando os fluxos físicos das atividades a serem desenvolvidas, utilizando a técnica de Linhas de Balanço como ferramenta, e tomando-se ações corretivas na fase de planejamento destas, as perdas inerentes ao processo produtivo na construção civil poderão ser reduzidas. / Abstract: The construction industry faces a phase of adequacy to the country's financial reality, where the improvement in the production is requisite to reduce costs and to keep the company competitive. The search for balance the production and leveling the resources, during the planning, aims to facilitate the taking of decisions during the construction. This study analyzes the planning of repetitive enterprises detaching situations that identify future problems of production during the construction. Two studies of case had been carried through in repetitive residential condominiums. The monthly measurements of the services executed in the first study of case and the joined problems had served of basement for the elaboration of the second study of case planning. Analyzing the physical flows of the activities to be developed, using the technique of Lines of Balance as tool, and taking corrective actions in the phase of planning of these, the inherent losses of the productive process in the civil construction could be reduced. / Mestrado / Edificações / Mestre em Engenharia Civil

This research is motivated by the need for considering lot sizing while accepting customer orders in a make-to-order (MTO) environment, in which each customer order must be delivered by its due date. Job shop is the typical operation model used in an MTO operation, where the production planner must make three concurrent decisions; they are order selection, lot size, and job schedule. These decisions are usually treated separately in the literature and are mostly led to heuristic solutions. The first phase of the study is focused on a formal definition of the problem. Mathematical programming techniques are applied to modeling this problem in terms of its objective, decision variables, and constraints. A commercial solver, CPLEX is applied to solve the resulting mixed-integer linear programming model with small instances to validate the mathematical formulation. The computational result shows it is not practical for solving problems of industrial size, using a commercial solver. The second phase of this study is focused on development of an effective solution approach to this problem of large scale. The proposed solution approach is an iterative process involving three sequential decision steps of order selection, lot sizing, and lot scheduling. A range of simple sequencing rules are identified for each of the three sub-problems. Using computer simulation as the tool, an experiment is designed to evaluate their performance against a set of system parameters. For order selection, the proposed weighted most profit rule performs the best. The shifting bottleneck and the earliest operation finish time both are the best scheduling rules. For lot sizing, the proposed minimum cost increase heuristic, based on the Dixon-Silver method performs the best, when the demand-to-capacity ratio at the bottleneck machine is high. The proposed minimum cost heuristic, based on the Wagner-Whitin algorithm is the best lot-sizing heuristic for shops of a low demand-to-capacity ratio. The proposed heuristic is applied to an industrial case to further evaluate its performance. The result shows it can improve an average of total profit by 16.62%. This research contributes to the production planning research community with a complete mathematical definition of the problem and an effective solution approach to solving the problem of industry scale.

[pt] O cenário atual do mercado brasileiro é composto principalmente por micro e pequenas empresas, que crescem a cada ano, mas possuem baixa taxa de sobrevivência se comparada a de outros países. Uma vez que esses empreendimentos contribuem fortemente com o PIB do país, garantir a sobrevivência desse grupo é de suma importância para a economia brasileira. Neste trabalho, foi desenvolvido um modelo matemático para otimizar a produção de uma microempresa produtora de salgados. Através do modelo, determinam-se as quantidades de insumos a serem compradas de fornecedores, as quantidades a serem produzidas de itens intermediários e finais, em cada período do horizonte de planejamento, de modo a atender a demanda a um menor custo total. Para isso, foi realizado um levantamento sobre as características da produção da microempresa estudada e observou-se que um dos motivos que a impedem de ser competitiva é a falta de conhecimento e de aplicação de ferramentas de planejamento e controle da produção. Para avaliar o desempenho do modelo desenvolvido foram realizados testes com dados reais, e, os resultados obtidos para diferentes cenários da demanda mostram que o modelo pode ser útil para apoiar as decisões de dimensionamento de lotes de compra e de produção, pois mostram que os custos ótimos obtidos são menores que os custos obtidos pela empresa sem o uso da otimização. / [en] The current scenario of the Brazilian market is composed mainly of micro and small enterprises that grow every year, but have low survival rate compared to other countries. Once these businesses contribute greatly to the country s GDP, ensuring the survival of this group is of paramount importance to the Brazilian economy. In this work, a mathematical model was developed to optimize the production of a micro producer of snacks. Through the model, the quantities of inputs to be purchased from suppliers and the quantities of intermediate and final items to be produced in each period of the planning horizon are determined, in order to meet demand at a lower total costs. For this, a survey was conducted on the characteristics of the production of the studied micro company and it was observed that one of the reasons that prevent them from being competitive is the lack of knowledge and application of tools for planning and control of production. To evaluate the performance of the developed model tests were carried out with real data, and the results of different scenarios for the demand show that the model can be useful to support decisions on lot sizing of purchasing and production, showing that the obtained optimal costs are less than the costs obtained by the company without the use of optimization.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The Peruvian textile industry is a highly competitive market and is one of the main economic engines of the country. The sector provides more than 463 thousand jobs and represents 7.4% of the GDP. Most of the companies, mostly family businesses, do not have enough knowledge to implement a management model according to productivity standards and expected level of service. This article proposes a production model for the clothing industry based on Lean management, combining SIPOC, VSM, 5S techniques and a production system to increase profitability in the short term and make it sustainable in time. The model is validated by a case study in a representative company of the sector. The proposed activities were monitored through the study of work indicators, in which the results indicate an increase in productivity by 59% and the fulfillment by 48%.

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