Thesis (MSc)--University of Stellenbosch, 2006. / Please refer to full text for abstract

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In this thesis was a model developed, in order to improve deficiencies in existing literature regarding the layout problem and to give companies a comprehensible user-friendly procedure on how to design competitive production processes, plant layouts and material handling systems. The model consists of six phases that can be used sequentially in order to design, evaluate, implement and maintain effective plant layouts and material handling systems. The model can also be used to examine and optimize processes. The first four phases of the model were tested successfully in a case study at Holtab AB, a medium sized manufacturing company in Tingsryd.

<p>In this thesis was a model developed, in order to improve deficiencies in existing literature regarding the layout problem and to give companies a comprehensible user-friendly procedure on how to design competitive production processes, plant layouts and material handling systems. The model consists of six phases that can be used sequentially in order to design, evaluate, implement and maintain effective plant layouts and material handling systems. The model can also be used to examine and optimize processes. The first four phases of the model were tested successfully in a case study at Holtab AB, a medium sized manufacturing company in Tingsryd.</p>

In this competitive world with rapid growth of markets, the main goal of any company is to attain an edge over its competitors. In order to achieve this goal a company has to continually improve its process and eliminate the wastes in the process while not compromising on the quality of the product and customer satisfaction. Though Eco Supplies Solar AB is one of the largest producers of Photovoltaic solar modules in Scandinavia, the need for improvement is vital to match with growing requirements and to maintain its position in the market. This master thesis was done for Eco Supplies Solar AB, so as to help them identify the waste along their value stream process. The project was divided into three phases. The first phase of the project was to map and analyze the plant layout as well as analyze the worker movement. This helped to understand the various movements through the entire process of production and the associated distances and time. The second phase of the thesis was the execution of the Value Stream Mapping. For this purpose the entire production process was walked through and through several interviews the data was collected. The current state value stream map gave a one page static picture of the key areas of waste within the process and to suggest necessary changes so as to improve the efficiency. The suggested changes are implemented and the future state map is drawn. The results from the current state and future state map are calculated theoretically and analyzed. The third phase is the use of Simulation to understand the behavioral effects of each the processes and to determine the overall change in productivity if the changes are implemented. It is difficult to implement changes in a production plant that works continuously for 24 hours. That would interrupt production and also lead to large costs. The easier and most optimal solution to implement changes, understand the behavior of each process before and after the changes and to analyze the changes is to run a simulation model of the current and future state. The simulation is done using Extend Sim software and the results are analyzed further. The main aim of the thesis was to analyze the current plant layout and the product process and develop a methodology to identify visualize and measure the wastes in the production process of Photovoltaic solar modules.

Plant layout procedures available today consider either the quantitative attribute or the qualitative attribute of the layout problem. These procedures are based on maximizing or minimizing one objective function. Some of the procedures that address the multi-attribute nature of the plant layout problem are based on assigning weights to objective functions and then solving the problem by heuristic methods. Exact methods guarantee optimal solution but are computationally intensive for large sized problems. Heuristic methods do not guarantee optimal solution, but are computationally less intensive and relatively faster than the exact methods. This thesis suggests a procedure for solving the multi-attribute plant layout problem. The procedure is based on formulating the plant layout problem as a Quadratic Assignment Problem. Solution to the formulation is achieved by solving it by a combination of exact and heuristic methods. This solution procedure gives better results than just the heuristic method and is not computationally intensive. A computer implementation of the proposed procedure is developed in "C" programming language. A detailed experimentation is conducted to study the performance of the proposed procedure as compared to a well known procedure called Blocplan. The layouts generated by the proposed procedure are found to be much better than those generated by Blocplan. In the literature there is no discussion on the criticality of a layout to the change in flow related input data. An analysis is performed to study the affect of change in flow related input data on the final layout and a measure is developed for determining the criticality of a given layout to the change in flow related input data for the case of equal size departments. / M.S.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This study proposes a production model that increases the manufacturing capacity in a small and medium-sized enterprise (SME) of garments with an aim to reduce the nonfulfillment of order deliveries. An assessment has been done and waiting times between production processes have been identified, along with defective products and inefficient work methods. This study proposes the design of a lean manufacturing model under the change management approach, whose methodology comprises five phases. In phase 0, awareness and training sessions are conducted (change management). Then, phase 1 reorganizes the work area (plant layout re-distribution and 5S) and phase 2 seeks better workload balances (line balance and Heijunka implementation). Later, phase 3 standardizes work methods (standardization). Finally, the proposed model will be validated to determine whether the selected operating tools are supported by the awareness that contributes to increasing production. © 2021, Springer Nature Switzerland AG. / Revisión por pares

As empresas de manufatura, nos dias atuais, estão incessantemente em busca de redução de custos, motivadas pela concorrência e competição, que são características fortes da globalização. No Sistema Toyota de Produção (OHNO, 1988) é ressaltada a questão dos sete desperdícios que podem existir em um processo e que, consequentemente, geram custos no produto sem, contudo agregar valor ao mesmo. Um dos desperdícios mais comumente encontrados são os do fluxo do produto semiacabado (WIP), matéria-prima ou produto acabado. O estudo de Layout visa otimizar a disposição dos recursos dentro de um processo de modo a minimizar, entre outros, o fluxo de materiais. O presente estudo visa apresentar um caso real de uma grande empresa de autopeças na região de Curitiba, PR, que gasta milhões por ano em mudanças de Layout. O objeto de estudo é a linha de montagem de um determinado componente que esta empresa fabrica. Através do uso de Métodos Heurísticos propõe-se uma abordagem para a otimização do Layout desta linha de montagem. Esta abordagem foi dividida em duas etapas. Na primeira etapa, foi resolvido o problema de formação de células (visando melhorar os tempos computacionais, bem como a qualidade da solução), visando associar as máquinas disponíveis às peças a serem fabricadas. Na segunda etapa, resolve-se o problema de otimização do layout, considerando as associações de máquinas às peças feitas na primeira etapa. Nas duas etapas testou-se o uso de uma abordagem meta-heurística (busca tabu) híbrida, bem como o método exato denominado Branch-and-Bound (este na primeira etapa), para resolver o problema. Os resultados encontrados no arranjo físico das máquinas mostraram-se bastante promissores. / Nowadays, the manufacturing enterprises are constantly looking for costs reduction, driven by rivalry and competition, which are strong globalization characteristics. In the Toyota Production System (OHNO, 1988), are highlighted the seven wastes which can exist in a manufacturing process and that, consequently, generate costs to the product without, however, adding value to it. Some commonly found wastes are the work-in-process (WIP), raw material or finished products flow wastes. The layout study aims to optimize the layout of facilities inside a process to minimize, among others, the materials flow. This study aims to present a real case of a huge auto parts manufacturer enterprise located in Curitiba, PR, which spends millions a year on layout changes. The object of study is the assembly line of a specifical component that this company manufactures. Using Heuristic methods, it proposes an approach for the layout optimizing of this assembly line. This approach was divided in two stages: in the first one, the cell formation problem (in order to improve the computational time, as well as the solution quality) was solved in order to associate machines to parts. In the second stage, the layout optimizing problem is solved, considering the combination of machines to parts (made in first stage). In both stages the hybrid meta-heuristics approach (tabu search), as well as the Exact method so called Branch-and-Bound (this on first stage), were tested to solve this problem. The results found on layout of facilities were quite promising.

As empresas de manufatura, nos dias atuais, estão incessantemente em busca de redução de custos, motivadas pela concorrência e competição, que são características fortes da globalização. No Sistema Toyota de Produção (OHNO, 1988) é ressaltada a questão dos sete desperdícios que podem existir em um processo e que, consequentemente, geram custos no produto sem, contudo agregar valor ao mesmo. Um dos desperdícios mais comumente encontrados são os do fluxo do produto semiacabado (WIP), matéria-prima ou produto acabado. O estudo de Layout visa otimizar a disposição dos recursos dentro de um processo de modo a minimizar, entre outros, o fluxo de materiais. O presente estudo visa apresentar um caso real de uma grande empresa de autopeças na região de Curitiba, PR, que gasta milhões por ano em mudanças de Layout. O objeto de estudo é a linha de montagem de um determinado componente que esta empresa fabrica. Através do uso de Métodos Heurísticos propõe-se uma abordagem para a otimização do Layout desta linha de montagem. Esta abordagem foi dividida em duas etapas. Na primeira etapa, foi resolvido o problema de formação de células (visando melhorar os tempos computacionais, bem como a qualidade da solução), visando associar as máquinas disponíveis às peças a serem fabricadas. Na segunda etapa, resolve-se o problema de otimização do layout, considerando as associações de máquinas às peças feitas na primeira etapa. Nas duas etapas testou-se o uso de uma abordagem meta-heurística (busca tabu) híbrida, bem como o método exato denominado Branch-and-Bound (este na primeira etapa), para resolver o problema. Os resultados encontrados no arranjo físico das máquinas mostraram-se bastante promissores. / Nowadays, the manufacturing enterprises are constantly looking for costs reduction, driven by rivalry and competition, which are strong globalization characteristics. In the Toyota Production System (OHNO, 1988), are highlighted the seven wastes which can exist in a manufacturing process and that, consequently, generate costs to the product without, however, adding value to it. Some commonly found wastes are the work-in-process (WIP), raw material or finished products flow wastes. The layout study aims to optimize the layout of facilities inside a process to minimize, among others, the materials flow. This study aims to present a real case of a huge auto parts manufacturer enterprise located in Curitiba, PR, which spends millions a year on layout changes. The object of study is the assembly line of a specifical component that this company manufactures. Using Heuristic methods, it proposes an approach for the layout optimizing of this assembly line. This approach was divided in two stages: in the first one, the cell formation problem (in order to improve the computational time, as well as the solution quality) was solved in order to associate machines to parts. In the second stage, the layout optimizing problem is solved, considering the combination of machines to parts (made in first stage). In both stages the hybrid meta-heuristics approach (tabu search), as well as the Exact method so called Branch-and-Bound (this on first stage), were tested to solve this problem. The results found on layout of facilities were quite promising.