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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Método de apoio à decisão de escolha de tecnologia em sistemas flexíveis de manufatura: estudo de caso

Mâncio, Vagner Gerhardt 03 July 2015 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-02-15T15:42:38Z No. of bitstreams: 1 Vagner Gerhardt Mâncio_.pdf: 2330651 bytes, checksum: 51d1129f6c7064f70ea101a75bca32d1 (MD5) / Made available in DSpace on 2016-02-15T15:42:38Z (GMT). No. of bitstreams: 1 Vagner Gerhardt Mâncio_.pdf: 2330651 bytes, checksum: 51d1129f6c7064f70ea101a75bca32d1 (MD5) Previous issue date: 2015-07-03 / Nenhuma / A competição entre as empresas é cada vez mais um fator de sobrevivência, e a busca de diferenciais é o principal objetivo para que as empresas tornem-se destaques no mercado e se mantenham competitivas. Com o objetivo de contribuir para a evolução das empresas com variedade de produtos e uma taxa média de produção, desenvolveu-se esta pesquisa sobre a viabilidade de altos investimentos em automação e a criação de um método para a escolha de equipamentos a partir de uma visão estratégica, considerando as principais dimensões de competição: custo, qualidade, flexibilidade, entrega. A pesquisa delimita-se no campo de Sistemas Flexíveis de Manufatura – do inglês Flexible Manufacturing System (FMS) –, cujas análises estratégicas e de equipamentos de automatização tenham características de sistemas flexíveis. A pesquisa foi desenvolvida na metodologia de modelagem quali-quantitativa, na qual, através da modelagem dos cenários, puderam ser realizadas avaliações qualitativas e quantitativas; o Método de Análise Hierárquica – do inglês Analytic Hierarchy Process (AHP) – foi utilizado para determinar o cenário que melhor combina com a principal variável competitiva. Para o desenvolvimento da pesquisa, foram coletadas opiniões de especialistas de empresas sobre os pesos comparativos do método AHP e sobre os equipamentos de automação que fazem parte dos cenários criados. O cenário 1 possui layout escada com a movimentação dos materiais realizado por esteiras através de pallets, cuja manipulação é realizada por sistemas pneumáticos. O cenário 2 possui layout campo aberto com a movimentação dos materiais realizado por veículos guiados automaticamente – do inglês Automated Guided Vehicle (AGV), capazes de abastecer e descarregar os equipamentos. O cenário 3 possui layout centrado no robô, com 3 robôs que se movimentam em uma esteira para abastecer e desabastecer os equipamentos. Foram propostos dois métodos de cálculo do mérito final dos cenários, e, para ambos, o melhor cenário foi o 3. Adicionalmente, concluiu-se que adotar o cenário 3 é melhor do que não fazer nada, ou seja, continuar com a instalação atual da célula estudada. / The competition between companies is increasingly a factor of survival, and the search for differential is the main objective for companies to become highlights in the market and remain competitive. In order to contribute to the development of companies with a variety of products and an average rate of production, this research was carried out on the feasibility of large investments in automation and the creation of a method for choosing equipment from a vision strategic, considering the main dimensions of competition: cost, quality, flexibility, delivery. The research is delimited in the Flexible Manufacturing Systems field (FMS) whose strategic analysis and automation equipment have flexible systems characteristics. The research was conducted in the qualitative and quantitative modeling methodology, in which, through the modeling of scenarios, could be carried out qualitative and quantitative assessments; the Analytic Hierarchy Process (AHP) was used to determine the setting that best suits the key competitive variable. For the development of research, business expert opinions were collected on the comparative weights of AHP and on the automation equipment that are part of the created scenarios. Scenario 1 has ladder layout with the movement of the materials carried by pallets through mats, in which the handling of materials is achieved by pneumatic systems. Scenario 2 has the open layout with the movement of materials held by Automated Guided Vehicle (AGV), able to supply and unloading equipment. Scenario 3 has focused on the layout robot, in which there are three robots, moving on a conveyor and load and unload the equipment. Two methods of calculating the final merit of the scenarios were proposed. By both methods, the best scenario was the 3. Additionally, the conclusion is that adopting the scenario 3 is better than doing nothing, that is, continue with the current installation of cell studied.
22

Modeling and Analysis of Two-Part Type Manufacturing Systems

Jang, Young Jae, Gershwin, Stanley B. 01 1900 (has links)
This paper presents a model and analysis of a synchronous tandem flow line that produces different part types on unreliable machines. The machines operate according to a static priority rule, operating on the highest priority part whenever possible, and operating on lower priority parts only when unable to produce those with higher priorities. We develop a new decomposition method to analyze the behavior of the manufacturing system by decomposing the long production line into small analytically tractable components. As a first step in modeling a production line with more than one part type, we restrict ourselves to the case where there are two part types. Detailed modeling and derivations are presented with a small two-part-type production line that consists of two processing machines and two demand machines. Then, a generalized longer flow line is analyzed. Furthermore, estimates for performance measures, such as average buffer levels and production rates, are presented and compared to extensive discrete event simulation. The quantitative behavior of the two-part type processing line under different demand scenarios is also provided. / Singapore-MIT Alliance (SMA)
23

On Manufacturing System Development in the Context of Concurrent Engineering

Aganovic, Dario January 2004 (has links)
This thesis presents an extension of the contemporaryengineering design theory towards a unified view onsimultaneous development of products and manufacturing systems,i.e. concurrent engineering. The traditional engineering design theory explains therealization of a product design as a development of productstructure from four perspectives: technical process, function,technical solution, and physical embodiment. This thesisextends the engineering design theory with a set of definitionsand universal statements. These definitions and universalstatements describe manufacturing systems from same fourperspectives. In that context they also describe therelationship between a product and its manufacturing system.The thesis contributes to the creation of a single theoreticalsystem based on an integration of theories from two engineeringdesign schools, the WDK and the Axiomatic Design. WDKtheoriesare in this new context utilized for qualitative synthesis ofthe developed artifacts, while the Axiomatic Design is utilizedfor structuring and analyzing the corresponding quantitativeparameters. The definitions and universal statements describe thedevelopment structures for productsand manufacturing systems.This description is utilized for definition of a system fordevelopment of these structures, i.e. (i) a stage-gate-basedmanufacturing system development process, (ii) a developmentmethodology toolbox, and (iii) an information managementframework consisted of an information model harmonized with thesystems engineering data management standard STEP AP 233. The research has been carried out in a close collaborationwith Swedish manufacturing industry. The utilized researchmethodology is the hypothetic- deductive method, with casestudy as an observation method. Keywords:Concurrent Engineering, Engineering Design,Development Methods and Tools, Manufacturing System,Information Management.
24

Information modelling for the manufacturing system life cycle

von Euler-Chelpin, Astrid January 2008 (has links)
This thesis deals with information modelling within the scope of the manufacturing system life cycle, i.e. the development phase and the operation phase. Information modelling defines and structures information that needs to be managed, and is thereby an important step towards realising efficient information management throughout the manufacturing system life cycle. The research goal of this work was to find a modelling approach that simplifies management and integration of manufacturing system information, both within and between the development and operation phases. The starting point was an assumption that information integration requires a common information model for the manufacturing system life cycle. The approach was to evaluate the usefulness of the STEP standards AP214 and AP239 (PLCS) regarding how they meet the information requirements. Case studies within the automotive industry were carried out for gathering test data. Modelling experience showed that PLCS has the most suitable scope since it can represent the manufacturing system from a life cycle perspective. However, the generic character of PLCS introduced other issues, such as how to ensure consistent instantiation. Further guidance is needed regarding how to use PLCS for representing domain-specific objects such as machining centres. As a response to the inconsistency issue, a concept model of a machining centre was developed to guide the instantiation of PLCS. However, it was found that there are multiple ways to translate the concept model to PLCS depending on viewpoint. Moreover, the characteristics of information management within the operation phase were found to be notably different compared to characteristics of the development phase. For these reasons, it is discussed whether or not a common modelling format for the whole manufacturing system life cycle is appropriate or even realisable. From a practical viewpoint, it is concluded to be both inevitable and necessary to find appropriate delimitations and interfaces between complementary information models. A promising step towards information integration is to classify the information concepts of different models according to terms defined in concept models. / QC 20100921
25

Job Scheduling Considering Both Mental Fatigue and Boredom

Jahandideh, Sina 25 January 2012 (has links)
Numerous aspects of job scheduling in manufacturing systems have been the focus of several studies in the past decades. However, human factors in manufacturing systems such as workers’ mental conditions are still neglected issues and have not received adequate attentions. Job boredom and mental fatigue are both aspects of workers’ mental condition. They affect work performances by increasing sick leave duration and decreasing work productivity. On the other hand, job rotation could be an alternative strategy to cope with such human issues at work. The benefits of job rotation for both employees and firms have been widely recognized in the literature. Although some studies found job rotation as a means to reduce workers' physical work-related traumas, they did not consider the effect of variable mental conditions on workers. Despite the proven importance of boredom and mental fatigue at the workplace, they have not been a combined precise objective of any job rotation problem in current literature. The study of mental conditions proposed in this paper attempts to extend the previous works by addressing new methods and developing a feasible solution to increase manufacturing productivity. A new job scheduling program has been designed specifically which combines a new job rotation model and a job assignment method.
26

Job Scheduling Considering Both Mental Fatigue and Boredom

Jahandideh, Sina 25 January 2012 (has links)
Numerous aspects of job scheduling in manufacturing systems have been the focus of several studies in the past decades. However, human factors in manufacturing systems such as workers’ mental conditions are still neglected issues and have not received adequate attentions. Job boredom and mental fatigue are both aspects of workers’ mental condition. They affect work performances by increasing sick leave duration and decreasing work productivity. On the other hand, job rotation could be an alternative strategy to cope with such human issues at work. The benefits of job rotation for both employees and firms have been widely recognized in the literature. Although some studies found job rotation as a means to reduce workers' physical work-related traumas, they did not consider the effect of variable mental conditions on workers. Despite the proven importance of boredom and mental fatigue at the workplace, they have not been a combined precise objective of any job rotation problem in current literature. The study of mental conditions proposed in this paper attempts to extend the previous works by addressing new methods and developing a feasible solution to increase manufacturing productivity. A new job scheduling program has been designed specifically which combines a new job rotation model and a job assignment method.
27

Study on Architecture-Oriented Electric Arc Furnace Manufacturing System Model

Huang, Bo-ham 25 June 2009 (has links)
The electric arc furnace steelmakers produce steel across wide ranging sizes and different quality levels. The method of using electric arc for melting is an important process to produce steel from iron or scraps. The diversity of products and markets makes the steelmakers to operate within a large number of constraints of limited enterprise resources, so the electric arc furnace manufacturing system faces problems to integrate the enterprise resource planning system with the manufacturing execution system. The international automation society has come out a solution with an international standard, also known as ISA-95 aimed to help manufacturing industries such as electric arc furnace steelmakers, for the integration of enterprises and control systems. However, ISA-95 only emphasizes on the integration of enterprises and control systems, but does not provide a whole picture of the entire system. This research utilizes the tool of system architecture to develop the architecture-oriented electric arc furnace manufacturing system model, abbreviated as AOEAFMSM, to illustrate coherently the structure view and the behavior view of the electric arc furnace manufacturing system. Furthermore, AOEAFFMSM is able to fully describe many other views of the electric arc furnace manufacturing system. This capability satisfies everybody¡¦s need for capturing different views of the system. Consequentially, AOEAFFMSM simplifies the software development and reduces many communication difficulties among system developers and customers. In modeling the electric arc furnace manufacturing system model, AOEAFFMSM is superior to ISA-95.
28

On Manufacturing System Development in the Context of Concurrent Engineering

Aganovic, Dario January 2004 (has links)
<p>This thesis presents an extension of the contemporaryengineering design theory towards a unified view onsimultaneous development of products and manufacturing systems,i.e. concurrent engineering.</p><p>The traditional engineering design theory explains therealization of a product design as a development of productstructure from four perspectives: technical process, function,technical solution, and physical embodiment. This thesisextends the engineering design theory with a set of definitionsand universal statements. These definitions and universalstatements describe manufacturing systems from same fourperspectives. In that context they also describe therelationship between a product and its manufacturing system.The thesis contributes to the creation of a single theoreticalsystem based on an integration of theories from two engineeringdesign schools, the WDK and the Axiomatic Design. WDKtheoriesare in this new context utilized for qualitative synthesis ofthe developed artifacts, while the Axiomatic Design is utilizedfor structuring and analyzing the corresponding quantitativeparameters.</p><p>The definitions and universal statements describe thedevelopment structures for productsand manufacturing systems.This description is utilized for definition of a system fordevelopment of these structures, i.e. (i) a stage-gate-basedmanufacturing system development process, (ii) a developmentmethodology toolbox, and (iii) an information managementframework consisted of an information model harmonized with thesystems engineering data management standard STEP AP 233.</p><p>The research has been carried out in a close collaborationwith Swedish manufacturing industry. The utilized researchmethodology is the hypothetic- deductive method, with casestudy as an observation method.</p><p><b>Keywords:</b>Concurrent Engineering, Engineering Design,Development Methods and Tools, Manufacturing System,Information Management.</p>
29

Mechaninių gaminių integruotos gamybos sistemos modelio sukūrimas / Integrated model of manufacturing system for mechanical products

Borusas, Henrikas 29 September 2008 (has links)
Baigiamajame magistro darbe pateikiamos teorinės integruotos gamybos sistemos galimybės ir prielaidos, įdiegimo funkcijos ir etapai. Analizuojamos integruotos gamybos sistemos integravimo praktinės galimybės realiam mechaniniam gaminiui, nurodoma laukiama nauda ir kiti privalumai. / The practical realization of model theoretical bases to medium Lithuanian company X is carried out. Considered company in manufacturing business of small trucks components’ is involved. It applies the various metal profiles as materials and machining, welding and painting operations. The company business process was modeled, tested and validated. It works on the virtual prototypes at the early business conception stage. Main task of developed model in this stage is forecasting of manufacturing cost and decision making selecting suppliers and partners. The results and conclusions of work are presented.
30

QUALITY ANALYSIS IN FLEXIBLE MANUFACTURING SYSTEMS WITH BATCH PRODUCTIONS

Wang, Junwen 01 January 2010 (has links)
To improve product quality and reduce cost, batch production is often implemented in many exible manufacturing systems. However, the current literature does not provide any method to analyze the quality performance in a flexible manufacturing system with batch production. In this research, we present an analytical method with closed-form formula to evaluate the quality performance in such systems. Based on the model, we discover and investigate monotonic and non-monotonic properties in quality to provide practical guidance for operation management. To improve product quality, we introduce the notions of quality improvability with respect to product sequencing. In addition, we develop the indicators for quality improvability based on the data available on the factory floor rather than complicated calculations. We define the bottleneck sequence and bottleneck transition as the ones that impede quality in the strongest manner, investigate the sensitivity of quality performance with respect to sequences and transitions, and propose quality bottleneck sequence and transition indicators based on the measured data. Finally, we provide a case study at an automotive paint shop to show how this method is applied to improve paint quality. Moreover, we explore a potential application to reduce energy consumption and atmospheric emissions at automotive paint shops. By selecting appropriate batch and sequence policies, the paint quality can be improved and repaints can be reduced so that less material and energy will be consumed, and less atmospheric emissions will be generated. It is shown that such scheduling and control method can lead to significant energy savings and emission reduction with no extra investment nor changes to existing painting processes. The successful development of such method would open up a new area in manufacturing systems research and contribute to establish a solid foundation for an integrated study on productivity, quality and exibility. In addition, it will provide production engineers and operation managers a quantitative tool for continuous improvement on product quality in flexible manufacturing environment

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