• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 41
  • 23
  • 9
  • 5
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 99
  • 99
  • 36
  • 26
  • 24
  • 20
  • 19
  • 15
  • 14
  • 12
  • 11
  • 11
  • 11
  • 11
  • 11
  • 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.
11

Necessary and sufficient conditions for deadlock in a manufacturing system

Deering, Paul E. January 2000 (has links)
No description available.
12

Technology, Location, Price, and System Design Decisions for a Global Manufacturing Company

Cosner, Jeremy D. 29 December 2008 (has links)
No description available.
13

Supporting the Design of Reconfigurable Production Systems

Rösiö, Carin January 2012 (has links)
To compete, manufacturing companies need production systems that quickly can respond to changes. To handle change drivers such as volume variations or new product variants, reconfigurability is advocated as a competitive means. This implies an ability to add, remove, and/or rearrange the structure of the production system to be ready for future changes. Still, it is not clear how the production system design process can capture and support the design of reconfigurable production systems. Therefore, the objective of this thesis is to increase the knowledge of how to support the design of reconfigurable production systems. Reconfigurability could be defined by a number of reconfigurability characteristics including convertibility, scalability, automatibility, mobility, modularity, integrability, and diagnosability. In eight case studies, reconfigurability characteristics in production system design were studied in order to investigate reconfigurability needs, knowledge, and practice in manufacturing companies. In three of the case studies reconfigurable production systems were studied to identify the links between change drivers and reconfigurability characteristics. In the remaining five case studies, reconfigurability in the production system design processes was addressed in terms of needs, prerequisites, and consideration. Based on the literature review and the case studies, support for reconfigurable production system design is suggested including two parts. The first part comprises support for analyzing the need for reconfigurability. Based on relevant change drivers the need for reconfigurability must be identified to enable selection of right type and degree of reconfigurability for each specific case of application. A comprehensive view of the reconfigurability characteristics is presented and links between change drivers and reconfigurability characteristics are described. The characteristics are divided into critical characteristics, that lead to a capacity or functionality change of the production system, and supporting characteristics, that reduce system reconfiguration time but do not necessarily lead to a modification of functionality or capacity of the production system. The second part provides support in how to consider reconfigurability in the production system design process. A holistic perspective is crucial to design reconfigurable production systems and therefore constituent parts of a production system are described. According to their character physical, logical, and human reconfiguration must be considered through the whole production system design process.
14

Investment Model to Evaluate Changeable Manufacturing Systems : An real options approach to measure the value of flexibility for investments in an industrial context / Investeringsmodel för utvärdering av föränderliga tillverkningssystem

Olsson, Fredrik, Werthén, Alexander January 2021 (has links)
Purpose: The purpose of the study is to develop an investment model which can be applied during the design of a manufacturing system, that considers DMS, FMS, and RMS. With the aim of the developed model is to give decision makers monetary basis for the added from changeability. To fulfill the purpose three research questions was created:   What methods in academia are currently used to evaluate changeable manufacturing system investments?  What methods in industry are currently used to evaluate manufacturing system investments? How can an investment model be adapted to incorporate both academia and industry preferences? Method: A single-case-study was conducted within a company that is transitioning into a more reconfigurable manufacturing system. This created an empirical framework for a practical model. In parallel with the case study a literature study was conducted to attain a theoretical framework for the study. The first research question was answered with the literature study. The second research question was answered through the case study, including document studies, interviews, and a focus group, complemented with a literature study. From the theoretical and empirical framework, research question three was answered by developing the investment model following the model creation method suggested by Mitroff et al. (1974).  Implication: The wide adoption of the reconfigurable manufacturing system has yet to be fulfilled in industry, partially hinder by finding economic motivation at the investment evaluation of such a system. The focal company and most other western companies use a net present value to evaluate investments. This approach has been proved inadequate to describe the benefits of a changeable system. Literature suggests that a real option approach could successfully describe the benefits of changeability. However, the approach has been perceived by industry to be too complex. Therefore, a model needed to have enough complexity to comprehend aspect of changeability, while still be simplistic enough gain acceptance from industry. The developed model supplements traditional NPV evaluation with a real options approach, adding scenarios to incorporate uncertainties. The study indicates that it is possible to present the monetary value of added flexibility from changeable manufacturing systems in a simplistic way.
15

Benefits & barriers of implementing reconfigurable jigs : A study in offsite manufacturing of unique house elements in Sweden

Sege, Victoria, Balta, Pelda January 2019 (has links)
The aim of this paper is to identify the enablers, barriers and benefits of implementing reconfigurable jigs in the off-site manufacturing of unique house elements. Due to de- mands on customization, volume and lowering the cost, there is a need to increase flex- ibility in the industry. The paper focuses on mainly two phases of implementation, which are manufacturing, design and engineering. The research questions are answered by applying a single case study method, taking place in a Swedish house manufacturing company. The study consists of four different techniques – interviews, time study, observations, and questionnaire which are sup- ported with an additional literature review. Hence, research questions are answered from a triangulation approach providing nuanced and dynamic perspectives. From observations and time study it is concluded that in current situation, changeover in manufacturing is time-consuming due to the difference in complexity of product var- iants, along with a complex and inefficient setup process that is not responsive to a changeable environment. Findings imply that the barriers in both phases include lack of knowledge about reconfigurability, communication, current capabilities of CAD sys- tems as well as training and education. Enablers are found to be awareness of the needs of improvements, long-term mindset and working with product platforms. The benefits of implementing reconfigurable jigs include a reduction of setup time in manufacturing, better storage and sharing of information along with a better interpretation of that in- formation, a better structure in the organisation.
16

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.
17

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.
18

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
19

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.
20

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.

Page generated in 0.1439 seconds