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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.
51

Razvoj sistema za simultano projektovanje proizvoda i tehnoloških procesa / Development of an System for Simultaneously Product and Process Planning Design

Borojević Stevo 03 July 2015 (has links)
<p>U okviru istraživanja na predmetnoj disertaciji prikazana je analiza stanja i pravci razvoja u oblasti simultanog projektovanja proizvoda i tehnoloških procesa. Detaljnije su opisane tehnike CAD/CAPP integracije na bazi tehnoloških tipskih formi i vještačke inteligencije. Na bazi ovih analiza razvijen je model simultanog projektovanja proizvoda i tehnoloških procesa. Na osnovu modela sistema, razvijen je programski sistem za simultano projektovanje proizvoda i tehnoloških procesa. Prikazani su rezultati primjene razvijenog sistema na primjeru hidraulične prese za ugaono savijanje lima, kao proizvoda, i hidrauličnog cilindra, kao dijela proizvoda. Disertacija obuhvata i moguće pravce budućeg istraživanja.</p> / <p>The research in this dissertation encompassed state-of-the-art and future development in the field of simultaneously product and process planning design. Technics of CAD/CAPP integration based at manufacturing features and artificial intelligence are described in detail. Based on this analysis it was developed a model of simultaneously product and process planning design. Based on this model, program system for simultaneously product and process planning design was developed. Case studies were presented at the example of hydraulics press brake for sheet metal bending, as products, and hydraulics cylinder, as part of the product. In dissertation it was also suggested directions of future investigation in this field.</p>
52

Otimização do planejamento de processos de montagem final da indústria automotiva. / Automotive industry general assembly process planning optimization.

Hirayama, Roberto Eiji 18 October 2005 (has links)
Este trabalho teve como objetivo propor uma metodologia para otimizar o planejamento de processos de montagem final da indústria automotiva. A metodologia proposta foi elaborada com base na revisão bibliográfica e no Mapeamento de Processos Críticos da atividade de planejamento de processos de montagem final durante o desenvolvimento de produtos, tendo como referência a subsidiária brasileira de uma montadora. A metodologia proposta consiste em aplicar o PFMEA (Process Failure Mode and Effect Analysis) associado às seguintes ferramentas de qualidade: Brainstorming, Benchmarking, Lições Aprendidas, Sistemas À Prova de Erros, Diagramas de Causa e Efeito e 5 Por Quês. Neste trabalho foi adotada a realização de uma pesquisa explicativa com metodologia de pesquisa-ação. Foram criados procedimentos para que a metodologia proposta fosse aplicada experimentalmente na unidade de análise deste trabalho. A fase de coleta de dados foi feita através de três estudos de caso. Com base nos resultados obtidos, foram analisados os benefícios da aplicação da metodologia proposta e os procedimentos para formar equipes para realizar estudos de PFMEA, no contexto da Engenharia Simultânea. Foi observado que a aplicação da metodologia proposta por este trabalho proporcionou importantes benefícios para o planejamento de processos de montagem final, a especificação técnica de equipamentos de montagem e o desenvolvimento de produtos. / The objective of this work was to propose a methodology to optimize the general assembly process planning of automotive industry. The proposed methodology was elaborated based on bibliographic revision and a Critical Process Mapping regarding general assembly process planning activity during product development, referring to a Brazilian automaker subsidiary. The proposed methodology consists in applying PFMEA (Process Failure Mode and Effect Analysis) associated with the following quality tools: Brainstorming, Benchmarking, Lessons Learned, Error Proof Systems, Cause and Effect Diagrams, and 5 Why’s. Explicative research with action research method was adopted in this work. Procedures were created to experimentally apply the proposed methodology to the analysis unit of this work. The data collect phase was performed through three case studies. Based on the experimental results, advantages of the proposed methodology and PFMEA team formation were analyzed, in the context of Simultaneous Engineering. It was observed that the implementation of the proposed methodology provided important benefits to general assembly process planning, assembly equipment technical specification and product development.
53

Semi-automated process planning and cost estimation of turned components based on CATIA V5 Machining

Cheung, Ching Chi January 2008 (has links)
<p>To be more competitive in the market, many companies are trying to speed up the quotation process and quote more attractive prices. Therefore, they have identified a need for support in the quotation process in order to reduce the quotation lead-time and ensure a higher level of accuracy in the cost estimations. The Quotation Calculator, an application program, has been developed as part of the degree thesis which was carried out at AB Norrahammars Mekaniska Verkstad, NMW 2006/07. This Quotation Calculator can be operated to calculate the material and manufacturing costs of a new product.</p><p>NMW has recently acquired licenses for CATIA V5, Dassault Systems, for the purpose of making process planning and NC-programming more efficient. NMW wants to generate the data needed from the machining module for the cost calculations. Hence this project was initiated in order to extract data from CATIA V5 for further use in Quotation Calculator or other computer system in NMW.</p><p>This work has resulted in a system developed with a common hosted programming language to extract and transfer information. The system retrieves model geometry from CAD and information on process planning from CAM, then matches the information in the application for the purpose of cost estimation. The system once developed, is supposed to be used for every new product. For this approach, the relationship of the data from CATIA V5 and the Quotation Calculator has been analyzed.</p><p>Within this thesis, the focus is on production cost estimation. The method used here is programming in Visual Basic Editor to extract information from the machining module in CATIA V5 and then import them to Microsoft Excel. With standard operations, tables of data and several inputs, the cost calculation and hence the quotation process can be automatically implemented. This work has been generated with the Quotation Calculator. With the correct input data to process planning and this new quotation system, the machining time and the costs can be estimated more accurately and easier. The time and cost information is made available for decision making. As a result, the lead time for the quotation process will be shortened and a relatively more attractive price can be quoted to the customers.</p>
54

Process for preparing work instructions : A multiple case study at Volvo Group Trucks Operations / Kartläggning av beredningsprocessen : En multipel fallstudie på Volvo Lastvagnar

Jansson, Sofie, Delin, Frida January 2015 (has links)
A study made by Johansson, Fast-Berglund and Moestam (in press) shows that diversity regarding how information is used exists in global production networks. To be closer to markets, organizations have chosen to globalize their business which is one reason for why diversity arises. This because product types and brands historically have been different. One company that is currently working with improving consistency among processes is Volvo Group Trucks Operations (GTO). The company wants to evaluate how the process for preparing assembly work instructions looks like at different sites within their production network. This enables Volvo GTO to start their work towards a standardized process and uniformity. A starting point for this is to make a current state analysis of the process for preparing assembly work instructions when producing Volvo trucks, engines and transmissions in Sweden. The purpose is to identify key activities within the process and important factors to consider when standardizing the process. This is done on three sites, one for each area. Volvo GTO is the part of the Volvo Group that covers all production of engines and transmissions as well as the production of Volvo, Renault, Mack, and UD trucks. In 2012 the group choose to reorganize from brand based where each brand was an own organization to joint units, for example center of development, operations etc. This has led to a greater need of one common process for preparing assembly work instructions in order to create uniformity among the brands Volvo, Renault, Mack, and UD trucks. The result of the current state analysis shows that the process for preparing assembly work instructions is differently performed depending on the site studied. Despite this, some activities in each process are similar. These were found to be: design, review, time setting, time analysis, balancing, station marking, create assembly work instructions, and share information. Since some activities actually are similar, it would be possible to standardize the process for preparing assembly work instructions in the future. Important to consider when standardizing a process is to create awareness and involvement among employees. It is also important to have the management committed as well as uniformity among IT systems used when performing a process. One last thing to consider is that the process needs to be adaptable because sites are located all over the world and have different culture and regulations. / En studie gjord av Johansson, Fast-Berglund och Moestam (i tryck) visar variation i hur information hanteras i globala produktionsnätverk. För att komma närmre marknader har organisationer valt att globalisera sin verksamhet, vilket är en anledning till varför variation uppstår. Detta eftersom produkttyper och märken historiskt har varit annorlunda. Ett företag som för närvarande arbetar med att förbättra enhetligheten mellan processer är Volvo Group Trucks Operations (GTO). De vill utvärdera hur processen för framställning av monteringsarbetsinstruktioner ser ut på olika siter inom produktionsnätverket. Detta gör det möjligt för Volvo GTO att starta sitt arbete mot en standardiserad process och enhetlighet mellan siter. En början i detta arbete är att göra en nulägesanalys av processen för framställning av monteringsarbetsinstruktioner vid produktion av Volvo lastvagnar, motorer och växellådor i Sverige. Syftet är att identifiera nyckelaktiviteter inom processen och viktiga faktorer att tänka på när man standardisera processen. Detta sker på tre siter, en inom varje område. Volvo GTO är den del av Volvokoncernen som omfattar all tillverkning av motorer och växellådor samt produktion av Volvo, Renault, Mack och UD lastvagnar. År 2012 valde Volvokoncernen att omorganisera från varumärkesbaserad till organisatoriska enheter, till exempel utveckling, tillverkning etc. Detta har lett till ett ökat behov av en gemensam process för framställning av monteringsarbetsinstruktioner för att skapa enhetlighet mellan varumärkena. Resultatet av denna nulägesanalys visar att processen för framställning av monteringsarbetsinstruktioner utförs annorlunda beroende på siten som studerats. Trots detta är vissa aktiviteter i varje process liknande. Dessa visade sig vara: design, granskning, tidsättning, tidsanalys, balansering, stationsmärkning, skapa monteringsarbetsinstruktioner och dela information. Eftersom vissa aktiviteter faktiskt är lika skulle det vara möjligt att standardisera processen för framställning av monteringsarbetsinstruktioner i framtiden. Viktigt att tänka på när man standardisera en process är att skapa medvetenhet och engagemang bland medarbetarna. Det är också viktigt att ha ledningens engagement och stöd samt enhetlighet mellan IT system som används för att utföra processen. En sista sak att tänka på är att processen måste kunna anpassas då siter är placerade över hela världen och har olika kultur och lagar. / GAIS (Global Assembly Instruction Strategy)
55

Semi-automated process planning and cost estimation of turned components based on CATIA V5 Machining

Cheung, Ching Chi January 2008 (has links)
To be more competitive in the market, many companies are trying to speed up the quotation process and quote more attractive prices. Therefore, they have identified a need for support in the quotation process in order to reduce the quotation lead-time and ensure a higher level of accuracy in the cost estimations. The Quotation Calculator, an application program, has been developed as part of the degree thesis which was carried out at AB Norrahammars Mekaniska Verkstad, NMW 2006/07. This Quotation Calculator can be operated to calculate the material and manufacturing costs of a new product. NMW has recently acquired licenses for CATIA V5, Dassault Systems, for the purpose of making process planning and NC-programming more efficient. NMW wants to generate the data needed from the machining module for the cost calculations. Hence this project was initiated in order to extract data from CATIA V5 for further use in Quotation Calculator or other computer system in NMW. This work has resulted in a system developed with a common hosted programming language to extract and transfer information. The system retrieves model geometry from CAD and information on process planning from CAM, then matches the information in the application for the purpose of cost estimation. The system once developed, is supposed to be used for every new product. For this approach, the relationship of the data from CATIA V5 and the Quotation Calculator has been analyzed. Within this thesis, the focus is on production cost estimation. The method used here is programming in Visual Basic Editor to extract information from the machining module in CATIA V5 and then import them to Microsoft Excel. With standard operations, tables of data and several inputs, the cost calculation and hence the quotation process can be automatically implemented. This work has been generated with the Quotation Calculator. With the correct input data to process planning and this new quotation system, the machining time and the costs can be estimated more accurately and easier. The time and cost information is made available for decision making. As a result, the lead time for the quotation process will be shortened and a relatively more attractive price can be quoted to the customers.
56

Otimização do planejamento de processos de montagem final da indústria automotiva. / Automotive industry general assembly process planning optimization.

Roberto Eiji Hirayama 18 October 2005 (has links)
Este trabalho teve como objetivo propor uma metodologia para otimizar o planejamento de processos de montagem final da indústria automotiva. A metodologia proposta foi elaborada com base na revisão bibliográfica e no Mapeamento de Processos Críticos da atividade de planejamento de processos de montagem final durante o desenvolvimento de produtos, tendo como referência a subsidiária brasileira de uma montadora. A metodologia proposta consiste em aplicar o PFMEA (Process Failure Mode and Effect Analysis) associado às seguintes ferramentas de qualidade: Brainstorming, Benchmarking, Lições Aprendidas, Sistemas À Prova de Erros, Diagramas de Causa e Efeito e 5 Por Quês. Neste trabalho foi adotada a realização de uma pesquisa explicativa com metodologia de pesquisa-ação. Foram criados procedimentos para que a metodologia proposta fosse aplicada experimentalmente na unidade de análise deste trabalho. A fase de coleta de dados foi feita através de três estudos de caso. Com base nos resultados obtidos, foram analisados os benefícios da aplicação da metodologia proposta e os procedimentos para formar equipes para realizar estudos de PFMEA, no contexto da Engenharia Simultânea. Foi observado que a aplicação da metodologia proposta por este trabalho proporcionou importantes benefícios para o planejamento de processos de montagem final, a especificação técnica de equipamentos de montagem e o desenvolvimento de produtos. / The objective of this work was to propose a methodology to optimize the general assembly process planning of automotive industry. The proposed methodology was elaborated based on bibliographic revision and a Critical Process Mapping regarding general assembly process planning activity during product development, referring to a Brazilian automaker subsidiary. The proposed methodology consists in applying PFMEA (Process Failure Mode and Effect Analysis) associated with the following quality tools: Brainstorming, Benchmarking, Lessons Learned, Error Proof Systems, Cause and Effect Diagrams, and 5 Why’s. Explicative research with action research method was adopted in this work. Procedures were created to experimentally apply the proposed methodology to the analysis unit of this work. The data collect phase was performed through three case studies. Based on the experimental results, advantages of the proposed methodology and PFMEA team formation were analyzed, in the context of Simultaneous Engineering. It was observed that the implementation of the proposed methodology provided important benefits to general assembly process planning, assembly equipment technical specification and product development.
57

Feature technology and its applications in computer integrated manufacturing

Ding, Lian January 2003 (has links)
Computer aided design and manufacturing (CAD/CAM) has been a focal research area for the manufacturing industry. Genuine CAD/CAM integration is necessary to make products of higher quality with lower cost and shorter lead times. Although CAD and CAM have been extensively used in industry, effective CAD/CAM integration has not been implemented. The major obstacles of CAD/CAM integration are the representation of design and process knowledge and the adaptive ability of computer aided process planning (CAPP). This research is aimed to develop a feature-based CAD/CAM integration methodology. Artificial intelligent techniques such as neural networks, heuristic algorithms, genetic algorithms and fuzzy logics are used to tackle problems. The activities considered include: 1) Component design based on a number of standard feature classes with validity check. A feature classification for machining application is defined adopting ISO 10303-STEP AP224 from a multi-viewpoint of design and manufacture. 2) Search of interacting features and identification of features relationships. A heuristic algorithm has been proposed in order to resolve interacting features. The algorithm analyses the interacting entity between each feature pair, making the process simpler and more efficient. 3) Recognition of new features formed by interacting features. A novel neural network-based technique for feature recognition has been designed, which solves the problems of ambiguity and overlaps. 4) Production of a feature based model for the component. 5) Generation of a suitable process plan covering selection of machining operations, grouping of machining operations and process sequencing. A hybrid feature-based CAPP has been developed using neural network, genetic algorithm and fuzzy evaluating techniques.
58

Optimisation multicritères de gammes d'usinages / Multicriteria Optimisation of Machining Process Plans

Delolme, Laurent 03 May 2017 (has links)
L’objectif de ces travaux est de développer une méthodologie de génération automatique de gammes d’usinage optimises et innovantes qui permettent aux sous-traitants aéronautiques de faire face aux problématiques de productivité et de compétitivité actuelles. Dans un premier temps, un état de l’art sur les systèmes existants de génération de gammes est présenté et permet d’introduire les limites des systèmes actuels. Une méthodologie en quatre étapes est ensuite proposée, permettant à l’utilisateur d’obtenir des gammes d’usinage optimisées respectant son savoir-faire et son expérience et introduisant de l’innovation. Cette méthodologie s’appuie sur une représentation du comportement décisionnel des méthodistes dans une situation donnée ainsi que face au risque à l’industrialisation et élargit la formalisation de la performance d’une gamme en prenant en compte d’autres critères de performance autres que le temps d’usinage ou le coût global. Ainsi, un état de l’art sur les méthodes d’aide à la décision multicritère permet de sélectionner la méthode pour l’agrégation des performances par rapport à la problématique industrielle. Après une description géométrique et technologique de la pièce et la création par les méthodistes, d’opérations d’usinage élémentaires, un algorithme génétique est utilisé pour générer des gammes optimisées. Lors d’une dernière étape, la méthodologie présente les meilleures gammes générées au méthodiste et l’utilisation de la théorie du choix social lui permet de cibler les gammes les plus performantes à implanter, en intégrant un critère de risque à l’industrialisation. Cette méthodologie a été appliquée à une pièce de train d’atterrissage usinée en alliage de Titane et a permis une diminution de 25% du temps d’usinage tout en augmentant la fiabilisation. Des perspectives d’amélioration de l’outil d’aide à la décision, à diverses étapes de la méthodologie, sont enfin proposées. / The objective of this work is to develop a Computer-Aided Process Planning (CAPP) methodology to allow aeronautical subcontractors to face the current productivity and competitiveness problems. To start, a state of the art on the existing CAPP systems is presented and introduce the limits of the current systems. A four-step methodology is then proposed, allowing the user to obtain optimized machining ranges respecting his know-how and experience and introducing innovation. This methodology is based on a representation of the decision-making behavior of the process planners in a given situation as well as the risk of industrialization and broadens the formalization of the performance by taking into account performance criteria other than the machining time or cost. Thus, a state of the art on multicriteria decision-making methods helps to select the method for the aggregation of performance in relation to the industrial problem. After a geometrical and technological description of a mechanical part and the creation by the process planners of elementary machining operations, a genetic algorithm is used to generate optimized ranges. In a final step, the methodology presents the best process plans generated to the process planners and the use of the social choice theory allows to target the most efficient ones to choose, integrating a risk criterion based on tool deflection. This methodology was applied to a Titanium alloy machined landing gear part and allowed a 25% reduction in machining time while increasing reliability. Finally, prospects for improving the decision-making tool at various stages of the methodology are proposed.
59

Riskhantering vid artikelintroduktioner och produktionsförändringar inom fordonsindustrin : - En fallstudie av Process-FMEA vid Scania CV

Eriksson, Anna, Landström, Niklas January 2021 (has links)
Det finns en trend mot snabbare marknadsintroduktioner inom fordonsindustrin, vilket kräver tids- och kostnadseffektiva produktutvecklingsprocesser samtidigt som det sker ett kontinuerligt arbete för att förbättra kvaliteten på produkterna. Kvalitetsavvikelser på artiklar är kostsamma, leder till kassationer och miljöbelastningar, innebär säkerhetsrisker och försvårar planeringen inom tillverkningsorganisationer. För en hållbar tillväxt inom fordonsindustrin har den ideella organisationen Automotive Industry Action Group (AIAG) tagit fram den internationella kvalitetsstandarden IATF 16969. En del i att uppfylla IATF 16969 är att använda sig av Production Part Approval Process (PPAP), där riskhanteringsmetoden Failure Mode and Effects Analysis (FMEA) ingår. Process-FMEA (PFMEA) är en variant av FMEA som används vid kvalitetssäkring av tillverkningsprocessen. Studien syftade till att undersöka hur fordonstillverkare på ett framgångsrikt sätt kan tillämpa PFMEA vid artikelintroduktioner och produktionsförändringar. För att uppfylla syftet utfördes en fallstudie där styrkor och brister med nuvarande arbetssätt kartlades. Detta gjordes via 28 intervjuer vid två av Scanias bearbetande senheter, intervjuer med fem andra stora fordons- och komponenttillverkare samt en observationsstudie av tolv utförda PFMEA:or vid Scania. Resultatet från studien bekräftade gap mellan teoretisk framställning av PFMEA och praktisk tillämpning. De gap som identifierades gäller vilka avgränsningar som görs, användningen av risktalet, i vilka situationer PFMEA används som beslutsunderlag, processtödens uppbyggnad, avsaknaden av systemstöd, hur PFMEA ska itereras, brist på en standardiserad inlärningsprocess och sammankopplingen mellan relaterade verktyg. För respektive gap presenteras sedan framgångsfaktorer i rapporten. I avslutande rekommendationer framhölls vikten av att utgå från organisationens förutsättningar, strategi, mål och framtida vision vid tillämpning av PFMEA. Det behövs standardiserade inlärnings- och arbetsprocesser i enlighet med Lean samt tydliggöras hur informationsöverföringen mellan PFMEA, Design-FMEA, Design For Manufacturing-arbetet, styrplan, flödesschema och avvikelsesystem ska ske. Vidare rekommenderades framtagning av kravspecifikation för ett digitalt stödsystem i syfte att möjliggöra enklare och mer tidseffektiv informationsöverföring och erfarenhetsåterföring inom organisationen. Avslutningsvis antas kunskapsbidraget från studien vara av störst intresse för artikeltillverkare inom fordonsindustrin. Vid andra organisatoriska förutsättningar än vid Scanias tillverkande enheter, bör särskild uppmärksamhet ägnas åt rekommendationerna för arbetsprocesser, avvikelsesystem och organisationsstruktur. / There is a trend towards faster market introductions in the automotive industry, which requires time and cost effective product development processes at the same time as there is a continual effort to increase the quality of the products. Deviations in the quality of components are costly, lead to scrapping and environmental burdens, involve safety risks and complicate planning within manufacturing organizations. For sustainable growth in the automotive industry, the non-profit organization Automotive Industry Action Group (AIAG) has developed the international quality standard IATF 16969. A part of complying with IATF 16969 is the use of the Production Part Approval Process (PPAP), which includes the risk management method Failure Mode and Effects Analysis (FMEA). Process-FMEA (PFMEA) is a variant of FMEA used for quality assurance of the manufacturing process. The study aimed to investigate how vehicle manufacturers can successfully  apply PFMEA for introductions of components and changes in the production. To fulfill the purpose, a case study was conducted where strengths and shortcomings with current working methods were mapped. This was done by 28 interviews at two of Scania's manufacturing units and interviews with five other major vehicle and component manufacturers, as well as an observational study of twelve PFMEA:s performed at Scania. The results from the study confirmed gaps between existing research regarding PFMEA and the practitical application. The gaps identified concern the delimitations made, the use of the risk priority number, the situations in which PFMEA is used as a basis for decisions, the structure of process support, the lack of system support, how PFMEA should be iterated, lack of a standardized learning process and the connection between related tools to PFMEA. For each gap, success factors are presented in the report. In general, the importance of starting from the organisation's conditions, strategy, goals and future vision when applying PFMEA was emphasized. There is a need for standardized learning and work processes in accordance with Lean and clarification about how the information transfer between PFMEA, Design-FMEA, Design For Manufacturing, control plan, flowchart and deviation system should take place. Furthermore, the development of RFQ material for a digital support system was recommended in order to enable simpler and more time-efficient information transfer and lessons learned within the organization. In conclusion, the knowledge contribution from the study is assumed to be of greatest interest to part manufacturers in the automotive industry. In other organizational conditions than at Scania's manufacturing units, special attention should be paid to the recommendations for work processes, deviation systems and organizational structure.
60

Semantic Agent Based Process Planning for Distributed Cloud Manufacturing

Sarkar, Arkopaul 02 June 2020 (has links)
No description available.

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