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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.
1

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.
2

RMS capacity utilisation: product family and supply chain

Abdi, M. Reza, Labib, A.W. 06 September 2016 (has links)
yes / The paper contributes to development of RMS through linkage with external stakeholders such as customers and suppliers of parts/raw materials to handle demand fluctuations that necessitate information sharing across the supply chain tiers. RMS is developed as an integrated supply chain hub for adjusting production capacity using a hybrid methodology of decision trees and Markov analysis. The proposed Markov Chain model contributes to evaluate and monitor system reconfigurations required due to changes of product families with consideration of the product life cycles. The simulation findings indicate that system productivity and financial performance in terms of the profit contribution of product-process allocation will vary over configuration stages. The capacity of an RMS with limited product families and/or limited model variants becomes gradually inoperative whilst approaching upcoming configuration stages due to the end of product life cycles. As a result, reconfiguration preparation is suggested quite before ending life cycle of an existing product in process, for switching from a product family to a new/another product family in the production range, subject to its present demand. The proposed model is illustrated through a simplified case study with given product families and transition probabilities.
3

Développement d’une nouvelle famille d’indicateurs de performance pour la conception d’un système manufacturier reconfigurable (RMS) : approches évolutionnaires multicritères / Development of a new family of performance indicators for the design of a reconfigurable manufacturing system (RMS) : multi-criteria evolutionary approaches

Haddou Benderbal, Hichem 20 June 2018 (has links)
L'environnement manufacturier moderne est face à un bouleversement de paradigmes nécessitant plus de changeabilité au niveau physique et logique. Un système manufacturier Changeable est défini comme un système de production ayant les capacités de faciliter les changements adéquats, permettant d'ajuster ses structures et ses processus en réponse aux différents besoins. Dans ce contexte, les systèmes manufacturiers doivent se doter d’un très haut niveau de reconfigurabilité, qui est considérée comme l’un des facteurs majeurs du concept de changeabilité. En effet, dans la vision de l'Usine du Futur, la reconfigurabilité est essentielle pour s'adapter efficacement à la complexité croissante des environnements manufacturiers. Elle assure une adaptation rapide, efficace et facile de ces systèmes tout en étant réactif, robuste et économiquement compétitif. L’objectif est de répondre aux nouvelles contraintes internes et externes telles que la globalisation, la variété des produits, la personnalisation de masse ou le raccourcissement des délais. À travers cette thèse, nous étudions la problématique de conception des systèmes manufacturiers reconfigurables (Reconfigurable Manufacturing System – RMS). L’objectif consiste à concevoir des systèmes réactifs en se basant sur leurs capacités en matière de reconfigurabilité. Nous avons étudié ce problème sur trois niveaux : (i) le niveau des composantes, relatif aux modules des machines reconfigurables, (ii) le niveau des machines et leurs interactions, ainsi que l’impact de ces interactions sur le système et (iii) le niveau de l'atelier, composé de l'ensemble des machines reconfigurables. Nous avons développé pour chaque niveau, des indicateurs de performance afin d’assurer les meilleures performances du système conçu, tels que l’indicateur de modularité, l’indicateur de flexibilité, l’indicateur de robustesse et l’effort d'évolution d'un système reconfigurable. Pour l'ensemble des problèmes étudiés, nous avons développé des modèles d’optimisation multicritère, résolus à travers des heuristiques ou des métaheuristiques multicritères (comme le recuit simulé multicritère (AMOSA) et les algorithmes génétiques multicritère (NSGA-II)). De nombreuses expériences numériques et analyses ont été réalisées afin de démontrer l’applicabilité de nos approches / The modern manufacturing environment is facing a paradigm shift that require more changeability at physical and logical levels. A Changeable Manufacturing System is defined as a production system that has the ability to facilitate the right changes, allowing the adjustment of its structures and processes in response to the different needs. In this context, manufacturing systems must have a very high level of reconfigurability, which is considered to be one of the major enablers of changeability. From the perspective of the “Factory of the future”, the reconfigurability is essential to effectively adapt to the ever-increasing complexity of manufacturing environments. It allows a rapid, efficient and easy adaptation of these systems while being responsive, robust and economically competitive. The objective is to respond to new internal and external constraints in terms of globalization, variety of products, mass customization, and shorter lead times. Through this thesis, we study the problem of design of reconfigurable manufacturing systems (RMS) that meets these requirements. The goal is to design responsive systems based on their key features of reconfigurability. We have studied the RMS design problem on three levels: (i) the level of the components, relating to the modules of the reconfigurable machines, (ii) the machine level and their interactions, as well as the impact of these interactions on the system and (iii) the workshop level composed of all the reconfigurable machines. We have developed for each level, performance indicators to ensure a better responsiveness and a high performance of the designed system, like the modularity index, the flexibility index, the robustness index and the layout evolution effort of a reconfigurable system. For each of the studied problems, we developed multicriteria optimization models, solved through heuristics or multicriteria metaheuristics (such as archived multi-objective simulated annealing (AMOSA) and multi-objective genetic algorithms (NSGA-II)). Numerous numerical experiments and analyzes have been performed to demonstrate the applicability of our approaches
4

DEVELOPMENT OF ASSESSMENT CRITERIA FOR RECONFIGURABILITY IN A MANUFACTURING SYSTEM

Banavara Srikanth, Karthik, Shetty, Savin January 2018 (has links)
To survive in the global market the manufacturing companies need to meet the cus-tomer demands quickly and effectively. Therefore, lot of companies are striving to overcome the demand fluctuation and uncertainty. RMS is a concept which handles uncertainty easily by running the product mix and varying the level of volume accord-ing to the requirement. The reconfigurability level of manufacturing system is as-sessed by evaluating the criteria affecting the characteristics of the system.The characteristics of reconfigurability are scalability, customization, convertibility, modularity, integrability and diagnosability. A RMS achieves quick and cost effective changes through customization and convertibility, it handles volume variations through scalability. These characteristics are achieved with the help of modularity and integrability. A detailed assessment of a manufacturing system based on these charac-teristics will indicate its level of reconfigurability. Hence assessment of a manufactur-ing system for reconfigurability becomes necessary in the current turbulent market conditions.This research presents a method to assess the reconfigurability in a manufacturing system. The research is divided into two parts where, in the first part a qualitative as-sessment method is developed, and it is then tested in the second part. The study uses two research methods namely literature review and case study. Based on literature re-view assessment criteria for each characteristic of reconfigurability are listed and an assessment method is developed. The assessment method uses a radar chart to repre-sent the level of reconfigurability. This is supported with a case study where the de-veloped assessment method is tested and validated.
5

Conceptual decision support tool for RMS-investments : A three-pronged approach to investments with focus on performance metrics for reconfigurability

Eriksson, Gustav, Isendahl, Johan January 2020 (has links)
Today's society is characterized by a high degree of change where the manufacturing systems are affected by both internal and external factors. To adapt to current manufacturing requirements in the form of short lead-time, more variants, low and fluctuating volumes, in a cost-efficient manner, new approaches are needed. As the global market and its uncertainties for products and its lifecycles change, a concept called 'reconfigurable manufacturing system' has been developed. The idea is to design a manufacturing system for rapid structural change in both hardware and software to be responsive to capacity and functionality. A company's development towards the concept is often based on a strategy of incremental investments. In this situation, the challenges are to prioritize the right project and maximize the performance as well as the financial efficiency of a multi-approach problem. The report is based on three different issues. Partly how to standardize relevant performance-based metrics to measure current conditions, how new performance-based metrics can be developed in collaboration with reconfigurability characteristics, and set a direction for how decision models can be used to optimize step-based investments. The study is structured as an explorative study with qualitative methods such as semi-structured interviews and document study to get in-depth knowledge. Related literature addresses concepts in search areas such as reconfigurable manufacturing system, key performance indicators, investment decisions, and manufacturing readiness levels. The findings are extracted from interviews and document studies that generate a focal company setting within the automotive industry, which acts as the foundation for further analysis and decisions throughout the thesis. The analysis results in sixteen performance measurements where new measures been created for product flexibility, productionvolume flexibility, material handling flexibility, reconfiguration quality and diagnosability using reconfigurability characteristics. A conceptual decision support model is introduced with an underlying seven-step investment process, analyzing lifecycle cost, risk triggered events in relation to cost, and performance measurements. The discussion chapter describes how different approaches are used during the project that has been revised by internal and external factors. Improvement possibilities regarding method choice and the aspects of credibility, transferability, dependability, and conformability are discussed. Furthermore, the authors argue about the analysis process and how the result has been affected by circumstances and choices. The study concludes that a three-pronged approach is needed to validate the investment decision in terms of system performance changes, cost, and uncertainty. The report also helps to understand which performance-based metrics are relevant for evaluating manufacturing systems based on operational goals and manufacturing requirements.
6

Simulation-based multiobjective optimization and availability analysis of reconfigurable manufacturing systems

Del Riego Navarro, Andrés, Rico Pérez, Álvaro January 2021 (has links)
Due to the changes and improvements that have occurred over the years, the manufacturing sector has evolved. Companies in the 21st-century face changes in the marketplace that are difficult to predict due to international competition and the rapid emergence of new products. To cope, companies must reinvent themselves and design manufacturing systems that seek to produce quality and low-cost products, and respond to the changes that must be faced. These capabilities are encompassed in reconfigurable manufacturing systems (RMS), capable of dealing with uncertainties quickly and economically. On the other hand, production planning with this type of system presents a significant challenge. Although simulation-based optimization techniques have been applied to address certain RMS challenges, only a few studies have applied simulation-based multi-objective optimization to simultaneously address several conflicting design objectives, as is the case in this project. This project aims to investigate some aspects using SBMO that directly affect the performance of a plant and demonstrate the usefulness of the method. / <p>Det finns övrigt digitalt material (t.ex. film-, bild- eller ljudfiler) eller modeller/artefakter tillhörande examensarbetet som ska skickas till arkivet.</p>
7

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.
8

Formalisation de la démarche de conception d'un système de production mobile : intégration des concepts de mobilité et de reconfigurabilité / Formalisation of a mobile manufacturing system design approach : integration of mobility and reconfigurability concepts

Benama, Youssef 12 February 2016 (has links)
Dans cette thèse nous analysons dans quelle mesure le concept de mobilité peut être pris en compte dans la démarche d'analyse et de conception de systèmes de production. Notre apport vise à formaliser la démarche d'analyse et de conception de ce dernier, explicitant les décisions à prendre, les informations nécessaires et les critères de décision à mettre en place. Dans cet objectif, deux niveaux d'analyse ont été distingués : un niveau local concernant un site de production et un niveau global comprenant un ensemble de sites.Le premier niveau local considère un seul site de production. A ce niveau nous avons proposé une approche prenant en compte les caractéristiques du site de production. Dans notre contexte, le choix de la localisation géographique de production est imposé par le client. De ce fait, la conception du système de production doit s'adapter à cette contrainte. D'un point de vue conception, quatre questions sont abordées : (1) dans quelle mesure le concept de mobilité peut être intégré dans une démarche de conception de système de production mobile ? (2) quelles caractéristiques de l'environnement de production doivent être prises en compte ? (3) comment déterminer ce qu'il faut produire sur site ou ce qu'il serait opportun d'externaliser ? et (4) compte tenu des informations obtenues quelle est la meilleure configuration du SPM à envisager et selon quels critères de choix ? La réponse à ces questions conduit à la proposition d'une configuration du SPM adaptée pour un seul site de production.Le deuxième niveau global traite la problématique de mobilité successive multi sites. En effet, pour être rentabilisé le système de production doit être mobilisé sur plusieurs sites de production. A chaque changement de site de production, une reconfiguration du système de production s'impose en se basant sur la configuration existante (version i-1). LaThèse de Youssef BENAMAreconfigurabilité concerne d'une part l'architecture interne du système (choix des machines, recrutement de nouvelles équipes locales, etc) et d'autre part l'organisation de la chaîne d'approvisionnement du SPM (faire en interne ou externaliser, fournisseur local, etc.). A ce niveau global d'analyse, nous proposons deux modèles d'analyse : (1) un premier modèle pour l'analyse de la reconfigurabilité interne. Ce modèle d'analyse permet d'adapter le nombre de lignes de production et le nombre d'équipes en fonction d'un scénario de demande (localisations géographiques, capacité nécessaire par site). L'originalité de notre proposition consiste d'une part en l'évaluation des coûts de reconfiguration nécessaires et d'autre part l'appréciation du niveau d'adéquation de la configuration proposée avec le contexte du site de production via l'utilisation de l'indicateur de mobilité. (2) Le deuxième modèle d'analyse concerne la reconfigurabilité de la chaîne d'approvisionnement amont du SPM. Il consiste en une adaptation du modèle d'aide à la décision "faire ou faire faire" par l'intégration d'un côté de l'importance du site de production et d'un autre côté des spécificités de chaque site de production.La démarche d'analyse proposée est illustrée sur le cas industriel concernant la conception d'une usine mobile pour la fabrication et l'installation sur site de composants de centrales solaires thermodynamiques. / In this thesis we analyse how the concept of mobility can be taken into account in the analysis and design of production systems. Our contribution aims to formalize the analysis and design process, explaining the decisions, the necessary information and decision criteria to be taken into account. For this purpose, two levels of analysis were distinguished: a local level concerning one production site and a global level including a set of sites.The first level considers one production site. At this level we have proposed an approach that takes into account the characteristics of the production site. In our context, the choice of the geographical location of production is imposed by the final client. Therefore, the design of the production system should be adapted to this constraint. From a design perspective, four questions are addressed: (1) To what extent the concept of mobility can be integrated into a mobile production system design approach? (2) What characteristics of the production environment must be taken into account? (3) How to determine what to produce on site or that it would be appropriate to outsource? And (4) taking into account all obtained information what is the best configuration of the mobile production system to consider and according towhich criteria? The answer to these questions led to the proposal of a configuration of SPM suitable for a single production site.The second Level of analysis addresses the problem of global mobility. In order to be profitable, the production system must be used on several production locations. every change of production location led to a need of reconfiguration of the Production System. Reconfigurability Concerns the internal architecture of the system (machine selection, recruitment News local teams, etc.) as well as the organization of the SPM supply chain. Fot this global level, we propose two analytical models: (1) the first model for the analysis of internal reconfigurability. This analysis model is used to adapt the number of production lines and the number of teams according to a production scenario (Geographical locations, necessary capacity per site). The originality of our proposal consists on the assessment of costs to support reconfiguration and the appreciation the convenience level with the context of the production site by using the mobility indicator. (2) Second model to analyse Concerns reconfigurability of the upstream supply chain of PMS. It Consists in June adaptation of the model using the decision "to do ou do" by integrating A side of the importance of the production site and another side Specifics Each of the production site.The proposed approach is illustrated on an industrial case concerning the design of a mobile manufacturing plant used to produce in-site and Install components of solar plant

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