Syftet med studien är att öka vår förståelse för hur slöserier påverkar ett internt material och produktionsflöde i en producerande verksamhet, för att kunna ge förslag på effektiviseringar av denna process. Studien är utförd på företaget Växjöfabriken Produktions AB som är beläget i Växjö och utför skärande bearbetning på gjutgods. Efter att ha studerat befintliga teorier skapade vi vår teoretiska utgångspunkt med det urval av teorier som vi ansåg vara viktiga för studien. Från dessa genererade vi en analysmodell som sedan låg till grund för det fortsatta arbetet. Analysmodellen gav ett strukturerat arbetssätt för att samla in empirisk fakta från företaget som vi sedan använde för att göra en analyserande jämförelse med vår teoretiska utgångspunkt. Första steget i processen var att utföra en processkartläggning på företaget där vi dokumenterade all data tillhörande produktionsprocessen. Processkartläggningen visualiserades sedan med avseende på de flödesvägar som materialet färdas på vid respektive maskin som var inkluderad i vår undersökning. Kartläggningen innefattar även lagerhantering och en granskning av den nuvarande layouten. Med processkartläggningen som grund utförde vi sedan en nulägesanalys där vi analyserade det interna material- och produktionsflödet. Genom analysen kunde slöserier som är relaterade till Växjöfabrikens materialhantering identifieras. De identifierade slöserierna går, till stor del, att relatera till en bristande strategi för hur layouten är planerad och ett system där man placerar nya fysiska tillgångar där det finns ledigt utrymme. Med dessa slutsatser som utgångspunkt började vi ett arbete med att generera nya layoutalternativ med syftet att reducera de slöserier som idag har en inverkan på processen. Den första layouten är genererad utan hänsyn till de restriktioner som finns på fabriken i form av svårflyttade arbetsceller. Denna layout är framtagen för att påvisa hur ett optimalt materialflöde med maximalt reducerade slöserier skulle kunna se ut om det hade funnits en långsiktig strategi från start. Vid genereringen av nästa layout, där vi har tagit hänsyn till de restriktioner som finns, strävade vi efter att utforma ett flöde som påminner om den tidigare nämnda layouten utan restriktioner så mycket som möjligt. I de avslutande kapitlen diskuterar vi resultatet av layoutförslagen för att komma fram till våra slutsatser och rekommendationer på förbättringar som vi anser är praktiskt genomförbara och gynnsamma för Växjöfabriken Produktions AB. / The purpose of this bachelor thesis is to increase our understanding of the different types of waste that affects the internal material- and production flow in a manufacturing company. The study was conducted in order to provide recommendations to improve the efficiency of the process. The study was performed at the company Växjöfabriken Produktions AB, which is located in Växjö and performs cutting processing on casted details. After studying existing theories we created our theoretical base with a selection of theories that we considered important for the study. From these, we generated an analytical model that formed the basis for the continued work in this study. The analytical model provided a structured approach for collecting empirical data from the company, which we then used to make an analytical comparison with our theoretical base. The first step in the process was to conduct a process mapping at the company where we documented all of the data associated with the process. The mapping was then visualized with respect to the flowpaths that the material travels on each machine that were included in our study. The survey also includes the inventory handling and an inspection of the current factory layout.With the process mapping as a basis, we performed an analysis of the current situation in which we analyzed the material and inventory handling, as well as the production layout. With the analysis, we could then identify the different types of waste that belong to the handling of materials that Växjöfabriken currently undertake. The wastes that were found was, in large part, related to a lack of strategy for how the layout is planned. It was also related to a system that places new equipment where there is free space instead of basing its position on a long-term plan for further expansion. With these findings as a starting point, we began to develop new layout options with the aim of reducing the wastes that we found have impact on the process. The first layout is generated without regard to the restrictions that exist at the factory in the form of robotic workstations that are difficult to move. This layout is designed to demonstrate how an optimal material flow with wastes, reduced to a maximum, would look like if there had been a long-term strategy from the start. The development of the next layout, where we had taken the restrictions into account, we sought a design that would get us as close to the previously mentioned one as possible. In the last chapters we discuss the results of newly developed layouts in order to reach conclusions and recommendations for improvements that we believe is feasible and beneficial for Växjöfabriken Produktions AB.

Examensarbete utfördes på CA-Verken i Sävsjö som bl.a. tillverkar hydraulcylindrar. De senaste två år har CA-Verken haft en kraftig ökning av omsättningen och det som står i vägen för fortsatt expansion är produktionen som har begränsad kapacitet. Målet med detta arbete är att studera CA-Verkens produktionsflöde för att kunna identifiera flaskhalsen/flaskhalsarna och därefter ge förslag på lösningar och förbättringar. Den teorin som har använts som grund till arbetet är Theory of Constraints (TOC). Intervjuer, företagets affärssystem och observationer har använts vid datainsamling. Genom analysering av produktionsflödet för cylindrar som står för den största delen av omsättningen identifierades monteringen som flaskhals. För att kunna optimera produktionsflödet krävs det att monteringen utnyttjas effektivt samt att olika störningar och slöserier i monteringsprocessen elimineras. / This diplomawork is a study of the making of hydraulic cylinders at CA-Verken, a Swedish company located in Sävsjö. The last two years has showed a substantial increase of the company’s turnover. The only remaining obstacle of an ongoing expansion is the limited capacity of the company’s production. The purpose of this diplomawork is, for that particular reason, to study CA-Verkens production flow in order to identify the bottleneck-issues and ultimately be able to suggest possible solutions and improvements concerning the production process. The theoretic foundation of this study is based on the Theory of Constraints (TOC). Interviews, company business systems and observations have been used as important sources during the collection of data. By analysing the production flow concerning the cylinders, which represents the greatest deal of the company’s turnover, the assembly was identified as a bottleneck-issue. In order to optimize the torrent of production it’s necessary for the company to increase the efficiency of the assembly and eliminate different disturbances as well as all unnecessary wastefulness in the process.

Materialfluss-Systeme für den Stückgut-Transport auf der Basis von Stetigförderern sind meist modular aufgebaut. Das Verhalten gleichartiger Materialfluss-Elemente unterscheidet sich durch technische Parameter (z.B. geometrische Größen) und durch unterschiedliche logistische Belastungen der Elemente im System. Durch die in der Arbeit getroffenen Modellannahmen werden für die Elemente nur lokale Steuerungsregeln zugelassen und für das System Blockierfreiheit vorausgesetzt. Das Verhalten eines Materialfluss-Elements hängt dann nicht mehr von Zuständen anderer Elemente des Systems ab sondern nur noch von den stochastischen Prozessen des Eintreffens von Transporteinheiten. Die Auslastung eines Elements, die Quantile der Warteschlangenlängen an seinen Eingängen und die Variationskoeffizienten seiner Abgangsströme sind statistische Kenngrößen. Sie hängen im Wesentlichen nur von der Klasse des Elements, seinen technischen Parametern, den Parametern der Eingangsströme und der lokalen Transportmatrix ab. Diese funktionellen Abhängigkeiten sind im Allgemeinen nicht analytisch handhabbar. Da diese Funktionen stetig differenzierbar und beschränkt sind und von relativ viele Eingansgrößen anhängen, sind neuronale Netze gut geeignet für numerische Näherungen. Mit Hilfe von einfachen neuronalen Netzen können die statistischen Kenngrößen numerisch approximiert werden. Aus einzelnen Teilmodellen kann ein hybrides Modell des gesamten Systems zusammengesetzt werden. Anhand von einigen Beispielen wird die Güte der Modellierung bewertet. / Material flow systems are normally built with a modular structure. The behavoir of similar elements only differs by technical parameters (e.g. geometriy), and by different logistic loads of the elements in the system. In this paper, a new model is being developed for a non-blocking system with non-global control rules. The behavior of a flow of a material flow element is assumed not to depend on the conditions of other elements of the system, but only on stochastic processes of the arrival of transportation units. The rate of utilization of an element, the quantiles of the queue lengths at its inputs, and the dispersion of its output stream are statistic characteristics. They depend only on the type of the element, its technical parameters, the parameters of the input streams, and the local transportation matrix. These functional dependencies are not analytically manageable. But due to their properties, neural nets are well suited for numeric approximations of these statistic functions. The single models can be used to compose a hybrid model of the whole system. A few examples show the quality of the new modeling technique.

<p>Examensarbete utfördes på CA-Verken i Sävsjö som bl.a. tillverkar hydraulcylindrar. De senaste två år har CA-Verken haft en kraftig ökning av omsättningen och det som står i vägen för fortsatt expansion är produktionen som har begränsad kapacitet.</p><p>Målet med detta arbete är att studera CA-Verkens produktionsflöde för att kunna identifiera flaskhalsen/flaskhalsarna och därefter ge förslag på lösningar och förbättringar. Den teorin som har använts som grund till arbetet är Theory of Constraints (TOC). Intervjuer, företagets affärssystem och observationer har använts vid datainsamling. Genom analysering av produktionsflödet för cylindrar som står för den största delen av omsättningen identifierades monteringen som flaskhals.</p><p>För att kunna optimera produktionsflödet krävs det att monteringen utnyttjas effektivt samt att olika störningar och slöserier i monteringsprocessen elimineras.</p> / <p>This diplomawork is a study of the making of hydraulic cylinders at CA-Verken, a Swedish company located in Sävsjö. The last two years has showed a substantial increase of the company’s turnover. The only remaining obstacle of an ongoing expansion is the limited capacity of the company’s production.</p><p>The purpose of this diplomawork is, for that particular reason, to study CA-Verkens production flow in order to identify the bottleneck-issues and ultimately be able to suggest possible solutions and improvements concerning the production process.</p><p>The theoretic foundation of this study is based on the Theory of Constraints (TOC). Interviews, company business systems and observations have been used as important sources during the collection of data. By analysing the production flow concerning the cylinders, which represents the greatest deal of the company’s turnover, the assembly was identified as a bottleneck-issue.</p><p>In order to optimize the torrent of production it’s necessary for the company to increase the efficiency of the assembly and eliminate different disturbances as well as all unnecessary wastefulness in the process.</p>

The results from this study show that it is possible to obtain data series on the steel scrap collection based on mass balance model on the crude steel production figures by steelmaking reactor type and additional knowledge on process metallurgy as well as information on inputs and outputs into the reactors with an area correlation coefficient of 0,91 compared to data obtained from trade statistics. Furthermore, the study shows that based on a new method it is possible to calculate the time duration of mass flows on a continuous basis. Furthermore, two complementary statistical dynamic material flow models that can be used to calculate the societal recycling rates of steel was constructed. These statistical models contribute to a standardized way of obtaining consistent results. The new models are able to segregate the non-recirculated amounts of steel into the hibernating steel stock available for future collection from the amounts of losses based on statistics. The results show that it is possible to calculate the amounts of steel scrap available for steelmaking at a given point in time. In addition, based on the new models it is possible to calculate recycling trends in society. Also, the models are able to calculate robust forecasts on the long-term availability of steel scrap, and test if forecast demand of steel scrap exceeds a full recovery. This due to that the steel scrap generation is a function of the collection rate of steel scrap. Also, a method for obtaining representative samplings on the alloy content in steel scrap called random sampling analysis (RSA) was developed. The results from the RSA show that it is possible to optimize the recovery of valuable elements in the production process of steelmaking based on the information on the composition of steel scrap. / <p>QC 20151020</p>

Human food consumption has changed from the late 19th century to the turn of the millennium, and so has the need for resources to sustain this consumption. For the city of Linköping, situated in southeastern Sweden, the environmental imprint of an average inhabitant’s food consumption is studied from the year 1870 to the year 2000. The average consumer is the driving factor in this study, since changes in food consumption have a direct influence on the environmental imprint. This thesis analyses the environmental imprint of human food consumption from a historical perspective, by applying two different methods. An analysis of the average Swedish food consumption creates the basis for a material flow analysis of nitrogen and phosphorus, as well as a study of the spatial imprint. Emissions of nitrogen and phosphorus into the hydrosphere have decreased over this period for the system of food consumption and production for an average consumer, while the input via chemical fertilizer has increased significantly. The efficiency of this system could be increased if for instance more phosphorus in human excreta would be reused within the system instead of large deposition and losses into the hydrosphere. The spatial imprint of human food consumption shows, given the changing local preconditions, that less space would be needed for regional production of the consumed food. However, the share of today’s import and thus globally produced food doubles this spatial imprint. The results of this study show not only a strong influence of the consumption of meat and other animal products on the environmental imprint, but also great potential in the regional production of food. In the context of an increasing urban population, and thus additional billions of people who will live at an increasing distance from the agricultural production land, concern for the direct effects of our human food consumption can be of decisive importance for future sustainable food supply.

Les conséquences de nos modes de production et de consommation sur l’environnement mondial sont reconnues et analysées depuis plusieurs décennies : changement climatique, effondrement de la biodiversité, tensions sur de nombreuses ressources stratégiques etc.Notre travail s’inscrit dans un courant de pensée visant à développer d’autres indicateurs de richesse. Dans une perspective de durabilité forte, nous nous concentrons sur une comptabilité biophysique (non monétaire), apte à pointer les externalités environnementales. Si une part importante des recherches dans ce domaine a été dédiée aux échelons nationaux, nous nous intéressons ici aux échelles locales, et en particulier aux régions françaises. Après avoir étudié les caractéristiques d’outils existants mobilisés dans les domaines de l’économie écologique et de l’écologie industrielle, comme l’Empreinte Ecologique, l’Analyse de Flux de Matières (AFM), l’Analyse de Cycle de Vie ou l’Analyse Entrée-Sortie, nous nous focalisons sur les filières de production que nous analysons à partir des quantités de matières qu’elles mobilisent au cours des étapes de production, transformation, transport et consommation. La méthode développée, AFM Filière, permet de produire des schémas de flux cohérents au niveau national, dans chaque région, et quand les données le permettent, à des niveaux infra-régionaux. Ceux-ci sont basés sur un processus systématique de réconciliation des données disponibles. Nous évaluons la précision de ces données d’entrée, ce qui permet de fournir des intervalles de confiance sur les résultats, pouvant à leur tour pointer vers des manques de connaissance. En particulier, nous fournissons une évaluation détaillée de la précision de l’enquête permanente sur le transport routier de marchandises (TRM), une pièce maîtresse de l’AFM Filière. Nous montrons au passage que réaliser le bilan matières sur une période de plusieurs années permet non seulement de s’affranchir du problème des stocks, mais aussi de réduire significativement l’incertitude sur les échanges entre régions. Nous adaptons par la suite la méthode des chaînes de Markov absorbantes pour tracer les flux jusqu’à leur destination finale et allouer les pressions sur l’environnement produites tout au long de la filière. Les flux de matières peuvent également être couplés à des modèles économiques afin de prévoir leur évolution en réponse à certaines politiques. En collaboration avec le Laboratoire d’Economie Forestière (LEF), nous fournissons ainsi la première tentative de représentation des flux sur la filière forêt-bois française, et analysons l’impact de différentes politiques de réduction des exports de bois brut sur l’économie et sur les flux physiques. Enfin, nous montrons comment il serait possible d’articuler ces analyses de filières avec les méthodes d’analyse qualitative déployées dans le domaine de l’écologie territoriale, et en particulier, l’analyse des jeux d’acteurs dans la filière. Nous situons notre travail dans le cadre normatif de la démocratie délibérative. A ce titre, nous réfléchissons aux apports de la comptabilité biophysique aux processus de décisions publiques incluant diverses parties prenantes. Nous dressons un panorama des modes de décision, des étapes clé d’un processus d’aide à la décision, des méthodes multicritères mais également des différentes formes que peut prendre la participation des citoyens. Nous proposons finalement une méthode d’aide à la délibération fondée sur l’élicitation de la satisfaction et du regret éprouvé par chaque partie prenante face à un futur donné. Celle-ci vise à organiser la discussion sur le mode du consensus apparent, qui facilite par nature le respect des minorités. Enfin, en partant des principales critiques adressées à la quantification, nous proposons en conclusion une réflexion sur les conditions qui permettraient de mettre la comptabilité écologique au service de l’émancipation démocratique. / The consequences of our modes of production and consumptions on the global environment have been recognized and analyzed for many decades: climate change, biodiversity collapse, tensions on numerous strategic resources etc. Our work follows a line of thought aiming at developing other indicators of wealth, alternative to the Growth Domestic Product. In particular, in a perspective of strong sustainability, we focus on biophysical (non-monetary) accounting, with the objective of pinpointing environmental externalities. A large part of existing research in this domain being targeted towards national levels, we rather focus on subnational scales, with on strong emphasis on French regions. With decentralization policies, these territories are indeed given increasing jurisdiction and also benefit from greater margins of action than national or international levels to implement a transition to sustainability. After studying the characteristic of existing tools used in the fields of ecological economics and industrial ecology, such as the Ecological Footprint, Material Flow Analysis (MFA), Life Cycle Assessment or Input-Output Analysis, we focus on supply chains that we analyze through the quantities of materials they mobilize during the production, transformation, transport and consumption steps. The method developed, the Supply-Chain MFA, provides coherent flow diagrams at the national scale, but also in every region and, when data allow it, at infra-regional levels. These diagrams are based on a systematic reconciliation process of available data. We assess the precision of input data, which allows to provide confidence interval on results, and in turn, to put the light on lacks of knowledge. In particular, we provide a detailed uncertainty assessment of the French domestic road freight survey (TRM), a crucial piece of the Supply-Chain MFA. By doing so, we show that undertaking the study on a period of several years not only solves the issue of stocks but also significantly reduces uncertainties on trade flows between regions. We then adapt the Absorbing Markov Chains framework to trace flows to their final destination and to allocate environmental pressures occurring all along the supply chain. For instance, in the case of cereals, we study energy consumption, greenhouse gas emissions, the blue water footprint, land use and the use of pesticides. Material flows can also be coupled with economic modeling in order to forecast how they will likely respond to certain policies. In collaboration with the laboratory of forest economics (LEF), we thusly provide the first attempt of representing the whole French forest-wood supply-chain, and we analyze the impact of a set of policies on both the economy and physical flows. Finally, we show the opportunities of linking these supply-chain results with qualitative methods unfold in the domain of territorial ecology, stakeholder analysis in particular. We situate our work in the normative framework of deliberative democracy and are therefore interested in the contributions of biophysical accounting to public decision processes that include diverse stakeholders. We propose an overview of decision modes, key steps of decision-aiding, multicriteria methods, but also of the various forms taken by citizen participation. We eventually design a deliberation-aiding method, based on elicitation of each stakeholder’s satisfaction and regret regarding a given future. It aims at organizing the discussion on an apparent consensus mode, which by nature facilitates the respect of minorities. Finally, based on the main criticisms addressed to quantification, we propose in conclusion thoughts on the conditions that could put biophysical accounting at the service of democratic emancipation.

The movement and handling of material are necessary activities, however, commonly regarded as waste. Moving and handling material more times and over longer distance than necessary is time consuming, costly and unproductive. Therefore, a suitable material handling (MH) system with appropriate facility layout is advocated. The purpose of this thesis is to explore options for material flow improvements and handling of material in production area. This comprises of a study of the material flow from storage to production areas and the handling of material in production section A. If necessary for improvements of material flow, a change in layout design will be recommended. The research approach for this thesis is a case study where data has been collected from documents, observations and interviews. The study shows that 9 % of the production time of one article is spent on manual material handling (MMH). These activities are classified as both waste and necessary, however not adding any value. The same applies for the material flow. Unnecessary distances of movements are caused by the current location of storage, operations and lack of proper structure for handling and moving material. The contribution of this study is a list of suggestions for improving the material flow and handling. Changes for improvements are, namely, availability of appropriate equipment, storing materials closer to the operations and investing in automation and vision systems with cameras of robots. The material flow and the way the material is handled can further beimproved by a change in the layout of the production area. Connecting and rearranging operations can shorter and ease the movement of material with ample space to handle the material.

Till följd av ökande krav från kunder blir dagens konkurrenssituation på marknaden allt hårdare för företag. Dessa krav bidrar till att företagen måste satsa på ökad effektivitet och långsiktig lönsamhet. Lean är ett känt begrepp inom industrin som vid implementering syftar till att reducerar eller eliminera slöseri i informations- och materialflöden vilket leder till effektivisering. Denna studie bygger på ett problem som existerar i ett flertal informations- och materialflöden i en processindustri. Fallföretaget i denna studie är Iggesund Paperboard som önskar klarhet angående flödena samt minskade ledtider och lagernivåer. Syftet med studien är att undersöka hur internt materialflöde samt beställning och prognostisering av material kan effektiviseras för att reducera ledtid och lagernivåer. Studien utfördes genom en fallstudie där datainsamling på fallföretaget samlades in genom intervjuer, observationer och dokumentstudier. Parallellt samlades information också in genom litteratur. Datainsamlingen utgjorde sedan underlag till analys och slutsatser för denna studie. Resultatet i form av kartläggningen av informations- och materialflöden visar på ett komplext flöde med många aktiviteter som bidrar till slöseri. Orsakerna till slöseri i flödena är varierande och bidrar till ökade ledtider och lagernivåer. Vid kartläggningen utformades två bilder med två värdeflöden i varje bild som tillsammans med förbättringsförslag kan skapa kontroll och minska ledtider och lagernivåer. Det vetenskapliga bidrag som denna studie frambringar är att utöka kunskapen inom dokumentering och analysering, samt tillämpning av lösningar baserade på filosofin inom Lean, för administrativa arbetsuppgifter. Bidraget är således att kombinera och utföra samma tillämpning på ett informations- och materialflöde i helhet och inte var för sig. Förslag till vidare forskning är att utföra undersökningen som gjort i studien under en längre tidsperiod samt i fler miljöer för att ge prov på ökad trovärdighet. / Companies meet tougher competition at the marketplace as a consequence of increasing customer demand. As a result they have to focus on increasing their efficiency and look for long-term profitability. Lean is a known concept within the world of industries that aims to reduces or eliminates waste in information- and material flows which will lead to effectiveness. The findings of his study are based on a problem within a process industry. The problem comprises information- and material flows where the company Iggesund Paper requests clarity in the flows, and reduced lead time and stock levels. The purpose with this study is to investigate how internal material flow, forecasting orders and ordering materials can be developed to be more efficient and reduce lead-time and stock levels. This study is carried out as a case-study where the data was collected through interviews, observations, document studies and literature review. The data collection gave a solid ground for further analysis and conclusions. The value stream mapping and the description of the information- and material flows indicates and identifies complexity and activities contributing to waste. This situation leads to increasing lead-times and stock levels. The cause of the situation is varied but with the maps of the flows and the improvement proposals improvements can be made and effectiveness can be achieved. The theoretical contribution of this study is to extend research and considering applying tools within the Lean philosophy on administrative work, and together with the same application on work with material flow this study combine the proposals of improvements for the entire process. Suggestions for further research are to extend the time of the field study and likewise apply the methods of the study in additional situations to extend the validity and reliability.

L'amélioration de la gestion des ressources naturelles est nécessaire pour répondre aux nombreux enjeux liés à leur exploitation. Ce travail propose une méthodologie d'optimisation de leur gestion, appliquée au cas du cuivre en France. Quatre critères permettant de juger les stratégies de gestion ont été retenus : le coût, les impacts environnementaux, la consommation énergétique et les pertes de ressources. La première étape de cette méthodologie est l'analyse de la situation actuelle, grâce à une modélisation du cycle français du cuivre de 2000 à 2009. Cet examen a montré que la France importe la quasi-totalité de ses besoins sous forme de cuivre raffiné, et a une industrie de recyclage peu développée. Suite à ces premiers résultats, la problématique du traitement des déchets de cuivre, et notamment de leur recyclage, a été étudiée. Une stratégie de modélisation des flux recyclés, basée sur la construction de flowsheets, a été développée. La formulation mathématique générale du problème a ensuite été définie : il s'agit d'un problème mixte, non-linéaire et a priori multiobjectif, qui a une contrainte égalité forte (la conservation de la masse). Une étude des méthodes d'optimisation a conduit à choisir un algorithme génétique (AG). Une alternative a également été envisagée pour résoudre le problème multiobjectif par programmation linéaire en le linéarisant "sous contrainte". Ce travail a mis en évidence la nécessité de développer une filière de recyclage efficace des déchets électriques et électroniques en France. Il a de plus montré que le cuivre contenu dans les déchets ne permet pas de couvrir la demande et qu'il est nécessaire d'importer du cuivre, de préférence sous forme de débris. / Improving the natural resources management is necessary to address the many issues related to their exploitation. This work proposes an optimization methodology for their management, applied to the case of copper in France. Four criteria are identified to assess management strategies: cost, environmental impacts, energy consumption and resource losses. The first step of this methodology is the analysis of the current situation, by modelling the French copper cycle from 2000 to 2009. This analysis showed that France imports almost all of its needs as refined copper, and has an underdeveloped recycling industry. Following these initial results, the problematic of copper wastes, including recycling, has been investigated. A recycled flow modelling strategy has been developed, based on the construction of flowsheets. The general mathematical formulation of the problem is then defined. It is a non-linear, mixed and a priori multiobjective problem, with a strong equality constraint (mass conservation). A review of optimization methods has led to choose a genetic algorithm (GA). An alternative was also proposed to solve the multiobjective problem with linear programming, by linearizing it under constraint. This work has highlighted the necessity of developing an effective recycling field of wastes from electric and electronic equipment in France. It also showed that the copper contained in wastes does not meet the demand, so that France needs to import copper, preferably as scraps.