Design for Disassembly and Sustainability Assessment to Support Aircraft End-of-Life Treatment

RÉSUMÉ L’industrie aéronautique se développe vers une économie circulaire avec la réutilisation de ses matériaux et composants. Pourtant, chaque année, des centaines d’avions finissent à l’enfouissement sans un traitement approprié. Pour faire face à ce problème, cette recherche s’est principalement concentrée sur deux approches à savoir l’amélioration de la conception des avions en fin de vie au niveau de la phase de développement et l’amélioration des méthodes de traitement pour les avions retirés du marché lesquelles ont été conçus il y a des décennies. L’amélioration des produits durant sa phase de développement apparait comme une solution prometteuse pour maximiser le taux de revalorisation du produit. En attendant, le désassemblage apparait comme une activité évidente autant à la fin de vie du produit que durant sa période de fonctionnement (par exemple la maintenance des avions). Dans cette thèse, une nouvelle approche est introduite en vue d’être implémentée durant la phase de conception d’un avion, afin d’améliorer le désassemblage futur des avions en fin de vie. Pour ce faire, les travaux de désassemblage seront abordés comme un problème de prise de décision multicritères. Cinq paramètres sont considérés sur la base des expériences accumulées durant les travaux de désassemblage d’un avion régional Bombardier : « l’accessibilité », « les surfaces de contact », « les outils requis », « les types de connections » et « la quantité et les variantes des différentes connections ». Une méthode d’évaluation par pointage utilisant les méthodes de « conception pour l’expérimentation » (en anglais « Design of Experiment », ou l’acronyme « DOE ») et TOPSIS est développée. Les résultats d’ANOVA ont montré un taux de fiabilité de 94.3 % confirmant la pertinence du modèle. Le modèle proposé peut être facilement utilisé par les décideurs et les concepteurs en vue de la réingénierie, pour améliorer le désassemblage et, plus généralement, la valorisation des futurs avions en fin de vie. En vue d’améliorer les méthodes de traitement pour la fin de vie des avions, nous avons implémenté huit différentes stratégies de désassemblage/démantèlement sur la carcasse de l’avion mentionné ci-dessus. La durabilité et le développement durable deviennent de plus en plus le centre d’attention des industries. Agissant comme un fournisseur pour des industries plus influentes, les entreprises de démantèlement/recyclage devraient se concentrer sur des stratégies leur permettant une amélioration de leurs positions sur le marché. Un des facteurs clé serait de pratiquer la durabilité et le développement durable dans tous les procédés de démantèlement et de recyclage.----------ABSTRACT Despite aerospace industries are moving toward circular economy and reutilization of materials and components, every year hundreds of aircrafts end up in landfills without an appropriate treatment. To address this problem, this thesis has been focused on two main approaches: amelioration of aircraft design for end-of-life at the development phase and improvement of end-of-life treatment methods for aircrafts that have been designed decades ago and are currently retired. Amelioration of product design at the development phase stands as a very promising approach to increase the product recoverability rate. Meanwhile, disassembly appears as an inevitable activity for products not only at the end-of-life but also during the products life time and maintenance. In this thesis, a new approach is introduced to be implemented at the design phase for improving aircraft disassemblability at the end-of-life. For that, disassembly job was tackled as a multi-criteria decision-making problem. Five parameters were considered based on the experience accumulated during the disassembly work on a Bombardier Regional Jet aircraft: “Accessibility”, “Mating face”, “Tools required”, “Connection type”, and “Quantity and variety of connections”. A novel disassembly scoring model using a hybrid design of experiment (DOE) and TOPSIS method was developed. The results from ANOVA showed a 94.30% of reliability, and testified the adequacy of the model. The proposed model can be easily used by decision-makers, and designers for reengineering purposes to improve the disassembly and in a broader scope recoverability of the future aircrafts at the end-of-life. Towards the improvement of end-of-life treatment methods, in this work we have implemented eight different disassembly/dismantling strategies on the carcass of the above mentioned aircraft. Sustainability and sustainable development are more and more becoming the center of attention for different industries. Acting as a supplier for bigger industries, aircraft dismantler/recycler businesses should focus on strategies that allow to ameliorate their current position in the market. One of the key factors is to practice sustainability and sustainable development in all the dismantling and recycling processes. In this direction, the eight strategies employed were evaluated and compared in terms of sustainability. 19 indicators were defined to assess the environmental, social, and economic impacts of each strategy. The input data were provided from the experts who were engaged into the strategies implementation

Evaluation of Cost-Effectiveness Criteria in Supply Chain Management: Case Study

The aim of this paper is to evaluate and prioritize the proposed cost-effectiveness criteria in supply chain management using fuzzy multiple attribute decision-making (MADM) approach. Over the past few years, the determination of suitable cost-effectiveness criteria in the supply chain has become a key strategic issue. However, the nature of these kinds of decisions is usually complex and unstructured. Many quantitative and qualitative factors must be considered to determine the suitable criteria. As the human decision-making process usually contains fuzziness and vagueness, a hierarchy of MADM model based on fuzzy-sets theory is used in this research. Using a fuzzy analytic hierarchy process (FAHP), the weights of criteria and subcriteria are determined and then the final ranking is determined by technique for order preference by similarity to ideal solution (TOPSIS). Finally, fuzzy TOPSIS (FTOPSIS) is employed to compare the results with classic TOPSIS. This paper concludes that the subcriteria in all the items are in the same rank

Evaluation of cost-effectiveness criteria in supply chain management : case study

The aim of this paper is to evaluate and prioritize the proposed cost-effectiveness criteria in supply chain management using fuzzy multiple attribute decision-making (MADM) approach. Over the past few years, the determination of suitable cost-effectiveness criteria in the supply chain has become a key strategic issue. However, the nature of these kinds of decisions is usually complex and unstructured. Many quantitative and qualitative factors must be considered to determine the suitable criteria. As the human decision-making process usually contains fuzziness and vagueness, a hierarchy of MADM model based on fuzzy-sets theory is used in this research. Using a fuzzy analytic hierarchy process (FAHP), the weights of criteria and subcriteria are determined and then the final ranking is determined by technique for order preference by similarity to ideal solution (TOPSIS). Finally, fuzzy TOPSIS (FTOPSIS) is employed to compare the results with classic TOPSIS. This paper concludes that the subcriteria in all the items are in the same rank

Optimization of multi-echelon supply chain kanban model using genetic algorithm

A supply chain system (SCS) consists of organizations or companies that utilizes approaches to have an effective relation between suppliers, manufacturers, warehouses, distribution centers, retailers and finally, the customers. Kanban system is an efficient and easy system to be implemented. In a kanban system each plant sends signals to the following plant for needed parts. The kanban withdraws parts instead of pushing parts from one station to another station. The workstations are located along the production lines and only produce or deliver desired components when they receive a card. The number ofkanbans can significantly influence the load balance between processes and the amount of orders suppliers need to obtain from subcontractors. Large kanban size results in large amount of WIP inventory at each workstation. On the other side, although reducing kanban size causes a decrease in WIP inventory it leads to transportation increases as well as reduction in the system throughput rate. In this study a multi-echelon supply chain system controlled by kanban system, is considered. Decision making is based on determination of the number of kanbans as well as economic-quantity order of products. Since the adopted model used in this study is mixed integer non-linear programming (MINLP) type and solving it by exact algorithm such as branch and bound (B&B) takes a lot of time, a heuristic method via Genetic algorithm (GA) is presented. Some problems are solved by our proposed GA to illustrate the performance ofthe method

Towards a Sustainable Disassembly/Dismantling in Aerospace Industry

AbstractThe quality of recycled material in a recycling process is actively influenced by an appropriate disassembly/dismantling strategy. In recycling the carcass of the aircraft, it is suitable to separate and classify different aluminum grades into their main alloys family before sending them to recycling center. However, due to complexity in the aircraft structure, fully disassembly/dismantling or fully shredding the aircraft is not economically or environmentally viable, respectively. For this reason, this work discusses eight different disassembly/dismantling strategies that have been done on a real Bombardier Regional Jet aircraft. The study proposes an approach to assess the sustainability influence of these strategies, as an important parameter that should be considered to select the most suitable strategy. This concept can be improved in order to be used in aerospace industry as an accurate method that allows to take the best decision depending on the concurrent situation