Optimisation des performances des systèmes de manufacturiers en contexte de chaîne d'approvisionnement en boucle fermée

Abstract

The scarcity of raw materials, environmental constraints and the globalization of markets are pushing companies to integrate reuse in their supply chains and to improve the quality of their products. This context forces companies to address the problem of optimizing their production chain by integrating aspects of reuse and quality control. Thus, the main objective of this project is to develop joint optimal policies for production, reuse, maintenance and quality control of hybrid production systems. The deterioration of the machines and the quality of the products are all new uncertain factors considered in this work. The objectives of this study are to develop a hybrid production structure, to develop production strategies, to determine the maintenance policy and to propose a product quality inspection policy. To achieve all these objectives, we divided the main problem into 3 sub-problems developed in three parts as follows: The first part conducts an optimization study of a production system consisting of an unreliable production unit, which degrades over time. This degradation affects the quality of the products. The objective of this part is to propose strategies for production, maintenance and quality control in order to improve the quality of products and reduce the total cost. To achieve this goal, we used a stochastic dynamic programming approach to develop the optimum conditions of Hamilton-Jacobi-Bellman (HJB) type. Then, we simulated a practical application in a Quebec company specialized in the production of fire pumps. This application allowed us to propose new policies for production, maintenance and quality control of products. Other companies could implement the proposed policies. However, in this part, the influence of the production rate on the degradation of the machine is not considered. In the second part, this production rate is incorporated and the option of adding a second machine as developed in Amie et Al. (2015) is adopted. The System remains unreliable and produces the same type of parts. The problem was modeled, and a stochastic dynamic programming approach is used to develop the HJB type optimum conditions. The results obtained allowed to propose production, maintenance and quality control policies. Although the results obtained in parts 1 and 2 are very satisfactory, they do not address the challenges faced by companies that reuse end-of-life products. Thus, the third part of this work integrates reverse logistics. The second machine will source end-of-life products. This part allows us to conduct an optimal study for a hybrid system (closed loop). All random factors such as: breakdowns, repairs and degradation of the machines are considered. A stochastic dynamic programming approach will be used to develop the optimal conditions of the HJB type. The results will allow the development of joint optimal policies for production, reuse, maintenance and quality control of manufactured and remanufactured products.

Date	29 Jan 2022
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Jean-Pierre Kenné (Supervisor) & Lucas Hof (Co-supervisor)