Contrôle et planification de la production intégrant la reconfiguration dynamique des installations dans un contexte de logistique inverse

Abstract

The current thesis addresses the production planning and control problem within unreliable hybrid manufacturing remanufacturing systems that use both raw materials and returned products in the production process. Such a system brings greater managerial complexity as compared to traditional manufacturing systems especially with the presence of random events, which are often neglected in literature. These include the breakdown of production facilities, the supply of both raw materials and returns in terms of time, quantity and quality. This research project is motivated by multiple related reports from real cases underscoring the need for efficient control policies that are practical for real-life unreliable hybrid systems. The contributions of this thesis are presented in four phases. The first phase addresses the production planning and control problem for unreliable hybrid systems composed of dedicated facilities, which dedicate each production process (manufacturing or remanufacturing) to a separate facility. The important issue of integrating some key elements such as the supply of both raw materials and returns, the disposal option of returns and the stock dynamics is considered. A resolution approach combining a critical review of literature and a simulation-based optimization technique is applied in order to determine an efficient structure of control policies and to optimize their parameters in terms of costs. The second phase extends the previous work by considering unreliable hybrid systems where both manufacturing and remanufacturing operations are performed in a shared facility. In this context, the role of setup operations to switch from a manufacturing mode to a remanufacturing mode and vice versa becomes crucial. The same resolution approach is adopted to develop a better structure of control policies in terms of costs compared to those found in the literature and to provide a better understanding of the influence of setup on this class of systems. The third phase is an extension of the two previous works considering unreliable hybrid manufacturing-remanufacturing systems composed of mixed dedicated and shared facilities. A dynamic stochastic model is proposed, and the optimality conditions developed are solved numerically to determine the structure of control policies, which jointly optimize the manufacturing and remanufacturing rates and the decision-making process of setup in terms of costs. The fourth phase integrates the variability of returned products quality into production planning and control problem within unreliable hybrid manufacturing remanufacturing systems. The considered system is composed of mixed dedicated and shared facilities, which are able to produce a proportion of non-conforming products. This proportion depends on the quality of both raw materials and returns used in the production process. Two categories of returns are considered and are classified according to the time required to remanufacture them as well as the proportion of defective units. A stochastic optimization model is developed considering the manufacturing, remanufacturing and setup decisions that are necessary to change the production mode and the category of returns is use. A resolution approach combining numerical methods, simulation and statistical analysis are then adopted to determine the optimal structure of the integrated control policies and optimize their parameters in terms of costs. This thesis provides solutions to a class of the production planning and control problem within hybrid manufacturing-remanufacturing systems. It develops efficient structures for production control policies and contributes to a better understanding of the behavior of hybrid systems evolving on a dynamic and stochastic environment. Numerical examples and in-depth sensitivity analysis are carried out as illustration in order to validate the structures obtained of integrated control policies. In addition, this thesis applies a global resolution approach, which is better aligned with the concerns of production managers and offers a powerful technique to effectively control such complex systems.

Date	6 Jan 2021
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Ali Gharbi (Supervisor) & Adnène Hajji (Co-supervisor)