Maîtrise des systèmes industriels : optimisation de la conception des lignes de production

During the design phase of a production system, all functional and technological alternatives should be explored in order to propose the best possible solutions. This often results in a combination of several sub-problems such as: selection of pieces of equipments from a set of candidate solutions for each manufacturing operation, dimensioning and allocation of buffers and storage areas, balancing workload among the different workstations, the specification of the type and capacity of the material handling system and the layout of equipments which consists of determining which workstations should be adjacent to each other and how they should be connected.In this context, we were interested in performance evaluation and optimization of serial production lines which are very common in high volume production systems.We have proposed a new analytical method, known as « Equivalent Machines Method» to evaluate the production line throughput. This method has the advantages to be more accurate and faster than the existing approaches in the literature.We have also established the relevance of this method for evaluating the production rate of series-parallel systems and other serial lines with machines having multiple failure modes.We have also developed a new algorithm based on nonlinear programming approach to solve the buffer allocation problemLors de la phase de conception d'un système de production, toutes les alternatives fonctionnelles et technologiques doivent être étudiées afin de proposer la ou les meilleures solutions possibles. Ceci se traduit souvent par une conjugaison de plusieurs sous-problèmes tels que: la sélection de pièces d'équipements à partir d'un ensemble de solutions candidates pour chaque opération de fabrication; l'équilibrage et le dimensionnement des postes de travail; le dimensionnement des zones de stockage; le dimensionnement des systèmes de transport et l'aménagement des emplacements.Dans ce contexte, nous nous sommes intéressés à l’évaluation des performances ainsi qu’à l’optimisation de la conception d’un système de production très répandus dans l'industrie manufacturière à gros volume à savoir les lignes de production en série.Nous avons proposé une nouvelle méthode analytique d’évaluation de performances dite « Méthodes par Machines Equivalentes ». Cette méthode présente les avantages d'être plus précise et plus rapide que les approches existantes dans la littérature. Nous avons aussi montré la pertinence de cette méthode pour l’évaluation du taux de production des systèmes en configuration séries-parallèles ainsi que les lignes avec des machines ayant plusieurs modes de défaillance. Nous avons aussi développé un nouvel algorithme de programmation non linéaire afin d’optimiser le dimensionnement des stocks intermédiaire

Mathematical modeling, analysis and optimization of production lines design

Lors de la phase de conception d'un système de production, toutes les alternatives fonctionnelles et technologiques doivent être étudiées afin de proposer la ou les meilleures solutions possibles. Ceci se traduit souvent par une conjugaison de plusieurs sous-problèmes tels que: la sélection de pièces d'équipements à partir d'un ensemble de solutions candidates pour chaque opération de fabrication; l'équilibrage et le dimensionnement des postes de travail; le dimensionnement des zones de stockage; le dimensionnement des systèmes de transport et l'aménagement des emplacements.Dans ce contexte, nous nous sommes intéressés à l’évaluation des performances ainsi qu’à l’optimisation de la conception d’un système de production très répandus dans l'industrie manufacturière à gros volume à savoir les lignes de production en série.Nous avons proposé une nouvelle méthode analytique d’évaluation de performances dite « Méthodes par Machines Equivalentes ». Cette méthode présente les avantages d'être plus précise et plus rapide que les approches existantes dans la littérature. Nous avons aussi montré la pertinence de cette méthode pour l’évaluation du taux de production des systèmes en configuration séries-parallèles ainsi que les lignes avec des machines ayant plusieurs modes de défaillance. Nous avons aussi développé un nouvel algorithme de programmation non linéaire afin d’optimiser le dimensionnement des stocks intermédiairesDuring the design phase of a production system, all functional and technological alternatives should be explored in order to propose the best possible solutions. This often results in a combination of several sub-problems such as: selection of pieces of equipments from a set of candidate solutions for each manufacturing operation, dimensioning and allocation of buffers and storage areas, balancing workload among the different workstations, the specification of the type and capacity of the material handling system and the layout of equipments which consists of determining which workstations should be adjacent to each other and how they should be connected.In this context, we were interested in performance evaluation and optimization of serial production lines which are very common in high volume production systems.We have proposed a new analytical method, known as « Equivalent Machines Method» to evaluate the production line throughput. This method has the advantages to be more accurate and faster than the existing approaches in the literature.We have also established the relevance of this method for evaluating the production rate of series-parallel systems and other serial lines with machines having multiple failure modes.We have also developed a new algorithm based on nonlinear programming approach to solve the buffer allocation proble

Energy-efficient scheduling problem of a single machine with state dependent and time dependent electricity costs

International audienc

Ordonnancement sur une machine pour la minimisation du coût énergétique

International audienc

Planning and Scheduling Optimization

Optimizing the performance of services and industrial systems is a real lever for creating value for companies and society [...

Economic and Energetic Performance Evaluation of Unreliable Production Lines: An Integrated Analytical Approach

International audienc

A multi-objective approach for an energy-efficient buffer allocation

International audienc

New method to analyze production lines with unreliable machines and nite buers

International audienc

Joint pricing and lot-sizing problem with variable capacity

International audienceThis paper presents an extension to the classical capacitated lot-sizing problem. Demand for the products is price-dependent and modelized as an isoelastic function. The capacity is not considered as a parameter anymore, it becomes a decision variable for the company as the production, inventory and pricing decisions. This variable capacity leads to two variants of the problem: one with a time-dependent capacity and the other one a uniform capacity over the periods. We propose heuristic methods, which are based on Lagrangian multipliers, to solve variations of the problem. The methods provide high-quality results

Complexity analysis of energy-efficient single machine scheduling problems

International audienceThis paper deals with the complexity analysis of several energy-oriented single-machine scheduling problems addressed in the literature. The considered machine may be in different states: OFF, ON, Idle, or in transitions between them. The energy consumption of the machine at each time-slot is state-dependent. The objective is the minimization of the total energy consumption costs over the planning horizon.For this purpose, two particular cases with constant energy price and increasing energy prices during all the time-slots are studied. These two problems are proved to be polynomial. Moreover, the general version of this problem with Time-Of-Use (TOU) energy prices and different processing times of the jobs is investigated in two versions: with and without the fixed sequence for the jobs. As the results, the version with the fixed sequence is proved to be polynomial, and the version without the fixed sequence (general version) is proved to be NP-hard.This paper also introduces different lower bounds to deal this general version of the problem. The performances of these lower bounds are discussed based on different numerical instances