publications

2025

1. Optimization problems with uncertain objective coefficients using capacities

   Tuan-Anh Vu, Sohaib Afifi, Eric Lefèvre, and Frédéric Pichon

   Annals of Operations Research, 2025

   DOI
2. G-UniRouting: A Graph-Based Unified Neural Model for Solving Multi-Attribute Vehicle Routing Problems

   Amine Jari, Sohaib Afifi, Rym Nesrine Guibadj, and Eric Lefevre

   In IEEE International Conference on Tools with Artificial Intelligence (ICTAI), 2025
3. A Graph Attention Model for the Team Orienteering Problem

   Iván Peña, Rym Guibadj, Cyril Fonlupt, and Sohaib Afifi

   In Intelligent Technology for Future Transportation, 2025

2024

1. A memetic based algorithm for simultaneous preventive maintenance scheduling and spare-parts inventory management for manufacturing systems

   Sohaib Afifi, Mustapha Hrouga, Anis Mjirda, and Hamid Allaoui

   Applied Soft Computing, 2024

   DOI
2. Optimization Under Severe Uncertainty: a Generalized Minimax Regret Approach for Problems with Linear Objectives

   Tuan-Anh Vu, Sohaib Afifi, Éric Lefèvre, and Frédéric Pichon

   In Proceedings of the International Conference on Belief Functions, 2024

   DOI
3. Problèmes d’optimisation avec un objectif linéaire évidentiel

   Tuan-Anh Vu, Sohaib Afifi, Eric Lefevre, and Frédéric Pichon

   In 25ème congrès de la Société Française de Recherche Opérationnelle et d’Aide à la Décision, (ROADEF), 2024
4. Une approche généralisée du regret minimax pour des problèmes d’optimisation sous incertitude sévère avec objectifs linéaires.

   Tuan-Anh Vu, Sohaib Afifi, Éric Lefèvre, and Frédéric Pichon

   In Rencontres Francophones sur la Logique Floue et ses Applications (LFA), 2024

2023

1. Enhanced iterated local search for the technician routing and scheduling problem

   Ala-Eddine Yahiaoui, Sohaib Afifi, and Hamid Allaoui

   Computers & Operations Research, 2023

   DOI
2. 0-1 Combinatorial Optimization Problems with Qualitative and Uncertain Profits

   Tuan-Anh Vu, Sohaib Afifi, Éric Lefèvre, and Frédéric Pichon

   In Integrated Uncertainty in Knowledge Modelling and Decision Making, 2023

   Series Title: Lecture Notes in Computer Science

   DOI
3. Optimization problems with evidential linear objective

   Tuan-Anh Vu, Sohaib Afifi, Eric Lefèvre, and Frédéric Pichon

   International Journal of Approximate Reasoning, 2023

   DOI
4. Modélisation et résolution de problèmes d’optimisation avec un objectif linéaire évidentiel

   Tuan-Anh Vu, Sohaib Afifi, Eric Lefevre, and Frédéric Pichon

   In 32èmes Rencontres Francophones sur la Logique Floue et ses Applications (LFA), 2023
5. Problème du plus court chemin avec poids évidentiels

   Tuan-Anh Vu, Sohaib Afifi, Eric Lefevre, and Frédéric Pichon

   In 24ème congrès de la Société Française de Recherche Opérationnelle et d’Aide à la Décision, (ROADEF), 2023
6. Projet multi-sites innovant pour étudiants de différents niveaux, vers la création d’infrastructures informatiques sécurisées et une collaboration renforcée

   Sylvain Merchez, Alain Trouillez, David Mercier, and Sohaib Afifi

   In 5ème Workshop Pédagogique Réseaux et Télécommunications, 2023
7. Une recherche locale itérée pour le problème de tournées de techniciens

   Ala-Eddine Yahiaoui, Sohaib Afifi, and Hamid Allaoui

   In 24e congrès annuel de la Société Française de Recherche Opérationnelle et d’Aide à la Décision (ROADEF), 2023

2022

1. On modelling and solving the shortest path problem with evidential weights

   Tuan-Anh Vu, Sohaib Afifi, Éric Lefèvre, and Frédéric Pichon

   In International Conference on Belief Functions, 2022

   DOI
2. Problème du plus court chemin avec poids évidentiels: Modélisation et résolution

   Tuan-Anh Vu, Sohaib Afifi, Eric Lefevre, and Frédéric Pichon

   In 31e Rencontres Francophones sur la Logique Floue et ses Applications (LFA), 2022
3. joint optimization of capacitated lot-sizing with lost sales and non-cyclical preventive maintenance

   Yuhan Guo, Mustapha Hrouga, Jiayao Liu, Sohaib Afifi, Hamid Allaoui, and Yu Zhang

   International Journal of Industrial Engineering, 2022

   DOI

2021

1. An Extension of Specificity-Based Approximations to Other Belief Function Relations

   Tekwa Tedjini, Sohaib Afifi, Frédéric Pichon, and Eric Lefèvre

   In Belief Functions: Theory and Applications, 2021

   Series Title: Lecture Notes in Computer Science

   DOI
2. The Vehicle Routing Problem with Time Windows and Evidential Service and Travel Times: A Recourse Model

   Tekwa Tedjini, Sohaib Afifi, Frédéric Pichon, and Eric Lefèvre

   In Symbolic and Quantitative Approaches to Reasoning with Uncertainty, 2021

   Series Title: Lecture Notes in Computer Science

   DOI
3. Un modèle de programmation par recours pour le VRPTW avec temps de service et de trajet évidentiels

   Tekwa Tedjini, Sohaib Afifi, Frédéric Pichon, and Eric Lefevre

   In 30e Rencontres Francophones sur la Logique Floue et ses Applications, (LFA), 2021
4. Iterated Local Search for the Technician Routing and Scheduling Problem

   Ala-Eddine Yahiaoui, Sohaib Afifi, and Hamid Allaoui

   In International Conference on Operations Research (OR 2021), 2021

2020

1. Un modèle à base de contraintes en fonction de croyance pour le problème de tournées de véhicules avec fenêtres de temps

   Tekwa Tedjini, Sohaib Afifi, Frédéric Pichon, and Eric Lefevre

   In 21ème congrès annuel de la société Française de Recherche Opérationnelle et Aide à la Décision (ROADEF), 2020
2. Vers une généralisation de l’approximation des fonctions de croyance

   Tekwa Tedjini, Sohaib Afifi, Frédéric Pichon, and Eric Lefevre

   In 29e Rencontres Francophones sur la Logique Floue et ses Applications (LFA), 2020

2019

1. Un modèle Belief-Constrained Programming pour le VRPTW avec temps de service et de trajet crédibilistes

   Tekwa Tedjini, Sohaib Afifi, Frédéric Pichon, and Eric Lefevre

   In 28e Rencontres Francophones sur la Logique Floue et ses Applications (LFA), 2019

2017

1. An inventory location routing model with environmental considerations

   Sanaa Lerhlaly, Maria Lebbar, Hamid Allaoui, Sohaib Afifi, and Driss Ouazar

   MATEC Web of Conferences, 2017

   DOI

2016

1. Local Search Analysis for a Vehicle Routing Problem with Synchronization and Time Windows Constraints in Home Health Care Services

   Laila En-nahli, Sohaib Afifi, Hamid Allaoui, and Issam Nouaouri

   In , 2016

   DOI
2. An integrated inventory location routing problem considering CO2 emissions

   Sanaa Lerhlaly, Maria Lebbar, Hamid Allaoui, Driss Ouazar, and Sohaib Afifi

   Contemporary Engineering Sciences, 2016

   DOI
3. Particle Swarm Optimization for the Location Routing Problem

   Sohaib Afifi, Laure. Devendeville, Corinne Lucet, and Aziz Moukrim

   In 6th International Conference on Metaheuristics and Nature Inspired Computing META’16, 2016
4. Heuristic solutions for the vehicle routing problem with time windows and synchronized visits

   Sohaib Afifi, Duc-Cuong Dang, and Aziz Moukrim

   Optim. Lett., 2016

   DOI
5. An inventory location routing problem with environmental considerations

   Sanaa Lerhlaly, Maria Lebbar, Hamid Allaoui, Sohaib Afifi, and Driss Ouazar

   In 3rd International Conference on Green Supply Chain, 2016
6. A multi-objective modelling to sustainable vehicle routing problem in home health care services: goal programming approach

   Laila En-nahli, Sohaib Afifi, Hamid Allaoui, Issam Nouaouri, Gilles Goncalves, and Cécile Carra

   In 3rd International Conference on Green Supply Chain, 2016
7. Une Méthode Hybride pour le Problème de Tournées de Véhicules avec Contraintes de Temps

   Sohaib Afifi and Aziz Moukrim

   In 17ème congrès annuel de la Société française de Recherche Opérationnelle et d’Aide à la Décision (ROADEF), 2016
8. Heuristique pour le Problème de Conception des Tournées du Personnel Soignant avec Contraintes Multiples dans les Structures d’Hospitalisation à Domicile

   Laila En-nahli, Sohaib Afifi, Hamid Allaoui, and Issam Nouaouri

   In 17ème congrès annuel de la Société française de Recherche Opérationnelle et d’Aide à la Décision (ROADEF), 2016
9. Local search analysis for a vehicle routing problem with synchronization and time windows constraints in home health care services

   Laila En-nahli, Sohaib Afifi, Hamid Allaoui, and Issam Nouaouri

   IFAC-PapersOnLine, 2016

   DOI
10. A multi-objective modelling to sustainable vehicle routing problem in home health care services: goal programming approach

    Laila En-nahli, Sohaib Afifi, Hamid Allaoui, Issam Nouaouri, Gilles Goncalves, and Cécile Carra

    In 3rd International Conference on Green Supply Chain, 2016

2015

1. Primal Heuristics for the Vehicle Routing Problem with Synchronized Visits

   Sohaib Afifi and Aziz Moukrim

   In Multidisciplinary International Conference on Scheduling : Theory and Applications, 2015

   PDF
2. Une heuristique pour un probleme de tournées de véhicules avec fenêtres de temps et des visites synchronisées

   Sohaib Afifi, Duc-Cuong Dang, and Aziz Moukrim

   In 16ème congrès annuel de la Société française de Recherche Opérationnelle et d’Aide à la Décision (ROADEF), 2015

2014

1. New Lower Bounds on the Number of Vehicles for the Vehicle Routing Problem with Time Windows

   Sohaib Afifi, Rym Nesrine Guibadj, and Aziz Moukrim

   In Integration of AI and OR Techniques in Constraint Programming, 2014

   Abs DOI

   The Vehicle Routing Problem with Time Windows (VRPTW) consists in determining the routing plan of vehicles with identical capacity in order to supply the demands of a set of customers with predefined time windows. This complex multi-constrained problem has been widely studied due to its industrial, economic and environmental implications. In this work, we are interested in defining the number of vehicles needed to visit all the customers. This objective is very important to evaluate the fixed costs for operating the fleet. In this paper, we provide an analysis of several lower bounds based on incompatibility between customers and on vehicle capacity constraints. We also develop an adaptation of Energetic Reasoning algorithm for VRPTW with a limited fleet. The proposed approach focuses on some time-intervals and exploits time constraints, incompatibility graph and bin packing models in order to obtain new valid lower bounds for the fleet size. Experiments conducted on the standard benchmarks show that our algorithms outperform the classical lower bound techniques and give the minimum number of vehicles for 339 out of 468 instances.

2013

1. A Simulated Annealing Algorithm for the Vehicle Routing Problem with Time Windows and Synchronization Constraints

   Sohaib Afifi, Duc-Cuong Dang, and Aziz Moukrim

   In Learning and Intelligent Optimization, 2013

   Abs DOI

   This paper focuses on solving a variant of the vehicle routing problem (VRP) in which a time window is associated with each customer service and some services require simultaneous visits from different vehicles to be accomplished. The problem is therefore called the VRP with time windows and synchronization constraints (VRPTWSyn). We present a simulated annealing algorithm (SA) that incorporates several local search techniques to deal with this problem. Experiments on the instances from the literature show that our SA is fast and outperforms the existing approaches. To the best of our knowledge, this is the first time that dedicated local search methods have been proposed and evaluated on this variant of VRP.

2. Un algorithme de recuit simulé pour le problème de tournées de véhicules avec fenêtres de temps et contraintes de synchronisation

   Sohaib Afifi, Duc-Cuong Dang, and Aziz Moukrim

   In 14ième congrès annuel de la Société française de Recherche Opérationnelle et d’Aide à la Décision (ROADEF), 2013