1 Preface

Each submission was peer-reviewed by at least two referees, according to the editorial policy of Optimization Letters. Like previous ICVNS conferences, this conference was intended to provide a stimulating environment in which researchers coming from various scientific fields can share and discuss their knowledge, expertise, and ideas related to the Variable Neighborhood Search (VNS) metaheuristic and its applications.

The conference was organized by the Khalifa University of Science and Technology (U.A.E.), the Department of Culture and Tourism of Abu Dhabi (U.A.E.), the EURO Working Group on Metaheuristics (EWG EU/ME), and the Association of European Operational Research Societies (EURO). The topics of the papers of this issue included, but were not limited to:

  • Methodologies:

    • General VNS,

    • Multiobjective VNS,

    • Hybrid VNS methods.

  • Applications:

    • Location, inventory, routing problems,

    • Scheduling problems,

    • Graph problems.

This special issue was initiated with Prof. Nenad Mladenović from Khalifa University (UAE) as the lead guest editor. Prof. Nenad Mladenović together with Prof. Pierre Hansen developed the Variable Neighborhood Search (VNS) methodology in 1997. Unfortunately, Prof. Nenad Mladenović passed away on Saturday 7 of May 2022 and thus the other two guest editors finalized this collection of articles.

Prof. Nenad Mladenović was a well respected and loved colleague for the operations research and metaheuristics community, at the international level, for his excellent scientific activity and sincerity. Also, he was the founder of the series of the International Conferences on Variable Neighborhood Search (ICVNS) dedicated to the VNS method and organized on a regular basis. Therefore, this special issue is dedicated to his memory.

As guest editors, we would also like to cordially thank all authors for their valuable submissions and all the reviewers for their fruitful comments. Additionally, we would like to express our appreciation to Prof. Mohammed Omar and all the Khalifa University colleagues for the organization of the conference in this beautiful place. Our special gratitude to the Editors-in-Chief of Optimization Letters, Prof. O. Prokopyev and Prof. P. Krokhmal, for their kind support. We sincerely hope that the readers will find the papers on this special issue interesting and helpful.

Guest Editors:

Nenad Mladenović, Angelo Sifaleras, and Andrei Sleptchenko.