This proceedings volume presents recent theoretical and practical advances in operational research (OR). The papers focus on a number of key areas including combinatorial optimization, integer programming, heuristics, and mathematical programming. In addition, this volume highlights OR applications in different areas such as financial decision making, marketing, e-business, project management, scheduling, traffic and transportation. The chapters are based on papers presented at the 13th Balkan Conference on Operations Research (BALCOR). BALCOR is an established biennial conference. The selected papers promote international collaboration among researchers and practitioners, with a particular focus on the Balkan countries.

This volume constitutes the proceedings of the 8th International Conference on Variable Neighborhood Search, ICVNS 2021, held in Abu Dhabi, United Arab Emirates, in March 2021.The 14 full papers presented in this volume were carefully reviewed and selected from 27 submissions. The papers describe recent advances in methods and applications of variable neighborhood search. Chapter "Reduced Variable Neighbourhood Search for the Generation of Controlled Circular Data" is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

This proceedings volume presents recent theoretical and practical advances in operational research (OR). The papers focus on a number of key areas including combinatorial optimization, integer programming, heuristics, and mathematical programming. In addition, this volume highlights OR applications in different areas such as financial decision making, marketing, e-business, project management, scheduling, traffic and transportation. The chapters are based on papers presented at the 13th Balkan Conference on Operations Research (BALCOR). BALCOR is an established biennial conference. The selected papers promote international collaboration among researchers and practitioners, with a particular focus on the Balkan countries.

This volume constitutes the post- conference proceedings of the 7th International Conference on Variable Neighborhood Search, ICVNS 2019, held in Rabat, Morocco, in October 2019. The 13 full papers presented in this volume were carefully reviewed and selected from 46 submissions. The papers describe recent advances in methods and applications of variable neighborhood search.