The BPU7 conference is a conference which takes place every three years organized by the Balkan Physical Union and its National Societies members. The purpose of these conferences is to bring together the scientists of the Balkan Countries, to publish the scientific achievements of Balkan physicists and to discuss and find solutions to the common problems these countries have in research and education.

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.