1. TUM School of Management, Technical University of Munich, 80333 Munich, Germany
2. Deutsche Post Chair of Optimization of Distribution Networks, School of Business and Economics, RWTH Aachen University, 52072 Aachen, Germany
3. Centre interuniversitaire de recherche sur les reseaux d’entreprise, la logistique et le transport, HEC Montréal, Montréal, Quebec H3T 2A7, Canada