SOR ’15, the 13th International Symposium on Operations Research in Slovenia to be held at Bled, Slovenia, 23-25 September 2015, will host two special sessions coorganized by SLAIS members: Qualitative MCDM and Metaheuristic Optimization. The paper submission deadline is 5 June 2015. Authors of selected papers will be invited to submit extended manuscripts for publication in Central European Journal of Operations Research.