SAN JUAN, PR:  Dr. Joseph Geunes, Dr. Yongpei Guan and Ph.D. student Jing Ma won the 2013 Best Paper Award in the Production Planning and Scheduling Track at the 2013 Industrial and Systems Engineering Research Conference.  The paper, “Quantity Discount Mechanisms in a Two-level Supply Chain,” was presented during the Annual Conference of the Institute of Industrial Engineers, which was held from May 18 through the 22 in San Juan, Puerto Rico.