“…Regarding the exact methods, seven approaches have been proposed for VBP, five Integer Linear Programming (ILP) formulations (Castillo-García & Hernández, 2019;Fraire et al, 2014;Jain, Saran & Srivastava, 2016a) and two branch and bound algorithms (Fraire et al, 2014;Jain, Saran, & Srivastava, 2016b). In addition, there are three metaheuristic algorithms (Herrán, Colmenar, & Duarte, 2019;Jain, Saran & 2016c;Terán-Villanueva et al, 2019) and one constructive algorithm for VBP (González et al, 2015), totalizing four approximate solutions.…”