“…Although the MTVRP clearly has practical importance, the problem has not received much attention in the literature (Azi, Gendreau, & Potvin, 2007). Among the related studies, Alonso, Alvarez, and Beasley (2008), Mingozzi, Roberti, and Toth (2013), Olivera and Viera (2007), Petch and Salhi (2003), Salhi and Petch (2007), and Taillard, Laporte, and Gendreau (1996) simply examined a multi-trip extension of the original VRP. Azi et al (2007), Azi, Gendreau, and Potvin (2010), Brandão and Mercer (1997, 1998), and Tang, Yu, and Li (2015 incorporated multiple vehicle uses into the VRPTW to formulate a multi-trip VRPTW (MTVRPTW).…”