View source for The Vehicle Routing Problem with Drones: Extended Models and Connections

'''The Vehicle Routing Problem with Drones: Extended Models and Connections'''

Poikonen, Stefan; Wang, Xingyin; Golden, Bruce, “The Vehicle Routing Problem with Drones: Extended Models and Connections”, Wiley online library, (June 7, 2017) http://onlinelibrary.wiley.com/doi/10.1002/net.21746/full 

===Summary===
This article considers a truck that is carrying drones, so it is a combination of both drone and truck delivery. In short, they looked at the difference between a lot of slow drones and some fast drones. They found that if there are times when not all drones are in service (service not fully parallelized), greater drone speed dominates and if drone range or capacity is severely limited, a larger number of drones may dominate. Also, they stated that a drone will, for any destination, always travel a shorter (or just as long) path than a truck, because a drone isn’t bound to roads. Then, they also considered some routing problems, namely Close-enough-vehicle-routing-problem(CEVRP), vehicle-routing-problem-with-drones(VRPD) and vehicle-routing-problem(VRP) (CEVRP and VRP being known problems, and VRPD being the problem of this article). They found that CEVRP gives the optimal solutions of VRPD when the velocity of the drones is infinite and that VRP gives the optimal solution of the VRPD when the velocity of the drones is 0.