The Value of Preemptive Pick-Up Services in Dynamic Vehicle Routing for Last-Mile Delivery: Space-Time Network-Based Formulation and Solution Algorithms

Table 9

Optimal solution demonstration when  = 9.

Vehicle ID	Visiting sequence	Time sequence
1	[5-2-5-7-Depot]	[9,10]-[12,13]-[15,16]-[21,24]-[28,28]
2	[8-10-Depot]	[9,10]-[15,18]-[23,28]
3	[3-1-2-Depot]	[9,10]-[14,17]-[20,23]-[28,28]
4	[12-14-13-Depot]	[9,10]-[14,17]-[20,23]-[28,28]

Note. The first and second elements in [ _, _ ] denote the arrival and departure time at physical node/depot, respectively.