Vehicle time window start node

[jmonkiwi]

Hi everyone,

I'm currently working in a VRP with pickups and deliveries and time windows and I have 2 questions:

1. I have a vehicle that can start at any moment during the day. The thing is that, when I run the algorithm and print out the solution I found out that despite the fact that the vehicle starts at certain time and accomplish all the time windows restrictions, the vehicle could have start earlier and still fulfill all the time windows. So what I want ask is if there is something I can put, so that the vehicle starts as early as possible in order to fulfill all the orders within the time windows? maybe a penalization for late starts or something.

data['time_windows'] = [

            (39600, 86400), # 1
            (39600, 86400), # 2
            (39600, 86400), # 3
            (39600, 86400), # 4
            (39600, 86400), # 5
            (39600, 86400), # 6
            (39600, 86400), # 7
            (39600, 86400), # 8
            (39600, 86400), # 9
            (32400, 54000), # 10
            (39600, 86400), # 11
            (39600, 86400), # 12
            (39600, 86400), # 13
            (39600, 86400), # 14
            (39600, 86400), # 15
            (39600, 86400) # 16
            
    ]

 data['courier_shifts'] = [
        (0, 86400)
]

data['pickups_deliveries'] = [
        [1,2],
        [11,3],
        [12,4],
        [13,5],
        [14,6],
        [15,7],
        [16,8],
        [9,10]
    ]

Route for vehicle 0:
Start-> 9 Time(52913) -> 10 Time(54000) -> 14 Time(55857) -> 1 Time(55887) -> 16 Time(55917) -> 11 Time(55947) -> 13
Time(55977) -> 15 Time(56007) -> 12 Time(56037) -> 7 Time(57328) -> 6 Time(58699) -> 3 Time(61256) -> 5 Time(63672) -> 
4 Time(64185) -> 2 Time(64721) -> 8 Time(68202)

In this case the route starts at 52913 in the 9 node and reaches the 10 node in its time window upper bound limit, but as you see in the time windows, the vehicle could have started earlier.

2. Is there any way to write arbitrary objective functions in the VRP framework?