Setting cumulative time variable

[jysun95]

I'm solving a VRPTW case, which show results as

Route for vehicle 0:
0 Time(0,0) -> 88 Time(120,346) -> 11 Time(128,354) -> 12 Time(128,354) -> 46 Time(129,355) -> 43 Time(130,356) -> 40 Time(130,356) -> 6 Time(130,356) -> 100 Time(240,356) -> 57 Time(244,360) -> 84 Time(247,480) -> 30 Time(600,600) -> 39 Time(604,604) -> 66 Time(606,606) -> 64 Time(606,606) -> 73 Time(616,616) -> 0 Time(616,616)
Time of the route: 616min

Route for vehicle 1:
0 Time(0,0) -> 71 Time(120,480) -> 76 Time(240,599) -> 41 Time(600,600) -> 0 Time(600,600)
Time of the route: 600min

Route for vehicle 2:
0 Time(0,0) -> 80 Time(0,343) -> 32 Time(1,344) -> 60 Time(3,346) -> 28 Time(4,347) -> 51 Time(240,349) -> 91 Time(243,352) -> 5 Time(244,353) -> 21 Time(246,355) -> 10 Time(250,359) -> 8 Time(251,360) -> 4 Time(252,479) -> 96 Time(252,479) -> 23 Time(253,480) -> 38 Time(253,537) -> 55 Time(256,540) -> 54 Time(360,600) -> 108 Time(360,600) -> 145 Time(660,718) -> 116 Time(662,720) -> 135 Time(664,778) -> 99 Time(780,780) -> 141 Time(781,781) -> 63 Time(782,782) -> 143 Time(782,782) -> 134 Time(787,787) -> 117 Time(788,788) -> 150 Time(788,788) -> 149 Time(788,788) -> 144 Time(788,788) -> 121 Time(788,788) -> 72 Time(790,790) -> 1 Time(795,795) -> 14 Time(799,799) -> 0 Time(799,799)
Time of the route: 799min 

I've add a dummy start location which indicates zero distance to other location, which means distance[0][i] = 0 for i in all location.
I realize the algorithm solving the problem with minimizing the total time of route, but the calculation of the time of the route seems odd to me,
for example Route for Vehicle 1, the total time is 600 min but vehicle 1 actually start it's route at 120(time), and only need to visit location 71 between (120,480), so why isn't the Time of the route 480 at most then.
Another question is, how do I change my searching algorithm to minimizing the largest distance of route or longest time of route then minimizing the total, cause I'm a director of Logistics Department, I want to make sure all my couriers have task to finish everyday then finding the shortest total route.

[Mizux]

1. Did you force cumul var to zero (i.e. boolean to True) when using AddDimension() ?

2. To minimize the longest distance/time you can set a non zero (ed which is the default) coefficient to the GlobalSpan of the dimension
   this will add a cost equal to coefficient * (max_cumul_var_of_all_end_node - min_cumul_var_of_all_start_node)
   see: https://github.com/google/or-tools/blob/stable/ortools/constraint_solver/doc/VRP.md#global-span-constraints
   so if the coefficient is large enough and this cost is the dominant factor it should be minimized first by the solver...

[jysun95]

Thanks for replying, I didn't force cumul var to zero.

and these are my search parameters...

search_parameters = pywrapcp.DefaultRoutingSearchParameters()
search_parameters.first_solution_strategy = (
    routing_enums_pb2.FirstSolutionStrategy.SAVINGS)
search_parameters.local_search_metaheuristic = (
    routing_enums_pb2.LocalSearchMetaheuristic.TABU_SEARCH)
search_parameters.time_limit.seconds = 30

and these are the results

Objective: 182
Route for vehicle 0:
0 Time(0,0) -> 88 Time(120,346) -> 11 Time(128,354) -> 12 Time(128,354) -> 46 Time(129,355) -> 43 Time(130,356) -> 40 Time(130,356) -> 6 Time(130,356) -> 100 Time(240,356) -> 57 Time(244,360) -> 84 Time(247,480) -> 30 Time(600,600) -> 39 Time(604,604) -> 66 Time(606,606) -> 64 Time(606,606) -> 73 Time(616,616) -> 0 Time(616,616)
Time of the route: 616min

Route for vehicle 1:
0 Time(0,0) -> 71 Time(120,480) -> 76 Time(240,599) -> 41 Time(600,600) -> 0 Time(600,600)
Time of the route: 600min

Route for vehicle 2:
0 Time(0,0) -> 80 Time(0,343) -> 32 Time(1,344) -> 60 Time(3,346) -> 28 Time(4,347) -> 51 Time(240,349) -> 91 Time(243,352) -> 5 Time(244,353) -> 21 Time(246,355) -> 10 Time(250,359) -> 8 Time(251,360) -> 4 Time(252,479) -> 96 Time(252,479) -> 23 Time(253,480) -> 38 Time(253,537) -> 55 Time(256,540) -> 54 Time(360,600) -> 108 Time(360,600) -> 145 Time(660,718) -> 116 Time(662,720) -> 135 Time(664,778) -> 99 Time(780,780) -> 141 Time(781,781) -> 63 Time(782,782) -> 143 Time(782,782) -> 134 Time(787,787) -> 117 Time(788,788) -> 150 Time(788,788) -> 149 Time(788,788) -> 144 Time(788,788) -> 121 Time(788,788) -> 72 Time(790,790) -> 1 Time(795,795) -> 14 Time(799,799) -> 0 Time(799,799)
Time of the route: 799min

Route for vehicle 3:
0 Time(0,0) -> 9 Time(240,350) -> 2 Time(241,351) -> 24 Time(242,352) -> 98 Time(243,353) -> 19 Time(246,356) -> 120 Time(360,360) -> 89 Time(360,360) -> 115 Time(360,529) -> 79 Time(360,529) -> 124 Time(360,529) -> 132 Time(420,532) -> 56 Time(420,532) -> 110 Time(420,532) -> 103 Time(420,532) -> 130 Time(422,534) -> 118 Time(423,535) -> 113 Time(424,536) -> 22 Time(425,537) -> 129 Time(426,538) -> 109 Time(428,540) -> 104 Time(428,540) -> 102 Time(428,540) -> 61 Time(431,720) -> 151 Time(720,774) -> 86 Time(723,777) -> 148 Time(724,778) -> 140 Time(726,780) -> 131 Time(726,780) -> 136 Time(726,780) -> 152 Time(780,780) -> 146 Time(780,780) -> 0 Time(780,780)
Time of the route: 780min

Route for vehicle 4:
0 Time(0,0) -> 27 Time(0,360) -> 16 Time(240,360) -> 25 Time(240,360) -> 53 Time(241,479) -> 20 Time(241,479) -> 87 Time(242,480) -> 139 Time(600,780) -> 147 Time(780,780) -> 69 Time(780,780) -> 15 Time(782,782) -> 34 Time(783,783) -> 133 Time(783,783) -> 119 Time(785,785) -> 0 Time(785,785)
Time of the route: 785min

Route for vehicle 5:
0 Time(0,0) -> 126 Time(420,420) -> 0 Time(420,420)
Time of the route: 420min

Route for vehicle 6:
0 Time(0,0) -> 49 Time(480,539) -> 106 Time(481,540) -> 7 Time(600,719) -> 142 Time(600,719) -> 123 Time(601,720) -> 13 Time(604,772) -> 82 Time(606,774) -> 67 Time(607,775) -> 62 Time(609,777) -> 137 Time(780,780) -> 85 Time(780,780) -> 0 Time(780,780)
Time of the route: 780min

Route for vehicle 7:
0 Time(0,0) -> 112 Time(0,0) -> 50 Time(0,0) -> 0 Time(0,0)
Time of the route: 0min

Route for vehicle 8:
0 Time(0,0) -> 26 Time(0,360) -> 94 Time(120,477) -> 95 Time(121,478) -> 59 Time(123,480) -> 31 Time(660,660) -> 138 Time(660,660) -> 33 Time(661,661) -> 45 Time(661,661) -> 3 Time(662,662) -> 74 Time(663,663) -> 0 Time(663,663)
Time of the route: 663min

Route for vehicle 9:
0 Time(0,0) -> 92 Time(0,341) -> 111 Time(240,342) -> 78 Time(241,343) -> 77 Time(242,344) -> 48 Time(244,346) -> 101 Time(245,347) -> 17 Time(247,349) -> 52 Time(248,350) -> 47 Time(248,350) -> 70 Time(249,351) -> 90 Time(249,351) -> 107 Time(249,351) -> 65 Time(250,352) -> 105 Time(251,353) -> 97 Time(253,355) -> 75 Time(254,356) -> 35 Time(254,356) -> 93 Time(256,358) -> 36 Time(258,360) -> 37 Time(258,360) -> 127 Time(420,710) -> 125 Time(422,712) -> 114 Time(425,715) -> 29 Time(480,716) -> 18 Time(600,716) -> 83 Time(602,718) -> 58 Time(602,718) -> 128 Time(602,718) -> 81 Time(602,718) -> 122 Time(604,720) -> 42 Time(604,780) -> 68 Time(780,780) -> 44 Time(781,781) -> 153 Time(783,783) -> 0 Time(783,783)
Time of the route: 783min

Total time of all routes: 6226min