Insufficient time to serve a node in CVRPTW problem

[taox142]

Hello there,

First, thank you for the great work on the vrp solver. It is quite easy to use and really fast in many cases.

But I just came across this weird issue, that the route seems to be feasible, but the solver says "There is insufficient tiem to serve a node." I've attached the model details below. It is quite small, only ONE node.

Thank you in advance for looking into this. Please let me know if I need to clarify the issue clearer.

Best regards,
Tao

{
"MaxTotalVehiclesNumber": 10000,
"Points": [
{
"id": 0,
"name": "0",
"idCustomer": 0,
"serviceTime": 0.0,
"twBegin": 0,
"twEnd": 1821,
"penaltyOrCost": 0.0,
"demandOrCapacity": 0,
"incompatibleVehicles": []
},
{
"id": 1,
"name": "1",
"idCustomer": 1,
"serviceTime": 1023.6245850412403,
"twBegin": 212.37541495875976,
"twEnd": 1236.0,
"penaltyOrCost": 0.0,
"demandOrCapacity": 199,
"incompatibleVehicles": []
}
],
"VehicleTypes": [
{
"id": 1,
"startPointId": 0,
"endPointId": 0,
"name": "VEH1",
"capacity": 200,
"fixedCost": 0.0,
"varCostDist": 1,
"varCostTime": 0.0,
"maxNumber": 90,
"twBegin": 0.0,
"twEnd": 1821
}
],
"Links": [
{
"startPointId": 0,
"endPointId": 1,
"name": "",
"isDirected": true,
"distance": 171.40595088852663,
"time": 171.40595088852663,
"fixedCost": 0.0
},
{
"startPointId": 1,
"endPointId": 0,
"name": "",
"isDirected": true,
"distance": 244.24782496472716,
"time": 244.24782496472716,
"fixedCost": 0.0
}
],
"Parameters": {
"timeLimit": 3600,
"action": "solve",
"upperBound": 1000000,
"heuristicUsed": false,
"timeLimitHeuristic": 20,
"configFile": "",
"solverName": "CLP",
"printLevel": -1
}
}

[rrsadykov]

@najibprog, can you check this issue?

[najibprog]

Dear @taox142 thank you for your interest in our solver, the solver returns an error because for the first node, twBegin + serviceTime(1,236.00000000000006) > twEnd (1,236).

Best regards,
Najib

[taox142]

@najibprog, thank you for looking into the issue.

Yes, you are right. Even though I computed twEnd by twBegin + serviceTime, somehow, the computer messed up with the accuracy. I fixed the issue by setting twEnd = twBegin + serviceTime + 0.000001. Works now.

[najibprog]

Great! Thank you for taking the time to test, we think it will be better in the future to introduce rounding to 10^-(6) to avoid this kind of issue.

Best regards,
Najib