如果货件有多个尺寸，则Jsprit的解决方案不正确

Question

I am new to Jsprit. I tried to use multiple size of dimension in my shipment list. For example, some shipments I added size of dimension with WHEELCHAIRSPACE_INDEX and some shipments I use PASSENGERSEATS_INDEX in my createJob(). However the output seem like wrong.

public class Test {

static int WHEELCHAIRSPACE_INDEX = 0;

static int PASSENGERSEATS_INDEX = 1;

private VehicleType vehicleType_wheelchair;

private VehicleType vehicleType_solelypassenger;

private VehicleImpl vehicle1,vehicle1_2,vehicle2,vehicle2_2;

private VehicleRoutingProblem.Builder vrpBuilder;

private HardRouteConstraint wheelchair_bus_passenger_pickup_constraint;

private VehicleRoutingAlgorithm algorithm;

private VehicleRoutingProblem problem;

private VehicleRoutingTransportCosts costMatrix;

private static final String FILENAME = "C:\\Users\\admin\\Desktop\\test.txt";

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Examples.createOutputFolder();
    Test test = new Test();
    test.createVehicleType();
    test.createVehicle();
    test.createJob();
    test.createConstraint();
    test.createProblem();
    test.searchSolution();
}

private void searchSolution() {
    Collection<VehicleRoutingProblemSolution> solutions = algorithm.searchSolutions();
    VehicleRoutingProblemSolution bestSolution = Solutions.bestOf(solutions);
    SolutionPrinter.print(problem, bestSolution, SolutionPrinter.Print.VERBOSE);

    Plotter problemPlotter = new Plotter(problem);
    problemPlotter.plotShipments(true);
    problemPlotter.setLabel(Plotter.Label.SIZE);
    problemPlotter.plot("output/transportOfDisabledPeopleExample_problem.png", "disabled people tp");

    Plotter solutionPlotter = new Plotter(problem, Solutions.bestOf(solutions));
    solutionPlotter.plotShipments(true);
    solutionPlotter.setLabel(Plotter.Label.SIZE);
    solutionPlotter.plot("output/transportOfDisabledPeopleExample_solution.png", "disabled people tp");


}

private void createProblem() {


    StateManager stateManager = new StateManager(problem);

    ConstraintManager constraintManager = new ConstraintManager(problem, stateManager);
    constraintManager.addConstraint(wheelchair_bus_passenger_pickup_constraint);


    algorithm = Jsprit.Builder.newInstance(problem).setStateAndConstraintManager(stateManager,constraintManager).buildAlgorithm();
    algorithm.setPrematureAlgorithmTermination(new IterationWithoutImprovementTermination(100));
}

private void createConstraint() {
    wheelchair_bus_passenger_pickup_constraint = new HardRouteConstraint() {

        @Override
        public boolean fulfilled(JobInsertionContext insertionContext) {

            return true;
        }
    };
}

private void createJob() {
    com.graphhopper.jsprit.core.problem.job.Shipment.Builder builder1 = Shipment.Builder.newInstance("1");
    builder1.addSizeDimension(WHEELCHAIRSPACE_INDEX, 1);
    builder1.setPickupLocation(Location.newInstance("1a"));
    builder1.setDeliveryLocation(Location.newInstance("1b"));
    builder1.setDeliveryServiceTime(0);

    Shipment shipment1 = builder1.build();

    com.graphhopper.jsprit.core.problem.job.Shipment.Builder builder2 = Shipment.Builder.newInstance("2");
    builder2.addSizeDimension(PASSENGERSEATS_INDEX, 1);
    builder2.setPickupLocation(Location.newInstance("2a"));
    builder2.setDeliveryLocation(Location.newInstance("2b"));
    builder2.setDeliveryServiceTime(0);

    Shipment shipment2 = builder2.build();

    com.graphhopper.jsprit.core.problem.job.Shipment.Builder builder3 = Shipment.Builder.newInstance("3");
    builder3.addSizeDimension(WHEELCHAIRSPACE_INDEX, 1);
    builder3.setPickupLocation(Location.newInstance("3a"));
    builder3.setDeliveryLocation(Location.newInstance("3b"));
    builder3.setDeliveryServiceTime(0);

    Shipment shipment3 = builder3.build();

    com.graphhopper.jsprit.core.problem.job.Shipment.Builder builder4 = Shipment.Builder.newInstance("4");
    builder4.addSizeDimension(PASSENGERSEATS_INDEX, 1);
    builder4.setPickupLocation(Location.newInstance("4a"));
    builder4.setDeliveryLocation(Location.newInstance("4b"));
    builder4.setDeliveryServiceTime(0);

    Shipment shipment4 = builder4.build();

    com.graphhopper.jsprit.core.problem.job.Shipment.Builder builder5 = Shipment.Builder.newInstance("5");
    builder5.addSizeDimension(WHEELCHAIRSPACE_INDEX, 1);
    builder5.setPickupLocation(Location.newInstance("5a"));
    builder5.setDeliveryLocation(Location.newInstance("5b"));
    builder5.setDeliveryServiceTime(0);

    Shipment shipment5 = builder5.build();

    setTransportCost();

    vrpBuilder = VehicleRoutingProblem.Builder.newInstance();
    vrpBuilder.addVehicle(vehicle1);
    vrpBuilder.addVehicle(vehicle2);
    vrpBuilder.addVehicle(vehicle1_2);
    vrpBuilder.addVehicle(vehicle2_2);
    vrpBuilder.addJob(shipment1).addJob(shipment2).addJob(shipment3).addJob(shipment4);
    vrpBuilder.addJob(shipment5);

    vrpBuilder.setFleetSize(FleetSize.FINITE);
    vrpBuilder.setRoutingCost(costMatrix);
    problem = vrpBuilder.build();

}

private void setTransportCost() {
    // TODO Auto-generated method stub
    VehicleRoutingTransportCostsMatrix.Builder costMatrixBuilder = VehicleRoutingTransportCostsMatrix.Builder.newInstance(true);

    costMatrixBuilder.addTransportTime("0", "0", 0.0);
    costMatrixBuilder.addTransportTime("0", "1a", 2.0);
    costMatrixBuilder.addTransportTime("0", "1b", 3.3);
    costMatrixBuilder.addTransportTime("0", "2a", 2.0);
    costMatrixBuilder.addTransportTime("0", "2b", 4.3);
    costMatrixBuilder.addTransportTime("0", "3a", 3.5);
    costMatrixBuilder.addTransportTime("0", "3b", 3.0);
    costMatrixBuilder.addTransportTime("0", "4a", 1.5);
    costMatrixBuilder.addTransportTime("0", "4b", 2.7);
    costMatrixBuilder.addTransportTime("0", "5a", 1.2);
    costMatrixBuilder.addTransportTime("0", "5b", 3.5);

    costMatrixBuilder.addTransportTime("1a", "0", 2.0);
    costMatrixBuilder.addTransportTime("1a", "1a", 0.0);
    costMatrixBuilder.addTransportTime("1a", "1b", 2.5);
    costMatrixBuilder.addTransportTime("1a", "2a", 2.3);
    costMatrixBuilder.addTransportTime("1a", "2b", 4.4);
    costMatrixBuilder.addTransportTime("1a", "3a", 4.0);
    costMatrixBuilder.addTransportTime("1a", "3b", 4.0);
    costMatrixBuilder.addTransportTime("1a", "4a", 2.3);
    costMatrixBuilder.addTransportTime("1a", "4b", 4.5);
    costMatrixBuilder.addTransportTime("1a", "5a", 3.2);
    costMatrixBuilder.addTransportTime("1a", "5b", 1.5);

    costMatrixBuilder.addTransportTime("1b", "0", 3.3);
    costMatrixBuilder.addTransportTime("1b", "1a", 2.5);
    costMatrixBuilder.addTransportTime("1b", "1b", 0.0);
    costMatrixBuilder.addTransportTime("1b", "2a", 1.7);
    costMatrixBuilder.addTransportTime("1b", "2b", 2.2);
    costMatrixBuilder.addTransportTime("1b", "3a", 2.5);
    costMatrixBuilder.addTransportTime("1b", "3b", 3.4);
    costMatrixBuilder.addTransportTime("1b", "4a", 4.5);
    costMatrixBuilder.addTransportTime("1b", "4b", 5.0);
    costMatrixBuilder.addTransportTime("1b", "5a", 4.5);
    costMatrixBuilder.addTransportTime("1b", "5b", 2.2);

    costMatrixBuilder.addTransportTime("2a", "0", 2.0);
    costMatrixBuilder.addTransportTime("2a", "1a", 2.3);
    costMatrixBuilder.addTransportTime("2a", "1b", 1.7);
    costMatrixBuilder.addTransportTime("2a", "2a", 0.0);
    costMatrixBuilder.addTransportTime("2a", "2b", 2.3);
    costMatrixBuilder.addTransportTime("2a", "3a", 1.7);
    costMatrixBuilder.addTransportTime("2a", "3b", 1.8);
    costMatrixBuilder.addTransportTime("2a", "4a", 3.3);
    costMatrixBuilder.addTransportTime("2a", "4b", 3.2);
    costMatrixBuilder.addTransportTime("2a", "5a", 3.0);
    costMatrixBuilder.addTransportTime("2a", "5b", 2.9);

    costMatrixBuilder.addTransportTime("2b", "0", 4.3);
    costMatrixBuilder.addTransportTime("2b", "1a", 4.4);
    costMatrixBuilder.addTransportTime("2b", "1b", 2.2);
    costMatrixBuilder.addTransportTime("2b", "2a", 2.3);
    costMatrixBuilder.addTransportTime("2b", "2b", 0.0);
    costMatrixBuilder.addTransportTime("2b", "3a", 1.2);
    costMatrixBuilder.addTransportTime("2b", "3b", 2.8);
    costMatrixBuilder.addTransportTime("2b", "4a", 5.7);
    costMatrixBuilder.addTransportTime("2b", "4b", 4.5);
    costMatrixBuilder.addTransportTime("2b", "5a", 5.2);
    costMatrixBuilder.addTransportTime("2b", "5b", 4.3);

    costMatrixBuilder.addTransportTime("3a", "0", 3.5);
    costMatrixBuilder.addTransportTime("3a", "1a", 4.0);
    costMatrixBuilder.addTransportTime("3a", "1b", 2.5);
    costMatrixBuilder.addTransportTime("3a", "2a", 1.7);
    costMatrixBuilder.addTransportTime("3a", "2b", 1.2);
    costMatrixBuilder.addTransportTime("3a", "3a", 0.0);
    costMatrixBuilder.addTransportTime("3a", "3b", 1.5);
    costMatrixBuilder.addTransportTime("3a", "4a", 5.0);
    costMatrixBuilder.addTransportTime("3a", "4b", 3.3);
    costMatrixBuilder.addTransportTime("3a", "5a", 4.2);
    costMatrixBuilder.addTransportTime("3a", "5b", 4.3);

    costMatrixBuilder.addTransportTime("3b", "0", 3.0);
    costMatrixBuilder.addTransportTime("3b", "1a", 4.0);
    costMatrixBuilder.addTransportTime("3b", "1b", 3.4);
    costMatrixBuilder.addTransportTime("3b", "2a", 1.8);
    costMatrixBuilder.addTransportTime("3b", "2b", 2.8);
    costMatrixBuilder.addTransportTime("3b", "3a", 1.5);
    costMatrixBuilder.addTransportTime("3b", "3b", 0.0);
    costMatrixBuilder.addTransportTime("3b", "4a", 4.3);
    costMatrixBuilder.addTransportTime("3b", "4b", 1.8);
    costMatrixBuilder.addTransportTime("3b", "5a", 2.8);
    costMatrixBuilder.addTransportTime("3b", "5b", 5.0);

    costMatrixBuilder.addTransportTime("4a", "0", 1.5);
    costMatrixBuilder.addTransportTime("4a", "1a", 2.3);
    costMatrixBuilder.addTransportTime("4a", "1b", 4.5);
    costMatrixBuilder.addTransportTime("4a", "2a", 3.3);
    costMatrixBuilder.addTransportTime("4a", "2b", 5.7);
    costMatrixBuilder.addTransportTime("4a", "3a", 5.0);
    costMatrixBuilder.addTransportTime("4a", "3b", 4.3);
    costMatrixBuilder.addTransportTime("4a", "4a", 0.0);
    costMatrixBuilder.addTransportTime("4a", "4b", 3.6);
    costMatrixBuilder.addTransportTime("4a", "5a", 1.7);
    costMatrixBuilder.addTransportTime("4a", "5b", 3.8);

    costMatrixBuilder.addTransportTime("4b", "0", 2.7);
    costMatrixBuilder.addTransportTime("4b", "1a", 4.5);
    costMatrixBuilder.addTransportTime("4b", "1b", 5.0);
    costMatrixBuilder.addTransportTime("4b", "2a", 3.2);
    costMatrixBuilder.addTransportTime("4b", "2b", 4.5);
    costMatrixBuilder.addTransportTime("4b", "3a", 3.3);
    costMatrixBuilder.addTransportTime("4b", "3b", 1.8);
    costMatrixBuilder.addTransportTime("4b", "4a", 3.6);
    costMatrixBuilder.addTransportTime("4b", "4b", 0.0);
    costMatrixBuilder.addTransportTime("4b", "5a", 1.9);
    costMatrixBuilder.addTransportTime("4b", "5b", 5.7);

    costMatrixBuilder.addTransportTime("5a", "0", 1.2);
    costMatrixBuilder.addTransportTime("5a", "1a", 3.2);
    costMatrixBuilder.addTransportTime("5a", "1b", 4.5);
    costMatrixBuilder.addTransportTime("5a", "2a", 3.0);
    costMatrixBuilder.addTransportTime("5a", "2b", 5.2);
    costMatrixBuilder.addTransportTime("5a", "3a", 4.2);
    costMatrixBuilder.addTransportTime("5a", "3b", 2.8);
    costMatrixBuilder.addTransportTime("5a", "4a", 1.7);
    costMatrixBuilder.addTransportTime("5a", "4b", 1.9);
    costMatrixBuilder.addTransportTime("5a", "5a", 0.0);
    costMatrixBuilder.addTransportTime("5a", "5b", 4.7);

    costMatrixBuilder.addTransportTime("5b", "0", 3.5);
    costMatrixBuilder.addTransportTime("5b", "1a", 1.5);
    costMatrixBuilder.addTransportTime("5b", "1b", 2.2);
    costMatrixBuilder.addTransportTime("5b", "2a", 2.9);
    costMatrixBuilder.addTransportTime("5b", "2b", 4.3);
    costMatrixBuilder.addTransportTime("5b", "3a", 4.3);
    costMatrixBuilder.addTransportTime("5b", "3b", 5.0);
    costMatrixBuilder.addTransportTime("5b", "4a", 3.8);
    costMatrixBuilder.addTransportTime("5b", "4b", 5.7);
    costMatrixBuilder.addTransportTime("5b", "5a", 4.7);
    costMatrixBuilder.addTransportTime("5b", "5b", 0.0);

    costMatrix = costMatrixBuilder.build();
}

private void createVehicle() {
    Builder vehicleBuilder1 = VehicleImpl.Builder.newInstance("wheelchair_bus");
    vehicleBuilder1.setStartLocation(Location.newInstance("0")).setEndLocation(Location.newInstance("0"));
    vehicleBuilder1.setType(vehicleType_wheelchair);
    vehicleBuilder1.setEarliestStart(0);
    vehicleBuilder1.setLatestArrival(10);
    vehicle1 = vehicleBuilder1.build();

    Builder vehicleBuilder1_2 = VehicleImpl.Builder.newInstance("wheelchair_bus_2");
    vehicleBuilder1_2.setStartLocation(Location.newInstance("0")).setEndLocation(Location.newInstance("0"));
    vehicleBuilder1_2.setType(vehicleType_wheelchair);
    vehicleBuilder1_2.setEarliestStart(0);
    vehicleBuilder1_2.setLatestArrival(10);
    vehicle1_2 = vehicleBuilder1_2.build();

    Builder vehicleBuilder2 = VehicleImpl.Builder.newInstance("passenger_bus");
    vehicleBuilder2.setStartLocation(Location.newInstance("0")).setEndLocation(Location.newInstance("0"));
    vehicleBuilder2.setType(vehicleType_solelypassenger);
    vehicleBuilder2.setEarliestStart(0);
    vehicleBuilder2.setLatestArrival(10);
    vehicle2 = vehicleBuilder2.build();

    Builder vehicleBuilder2_2 = VehicleImpl.Builder.newInstance("passenger_bus_2");
    vehicleBuilder2_2.setStartLocation(Location.newInstance("0")).setEndLocation(Location.newInstance("0"));
    vehicleBuilder2_2.setType(vehicleType_solelypassenger);
    vehicleBuilder2_2.setEarliestStart(0);
    vehicleBuilder2_2.setLatestArrival(10);
    vehicle2_2 = vehicleBuilder2_2.build();
}

private void createVehicleType() {
    VehicleTypeImpl.Builder wheelChairTypeBuilder = VehicleTypeImpl.Builder.newInstance("wheelChairBusType");
    wheelChairTypeBuilder.addCapacityDimension(WHEELCHAIRSPACE_INDEX, 2);
    wheelChairTypeBuilder.addCapacityDimension(PASSENGERSEATS_INDEX, 4);
    //wheelChairTypeBuilder.setCostPerDistance(1);
    wheelChairTypeBuilder.setCostPerTransportTime(2);
    vehicleType_wheelchair = wheelChairTypeBuilder.build();

    VehicleTypeImpl.Builder soleyPassengerTypeBuilder = VehicleTypeImpl.Builder.newInstance("passengerBusType");
    soleyPassengerTypeBuilder.addCapacityDimension(PASSENGERSEATS_INDEX, 6);
    //soleyPassengerTypeBuilder.setCostPerDistance(1);
    soleyPassengerTypeBuilder.setCostPerTransportTime(2);
    vehicleType_solelypassenger = soleyPassengerTypeBuilder.build();
}

private static Location loc(Coordinate coordinate) {
    return Location.Builder.newInstance().setCoordinate(coordinate).build();
}

}

This is the output

Shipment 1 and shipment 5 is not assigned to job list. However, if I change add all size of dimension to PASSENGERSEATS_INDEX then all jobs are assigned correctly. Does that mean that the algorithm is not support multiple size of dimension?

I found that there is a solution which assign 4 jobs when I stepped into the code in debugging mode. However,it is consider as not accepted solution in Jsprit. From logically thinking, this solution should be the correct solution because it minimize the unassigned job (compare to original solution only assign 3 job).

Answer 1

When you built your cost matrix, you only specified travel time, not distances.

By default, the cost of an unassigned job depends on the the (maximum) distances between the pickup and delivery locations. Since distances aren't set, there is no penalty for unassigned jobs.

An easy solution would be to add some reasonable distance metric when you build the cost matrix:

     private void setTransportCost() {
        VehicleRoutingTransportCostsMatrix.Builder costMatrixBuilder = VehicleRoutingTransportCostsMatrix.Builder.newInstance(true);

        String[] locationIds = new String[] {"0", "1a", "1b", "2a", "2b", "3a", "3b", "4a", "4b", "5a", "5b"};
        for (String l1: locationIds) {
            for (String l2: locationIds) {
                if (!l1.equals(l2)) {
                    costMatrixBuilder.addTransportDistance(l1, l2, 5);
                }
            }
        }

       // ... on with original implementation ...