How to calculate return to depot time and make it hard constraint - optaplanner

Question

I am using the TimeWindowed version of the vehicle routing and I added to the vehicle an endOfShift time. I want to calculate the time of return to depot and make it hard constraint.
The returnToDepotTime is calculate in the ArrivalTimeUpdatingVariableListener, and I also changed the drl file I added
rule "returnToDepotBeforeEndOfShift"
when
Vehicle(endOfShift < returnToDepotTime, $endOfShift : endOfShift, $returnToDepotTime : returnToDepotTime)
then
scoreHolder.addHardConstraintMatch(kcontext, $endOfShift - $returnToDepotTime.intValue()); end
The problem is that OptaPlanner does not take returnToDepotTime into consideration and it is calculated but not taken by the hard constrains calculation. Any idea what to change?

Answer 1

Hi #Snukra thank you very much I solved it with a workaround I am saving everything in the last customer.
But I want to know where was my problem :)
So here is the important part of the vehicle object:
#PlanningEntity(difficultyComparatorClass = VehicleDifficultyComparator.class)
#XStreamAlias("Vehicle")
public class Vehicle extends AbstractPersistable implements Standstill {
Integer returnToDepotTime;
#CustomShadowVariable(variableListenerClass = ArrivalTimeUpdatingVariableListener.class, sources = { #CustomShadowVariable.Source(variableName = "returnToDepotTime") })
public Integer getReturnToDepotTime() {
return returnToDepotTime;
}
public void setReturnToDepotTime(Integer returnToDepotTime) {
this.returnToDepotTime = returnToDepotTime;
}
}
and this is the ArrivalTimeUpdatingVariableListener:
public class ArrivalTimeUpdatingVariableListener implements
VariableListener<Customer> {
public void beforeEntityAdded(ScoreDirector scoreDirector,
Customer customer) {
// Do nothing
}
public void afterEntityAdded(ScoreDirector scoreDirector,
Customer customer) {
updateVehicle(scoreDirector, customer);
}
public void beforeVariableChanged(ScoreDirector scoreDirector,
Customer customer) {
// Do nothing
}
public void afterVariableChanged(ScoreDirector scoreDirector,
Customer customer) {
updateVehicle(scoreDirector, customer);
}
public void beforeEntityRemoved(ScoreDirector scoreDirector,
Customer customer) {
// Do nothing
}
public void afterEntityRemoved(ScoreDirector scoreDirector,
Customer customer) {
// Do nothing
}
protected void updateVehicle(ScoreDirector scoreDirector,
Customer sourceCustomer) {
Standstill previousStandstill = sourceCustomer.getPreviousStandstill();
Integer departureTime = null;
Customer shadowCustomer = sourceCustomer;
Integer arrivalTime = 0;
Vehicle vehicle = null;
vehicle = sourceCustomer.getVehicle();
// here the start times are used
if (previousStandstill instanceof Customer) {
departureTime = ((Customer) previousStandstill).getDepartureTime();
arrivalTime = calculateArrivalTime(sourceCustomer, departureTime);
} else if (previousStandstill instanceof Vehicle) {
vehicle = (Vehicle) previousStandstill;
arrivalTime = calculateArrivalTimeFirstCustomer(sourceCustomer,
vehicle);
}
while (shadowCustomer != null
&& ObjectUtils.notEqual(shadowCustomer.getArrivalTime(),
arrivalTime)) {
scoreDirector.beforeVariableChanged(shadowCustomer, "arrivalTime");
shadowCustomer.setArrivalTime(arrivalTime);
scoreDirector.afterVariableChanged(shadowCustomer, "arrivalTime");
departureTime = shadowCustomer.getDepartureTime();
if (shadowCustomer.getNextCustomer() == null) {
scoreDirector.beforeVariableChanged(shadowCustomer,
"returnTimeToDepotIfLastOnTour");
//scoreDirector.beforeVariableChanged(vehicle,
// "returnToDepotTime");
int returnTimeToDepot = shadowCustomer.getArrivalTime()
+ shadowCustomer.getServiceDuration()
+ shadowCustomer.getTravelTimeTo(vehicle.getDepot());
vehicle.setReturnToDepotTime(returnTimeToDepot);
shadowCustomer
.setReturnTimeToDepotIfLastOnTour(returnTimeToDepot);
shadowCustomer.setEndOfShiftOfVehicle(vehicle.getEndOfShift());
scoreDirector.afterVariableChanged(shadowCustomer,
"returnTimeToDepotIfLastOnTour");
//scoreDirector.afterVariableChanged(vehicle,
// "returnToDepotTime");
}
shadowCustomer = shadowCustomer.getNextCustomer();
arrivalTime = calculateArrivalTime(shadowCustomer, departureTime);
}
}
private Integer calculateArrivalTimeFirstCustomer(Customer customer,
Vehicle vehicle) {
// calculate the earliest possible arrival time for this customer and
// this vehicle
int arrivalTime = vehicle.getStartOfShift()
+ customer.getLocation().getTravelTime(
vehicle.getStartLocation());
// if the time is before the redy time of a conatiner we take the ready
// time of a customer
if (customer.getReadyTime() > arrivalTime) {
arrivalTime = customer.getReadyTime();
}
return arrivalTime;
}
private Integer calculateArrivalTime(Customer customer,
Integer previousDepartureTime) {
if (customer == null) {
return null;
}
if (previousDepartureTime == null) {
// PreviousStandstill is the Vehicle, so we leave from the Depot
// at
// the best suitable time
int maxTime = Math.max(customer.getReadyTime(),
customer.getTravelTimeToPreviousStandstill());
return maxTime;
}
int arrivalTime = previousDepartureTime
+ customer.getTravelTimeToPreviousStandstill();
return arrivalTime;
}
}
The commented scoreDirector.beforeVariableChanged(vehicle, "returnToDepotTime"); and scoreDirector.afterVariableChanged(vehicle, "returnToDepotTime"); return the error.
Do you any have idea why?

Answer 2

Adjust the ArrivalTimeUpdatingVariableListener to also adjust the Vehicle's returnHomeTime for the Customer where getNextCustomer() is null.
If the scoreDirector is properly notified (before/afterVarChanged methods) that the Vehicle's returnHomeTime changed, the rules will update accordingly.