Or-tools: Dynamic vehicle routing problems

[bhack]

Can you add some DVRP example?

[cwelton]

I also would be interested in seeing this. I can't speak for bhack, but the scenario I would like to see is:

V: is a set of vehicles
R: Is a set of pickup and delivery requests
TW: Is a set of time window constraints on the pickup and delivery requests

1. An initial route is optimized
2. Several ticks go by in which the set of Vehicles V process a portion of the Pickup/Delivery requests
3. A new Request arrives
4. A new route is optimized subject to the constraints:
5. Vehicles start at their current locations, not at a depot
6. If a Pickup has already occurred on V[i] then V[i] must still perform the dropoff, unless the dropoff has also already occurred.
7. Pickups that have not yet occurred may still be shuffled between vehicles

This seems to be a use case for either the route locking functionality or the Preassignment, but the routes still allow intermediary nodes injected which seems to make locking not applicable and the fact that only some of the assignments are strict makes preassignment not quite right either? Is there a way to simply put the constraint that Location l must be serviced by V[i]?

[pocman]

We are using Ortools to model DVRP in production at Colisweb.
We found the Preassignment to be limited and are using a simple solution based on "already accepted" and "already refused deliveries".
To do so, we build the full model, as usual, and add a loop on nodes constraining the model.vehicleVar() (probably what @cwelton is looking for).

[aaaristo]

@lperron was this solved, if yes could you shed some light on it?

[amih77]

@pocman can you please elaborate?
I have a model of which a pickup and deliveries needs to be created dynamically.