Class Relaxation (1.11.2) 

Relaxation(mapping=None, *, ignore_unknown_fields=False, **kwargs)

If relaxations is empty, the start time and sequence of all visits on routes are fully constrained and no new visits may be inserted or added to those routes. Also, a vehicle's start and end time in routes is fully constrained, unless the vehicle is empty (i.e., has no visits and has used_if_route_is_empty set to false in the model).

relaxations(i).level specifies the constraint relaxation level applied to a visit #j that satisfies:

  • route.visits(j).start_time >= relaxations(i).threshold_time AND
  • j + 1 >= relaxations(i).threshold_visit_count

Similarly, the vehicle start is relaxed to relaxations(i).level if it satisfies:

  • vehicle_start_time >= relaxations(i).threshold_time AND
  • relaxations(i).threshold_visit_count == 0 and the vehicle end is relaxed to relaxations(i).level if it satisfies:
  • vehicle_end_time >= relaxations(i).threshold_time AND
  • route.visits_size() + 1 >= relaxations(i).threshold_visit_count

To apply a relaxation level if a visit meets the threshold_visit_count OR the threshold_time add two relaxations with the same level: one with only threshold_visit_count set and the other with only threshold_time set. If a visit satisfies the conditions of multiple relaxations, the most relaxed level applies. As a result, from the vehicle start through the route visits in order to the vehicle end, the relaxation level becomes more relaxed: i.e., the relaxation level is non-decreasing as the route progresses.

The timing and sequence of route visits that do not satisfy the threshold conditions of any relaxations are fully constrained and no visits may be inserted into these sequences. Also, if a vehicle start or end does not satisfy the conditions of any relaxation the time is fixed, unless the vehicle is empty.

Attributes
Name Description
level google.cloud.optimization_v1.types.InjectedSolutionConstraint.ConstraintRelaxation.Relaxation.Level
The constraint relaxation level that applies when the conditions at or after threshold_time AND at least threshold_visit_count are satisfied.
threshold_time google.protobuf.timestamp_pb2.Timestamp
The time at or after which the relaxation level may be applied.
threshold_visit_count int
The number of visits at or after which the relaxation level may be applied. If threshold_visit_count is 0 (or unset), the level may be applied directly at the vehicle start. If it is route.visits_size() + 1, the level may only be applied to the vehicle end. If it is more than route.visits_size() + 1, level is not applied at all for that route.

Classes

Level

Level(value)

Expresses the different constraint relaxation levels, which are applied for a visit and those that follow when it satisfies the threshold conditions.

The enumeration below is in order of increasing relaxation.

    This value must not be explicitly used in `level`.
RELAX_VISIT_TIMES_AFTER_THRESHOLD (1):
    Visit start times and vehicle start/end times
    will be relaxed, but each visit remains bound to
    the same vehicle and the visit sequence must be
    observed: no visit can be inserted between them
    or before them.
RELAX_VISIT_TIMES_AND_SEQUENCE_AFTER_THRESHOLD (2):
    Same as `RELAX_VISIT_TIMES_AFTER_THRESHOLD`, but the visit
    sequence is also relaxed: visits can only be performed by
    this vehicle, but can potentially become unperformed.
RELAX_ALL_AFTER_THRESHOLD (3):
    Same as `RELAX_VISIT_TIMES_AND_SEQUENCE_AFTER_THRESHOLD`,
    but the vehicle is also relaxed: visits are completely free
    at or after the threshold time and can potentially become
    unperformed.