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Unresolvable Tasks

When calling the GetPlan endpoint in Fleet Planner, the response includes an object called unresolvedTasks. It is a list of unresolvable tasks, consisting of a taskId and a list of reasons for why that task was unresolvable unresolvableReason.

Note that unresolvable tasks will also be returned by the Dispatch API if they were returned by underlying Fleet Planner call.

Detailed Explanation

Here is an explanation of all the possible reasons for why a task was unresolved:

Reason Explanation
VEHICLES_WITH_LOW_CAPACITY Vehicles with less than minimum capacity required to service the task.
VEHICLES_NOT_MATCHING_DESIRED_ID The specific vehicle requested is not currently available. This can happen if the vehicle is unavailable of if the vehicle is available but cannot service the task due to another reason. In the latter case, an additional unresolvable task is returned that specifies that reason.
VEHICLES_EXCLUDED Vehicles that are available and may be capable of servicing the task but are excluded for the task.
VEHICLES_CANNOT_COMPLETE_TRIP_ROUTE The trip is feasible but based on the current set of constraints, some vehicles in the fleet are not capable of completing the trip. Examples of such constraints are the temporary closure of roads or if the pickup or dropoff location is outside of the service area.
TRIP_IS_UNREACHABLE Either the trip's pickup or dropoff point is unreachable from each other or from any point in the map. For example, the trip's pickup and dropoff may be in different partitions or separate graph components, or the pickup or dropoff is somewhere completely unroutable like the ocean.
NO_VEHICLES_ARE_AVAILABLE There are no vehicles available to service the trip.
UNKNOWN The task was not resolved for an unknown reason.

Example Response of GetPlan

  "recommendations": [{...}],
  "unresolvedTasks": [{
    "taskId": "27637ffe-2ece-4a4c-a152-588933baace2",
    "unresolvableReason": [{
      "unresolvableReasonType": "UNKNOWN",
      "vehicleCount": 2
    }, {
      "unresolvableReasonType": "VEHICLES_CANNOT_COMPLETE_TRIP_ROUTE",
      "vehicleCount": 3

This response means that task 27637ffe-2ece-4a4c-a152-588933baace2 could not be resolved. Two vehicles could not be assigned to that task for unknown reasons, and three vehicles could not be assigned because they would not be able to complete the trip.