IVR CompartmentCompartment

Overview

Compartment modelling is typically used when large vehicles may have their carrying capacity broken up into areas, or compartments. We are interested in modelling the constraints that exist over collections of compartments. There may also be constraints between tasks as to which compartments they may be assigned to or the maximum holding capacity of a single compartment. Typical use cases for compartments include modelling upper and lower “decks” in a vehicle (where some products may not be placed on the upper deck), fuel compartments in a trailer where certain products may only be assigned to certain areas (such as petrol, diesel or paraffin). In addition, it would be typical in fuel modelling to include axel load constraints across compartments to ensure that the vehicle is stable across all transits on a particular route. This would form part of a compartment set constraint.

Applicable models

• IVR8 ivr8-yni1c9k2swof

Compartment

A compartment is the most granular unit available for modelling a portion of a vehicle’s carriage. A task is required to be assigned to a compartment if the dimensions of the task (i.e. the quantities specified in the attributes of a task) fall within the remaining compartment dimensions at that point in a particular route. This means that two tasks may be assigned to the same compartment if the sum of their dimensional quantities is within the capacity limits specified by the compartment.

As tasks cannot be “split”, if no compartment exists which is larger than the largest dimensional quantity on a particular task, then the task is considered trivially infeasible.

Schema definition

message Compartment {
  required string id = 1;
  repeated Capacity capacities = 2;
}

Fields

id

The unique identifier for this compartment definition. If there are duplicate compartment definitions in the model, the payload will be rejected.

capacities

A list of dimension constraints which indicate the maximum cumulative task quantity that may be assigned to this compartment in the course of a route.

Examples

This sample defines a compartment labelled c1 which has a maximum capacity of 1 tonne (the weight dimension is measured in kilograms).

id: "c1"
capacities {
  dimensionId: "weight"
  capacity: 1000
}

Compartment Capacity

A compartment capacity defines the dimensional constraint for a particular compartment. No collection of tasks may be assigned to the compartment where the cumulative sum of dimensional quantities at any point on a route exceeds the dimensional limit specified.

Schema definition

message Capacity {
  required string dimensionId = 1;
  required float capacity = 2;
}

Fields

dimensionId

The dimension to which this compartment capacity should be applied.

capacity

The maximum capacity of the dimension specified.

Examples

This example has two dimensions defined, a weight dimension, measured in kg’s and a height dimension measured in centimeters.

capacities {
  dimensionId: "weight"
  capacity: 750
}
capacities {
  dimensionId: "height"
  capacity: 100
}