# VRP with Heterogeneous Fleet

It’s a well-known constraint for a VRP when a fleet of vehicles is characterized by different capacities, costs or vehicle types. For example, a fleet can consist of Car, Truck, Pedestrian, Scooter, or Bicycle with different shift hours, capacities, distance/duration, and cost. This is called a Heterogeneous fleet VRP and it requires some specific settings in terms of vehicles to be solved. Let’s consider a solution for such a problem with some specific constraints.

Let’s say we have a fleet of two different types of vehicles - a car and a truck. They have different shift times, capacity, max distance and cost. Moreover, both vehicles start their shifts at the same location, but the car finishes its tour at another depot, which means its end location is different from the start location. Taking into account those different constraints for both vehicles, we will have to specify all of them separately for car_1 and truck_1.

Regarding the jobs that we are going to assign for the tour, there will be no specific constraints as the algorithm will consider all the constraints specified for the vehicles and calculate the route taking that into account. So for the jobs we specify the routine data - jobs ID, time, location, demand and priority (if needed), etc. The key constraints in this very problem will be the vehicles’ type and capacity, start and end location, the shift time, and jobs' demand. With the car's capacity of 10 and the truck's capacity of 40, we are going to execute 4 jobs with the demand of 2, 2, 6, and 40 respectively. Regarding all mentioned above, the problem for the Heterogeneous fleet VRP would look as follows:

### Problem

{
"fleet": {
"types": [
{
"id": "6d1dc02e19d6",
"profile": "car_1",
"costs": {
"fixed": 8.0,
"distance": 0.002,
"time": 0.009
},
"shifts": [
{
"start": {
"time": "2021-08-27T06:03:00Z",
"location": {
"lat": 52.530971,
"lng": 13.384915
}
},
"end": {
"time": "2021-08-27T13:03:00Z",
"location": {
"lat": 52.529953,
"lng": 13.314877
}
}
}
],
"capacity": [
10
],
"amount": 1
},
{
"id": "b47bb0d26e4c",
"profile": "truck_1",
"costs": {
"fixed": 13.0,
"distance": 0.002,
"time": 0.006
},
"shifts": [
{
"start": {
"time": "2021-08-27T14:03:00Z",
"location": {
"lat": 52.530971,
"lng": 13.384915
}
},
"end": {
"time": "2021-08-27T19:03:00Z",
"location": {
"lat": 52.530971,
"lng": 13.384915
}
}
}
],
"capacity": [
40
],
"amount": 1
}
],
"profiles": [
{
"type": "car",
"name": "car_1"
},
{
"type": "truck",
"name": "truck_1"
}
]
},
"plan": {
"jobs": [
{
"id": "job_1",
"deliveries": [
{
"places": [
{
"times": [
[
"2021-08-27T09:03:00Z",
"2021-08-27T15:03:00Z"
]
],
"location": {
"lat": 52.46274034612159,
"lng": 13.381744271815766
},
"duration": 780
}
],
"demand": [
2
]
}
]
}
},
{
"id": "job_2",
"deliveries": [
{
"places": [
{
"times": [
[
"2021-08-27T09:03:00Z",
"2021-08-27T15:03:00Z"
]
],
"location": {
"lat": 52.495709703500346,
"lng": 13.383026814092966
},
"duration": 840
}
],
"demand": [
2
]
}
]
}
},
{
"id": "job_3",
"deliveries": [
{
"places": [
{
"times": [
[
"2021-08-27T10:03:00Z",
"2021-08-27T18:03:00Z"
]
],
"location": {
"lat": 52.489639267111066,
"lng": 13.305679494421426
},
"duration": 540
}
],
"demand": [
6
]
}
]
}
},
{
"id": "job_4",
"deliveries": [
{
"places": [
{
"times": [
[
"2021-08-27T10:03:00Z",
"2021-08-27T19:03:00Z"
]
],
"location": {
"lat": 52.60353049998964,
"lng": 13.42085512158312
},
"duration": 1080
}
],
"demand": [
40
]
}
]
}
}
]
}
}


### Solution

The solution for this problem will look as follows:

{
"statistic": {
"cost": 184.654,
"distance": 48104,
"duration": 8949,
"times": {
"driving": 5709,
"serving": 3240,
"waiting": 0,
"break": 0
}
},
"tours": [
{
"vehicleId": "6d1dc02e19d6_1",
"typeId": "6d1dc02e19d6",
"stops": [
{
"location": {
"lat": 52.530971,
"lng": 13.384915
},
"time": {
"arrival": "2021-08-27T06:03:00Z",
"departure": "2021-08-27T09:06:45Z"
},
10
],
"activities": [
{
"jobId": "departure",
"type": "departure"
}
]
},
{
"location": {
"lat": 52.495709703500346,
"lng": 13.383026814092966
},
"time": {
"arrival": "2021-08-27T09:17:02Z",
"departure": "2021-08-27T09:31:02Z"
},
8
],
"activities": [
{
"jobId": "job_2",
"type": "delivery"
}
]
},
{
"location": {
"lat": 52.46274034612159,
"lng": 13.381744271815766
},
"time": {
"arrival": "2021-08-27T09:39:50Z",
"departure": "2021-08-27T09:52:50Z"
},
6
],
"activities": [
{
"jobId": "job_1",
"type": "delivery"
}
]
},
{
"location": {
"lat": 52.489639267111066,
"lng": 13.305679494421426
},
"time": {
"arrival": "2021-08-27T10:03:00Z",
"departure": "2021-08-27T10:12:00Z"
},
0
],
"activities": [
{
"jobId": "job_3",
"type": "delivery"
}
]
},
{
"location": {
"lat": 52.529953,
"lng": 13.314877
},
"time": {
"arrival": "2021-08-27T10:23:09Z",
"departure": "2021-08-27T10:23:09Z"
},
0
],
"activities": [
{
"jobId": "arrival",
"type": "arrival"
}
]
}
],
"statistic": {
"cost": 100.082,
"distance": 25413,
"duration": 4584,
"times": {
"driving": 2424,
"serving": 2160,
"waiting": 0,
"break": 0
}
}
},
{
"vehicleId": "b47bb0d26e4c_1",
"typeId": "b47bb0d26e4c",
"stops": [
{
"location": {
"lat": 52.530971,
"lng": 13.384915
},
"time": {
"arrival": "2021-08-27T14:03:00Z",
"departure": "2021-08-27T14:03:00Z"
},
40
],
"activities": [
{
"jobId": "departure",
"type": "departure"
}
]
},
{
"location": {
"lat": 52.60353049998964,
"lng": 13.42085512158312
},
"time": {
"arrival": "2021-08-27T14:32:08Z",
"departure": "2021-08-27T14:50:08Z"
},
0
],
"activities": [
{
"jobId": "job_4",
"type": "delivery"
}
]
},
{
"location": {
"lat": 52.530971,
"lng": 13.384915
},
"time": {
"arrival": "2021-08-27T15:15:45Z",
"departure": "2021-08-27T15:15:45Z"
},
0
],
"activities": [
{
"jobId": "arrival",
"type": "arrival"
}
]
}
],
"statistic": {
"cost": 84.572,
"distance": 22691,
"duration": 4365,
"times": {
"driving": 3285,
"serving": 1080,
"waiting": 0,
"break": 0
}
}
}
]
}


From this solution we can see the common statistics of the tour like total cost, distance and duration, total driving, serving, and waiting time as well as the detailed statistics of each vehicle’s tour separately, as they had different constraints which is typical for the Heterogeneous fleet.