Vehicle Routing Problem with Time Windows
- Go to Flavors section.
- Select Benchmarks / GeoMap / Route Sheet link of Capacitated Vehicle Routing Problem with Time Windows or Select VRPTW → Benchmarks / GeoMap / Route Sheet menu as shown in Figure.
- For this tutorial, select Benchmarks.
- VRPTW Benchmarks workspace will be launch as shown in Figure.
Each customer is represented as a time window which is visualized as the yellow segment between the blue section. The start of the yellow segment represents the ready time of customer (i.e. the earliest time at which a vehicle can start servicing the customer). The end of the yellow segment represents the due time of customer (i.e. the latest time before which a vehicle can still start servicing the customer). The depot represents the fully yellow station which has the largest time window.
- Take note of the caption title: VRPTW: Instances(c101)(Clark & Wright Savings)
- Click Schedule button to run Clark & Wright Savings solution method on c101 problem instance as shown in Figure.
A red line is added in the time window of each customer which indicates the time when the vehicle starts serving that customer.
- Double-click any station on the graph to display information related to that particular station (customer) as shown in Figure.
In Figure, vehicle ID 12 starts serving customer ID 62 at time 290 (between the time window 262-317). And, vehicle does not need to wait (Waiting Time = 0). The solution quality is 14701 for Clark & Wright Savings on c101 problem instance.
- Go to Default Scheduler Library in Scheduler tab.
- Double-click one scheduler method, i.e. SAM scheduler method.
- Take note of the caption title: VRPTW: Instances(c101)(SAM)
- Click Schedule button to run SAM solution method on c101 problem instance.
- Routing graph will be displayed in Problem View as shown in Figure.
As can be seen, the solution quality generated by SAM is 982, which is significantly better than that generated by Clark & Wright Savings.