"earliest_start" of a vehicle needs to be specified. If not specified, the vehicle starts at 0. Furthermore, it is not yet possible that the algorithm determines the start time of the vehicle. Therefore, your vehicles always start at
"earliest_start", no matter whether that makes sense or not.
For a number of problems, these two objectives, i.e. min completion_time and min vehicles AND min completion_time, yield the same results. Sometimes, however, these two objectives are competing objectives.
To illustrate this, the following 4 figures show an example.
You can see the objective specification in the left editor. As you can see in the first two figures, both objectives yield the same result. However, if you just specify that vehicles do not need to return to the depot (“return_to_depot”: false), both objectives yield different results.
Here you can find the example in json: minCompletionTime.txt (2.8 KB)
You can use our route editor to reproduce the results above and to play with different objectives.