Balance Between Routes

[retu2libc]

Not sure if this has been asked before, but I often find that if the teams have enough time to service all of the jobs, most teams get stuck with full schedules and the final team gets stuck with a partial schedule. It would be nice to be able to tell the solver to balance out the routes a little once it has kind of already found an optimal solution. Or is the advice just to repeatedly try shrinking the teams hours?

[jcoupey]

Definitely get the need, the short answer is that we don't provide this out of the box.

It would be nice to be able to tell the solver to balance out the routes a little once it has kind of already found an optimal solution.

You have to consider that saying a solution is "optimal" (or just good) is implicitely referring to an underlying optimization objective. The one we use is to minimize cost, basically a ponderation of travel time and distance as defined in vehicle.costs objects, so this does not account for "fairness" across drivers. Defining metrics around balancing routes is probably possible, think looking at differences in terms of number of tasks, working hours, travel distance, travel time, etc. But deciding how to combine some kind of "balancing score" with actual cost is 1. neither trivial nor absolute (how much extra money are you prepared to spend for a slightly better balanced solution?), 2. not necessarily doable to incorporate in the solving logic without harming performance.

What usually happens in practice is that routes are not balanced if the available resources are "oversized" for the available tasks.

repeatedly try shrinking the teams hours?

That would be a pragmatic approach that can yield good results, depending on your use-case. You may want to take a look at this script that is implementing this idea, though not to get a balanced solution but rather to minimize completion time.