FAQ¶

This is a list of frequently asked questions about PyVRP. Feel free to suggest new entries!

Installation¶

How do I install the latest PyVRP from main without having to compile things myself?¶: The latest prebuilt binaries can be found here.
How do I compile PyVRP from source on Windows machines?¶: None of the PyVRP developers have a functioning Windows development enviroment available, so we cannot help you troubleshoot this. If you have difficulty figuring out how to build PyVRP on Windows, consider using the Windows Subsystem for Linux (WSL) instead.

How can I model vehicle-specific service durations?¶: Rather than specifying an explicit service duration for the clients or depots, add the service duration to the duration all the edges leaving the location. Using route profiles, you can then set up different travel duration matrices for the vehicles that include the vehicle-specific service durations.
How can I model clients with multiple time windows?¶: By adding the client multiple times, once for each time window, and making the duplicate clients part of a ClientGroup. PyVRP will then select one of the alternatives to visit. See this tutorial notebook for an example of modelling with mutually exclusive groups.
How can I model open routing problems, without start or end depots?¶: By adding dummy start and end depots for the relevant vehicle types. Set zero distance and duration on edges leaving (for start depots) or entering (for end depots) the dummy depots. You can then drop these dummy depots from PyVRP’s solution in a post-processing step.

Why does PyVRP sometimes get stuck when using partial travel matrices?¶: PyVRP internally uses a large missing_value argument to set the distance and duration attributes of missing edges. This sometimes results in integer overflow, which can cause the solver to get stuck. Passing a smaller missing_value to solve() should fix this problem.