Proposed by Charles Thomas, Quentin Cappart, Pierre Schaus, Louis-Martin Rousseau

The problem consists in transporting patients to medical appointments given a fleet of vehicles. The main objective is to satisfy as much patient requests as possible. Additional objectives such as minimizing the waiting time or maximum ride time of the patients or towards minimizing costs could be considered.

Each request consists of a forward travel where the patient must be brought to their destination on time for their appointment, a backward travel that must be done after the end of the appointment or both. For back and forth requests, both travels must be done for the request to be satisfied. Patients are associated with categories restricting the vehicles that can take them and might be accompanied. Patients might also require some amount of time to embark/disembark vehicles. The vehicles have a limited capacity which must never be exceeded and are available at fixed times.

The data is provided as JSON files having the following format:

Instances are separated into three sets by difficulty.