News - Thesis announce

Date : June 29, 2021, 2 p.m. - Mohammed SKIREDJ - Visio-conférence

Proactive and Reactive planning for ambulance networks

This thesis deals with optimization methods for proactive planning of a large ambulance networks and reactive planning to update them during the day. The proactive solutions corresponding to the decisions of the morning, which decide the starting times of the drivers and their first visits. This plan must be robust in the sense of the best acceptance of requests that appear during the day. When new requests are revealed, reactive methods must offer solutions to integrate them into the current planning by balancing the efficiency and the acceptability of future requests.
The principal scientific challenges in the thesis are: (1) the integration of complex constraints, and (2) very large problems (several thousand) compared to those treated by the classical approaches. Complex business constraints involve staff recombination with vehicles change, working time management (start and end times, breaks, …).

For proactive planning, a Metaheuristic (Adaptive Large Neighborhood Search) with specific procedures to deal with the different difficulties already mentioned. The comparison of our ALNS algorithm with a manual planning method shows the importance of the developed method. Our algorithm is also very competitive with the state of the art (Resource Constrained Dial-a-ride Problem; Multi Trip Vehicle Routing Problem with Time Windows and Pick-and-Delivery Problem with Time Windows).
For reactive planning, a general framework of re-optimization strategies is proposed and allows establishing a various strategies in terms of anticipation, frequency and conservatism from three parameters. The best configurations found are compared to two manual approaches.


Members of Jury:

  •                   Andrea-Cynthia DUHAMEL, Université Le Havre Normandie (Reviewer)
  •                   Nacima LABADIE, Université de Technologie de Troyes (Reviewer)
  •                   Marc  SEVAUX, Université de Bretagne-Sud (Jury)
  •                   Yannick KERGOSIEN, Université de Tours (Jury)
  •                   Xiaolan XIE, Mines Saint Etienne (Director)
  •                   Thierry GARAIX, Mines Saint-Étienne (Suppervisor)
  •                   Romain ISSART, LOMACO (Invited)
  •                  Jérôme VENZAC, LOMACO (Invited)
  •                  Alexandre Mazier, Apis-Consulting (Invited).