Artelys contributes to SNCF Voyageurs’ OPTIPLACE project

A data-driven seating system

OPTIPLACE is a seat allocation algorithm developed for OUIGO trains.The project addresses a clear need: ensuring coherent, reliable seat placement that aligns with passenger expectations, while improving seat organisation in order to free up resellable seats during periods of high demand, all while taking into account the constraints specific to rail operations.

To achieve these objectives, the module integrates directly into the reservation system. Each day, it retrieves the initial seating plan for trains at D+4, optimises it according to several criteria, and then uploads the new proposal just before tickets are sent to passengers.

The reservation system then takes over again to handle new bookings up to departure, relying on the optimised seating plan generated by OPTIPLACE.

Towards more coherent and industrialised passenger seating

Thanks to this process, OPTIPLACE ensures more coherent, smooth and balanced seating across the trainsets, while incorporating the operational preferences defined by business teams. The project therefore helps secure and industrialise a key step in SNCF Voyageurs’ operational chain.

Artelys’ contribution

A heuristic phase, generating a list of candidate seats for each booking.

A mixed-integer linear programme, selecting the optimal assignment based on the defined business objectives

Beyond developing the module, Artelys contributed to several key aspects of the project, including:

Code quality improvement, documentation and industrialisation.

Integration of new data sources.

Co-design and prioritisation of business objectives.

Integration of the module within the existing process and its interface with the information system.

Definition of a suitable technical architecture (solver choice, infrastructure sizing, etc.).

Key figures

Since its progressive deployment in July 2024, OPTIPLACE has reached full operational scale and demonstrated its effectiveness. As of the end of August 2025, more than 15,000 trains have been optimised, including nearly 10,000 that benefited from seat release, amounting to more than 138,000 freed seats in total.