Highlights from ECCO 2025 in Marrakech, Morocco

By Gavin Le Roux

The 38th Annual Conference of the European Chapter on Combinatorial Optimisation (ECCO 2025) took place from the 8th to the 10th of May 2025 in Marrakech, Morocco. It was held at the Grand Mogador Hotel, a 5-star hotel located in Agdal, a popular residential area full of hotels located south of the city centre towards the Atlas Mountains and Ourika Valley. Thank you to the conference chair, Prof El-Ghazali Talbi, along with the organising and program committees for making everyone feel welcome and allowing everyone to present their latest research.

The conference commenced on Thursday with a 10-minute opening after registration followed by the first session about packing and covering problems at 09:00. The first and third days had single sessions where all approximately 50 delegates attended in the main room called “Ourika”. The second day’s presentations were split across two sessions running in parallel in the main room and the second room called “Andalous”, named after descendants of those who were expelled from the Iberian Peninsula during the early 17th century and found a new home in Morocco.

Gavin Le Roux from Stellenbosch University

Prof Juan-Jose Salazar-Gonzalez from the University of La Laguna in Tenerife, Spain then presented his work on travelling salesman problems with time consistency as the first keynote speaker after the first coffee break. There was a total of 5 coffee breaks throughout the duration of the conference where Moroccan tea was also served together with light meals. Close to the coffee breaks, I would always wonder what snacks would be served next as the food was of an exceptional quality and they would change what was served each time. Despite lunch not being included (it was recommended that we take a 5-minute walk to the nearby Almazar mall as there are several restaurant options at reasonable prices compared to those at the hotel), these breaks were something to look forward to. It also provided us with opportunities to network with other delegates and to get to know them on a more personal level. I unfortunately could not experience this at EURO’s conference in Copenhagen, Denmark last year as there are generally more than 2000 delegates at these large-scale conferences.

In the afternoon, there was a session on applications in combinatorial optimisation where I presented about memory-based ruin-and-recreate heuristics for the fixed charge transportation problem. This was followed by a presentation by Dr Julien Darlay (the second keynote speaker) who spoke about Hexaly (France), a new kind of global optimisation solver and one of the sponsors of the conference. Here, we learned about how Hexaly makes their software less complex and affordable so that mathematical optimisation can be accessible by every organisation. Some of the top companies in the world that use Hexaly include Amazon, Sony, Airbus, Starbucks, DSV, Bosch and TotalEnergies. The day then ended at 18:00 with the last session on algorithms.

The Friday was the busiest in terms of the number of presentations. Between 09:00 and 10:40, sessions on vehicle routing as well as scheduling & planning ran in parallel. This was followed by a coffee break. The sessions on matching & flow problems as well as cutting problems were from 11:10 to 12:30. After the 2-hour lunch during which I again made my way to the Almazar mall, sessions on metaheuristics and bioinformatics ran in parallel from 14:30 to 16:10. This was followed by the second coffee break of the day. Prof Suresh Sethi from the University of Texas in Dallas, USA then introduced us to integer programming approaches to forecast horizons in dynamic lot-size problems and extensions in the third keynote session from 16:40 to 17:40.

We then hopped on buses at 19:30 to take a 30-minute drive to the outskirts of Marrakech for the banquet dinner. We experienced an evening of Moroccan hospitality with a dinner show in Berber tents. After enjoying our shared meals of Moroccan cuisine on round tables, we moved to an outside seating area at around 22:30 full of performances by belly dancers, acrobats, fireworks and traditional folk music. Once the performances ended at 23:30, we made our way back to the buses and finally got back to our accommodations at around 00:30. It is going to be difficult for another conference to top the banquet of ECCO 2025!

The last day of the conference started with a session on location and assignment problems at 09:30 and ended with the last keynote session by Prof Luis Gouveia from the University of Lisbon in Portugal. He discussed models for the Hamiltonian p-Median Problem. The conference ended at 13:00 where everyone said their goodbyes.

Travelling all the way from Cape Town, South Africa, I obviously had to take a few days to explore the rest of Marrakech. It is a vibrant city brimming with history, culture and stunning architecture. At the heart of the city lies the bustling Jemaa el-Fnaa square, a UNESCO World Heritage site where snake charmers, street performers and market stalls create an unforgettable atmosphere. Just steps away, the souks offer a maze of narrow alleys filled with colourful textiles, spices and handcrafted goods. Next to the square, Koutoubia Mosque, with its soaring minaret, stands as an iconic symbol of Marrakech. I also explored the serene Jardin Majorelle, once owned by Yves Saint Laurent and marvelled at the intricate tilework of the Bahia Palace. Lastly, I got a glimpse into the city’s rich past, the Saadian Tombs and El Badi Palace, which provided a fascinating look at royal history. After exploring Marrakech, I highly recommend it to anyone considering to visit!