MODELIS: Innovative Solutions for Logistics, Production and Services

Optimizing delivery vehicle routes, factory operations and hospital staff schedules are just some of the issues being addressed by the MODELIS (1) team at the Laboratoire des Sciences du Numérique de Nantes (LS2N), which brings together researchers from IMT Atlantique and Nantes University. With a team of around fifteen research professors and twenty doctoral or post-doctoral students, MODELIS works on the optimization of production systems, logistics chains and transport networks. These systems are complex, because they may involve different products, several levels or various modes of transport - all with constraints linked in particular to the professions involved. And they also leave a lot of room for uncertainty - the data may be incomplete or altered, there may be frequent unforeseen events, the organization of the work may be flexible, and so on.
"We are looking to remove the technological barriers to problems that have so far been poorly solved or for which there is as yet no method of resolution," explains Fabien Lehuédé, one of the team's research professors.

IMT Atlantique professors Fabien Lehuédé and Olivier Péton are working on the Decarbomile project.

Theoretical expertise and business knowledge

To remove these technological barriers, MODELIS uses two types of tools: discrete mathematics, to model the problems and study their properties, and computer science, to develop optimization algorithms. "The aim is to create intelligent algorithms capable of finding the most appropriate solutions among a very large of number of possible solutions - like when a GPS device chooses between thousands of possible routes," continues Fabien Lehuédé. In addition to strong theoretical expertise, this approach requires a good understanding of the issues involved in the company's business.

Supplying supermarkets throughout France is a good example of the difficulties encountered. Managers have to make a multitude of strategic decisions - often with a cascade of choices: should regional warehouses be set up, and where? Is a hub necessary? Is it possible to join forces with other companies, and if so, which ones? Where should a hub be set up in the city centre, and to serve what area? Should we use piggyback transport or lorries - bearing in mind that lorries are already banned from certain urban areas by the regulations on LEZs and LTZs (2)? Can part of the journey be made by cargo bike? "Our work consists first of all in defining which method can provide an acceptable solution", explains Fabien Lehuédé. "Then, one of the avenues is to develop a combination of decisions, taking into account different parameters - cost, CO2 emissions, operating times, etc."

Decarbomile project: (green) last-mile logistics

The MODELIS team is taking part in Decarbomile, a major European project launched in September 2022 for a period of 4 years. Decarbomile aims to develop solutions for sustainable urban logistics and carbon-free "last mile delivery". This is an issue that concerns supermarkets, but also construction sites, small shops and all those involved in urban life. Issues to be addressed include the design of a multimodal network, the location of micro-hubs, and the development of optimization tools, among other topics.  
With an initial budget of 9.6 million euros, Decarbomile is mobilizing 4 laboratory urban areas (Hamburg, Istanbul, Logrono in Spain, and Nantes) and four 'satellites': Ghent (Belgium), Getafe (Spain), Tallinn (Estonia) and Sarajevo in Bosnia-Herzegovina. Each satellite will bring together all the players in its area - and in particular industrialists - to invite them to work together on specific cases. Participants will be able to use a common digital platform, as well as IT tools and connected objects, all of which should lead to the creation of demonstration models. In all, 31 partners from 11 countries are involved in the project: major groups (Migros, La Poste, etc.), SMEs, research centrers, etc.  

Decarbomile can take a variety of forms. In Hamburg, DHL is planning to test delivery using electric barges on the Martin River. Elsewhere, "intelligent crates" will be tested. In Nantes, the aim is to reduce pollution, test collaborative formulas for urban micro-hubs with "cargo bikes", and possibly use the bus and tram depots of the TAN (Nantes public transport). These are operating models that need to be rethought," stresses Fabien Lehuédé. Today, there are many parameters involved. A city that wants to create a hub comes up against a number of problems, because it involves the presence of a large lorry every day; environmental considerations weigh heavily; and voters also have their say... Hence the complexity of the decision-making process."

In this context, the MODELIS team's contribution focuses on two points. Firstly, in conjunction with an Italian software publisher, they are creating an urban network design tool for setting up hubs and lockers - software that could be used in Nantes. Researchers in Nantes are also working on a digital twin of the city, incorporating various simulations of logistics flows and optimization algorithms.

"Ultimately, the aim is to make the city 'work' in an optimized way, for example by improving existing solutions and making them interoperable," says Fabien Lehuédé. For the time being, the Decarbomile project is still in its early stages. It is too early to make recommendations on any particular solution. But one thing is certain: the collaboration of all the stakeholders involved in the project is essential.

(1) Modelling, Optimisation and Decision for Logistics, Industry and Services.
(2) Low Emission Zones and Limited Traffic Zones.