PhD Position F/ M Ecological and economic logistics service network design: Models and Decision Support Algorithms

A propos du centre ou de la direction fonctionnelle

The Inria University of Lille centre, created in 2008, employs 360 people including 305 scientists in 15 research teams. Recognised for its strong involvement in the socio-economic development of the Hauts-De-France region, the Inria University of Lille centre pursues a close relationship with large companies and SMEs. By promoting synergies between researchers and industrialists, Inria participates in the transfer of skills and expertise in digital technologies and provides access to the best European and international research for the benefit of innovation and companies, particularly in the region.For more than 10 years, the Inria University of Lille centre has been located at the heart of Lille's university and scientific ecosystem, as well as at the heart of Frenchtech, with a technology showroom based on Avenue de Bretagne in Lille, on the EuraTechnologies site of economic excellence dedicated to information and communication technologies (ICT).

Contexte et atouts du poste

This PhD thesis is part of the collaboration between INRIA and LOG'ISSIMO, a company of the French national postal service provider, La Poste. In what follows, the main challenges faced by LOG'ISSMO are described, and the thesis proposal is detailed in order to address some of them.

Context

As a result of the digitalization of exchanges, La Poste, like all postal operators, is facing an inexorable decline in its traditional mail business. Therefore, a key challenge for La Poste is to find new sources of growth in order to maintain and develop its business.

LOG'ISSMO's strategic business area is in the B2B (business-to-business) logistics sector. It is the delivery of goods to professionals, with volumes ranging from 3 parcels to 3 pallets. LOG'ISSIMO offers efficient first- and last-mile logistics solutions for small and large companies and local authorities. Its network is made up of 76 logistics platforms and 13,500 daily routes, enabling it to transport more than 35 million shipments a day.

LOG'ISSMO's development poses challenges in terms of structuring and supporting the growth of the business. In addition to scaling up its processes and resources, LOG'ISSIMO faces major challenges in clarifying its own logistics model, particularly with a view to combining it with La Poste's historical logistics activities.

There are many strategic questions to be answered that could benefit from decision support in a number of areas, including system performance:

• Manage the logistics network as effectively as possible. LOG'ISSIMO's offer is based on logistics terminals that were originally designed to sort mail and manage parcels, rather than more voluminous items. Therefore these infrastructures have to be modified so that LOG'ISSIMO can operate its logistics business efficiently. The question primarily concerns terminals both in terms of locations and of the overall service network in France. It also concerns the means of transport and their
• Reduce CO2 emissions at the lowest total cost. In order for Log'issimo's offer to be a success, the various services offered have to be consistent with La Poste's historical positioning and to be able to differentiate LOG'ISSIMO from the competition, by integrating the energy efficiency into all LOG'ISSIMO activities.
• Analyze and anticipate existing and/or potential break of bulk points via new customers or new services. Via our management tools and information systems, any logistics activity needs to be managed using appropriate performance indicators. Based on the logistics solutions identified, the challenge is to determine the most relevant KPIs for managing this new logistics activity.

The scope of the study covers the whole of France over a 3-year period.

Mission confiée

This thesis aims to answer three main questions: i) How can we design a logistics network that is both economically and ecologically efficient? ii) How can we adapt this network to new demands (location of products, transportation routes)? iii) What KPIs should we define, given solutions proposed by decision-support methods, to effectively manage the network?

The problems addressed in this thesis belong to two classes of transportation optimization problems. At a tactical level, it is similar to a logistics service network design problem (Belieres et al (2021), Belieres et al (2022)). In this problem, a logistics operator seeks to determine where products in a logistics network are stored so as to fulfil customer orders efficiently. The logistics network to be designed is a cost-effective multi-level distribution network, which includes the different types of warehouses and customer sites.

As the distributed products are in small quantities compared with vehicle capacities, consolidation is an effective strategy for reducing transport costs. Specifically, it involves routing products in such a way that vehicles carry multiple products at the same time, each of which may come from a different site and be destined for a different customer. At the operational level, this is a vehicle routing problem with pick-ups and deliveries (Parragh et al (2006), Koç et al. (2020)). This problem consists in elaborating a set of routes from a logistics platform to satisfy a set of transport requests characterized by a pick-up point and a delivery point for the goods.

After the mathematical modelling of the problems, the thesis work will focus on the development of heuristic approaches combining artificial intelligence and mathematical programming techniques. One of the main challenges in this thesis will be to solve these problems for the very large instances provided by LOG'ISSIMO in reasonable computational times, especially when considering new transport demands given an initial situation.

References

Belieres, S., Hewitt, M., Jozefowiez, N., & Semet, F. (2021). A time-expanded network reduction matheuristic for the logistics service network design problem. Transportation Research Part E: Logistics and Transportation Review, 147, 102203.

Belieres, S., Hewitt, M., Jozefowiez, N., & Semet, F. (2022). Meta partial benders decomposition for the logistics service network design problem. European Journal of Operational Research, 300(2), 473-489.

Koç, Ç., Laporte, G., & Tükenmez, İ. (2020). A review of vehicle routing with simultaneous pickup and delivery. Computers & Operations Research, 122, 104987.

Parragh, S. N., Doerner, K. F., & Hartl, R. F. (2006). A survey on pickup and delivery models part ii: Transportation between pickup and delivery locations. Journal für Betriebswirtschaft, 58, 81-117.

Principales activités

The work plan for this thesis will be as follows:

First, a comprehensive state of the art on the problems of logistics service network design and route planning with delivery and collection will be realized. This state-of-the-art will allow us to take advantage of the models and methods developed in the literature and to position the project in relation to existing studies.

Second, ad-hoc mathematical models will be developed, taking into account the specificities of the case proposed by LOG'ISSIMO, and then, heuristics combining artificial intelligence and mathematical programming techniques associated with the models will be designed, implemented, and evaluated

Finally, key performance indicators will be developed on the basis of the solutions provided to companies to enable system management.

Compétences

Technical skills and level required :

Good knowledge in combinatorial opimization, integer programming, heuristics

Coding: C++, Java

Avantages

• Subsidized meals
• Partial reimbursement of public transport costs
• Leave: 7 weeks of annual leave + 10 extra days off due to RTT (statutory reduction in working hours) + possibility of exceptional leave (sick children, moving home, etc.)
• Possibility of teleworking and flexible organization of working hours
• Professional equipment available (videoconferencing, loan of computer equipment, etc.)
• Social, cultural and sports events and activities
• Access to vocational training
• Social security coverage