24 February 2025
“To be selective, you have to start from the top; otherwise what seems easy will be complex,” points out Julien Trochu, Professor of Industrial Engineering at ÉTS. He gives the example of construction wood that we want to recover during a building restoration or demolition. The wood may have been contaminated by abrasives, lead paint or other materials. Where does the wood go?
As we are facing dwindling natural resources, it’s becoming imperative to reuse materials. Reverse logistics is a planning process that promotes the recovery of products in a circular chain. There are two types of reverse logistics: closed loop—end-of-life products returned to the original manufacturer—and open loop—end-of-life products collected by an independent manufacturer.
Reverse Logistics: Maximizing Recycling Efficiency
During an internship at ÉTS in 2012, Julien discovered the link between the environmental dimension and logistics operations. “How can we help industry find solutions that benefit all?” he wonders. His master’s and PhD work focused on the use of mathematical models to optimize logistics operations linked to the revaluation of residual materials. He explored a number of options, including setting up mobile sorting facilities. This avoids the degradation and increased contamination of materials jumbled together in a container, sent to a recycling facility, and ultimately rerouted to various destinations, or to the landfill altogether.
Julien Trochu earned his master’s degree from ÉTS in 2015, followed by a PhD from the same institution in 2019. That year, he won the Laurent Villeneuve Best Young Researcher Award at the International Congress of Industrial Engineering in front of his peers and professors. “It was the climax of all those years of hard work and perseverance,” says Julien.
Expanding His Knowledge
His research supervisor, Amin Chaabane, and his co-supervisor, Mustapha Ouhimmou, proved invaluable guides throughout his university career. Julien learned the research profession from them. Identifying a problem, looking at what already exists, finding an unexplored avenue, proposing solutions and then putting them to the test: that’s the challenge. And finally, to pass on this knowledge to so many students, who in turn will disseminate it in their various fields of interest. In any case, this is the mission Julien Trochu has taken on as a professor of Industrial Engineering at ÉTS.
Combining Psychology and Teaching
Psychology has always been an area of interest for Julien. Understanding the human mind encourages self-reflection. With this toolbox, he was able to bypass the roadblocks that littered his path from France to Montreal, and then throughout his long years of research. Had his passion for mathematics not led him down the engineering path, he would probably have chosen a career as a therapist. In fact, he uses psychology to deepen his relationship with his students and to encourage them to push their limits. If we can change as a society, we can also change as individuals, and vice versa.
Reverse logistics is a reaction to a problem. “The most effective way is to consider the end-of-life stage of a product from the very start of its design,” concludes Julien Trochu.
