The original idea for the film came in the early 2000s, when the Dardenne brothers read about a real-life case in a big French factory. There was a worker whose production output wasn't good enough for the other workers to get their bonuses, so that person was let go. They heard about similar cases in Belgium, Italy, and the U.S., and they all raised the question of solidarity.
Although she was required to shoot long 7-minutes takes, Marion Cotillard found the experience the most rewarding that she's been a part of. She recalled shooting certain takes 50-60 times, the record being 82 takes of the same scene.
Marion Cotillard is the most famous actor that the Dardenne brothers ever worked with and for the first time they cast an international A-list star. Cotillard is only the second non-Belgian actor to lead one of their films since I'm Thinking of You (1993). According to Luc Dardenne, he and his brother Jean-Pierre Dardenne knew that Cotillard was a great actress, but what interested them was transforming her body, familiar from her other films and from her advertising for Dior, and instead creating a character they had never seen her play before on film.
Marion Cotillard first met directors Jean-Pierre Dardenne and Luc Dardenne in 2011, on the set of Rust and Bone (2012) - the Dardenne brothers were co-producers on that film. They met Cotillard by chance, coming out of an elevator holding her baby, and were won over immediately. They looked at each other and said, "We would like to work with you." Luc said that driving back to Liège, Belgium, they didn't stop talking about her: her face, her look... "Hiring such a famous actress was an additional challenge for us. Marion was able to find a new body and a new face for this film," Jean-Pierre added.
Olivier Gourmet: Dardenne brothers regular plays Sandra's boss. This is his seventh appearance in a Dardenne brothers film.