As a journalist, it is rather rare to play in his professional setting. This is, however, the exercise proposed by the economist Suzanne de Treville, when she receives me in a room at the University of Geneva. So here I am, a producer of two kinds of jacket: one has a limited life expectancy because it is subject to fashion, the other, classic, can easily be sold off later. But producing it on site is a priori not profitable. By simulating the organization of production over five consecutive exercises, the player finds that a well-thought-out organization will nevertheless prove to be more lucrative by maximizing manufacturing in his country. Not to mention that it will drastically reduce its CO2 emissions.