Using Airbus's experience, this new case study discusses how exceptionally lean supply chains can generate catastrophic costs when something goes wrong. It asks: "Just what is the breaking point of a lean supply chain?" Coverage includes how Airbus must coordinate 1,500 suppliers to ramp up production on its popular A320 aircraft, how it copes with growing supplier consolidation, and how it might rectify problems and help valued suppliers. Focusing on issues facing virtually every manager of a lean supply chain, this case study offers exceptional value to both students and practitioners. Authors: Erika Marsillac, Old Dominion University; Tom McNamara, ESC-Rennes.