Why? When implementing lean in product development we should look at it from two angles. The first angle is the one that is mostly considered: we should develop products in a lean way, making the development process more efficient and effective. The second is often forgotten, however it was recognized already by the early experts on lean for product development (in particular Allen Ward): the developed product should be part of a lean system: a lean production process combined with lean distribution, selling and delivery processes. Already at an early stage, the engineers should consider this full system to prevent designing in wastes downstream.