Vector was hired because of its broad expertise in requirements engineering and product management. On the basis of lean development we evolved methods suitable for requirement elicitation, system analysis, specification, and integrated change management. Special attention was given to the interface of components and to handle standards important in these systems due to the safety-critical applications. After a pilot phase, where the techniques were evaluated and optimized for different project types, a suitable tool was introduced. We then coached team leaders and developers to take advantage of the resulting methods and tool support as fast and effective as possible.