In a companion paper [HVV04], we have investigated the deficiency of existing design approaches in supporting predictability for real-time control system development. A design approach is then introduced with an adequate support for efficient and consistent design and code generation. In this paper, this design approach is illustrated by a case study of a rail-road crossing system. The development process shows that our approach is able to properties not only between design descriptions at different abstraction levels, but also between the design model and the generated implementation.