The Time-Triggered Architecture (TTA) is a technology that is especially well suited for the design and implementation of ‘by-wire’ systems with demanding real-time and safety requirements. Design and prototyping require thorough planning. New hardware and software support simulation and prototyping of distributed real-time systems, easing the implementation of by-wire applications. Integrated tools support the whole design process from system setup to simulation and application programming. The paper describes a by-wire prototype design process based on the TTA and a currently available development environment.