This paper presents an overview of a process model and an object-oriented environment that supports the process model, for the development of complex real-time reactive systems described using Timed Reactive Object Model. The environment includes an animation tool consisting of a graphical user interface, an interpreter and a simulator, as well as an axiom generator and a verification manager. Debugging, simulating the consequences of exercising a computational step, and verifying invariant properties of an evolving design at different stages of the design process are all permitted.