An object based formal method for the development of real-time systems, called ATOM, is presented. The method is an integration of the real-time formal technique TAM (Temporal Agent Model) with an industry-strength structured methodology known as HRT-HOOD. ATOM is a systematic formal approach based on the refinement calculus. Within ATOM, a formal specification (or abstract description statement) contains Interval Temporal Logic (ITL) description of the timing, functional, and communication behavior of the proposed real-time system. This formal specification can be analyzed and then refined into concrete statements through successive applications of sound refinement laws. Both abstract and concrete statements are allowed to freely intermix. The semantics of the concrete statements in ATOM are defined denotationally in specification-oriented style using ITL.Funding received from the UK Engineering and Physical Sciences Research Council (EPSRC) through the Research Grant GR/M/0258
