This paper presents a real time simulation framework in which simulation models are specified by the real time DEVS (RT-DEVS) formalism. Here, real time simulation denotes the frameworks ability to interact with a surrounding environment, such as software components, hardware components or human operators. Typical examples are man-in-the-loop simulations such as a flight simulation or simulation of a controller with real time constraints. In such simulations, a simulator must handle external events in a timely manner We propose a real time, interactive simulation methodology which concurrently executes RT-DEVS models along with its environment in a time selective manner. The proposed simulation methodology employs an event-driven scheduling policy to meet timing requirements of RT-DEVS models. We developed a real time simulation kernel that supports the proposed simulation methodology. A simple example of real time, interactive simulation demonstrates effectiveness of the proposed methodology and the developed environment.