This paper describes a framework of real-time simulation for modeling heavy construction operations. Compared with the traditional offline simulation that uses stationary inputs, the capability of real-time simulation to dynamically incorporate new project data and adapt to changes in the operating environment offers the promise of improving the accuracy of project forecasting. In the proposed realtime simulation framework, dynamic data from construction operations are constantly captured and fed into a process-simulation model for short-term scheduling purposes. A prototype system was developed to demonstrate the structure of the proposed framework and its feasibility. The benefits of this simulation approach and future research requirements for achieving a higher-level modeling automation are also discussed in this paper.