Scalable simulation technology is the approach which uses an open-architecture system to produce high-fidelity simulators with options to meet a broad range of customer requirements. The customer objective for high-fidelity simulator training at lower life-cycle costs is addressed with the use of highly reliable, commercial off-the-shelf technologies and leveraging existing software investments. Depending upon acquisition and life-cycle support budgets, customers can choose from many options, such as visual systems, databases, and networking, to provide the best simulator capabilities to meet their training requirements. By using today's open architecture computer systems with extensive expansion capacity, scalable simulation also allows customers to add options, expand capabilities, and install upgrades at a future time without making costly modifications to the simulator. The scalable simulation approach and technology were used on the U.S. Air Force Unit Training Device (UTD) program, which provides high-fidelity flight and weapon system training at lower cost. Examples from the unit-level UTD program are cited to illustrate scalable simulation technologies and benefits.