Simulation technology for use in full or partial vehicle testing was developed in the 1970s. It requires meticulous multiaxial control coupled with the playback of frequency compensated realtime data. Simulation testing provides a virtual reproduction of actual service data, typically within 2% accuracy of load amplitudes.Use of this technology in automotive development became widespread in the 1980s. Recent advances have made simulation practical even on the component level, complementing more traditional testing techniques including simple playback, block loading and constant amplitude mechanical testing. As simulation technology has spread through the ground vehicle industry, so has the use of fatigue technology as a tool for data evaluation.This paper discusses the role of fatigue analysis in simulation testing, as well as its use for integrating simulation with more conventional forms of durability testing frequently used for evaluation of individual components.