The importance of developing test correlated analytical models, of critical or unique spacecraft hardware, is not limited to pre-flight design verification. Such thermal models can also be extremely useful tools in assessing on-orbit operational and temperature anomalies. This paper discusses the application of test correlated thermal models, developed for a complex electro-mechanical system, in support of on-orbit operational replanning in response to unexpected mechanism movement and electronics temperature levels. The modeling effort utilized a recently developed routine for chaining coordinate systems in TRASYS (Thermal Radiation Analysis System). Results from the modeling provided detailed data, which complemented the limited telemetry and supported the operational replanning to ensure acceptable performance would be maintained throughout the mission.