A system may include a memory storing a turbomachinery degradation model configured to model degradation of a turbine system over time. Further, the system may include a controller communicatively coupled to the memory, which derives a turbomachinery wash timing based on at least one input signal from the turbine system and the turbomachinery degradation model. The turbomachinery degradation model may derive a desired wash point by estimating a modeled power of the turbine system, a modeled heat rate of the turbine system, or both. Furthermore, the controller may use the desired wash point to determine a time for washing components of the turbine system.