The present disclosure relates to a method and an apparatus for liquid condition assessment in a liquid lubrication system for a work system operable in at least two different modes, the method comprising measuring monitored liquid condition data, determining a current operating mode of the work system, then based on the current operating mode, selecting a corresponding model, modeling corresponding simulated liquid condition data based on the model, assessing the liquid condition by comparing the monitored liquid condition data with the simulated liquid condition data, and providing a normally distributed data set for the liquid condition assessment.