1. An apparatus, comprising: a memory, storing parameters of a model of a refrigeration system derived from a refrigeration system configuration and measurements of actual operational parameters of the refrigeration system in a known state; at least one input adapted to receive operational physical parameters sufficient for performing a thermodynamic analysis of operation of the refrigeration system; a processor for estimating a difference in operating cost due to a deviance of the refrigeration system in an operating state from the refrigeration system in the known state by performing a thermodynamic analysis of the refrigeration system in the operating state based on at least the at least one input and the stored parameters in the memory; and an output for presenting the estimate of the difference in operating cost due to the deviance.