A method for automatically monitoring the performance of equipment includes compiling current operating conditions associated with current conditions (PMc). A historical database including a plurality of stored operating conditions and associated stored performance measure (PM*) is searched, each stored operating condition including at least one stored sensor reading, wherein at least one similar operating condition is identified in the search using distances between the current operating conditions and the stored operating conditions. The performance measure (PM*) associated with the similar operating condition is fit to generate a regression model. The regression model is applied to the current operating condition to generate an estimate for the performance measure for the current operating condition (PMe). A difference between PMc and PMe is computed. The first difference is compared to a predetermined threshold, wherein a warning is automatically generated if the first difference has a value greater than the predetermined threshold.