In a plasma processing system, a method for dynamically establishing a baseline is provided. The method includes processing a first substrate. The method also includes collecting a first signal data for the first substrate. The method further includes comparing the first signal data against the baseline. The method moreover includes including the first signal data in a recalculation of the baseline if the first signal data is within a confidence level range, which is in between a top level above the baseline and a bottom level below the baseline.