A method, apparatus, and a system for generating a binary mapping of wafer regions using measured value. A first measured value relating to processing a first workpiece is acquired. A second measured value relating to a second workpiece is acquired. At least a first region common to the first and second workpieces is defined. A determination is made as to whether the results associated with the first or second measured value is above a predetermined threshold. A first binary value is assigned to the first region based upon a determination that the results associated the first or second measured value data is above the threshold.