Statistical decision system

This invention relates to the field of testing integrated circuits. More particularly the invention relates to a system for applying the failure limits for various electronic characteristics of an electronic circuit at a point in time after the electronic characteristics of the integrated circuits have been sensed. A method for testing integrated circuits, where a predetermined set of input vectors is introduced as test input into the integrated circuits. The output from the integrated circuits in response to the predetermined set of input vectors is sensed, and the output from the integrated circuits is recorded in a wafer map, referenced by position designations. The recorded output for the integrated circuits is mathematically manipulated, and the recorded output for each of the integrated circuits is individually compared to the mathematically manipulated recorded output for the integrated circuits. Graded integrated circuits that have output that differs from the mathematically manipulated recorded output for the integrated circuits by more than a given amount are identified, and a classification is recorded in the wafer map for the graded integrated circuits, referenced by the position designations for the graded integrated circuits.