A method for determining the root causes of fail patterns in integrated circuit chips is provide wherein a known integrated circuit chip layout is used to identify a plurality of potential defects and a plurality of potential fail patterns in the integrated circuit chip. Correlations between the potential defects and the potential fail patterns that result from those defects are identified. Based on this identification, the potential fail patterns are grouped by common potential defect. An actual integrated circuit chip that is manufactured in accordance with the test layout is tested for failure patterns. These failure patterns are then compared to the groupings of potential fail patterns. When a match is found, that is when a given group of fail patterns is found in the actual integrated circuit chip, then the potential defect associated with the potential fail patterns to which the actual fail patterns are matched is identified. This defect is the root cause of the failure pattern in the actual chip.