Disclosed are methods and apparatus for determining whether to perform burn-in on a semiconductor product, such as a product wafer or product wafer lot. In general terms, test structures on the semiconductor product are inspected to extract yield information, such as defect densities. Since this yield information is related to the early or extrinsic instantaneous failure rate, one may then determine the instantaneous extrinsic failure rate for one or more failure mechanisms, such as electromigration, gate oxide breakdown, or hot carrier injection, based on this yield information. It is then determined whether to perform burn-in on the semiconductor product based on the determined instantaneous failure rate.