Scan diagnosis
Beginner
Using a failed chip’s test results to work out where on the chip the flaw probably is.
Novice
Software that takes a failing chip’s wrong outputs, traces them back through the circuit and simulates likely faults, to list where the defect probably is and what kind it is.
Expert
Judged by resolution (how many candidates) and accuracy (whether the real defect is among them). Volume diagnosis correlates results across many failing chips to find systematic yield problems and choose chips for physical failure analysis.