Burn-in
Beginner
Running chips hot and hard for hours, so weak ones fail in the factory instead of in a customer’s hands.
Novice
A stress test: chips run at raised temperature and voltage for hours so that weak ones, which would otherwise fail early in a customer’s product, fail in the factory instead.
Expert
Short burn-in (10–30 hours in the Delft course’s example) targets infant mortality; long burn-in runs hundreds of hours. It is expensive, so its length is balanced against reliability targets.