Burn-in Testing is the testing of the components of a system before it is put into service or before its assembly into the system. It is done to establish the load capacity of a component by forcing it into failure under supervised test conditions.
The plot of the Failure rate against time takes a shape of a Bathtub curve. This shows that the failure rate is high early in the product life cycle. The burn-in testing is done in a stressful and accelerated environment in order to determine the failure rate during this early stage of the product life cycle when the failure rate is high. The failed components would be improved upon and replaced thus preventing premature failure of the system. Since the Burn-in testing generally destroys the components, a trade-off needs to be made to ensure a high yield.
Cost Implications. Burn-in testing is not done for all components. It will generally depend upon the cost of the test, the cost of the component since it is damaged during the test, the cost of failure, the cost of warranty claims, and the cost of goodwill lost.
Advantages of Burn-in Testing
Higher reliability of the product.
Proactive prevention such as planned preventive maintenance.
Fewer customer returns leading to fewer service and call centers.
Better estimated lifespan of the product
Examples of Burn-in Testing
Electronic Components testing is done at high voltage, current or temperature.
Audio Equipment is tested by leaving it on for a large number of days.
Stress testing of ropes, wires, and jigs is done to assess the safe working load.
References
https://en.wikipedia.org/wiki/Burn-in
https://www.techopedia.com/definition/2161/burn-in-testing#:~:text=Burn-in%20testing%20is%20the%20process%20of%20increasing%20the,be%20replaced%20before%20the%20device%20reaches%20the%20consumer.