Environmental stress screening (ESS) refers to the process of exposing a newly manufactured or repaired product or component (typically electronic) to stresses such as thermal cycling and vibration in order to force latent defects to manifest themselves by permanent or catastrophic failure during the screening process. 

The surviving population, upon completion of screening, can be assumed to have a higher reliability than a similar unscreened population.

Stress screening test can be performed as part of the manufacturing process or it can be used in new product qualification testing.

An ESS system usually consists of a test chamber, controller, fixturing, interconnect and wiring, and a functional tester. 

Product reliability is a very basic requirement for today’s competitive marketplace. The reliability of electronic products can be substantially improved by the use of environmental stress screening (ESS) tests to minimise the risk of errors and failures of products and simultaneously improve the reputation of an organisation or a brand.
Designed to help electronics manufacturers detect product defects and production flaws,Atmars ESS test chamber is widely used to improve profitability by eliminating defective products.