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 tests need not be elaborate, for example, switching an electronic or electrical system on and off a few times may be enough to catch some simple defects that would otherwise be encountered by the end user very soon after the product was first used.
An ESS system usually consists of a test chamber, controller, fixturing, interconnect and wiring, and a functional tester.
Associated military terminology includes an operational requirements document (ORD) and ongoing reliability testing (ORT).
[2][3] The following is extracted from a paper on ESS testing prepared by the U.S. Air Force to provide standardized definitions and methods.
[4] The purpose of this paper is to provide standardized definitions and a roadmap of test processes for the Environmental Stress Screening (ESS) of replacement and repaired components used on Air Force systems.
OSS&E policy and instructions also require consistent engineering processes to ensure manufacturing and repair entities are accountable for delivering quality products, and to provide selection and qualification criteria for new sources of supply.
Random vibration and temperature cycling have proven to be the most successful forms of ESS in terms of effective flaw precipitation.
The testing of a production-representative unit to demonstrate that the design, manufacturing, assembly, and repair processes have resulted in hardware that conforms to the specification.
They demonstrate performance to purchase specification requirements and act as quality control screens to detect deficiencies of workmanship and materials.
Tailoring is the formal engineering task of using existing technical data (requirements, standards, specifications, test plans, etc.)