A shakedown in QA Software Testing, basically refers to the fast/high level testing that is performed to an application after it has been migrated or deployed to a given environment to assure that is up and running without major glitches, which means that is ready for being tested.
Normally this test is done as a pre-condition before receiving it from the previous environment. To give an idea the test may last 30 minutes and cover only the happy-path unit test scenarios.
The environments are normally “testing environments” and could be FIT, SIT, UAT. DIT doesn’t qualify for this type of testing and is not considered a “testing environment”.
A shakedown is a period of testing or a trial journey undergone by an application (a WS interaction in particular) and its associated transformations and environment settings, before being declared operational. Statistically, when new WS’s are being deployed, a proportion of the application components will fail after a relatively short period of use introducing bugs (defects), and those that survive this period can be expected to last for a much longer, and more importantly, predictable life-span (that’s the case for the common components used by multiple interactions). For example, if a transformation has a hidden flaw introduced during development, it will not be as reliable as other transformation of the same type that was previously used by another application and reused.