Once a system is deployed it is in service for years and decades. During this time the system and its operational environment is often corrected, changed or extended. Testing that is provided during this phase is called maintenance testing.
Usually maintenance testing is consisting of two parts:
- First one is, testing the changes that has been made because of the correction in the system or if the system is extended or because of some additional features added to it.
- Second one is regression tests to prove that the rest of the system has not been affected by the maintenance work.