It is recommended to perform exhaustive tests for covering all combinations of inputs and preconditions.

Exhaustive testing is a technique that covers all possible combinations of inputs and preconditions2. However, it is not recommended to perform exhaustive testing, as it is usually impractical and impossible due to the large number of test cases required2. Instead, risk analysis and priorities should be used to focus testing efforts on the most important and critical aspects of the system under test2.