In order to provide thorough integration testing, we follow several approaches. For verification of small systems, we apply the Big Bang approach by testing all integrated units at once. If only some modules are ready for testing and the duration of the test phase is limited, we implement an incremental approach by combining several modules that are logically related.
For the incremental method, we conduct “top down” or “bottom up” integration. Following the bottom up strategy, we verify the work of integrated modules starting from lower levels. Top down integration begins with testing modules from a higher level keeping the control flow of the system.
