System Integration Testing (SIT) is a type of testing that verifies the interactions between the modules of a software system. It involves the overall testing of a complete system of many subsystem components or elements, which may be composed of hardware, software, or both. The main objective of SIT is to ensure that all the subsystems have been integrated correctly and that the system meets its requirements and performs in accordance with the customer or user expectations. SIT is usually performed after system testing, which is a prerequisite for SIT. The deliverables of SIT are then passed to the User Acceptance Testing (UAT) round.
SIT can be performed using different methods, such as incremental methods, where integration tests are conducted on a system based on the target processor. The methodology used is usually Black Box Testing, and either bottom-up or top-down integration can be used. Test cases are defined using the high-level software requirements only. The subordinate stubs are replaced one at a time with actual modules depending on the approach selected (breadth first or depth first), and tests are executed as each module is integrated.
In summary, SIT is an important part of the software testing life cycle for collaborative projects, and it helps ensure that all the subsystems have been integrated correctly and that the system meets its requirements and performs in accordance with the customer or user expectations.
