What is the focus of system integration testing?

The focus of system integration testing is on testing the compatibility and interaction between different systems and software packages. This level of testing ensures that when various integrated components or systems work together, they function as intended, maintaining their integrity and reliability. By verifying that these systems can communicate correctly, transfer data seamlessly, and fulfill the required business processes, integration testing helps identify interface defects, protocol mismatches, and any other issues that may arise from the interaction of different systems.

Testing individual components is typically part of unit testing, where each piece of code is tested in isolation. Stress testing, on the other hand, evaluates how the system performs under heavy load or extreme conditions and is not the primary concern of integration testing. Lastly, user acceptance testing focuses on validating the system from the user's perspective to ensure it meets their needs before being deployed, which is distinct from the integration testing objectives.