| | System Integration Testing (SIT) | User Acceptance Testing (UAT) |
| Objective | SIT focuses on testing the integration and interaction between different modules or components of a system. It ensures that the individual modules work together as intended and that data flows correctly between them. | UAT is performed to validate the system’s readiness for end-user acceptance. It focuses on ensuring that the system meets the user requirements and performs as expected in real-world scenarios. |
| Timing | SIT is typically performed after unit testing and before UAT, in the middle of the testing cycle. | UAT is conducted after SIT and typically towards the end of the testing cycle, closer to the release or deployment phase. |
| Test Environment | SIT is conducted in a controlled test environment that simulates the production environment as closely as possible. | UAT is usually carried out in an environment that closely resembles the production environment. |
| Test Scope | SIT verifies the interfaces, data exchange, and functional behavior between different modules. It may also include testing system-level functionalities, such as security, performance, and error handling. | UAT tests the system from the end-user’s perspective, validating its usability, functionality, and compliance with user requirements or business processes. |
| Testers | SIT is primarily carried out by the development or testing team, focusing on technical aspects of the system. | UAT is primarily executed by end-users or business stakeholders who have a good understanding of the system’s intended use and business context. |
| Test Data | SIT uses test data specifically designed to cover different integration scenarios and exercise the interaction between modules. | UAT often employs real or realistic data to simulate actual usage scenarios and evaluate the system’s performance. |
| Defect Resolution | Issues identified during SIT are reported, tracked, and resolved by the development team before moving to UAT. | Issues discovered during UAT are reported, tracked, and resolved by the development or testing team, aiming to address any critical or high-priority issues before the system is released. |
