Difference between System Integration Testing (SIT) and User Acceptance Testing (UAT)

System Integration Testing (SIT) and User Acceptance Testing (UAT) have different purposes in the software testing process. System Integration Testing (SIT) ensures that different modules or systems work together correctly, focusing on the interactions between them. User Acceptance Testing (UAT) checks if the software meets user needs and business requirements, ensuring it is ready for real-world use. SIT is performed by developers and testers to identify integration issues, while UAT is conducted by end users to validate the system’s overall functionality.

What is System Integration Testing (SIT)?

For a better understanding of what is SIT first, we must understand what is System integration. so basically as the name itself suggests system integration refers to a set of phases where various components are incorporated into a single unit, and these units go for integration testing, the group of interaction between components is referred to as integration and testing these interactions and modules interaction is known as integration testing.

From another point of view, the SIT (system integration testing) is considered the combination of integration testing and system testing. At this point, we know what integration testing is. Now, we need to understand what system testing is. The testing performed on the absolute integrated products to check system compliance with specified requirements on functional and non-functional elements is referred to as system testing.

SIT is also considered a combination of integration testing and system testing.

What is User Acceptance Testing (UAT)?

UAT (User Acceptance Testing) is conducted at the end of the whole testing process when the product is ready to deliver. The main aim of software development is to develop software that is capable of satisfying user needs, rather than just fulfilling the system specifications. UAT is conducted when the product is ready to deliver it is also called as at the end of the whole testing process. UAT is used to validate whether the system is acceptable or not.

UAT validates that:

• The developed system fulfills the system requirement specifications
• The system has achieved the performance as documented in the system requirement statement.
• It could vary as defined in the contract.

Difference between System Integration Testing (SIT) and User Acceptance Testing (UAT)

1. Integration of individual units
2. Testing of the whole system
3. Appropriate software is used for writing test cases that is in accordance with software requirements.
4. This testing identifies errors such as UI errors, data flow errors, and interface errors.

1. Create a UAT plan on the basis of requirements
2. The gathered requirements are used to form scenarios.
3. Prepare test cases and test data
4. Execution of test cases for error checking
5. Project sent to production if no errors found
6. Any flaws or bugs must be fixed right away in order to get the product ready for release.

1. Top-down Integration Approach
2. Bottom-up Integration Approach

1. Alpha Testing
2. Beta Testing

Frequently Asked Questions on System Integration Testing (SIT) vs User Acceptance Testing (UAT)

1. Does SIT happen before or after UAT?

SIT completes at first, post system assembly, and it focuses on testing the integration of different parts of the system. While UAT is performed before the product release, it ensures that the product satisfies the needs and expectations of the end users.

2. Is SIT part of QA?

A Quality Assurance (QA) person usually performs system integration testing.

3. What comes before UAT testing?

Before performing UAT testing, all sorts of testing – unit, component, integration, and system – are performed by the testing or quality assurance team.