Difference between System Testing and Integration Testing

Introduction :

System testing and integration testing are two critical types of software testing that are used to ensure the quality and reliability of software products.

Integration testing is a type of testing that focuses on verifying the interfaces and interactions between software components or modules. It is conducted after unit testing and ensures that the individual components are integrated correctly and work together as intended. The primary goal of integration testing is to identify defects in the interfaces and interactions between software components and ensure that the software meets the requirements and specifications provided.

On the other hand, system testing is a type of testing that verifies the software’s behavior and functionality as a whole system. It is conducted after integration testing and ensures that all the individual components of the system are working together as intended. The primary goal of system testing is to identify defects in the system and ensure that it meets the requirements and specifications provided.

Both integration testing and system testing play a critical role in the software development lifecycle. Integration testing helps to ensure that the individual components are integrated correctly and work together as intended, while system testing helps to ensure that the software functions correctly as a whole system.

System Testing: While developing a software or application product, it is tested at the final stage as a whole by combining all the product modules and this is called as System Testing. The primary aim of conducting this test is that it must fulfill the customer/user requirement specification. It is also called an end-to-end test, as is performed at the end of the development. This testing does not depend on system implementation; in simple words, the system tester doesn’t know which technique between procedural and object-oriented is implemented. This testing is classified into functional and non-functional requirements of the system. In functional testing, the testing is similar to black-box testing which is based on specifications instead of code and syntax of the programming language used. On the other hand, non-functional testing, checks for performance and reliability by generating test cases in the corresponding programming language. 

Integration Testing: This testing is the collection of the modules of the software, where the relationship and the interfaces between the different components are also tested. It needs coordination between the project-level activities of integrating the constituent components at a time. The integration and integration testing must adhere to a building plan for the defined integration and identification of the bug in the early stages. However, an integrator or integration tester must have programming knowledge, unlike a system tester. 

Difference between System Testing and Integration Testing :

S. No.	Comparison	System Testing	Integration Testing
1.	Basic	Tests the finished product.	Validates the collection and interface modules.
2.	Performed	After integration testing	After unit testing
3.	Requires	Understanding of the internal structure and programming language.	Knowledge of just interlinked modules and their interaction.
4.	Emphasis	On the behavior of all module as a whole.	System functionalities interface between individual modules.
5.	Covers	Functional as well as non-functional tests.	Only functional testing.
6.	Test cases	Created to imitate real life scenarios.	Build to simulate the interaction between two modules.
7.	Approaches	big-bang, incremental and functional.	Sanity, regression, usability, retesting, maintenance and performance tests.
8.	Executed	Only by test engineers.	By test engineers as well as developers.
9.	Finding errors	System testing aids in locating system errors and any defect found to be regarded as system defect.	Integration testing assists in locating interface errors and any defect found is of individual module only.
10.	Functional and Non-functional Aspect	It is used to conduct both functional and non-functional testing.	It covers only integrated components’ functional aspects.
11.	Types	Functional testing Scalability testing Reliability testing Security testing Performance testing Usability testing Installation testing, etc.	Top-down Bottom-up Big-bang  Hybrid integration

Feature	System Testing	Integration Testing
Purpose	Verify software behavior and functionality as a whole system	Verify the interfaces and interactions between software modules
Focus	Entire system as a whole	Interactions between individual modules
Test Environment	Production-like environment	Simulated and controlled environment
Test Scenarios	Emphasis on end-to-end scenarios	Emphasis on testing module interactions
Test Data	Uses standard and realistic data	Uses test data to simulate module interactions
Test Duration	Conducted over a longer duration	Conducted over a shorter duration
Outcome	Identifies defects and bugs in the system	Identifies defects in module interactions
Testing Techniques	Black-box and White-box testing	Black-box and White-box testing
Test Execution Approach	Comprehensive approach, covering all functionalities	Incremental approach, testing one module at a time
Tools and Technologies	Test management tools, defect tracking tools	Test management tools, defect tracking tools
Risk and Impact	Focuses on functional and operational risks and impacts	Focuses on risks associated with module interactions