The System and Integration testing are the types of testing or test levels required to perform to detect the defects before the launch or delivery of the software product. The system and integration testing are distinguished depending on the which part of the developed software or product the test has been performed. System testing tests the behaviour of the entire system as specified by the scope of a development product. On the contrary, the integration testing tests the interfaces exists or created between components, interaction to different sections of the system like a file system, operating system, Hardware or interfaces among the systems.
The system testing is carried out at the end of the product development cycle while the integration testing is conducted between the product development cycle phase.
Content: System Testing Vs Integration Testing
|Basis for comparison||System Testing||Integration Testing|
|Basic||Tests the finished product.||Validates the collection and interface modules.|
|Emphasis||On the behavior of all module as a whole.||System functionalities interface between individual modules.|
|Performed||After integration testing||After unit testing|
|Covers||Functional as well as non-functional tests||Only functional testing|
|Requires||Understanding of the internal structure and programming language.||Knowledge of just interlinked modules and their interaction.|
|Test cases||Created to imitate real life scenarios.||Build to simulate the interaction between two modules.|
Definition of System Testing
When a software or application product is developed, it is tested at the final stage as a whole by combining all the product modules and this is known as System Testing. The prior aim of conducting this test is that it must meet the customer or user requirement specification. It is also known as an end-to-end test, as it can be performed at the end of the development. The system testing does not depend on system implementation; in simple words, the system tester isn’t aware of which technique among procedural and object-oriented is implemented.
The system testing is broadly classified into functional and non-functional requirements of the system. In the case of 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, in non-functional testing, it checks for performance and reliability through generating test cases in the corresponding programming language.
System testing is carried out in a controlled test environment such as software versions, testware and test data must be governed.
Definition of Integration Testing
Integration testing is the collection of the components (modules) of the software, where the relationship and the interfaces between the different components are also tested. It requires coordination between the project level activities of integrating the constituent components together at a time.
The integration and integration testing must adhere to a building plan for the proper integration and identification of the bug in the early stages.
However, an integrator or integration tester must have the programming knowledge, unlike system tester.
There are levels of integration testing, which involves:
- Component integration testing – It tests the interactions between the software modules and is conducted after component testing.
- System integration testing – In this testing, the various interactions between the different systems are tested, and it is performed after system testing.
Ways to implement Integration Testing
There are several ways to implement incremental integration testing:
- Top-down – The testing control flows from top to the bottom where it emphasis on the architectural structure and begins with GUI or main menu. Stubs are used to substitute the components.
- Bottom-up – It follows a bottom to top fashion in order to carry out integration testing, which uses drivers to substitute the components and systems.
- Functional incremental – The functional requirements are tested instead of structural in this testing strategy. Big-Bang is another variant where the modules are combined first then tested.
Testers or test engineers prefer an incremental approach of integration testing rather than big-bang, as this helps in early detections of the errors and defects. Usually, developers can also do integration testing who know the functional specification of the project but sometimes it also requires specific test engineers to check non-functional specifications.
Key Differences Between System Testing and Integration Testing
- The system testing involves the testing of the completely finalized product to check whether it satisfies the customers, based on the system requirements or not. On the other hand, the integration testing is different from the system in the way that, it tests only some modules and the contraction between them.
- The order of conducting these tests is as follows – unit test is performed priorly over the single modules. Then integration test and at the last the system testing is carried out.
- Integration testing includes just functional requirements of the product through any of the approaches like big-bang, incremental and functional. As against, system testing not only involves functional but non-functional requirements also. Sanity, regression, usability, retesting, maintenance and performance tests are the parts of the system testing.
- System testing can be considered as black box testing where the knowledge of code as well as the structure of the software is necessary. On the contrary, in integration testing, the tester need not know the in-depth knowledge of code.
System testing is a functional process where the functionality of the system as a whole is examined. Conversely, in integration testing, the previously integrated units are integrated according to the functional decomposition tree.