Levels of Testing

Brief Levels of Testing: 

At each level there are different possible number of Levels done for Testing . Under each number of 

levels there are individual tests performed and depending the type of SDLC process followed the tests are carries on. Normally there are 4 types of levels i.e 

1. Unit Testing 

2. System Testing

3.  Integration Testing

4. Acceptance Testing

1. Overview of Unit Testing: 

This type of Testing is carried out at the first level or also known as Component Testing or also known as White Box Testing. It mainly refers to verify and test the code functionality at the class level and test the functions part using Constructors and Destructor's.

This type of testing needs the good amount of knowledge to get the flow of the application and is mainly done by developers where they can test the functionality using Code Coverage analysis etc. Unit Testing does not cover entire testing but to test the basic flow of the application and to know the Code coverage.

This is also known as White Box Testing technique where if the Tester has the good amount of knowledge of Coding even the QA does the testing but normally it is assigned to Developer as he will be having entire knowledge of the application and basic flow of functions.

Before Testing starts Developer tries to remove all the errors from the application to get a good stable application.

In Unit Testing the developer tries to test the Code Coverage, Data flow analysis, Peer Code reviews, Static code analysis etc.  

2. Integration Testing:

The next phase of Testing is Integration Testing where the QA starts his testing and verifies the interface between 2 components i.e Component  Integration Testing and System  Integration Testing.

The testing allows you to test between 2 modules in a particular component or 2 systems sharing integrating between each other. As this is important for of level where the integration is important and dependable on one another module. So Both modules has to be integrated and tested successfully. As large number of Bugs raise in this level  of Testing.

3. System Testing: 

This type of Testing is mainly done for checking the Bugs in a particular System. This is also main form of  Testing where all the functionalities are tested and for every Level there are Testing Plan prepared as documentation for each level. Mainly in this type of testing there are few techniques are Boundary Value analysis, Equivalence partitioning, State Transition testing, Use case testing etc.

4. Acceptance Testing:

Final level of testing is done where all the levels are done and gone for client for approval. In this type of testing there are Alpha and Beta form of Testing done. At one end the application is given to client for checking the application and other for End User for any issues.