Software Testing Methods & Levels

Today I shall share some of the modus operandi of Testing that are being widely adopted in the IT industry.

Software testing methods are traditionally divided into white-box and black-box testing.

White Box Testing

 White box testing (also known as clear box testing, glass box testing or structural testing) uses an internal perspective of the system to design test cases based on internal structure. It requires programming skills to identify all paths through the software. The tester chooses test case inputs to exercise paths through the code and determines the appropriate outputs.

Black Box Testing

Black box testing takes an external perspective of the test object to derive test cases. These tests can be functional or non-functional, though usually functional. The tester selects valid and invalid input and determines the correct output. Internal structure of the Test object is not required to be known here.

Testing Levels

Tests are frequently grouped based on where they are added in the software development process. The main levels during the development process as defined by the Software Engineering Body of Knowledge [SWEBOK] guide are unit testing, integration testing, and system testing that are distinguished by the test target without implying a specific process model.

Unit testing

It is a testing usually carried out by programmers to see if individual units of source code are fit for use. A unit is the smallest part of an application.  In procedural programming unit may be an individual program, function, procedure etc., while in object oriented programming the smallest unit is a class.

Integration Testing

Integration testing is a phase of testing in which individual units/modules are tested as a group.

System Testing

It is done on a complete, integrated system to evaluate the systems performance with its specified requirements. System testing falls within the scope of black box testing, and as such, should require no knowledge of the inner design of the code or logic.