Levels of testing include the different methodologies that can be used while conducting Software Testing. Following are the main levels of Software Testing:
Functional Testing.
Non-Functional Testing.
Functional Testing
This is a type of black box testing that is based on the specifications of the software that is to be tested. The application is tested by providing input and then the results are examined that need to conform to the functionality it was intended for. Functional Testing of the software is conducted on a complete, integrated system to evaluate the system's compliance with its specified requirements.
Unit Testing
This type of testing is performed by the developers before the setup is handed over to the testing team to formally execute the test cases. Unit testing is performed by the respective developers on the individual units of source code assigned areas. The developers use test data that is separate from the test data of the quality assurance team.
The goal of unit testing is to isolate each part of the program and show that individual parts are correct in terms of requirements and functionality.
System Testing
This is the next level in the testing and tests the system as a whole. Once all the components are integrated, the application as a whole is tested rigorously to see that it meets Quality Standards. This type of testing is performed by a specialized testing team.
Regression Testing
Whenever a change in a software application is made it is quite possible that other areas within the application have been affected by this change. To verify that a fixed bug hasn't resulted in another functionality or business rule violation is Regression testing. The intent of Regression testing is to ensure that a change, such as a bug fix did not result in another fault being uncovered in the application.
Non-Functional Testing
This section is based upon the testing of the application from its non-functional attributes. Non-functional testing of Software involves testing the Software from the requirements which are non functional in nature related but important a well such as performance, security, user interface etc.
Performance Testing
It is mostly used to identify any bottlenecks or performance issues rather than finding the bugs in software. There are different causes which contribute in lowering the performance of software:
Network delay.
Client side processing.
Database transaction processing.
Load balancing between servers.
Data rendering.
Security Testing
Security testing involves the testing of Software in order to identify any flaws ad gaps from security and vulnerability point of view. Following are the main aspects which Security testing should ensure:
Confidentiality.
Integrity.
Authentication.
Availability.
Authorization.
Non-repudiation.
Software is secure against known and unknown vulnerabilities.
Software data is secure.
Software is according to all security regulations.
Input checking and validation.
SQL insertion attacks.
Injection flaws.
Session management issues.
Cross-site scripting attacks.
Buffer overflows vulnerabilities.
Directory traversal attacks.
Portability Testing
Portability testing includes the testing of Software with intend that it should be re-useable and can be moved from another Software as well. Following are the strategies that can be used for Portability testing.
Transferred installed Software from one computer to another.
Building executable (.exe) to run the Software on different platforms.
Portability testing can be considered as one of the sub parts of System testing, as this testing type includes the overall testing of Software with respect to its usage over different environments. Computer Hardware, Operating Systems and Browsers are the major focus of Portability testing.
