Software Testing and its fundamentals.

Software Testing is used to identify the accuracy, completeness and quality of a software application. It executes the software under several positive and negative conditions and checks for its compliance, functionality and performance. 

Understanding Error, Bug, Fault and Failure

The human action that results in an incorrect output  is an error. The presence of error while software execution is called a bug. The state of software with an error/bug is a fault.This event of deviation in software functionality from its intended result is called a failure.

 

Test:

A test is an action taken to find out if something is working as it is supposed to work. It involves simulating situations under  which the object is supposed to work.

Test Plan:

It is a descriptive document where the scope of testing, approach, resources, schedule and its related activities are described. The format and the content of a test plan can differ based on the processes, standards and the testing tools being used.

Test Case:

It is a set of conditions or input parameters which is used while execution. The actual output is then compared with the intended output to determine whether the system works as required.

Test Script:

A test script is used in automated testing. It is a set of instructions which are executed in an application under test. Many test automation frameworks can record/generate the test scripts. 

Methods of Software Testing

- White Box method: Also known as open box testing, in this method, the internal structure of the application under test is known to the tester.

- Black Box method: This is a testing method where the internal structure of the system is not known to the tester.

- Gray Box method: Being a combination of white box and black box testing, here the internal structure is partially known. It implies black box testing with access to the internal resources.

- Agile method: It follows the principles of the agile methodology and testing is carried out throughout the development process.

- Ad hoc method: This refers to random testing without any documentation or proper planning.

Levels of Software Testing

The different levels of softwaretesting are as follows:

- Unit Testing: Here individual methods of the application are tested. It is performed by using the white box method. 

- Integration Testing: Here the individual units are combined and tested as a group. Here, any of the white box, black box or grey box methods can be used for testing.

- System Testing: Here, the complete system is checked. This evaluates the compliance of the system with the requirements specified. Generally, the black box method is used to carry out this test.

- Acceptance Testing: This evaluates the system for its acceptability by checking its compliance level with the system requirements specification. Here, black box method is followed for the testing.

Types of Software Tests:

- Smoke Test

- Functional Test

- Usability Test

- Security Test

- Performance Test

- Regression Test

-Compliance Test

Phases of Software Testing

A software testing life cycle, STLC, defines the different phases in software testing. Although the phases are the same, but their sequence differs as per the Software Development Life Cycle(SDLC) followed and the management decisions. The phases may not be sequential as shown. They may also be carried out in parallel as well. The general phases of any STLC are as follows:

- Requirements Review

- Test Planning

- Test Designing

- Setting up Test Environment

- Test Execution

- Reporting

Conclusion

An effective software testing process delivers quality software which satisfies the user's requirements and expectations. It is an important part of Software Quality Control. With the rise in software competition, the need to ensure quality software is now a priority requirement.