Testing and Implementation | Testing Strategy In Software Engineering

We begin by testing in the small and move toward testing in the large. Various testing strategies for conventional software are unit testing, integration testing, validation testing, system testing.

Unit testing: In this type of testing techniques are applied to detect the errors from each software component individually.

Integration testing: It focuses on issues associated with verification and program construction as components begin interacting with one another.

Validation testing: It provides assurance that the software validation criteria meets all functional and performance requirements. 

System testing: In system testing all system elements forming the system is tested as a whole. 

Unit Testing:

In unit testing the individual components are tested independently to ensure the quality. The focus is to uncover the error in design and implementation. The various  tests that are conducted during the unit test are described as below. Module interfaces are tested for proper information flow ina nd out of the program.

Local data are examined to ensure that integrity is maintained. Boundary conditions are tested to ensure that the module operates properly at boundaries established to limit or restrict processing. All the basis paths are tested for ensuring that all statements in the module have been executed only once. All error paths should be tested.

Drivers and stub software need to be developed to test incomplete software. The driver is a program that accepts the test data and prints the relevant results. And the stub is a program that uses the module interfaces and performs the minimal data manipulation if required.

The unit testing is simplified when a component with high cohesion is designed. In such a design the number of test cases are less and one can easily predict or uncover errors.

Validation Testing:

The integrated software is tested based on requirements to ensure that the desired product is obtained. In validation testing the main focus is to uncover errors in system input or output, system functions and information data, system interfaces with external parts, user interfaces and system functions and performance.

Software validation can be performed through a series of black box tests. After performing the validation test there exists two conditions.

The function or performance characteristics are according to the specifications and are accepted. The requirement specifications are derived and the deficiency list is created. The deficiencies then can be resolved by establishing the proper communication with the customer.

Finally in validation testing a review is taken to ensure that all the elements of software configuration are developed as per requirements. This review is called configuration review or audit.

Acceptance testing:

The acceptance testing is a kind of testing conducted to ensure that the software works correctly in the user work environment.

The acceptance testing can be conducted over a period of weeks or months. The types of acceptance testing are alpha test and beta test.

Alpha test: The alpha testing is a testing in which the version of complete software is tested by the customer under the supervision of developer. This testing is performed at developer's site. The software is used in natural setting in presence of developer. This test is conducted in controlled environment.

Beta test: The beta testing is a testing in which the version of software is tested by the customer without the developer being present. This testing is performed at customer's site. As there is no presence of developer during testing, it is not controlled by developer. The end user records the problems and report them to developer. The developer then makes appropriate modification.