Essay: Testing

The term testing is a to discover Errors in the software and hardware part The following are the Testing Methodologies:
o Unit Testing.
o Integration Testing.
o User Acceptance Testing.
o Output Testing.
o Validation Testing.
Unit Testing
Unit testing focuses verification effort on the smallest unit of Software design that is the module. Unit testing exercises specific paths in a module’s control structure to ensure complete coverage and maximum error detection. This test focuses on each module individually, ensuring that it functions properly as a unit. Hence, the naming is Unit Testing.
During this testing, each module is tested individually and the module interfaces are verified for the consistency with design specification. All important processing path are tested for the expected results. All error handling paths are also tested.
Integration Testing
Integration testing addresses the issues associated with the dual problems of verification and program construction. After the software has been integrated a set of high order tests are conducted. The main objective in this testing process is to take unit tested modules and builds a program structure that has been dictated by design.
The following are the types of Integration Testing:
1 Top Down Integration
This method is an incremental approach to the construction of program structure. Modules are integrated by moving downward through the control hierarchy, beginning with the main program module. The module subordinates to the main program module are incorporated into the structure in either a depth first or breadth first manner.
2. Bottom-up Integration
This method begins the construction and testing with the modules at the lowest level in the program structure. Since the modules are integrated from the bottom up, processing required for modules subordinate to a given level is always available and the need for stubs is eliminated. The bottom up integration strategy may be implemented with the following steps:
‘ The low-level modules are combined into clusters into clusters that perform a specific Software sub-function.
‘ A driver (i.e.) the control program for testing is written to coordinate test case input and output.
‘ The cluster is tested.
‘ Drivers are removed and clusters are combined moving upward in the program structure
The bottom up approaches tests each module individually and then each module is module is integrated with a main module and tested for functionality.
7.1.3 User Acceptance Testing
User Acceptance of a system is the key factor for the success of any system. The system under consideration is tested for user acceptance by constantly keeping in touch with the prospective system users at the time of developing and making changes wherever required. The system developed provides a friendly user interface that can easily be understood even by a person who is new to the system.
7.1.4 Output Testing
After performing the validation testing, the next step is output testing of the proposed system, since no system could be useful if it does not produce the required output in the specified format. Asking the users about the format required by them tests the outputs generated or displayed by the system under consideration. Hence the output format is considered in 2 ways ‘ one is on screen and another in printed format.