JNTU B.Tech III SOFTWARE TESTING METHODOLOGIES Previous Question Paper (August - 2022 - R18)

Testing can demonstrate the presence of bugs but never their absence. While it validates that a program meets specific functional requirements, it cannot prove that a system is entirely 'fit for purpose' in a real-world environment, as testing is limited by time, resources, and the impossibility of exhaustive path coverage. Validation is a continuous process of reducing risk rather than achieving absolute certainty.

The following dichotomies define the testing landscape:

• Testing vs. Debugging: Testing is the process of executing a program to find faults, whereas debugging is the diagnostic process of locating and correcting the root cause of a known fault.
• Function vs. Structure: Functional testing (black-box) focuses on what the system does based on requirements, while structural testing (white-box) focuses on the internal logic and code paths.
• Random vs. Partition Testing: Random testing selects inputs without bias, while partition testing divides the input domain into equivalence classes to ensure representative coverage of different logic paths.
• Positive vs. Negative Testing: Positive testing verifies that the system performs as expected with valid inputs, whereas negative testing ensures the system handles invalid or unexpected inputs gracefully without crashing.

Bugs have significant consequences ranging from minor inconveniences to catastrophic failures. These include:

• Economic Impact: Increased costs due to rework, maintenance, and potential loss of revenue.
• Operational Impact: System downtime, performance degradation, or data corruption.
• Safety and Legal Impact: In critical systems, bugs can lead to physical harm, loss of life, or severe legal liabilities and loss of reputation.

Remedies for test bugs (faults in the test suite itself) include:

• Test Case Reviews: Peer reviews of test plans and scripts to identify logical errors before execution.
• Test Automation and Version Control: Using automated frameworks reduces manual errors, while version control ensures that test scripts remain synchronized with the current software build.
• Traceability Matrix: Maintaining a requirements traceability matrix ensures that every test case maps to a specific requirement, preventing redundant or invalid tests.
• Root Cause Analysis: When a test fails, perform a thorough investigation to determine if the failure is due to a genuine software defect or an error in the test environment, data, or script logic.