a) Create bi-directional traceability between test basis and test cases. (Test Design)

b) Reporting defects based on the failures observed. (Test Execution)

c) Define the objectives of testing. (Planning)

d) Check planned deliverables have been delivered. (Test Completion)

e) Comparing actual results with expected results. (Test Execution)

So the correct sequence is "c, a, e, b, d"

The test environment set up and validated during ​Test implementation ..... And remember that the test environment is "designed" during the " Test design".

Defect density is a measure of the number of defects found in a software component relative to its size. A higher defect density suggests that the component is more prone to defects and may have more hidden defects that were not found in the initial test cycle.

Why Option A is Correct:

·     High Defect Density in Subsystem C: The fact that subsystem C has a defect density 150% higher than average indicates it is likely to have more defects that have not yet been discovered. Therefore, it makes sense to allocate more testing resources to this subsystem in the next test cycle to uncover these hidden defects.

Why Other Options Are Incorrect:

B: Concentrating testing resources on subsystem A, which has a lower defect density, is not logical because it is less likely to have as many hidden defects as subsystem C.

C: While defect density alone is not the only factor to consider, a significantly higher defect density does provide a strong indicator that more defects may be present, warranting further detailed testing.

D: Equalizing the amount of testing over all modules is not efficient. Testing should be risk-based, focusing more on areas with higher defect densities or critical functionalities.

Example:

·     Subsystem C: If initial tests found 15 defects per 1000 lines of code, whereas the average is 6 defects per 1000 lines, this high defect density suggests more thorough testing is needed.

·     Subsystem A: If initial tests found 2.4 defects per 1000 lines of code, this lower defect density suggests fewer hidden defects are likely present.

By prioritizing testing resources based on defect density, you can more effectively identify and address areas of the software that are most likely to contain defects.

The test process should start as early as possible in the software development lifecycle. Starting the test process early helps identify and address defects at the earliest stages, which is more cost-effective and efficient.

Why Option C is Correct:

·     Early Involvement: Testing can begin during the requirements phase, even if the requirements are still in draft mode. This allows for early identification of potential issues or ambiguities in the requirements, which can be clarified before development progresses further.

·     Benefits of Early Testing: By starting the test process early, testers can create test plans, test cases, and prepare the testing environment. They can also participate in reviews of requirements and design documents to catch defects early.

Why Other Options Are Incorrect:

A. When the code is complete: Starting testing only after the code is complete is too late in the development process. It increases the risk of discovering defects that are more expensive and time-consuming to fix.

B. When the design is complete: Waiting until the design is complete delays the testing process unnecessarily. Testing activities, such as reviewing requirements and preparing test cases, can and should begin before the design phase is finished.

D. When the first code module is ready for unit testing: While this is an appropriate time to start unit testing, it is not the start of the overall test process. The test process includes activities that begin much earlier, such as reviewing requirements and planning tests.

Example:

·     Requirement Review: During the draft mode of software requirements, testers can review the requirements to ensure they are clear, complete, and testable. They can raise concerns or ambiguities that might lead to defects if not addressed early.

·     Test Planning: Testers can start planning the test strategy and designing test cases based on the draft requirements. This proactive approach ensures that the test process is aligned with the development process from the beginning.

By starting the test process when the software requirements are in draft mode, teams can ensure better quality and smoother progression through subsequent phases of development.

If the same tests are repeated over and over again, eventually the same set of test cases will no longer find any new defects. To overcome this “pesticide paradox”, test cases need to be regularly reviewed and revised, and new and different tests need to be written to exercise different parts of the software or system to find potentially more defects.

The mindset of the tester is much more than just show that the system works. Anyone can prove that the system is working , but the tester objective is actually to prove that the system does not work. This will reveal the defects in the system.

Acceptance testing is Testing to ensure that the system meets the needs of the organization and end user.

Unit testing is Testing performed on a single stand – alone module or unit of code.

Regression testing is Testing after changes have been made to ensure that no unwanted changes were introduced

Alpha testing is a type of acceptance testing is where Users test the application in the developers environment.

Big bang testing is a type of Integration testing where all the system's components being combined to form the system at once.

The system is currently operational and about to be retired, so we need to do "maintenance testing" which is done for operational delivered systems.

Maintainability testing on the other hand is done to make sure the system is maintainable and easy to fix defects in it if any. Maintainability testing is done when the system is still under development.

This statement correctly describes the sources from which test cases are derived for both component testing and system testing.

Why Option B is Correct:

Component Testing: This testing focuses on individual components or units of the software. The test cases are derived from component specifications, design specifications, or data models because these documents provide detailed information about the internal structure and behavior of the components.

System Testing: This testing focuses on the complete and integrated system. The test cases are derived from requirement specifications, functional specifications, or use cases because these documents describe the system's overall functionality and how it should behave in various scenarios.

Why Other Options Are Incorrect:

A: While it is true that component testing verifies the functioning of individual software modules, system testing does more than just verify interfaces between components; it verifies the entire system's functionality, including interactions with external systems.

C: Component testing can focus on both functional and non-functional characteristics, depending on the test objectives. System testing also focuses on both functional and non-functional characteristics, but this statement inaccurately suggests a strict separation.

D: System testing is typically the responsibility of a dedicated testing team rather than the users of the system. Users might perform acceptance testing, but system testing is conducted by professional testers.

Example:

Component Testing: A tester writes test cases based on the design specification of a login module to verify that it correctly handles input validation and authentication.

System Testing: A tester writes test cases based on the requirement specification to verify that the entire application, including the login module, user interface, database interactions, and reporting features, works as intended.

By accurately distinguishing the sources and focuses of test cases for component and system testing, option B provides a clear and correct comparison.