ACCA Audit and Assurance (F8) Practice Exam 2025 – The Complete All-in-One Guide to Achieve Exam Success

The correct choice indicates that dummy tests for control systems utilize both valid and invalid data. This approach is essential because it allows auditors and testers to evaluate how a control system operates under different scenarios. By incorporating valid data, testers can verify that the system functions correctly when provided with expected inputs. Conversely, using invalid data helps identify how the system handles exceptional or erroneous inputs, which is crucial for assessing the robustness and reliability of the control system.

The integration of both types of data ensures that the system is thoroughly vetted, demonstrating its capability to manage a variety of situations effectively. This testing methodology is a fundamental part of control system audits, as it reveals potential vulnerabilities or weaknesses and highlights areas that may require further attention or improvement. The dynamics between valid and invalid inputs are pivotal in understanding the system's behavior and performance.

In contrast, relying solely on historical data would not provide the comprehensive assessment needed for evaluating control systems. Non-existent data might serve a purpose in certain theoretical scenarios but would not reflect realistic conditions in practical testing. Focusing only on negative test data limits the scope of testing and potentially overlooks the necessary verification of proper functionality. Hence, the inclusion of both valid and invalid data is crucial for the thorough evaluation of control systems.