What is the reasonable approach to determine control effectiveness?

Determining control effectiveness involves evaluating whether the control is successfully achieving its intended objectives, which is the focus of the correct response. Effectiveness is ultimately measured by how well a control prevents, detects, or corrects issues related to risks. If a control fails to meet its objectives, it cannot be deemed effective, regardless of its type or capability to notify of failures.

When assessing control effectiveness, understanding that controls serve specific purposes is crucial. Controls are designed to manage risk, and thus their ability to fulfill these purposes directly correlates to their effectiveness in risk management. This evaluation usually involves testing the control against scenarios that reflect potential risks and assessing if the control appropriately mitigates those risks.

The other approaches, while they provide insight into controls, do not directly measure effectiveness in the context of risk management. For instance, identifying whether a control is preventive, detective, or corrective is useful but does not assess how well it operates in practice. Similarly, reviewing a control's capability for notification of failure or assessing its reliability can be part of a comprehensive evaluation, but they do not inherently confirm that the control meets its key objectives. Therefore, the emphasis on the control's ability to meet intended objectives is fundamental for understanding its overall effectiveness.