Residual risk is the risk that remains after the risk mitigation plans have been implemented. Residual risk reflects the effectiveness of the risk response in reducing the likelihood or impact of the risk. The best evidence that risk mitigation plans have been implemented effectively is the change in the level of residual risk. A change in the level of residual risk can be measured by comparing the risk level before and after the risk mitigation plans have been executed. A change in the level of residual risk can also be evaluated by comparing the actual residual risk with the target or acceptable residual risk. A change in the level of residual risk can demonstrate how well the risk mitigation plans have achieved the risk objectives and met the risk criteria. A change in the level of residual risk can also provide feedback and lessons learned for future risk management activities. References = Residual Risk: Definition, Formula & Management, Residual Risk: What It Is and How to Manage It, Residual Risk: How to Calculate and Manage It.

The most important key performance indicator (KPI) to monitor the effectiveness of disaster recovery processes is the percentage of IT systems meeting the recovery time objective (RTO) during the disaster recovery test. The RTO is the maximum acceptable time that a system or process can be unavailable after a disruption. The disaster recovery test is a simulation of a disaster scenario to evaluate the readiness and capability of the organization to restore its critical functions and systems. By measuring the percentage of IT systems meeting the RTO during the test, the organization can assess how well the disaster recovery processes meet the predefined objectives and standards. Percentage of IT systems recovered within the mean time to restore (MTTR), percentage of issues arising from the disaster recovery test resolved on time, and percentage of IT systems included in the disaster recovery test scope are other possible KPIs, but they are not as important as the percentage of IT systems meeting the RTO. References = ISACA Certified in Risk and Information Systems Control (CRISC) Certification Exam Question and Answers, question 12; CRISC Review Manual,
6th Edition, page 215.

Section: Volume B
Explanation:
Quantitative risk analysis is generally more complex and thus is costlier than qualitative risk analysis.
Incorrect Answers:
A: Neither of the two risk analysis methods is fully objective. Qualitative method subjectively assigns high, medium and low frequency and impact categories to a specific risk, whereas quantitative method subjectivity expressed in mathematical "weights".
C: To be effective, both processes require personnel who have a good understanding of the business. So there is equal requirement of skilled personnel in both.
D: Quantitative analysis generally has a better buy-in than qualitative analysis to the point where it can cause over-reliance on the results. Hence this option is not correct.