The biggest challenge is linking KRIs to specific risks to ensure that they accurately measure and signal potential exposures. If KRIs aren't directly connected to real risks, they won't effectively support risk management efforts. "A key challenge in developing KRIs is ensuring that they are directly linked to specific risks to provide meaningful and actionable insights." - CISM Review Manual 15th Edition, Chapter 1: Information Security Governance, Section: Key Risk Indicators (KRIs)* ISACA's practice questions highlight the importance of clear linkage for effective risk measurement.