The most important aspect of an incident response management program is the ability to detect incidents in a timely and accurate manner. Without effective detection, the organization cannot respond to incidents, mitigate their impact, or prevent their recurrence. The alerting tools and incident response team are responsible for monitoring the IT environment, identifying anomalies or threats, and notifying the appropriate stakeholders.
References
ISACA CISA Review Manual, 27th Edition, page 255
What is an incident response plan? And why do you need one?
ISACA CISA Certified Information Systems Auditor Exam ... - PUPUWEB