A full inventory of all hardware and software is essential for measuring the overall risk to an organization when a new vulnerability is disclosed, because it allows the security analyst to identify which systems are affected by the vulnerability and prioritize the remediation efforts. Without a full inventory, the security analyst may miss some vulnerable systems or waste time and resources on irrelevant ones. Documentation of system classifications, a list of system owners and their departments, and third-party risk assessment documentation are all useful for risk management, but they are not sufficient to measure the impact of a new vulnerability. References: CompTIA Security+ Study Guide: Exam SY0-701, 9th Edition, page 1221; Risk Assessment and Analysis Methods: Qualitative and Quantitative3