The most helpful information to review when determining a system’s criticality is the associated business impact analysis (BIA). A BIA is a process of identifying and evaluating the potential effects of disruptions to the organization’s critical business functions and processes. A BIA can help to determine the system’s criticality by assessing its impact on the organization’s objectives, performance, and value. Process flow, service level agreement (SLA), and system architecture are other possible information sources, but they are not as helpful as the BIA. References = ISACA Certified in Risk and Information Systems Control (CRISC) Certification Exam Question and Answers, question 4; CRISC Review Manual, 6th Edition, page 153.