To prioritize server replacements based on the likelihood of failure, the MTBF (Mean Time Between Failures) metric is most appropriate. MTBF provides a measure of the average time a server or system is expected to operate before experiencing failure. This allows the management team to assess which servers are more likely to fail soon, irrespective of the application criticality, and thus should be replaced first. CASP+ highlights the use of MTBF in hardware lifecycle management and risk assessments. Reference: CASP+ CAS-004 Exam Objectives: Domain 1.0 - Risk Management (MTBF in Hardware Lifecycle) CompTIA CASP+ Study Guide: Server Risk Assessments Using MTBF and Reliability Metrics