Electronic Prognostics (EP) is a technique used in high-reliability and high-availability systems to actively and proactively detect faults, allowing the reduction of system downtime and unplanned repairs. The approach of Sun Microsystems to EP consists of a Continuous System Telemetry Harness (CSTH) that is coupled with Sequential Probability Ratio Test (SPRT) and Multivariate State Estimation Technique (MSET) algorithms. This approach provides a unique and complete EP solution, harnessing the rich information from sensors and system variables, and providing means for their storage and analysis. The background theory behind SPRT and MSET techniques as well as their implementation for advanced EP in enterprise servers is presented in this paper. Ó 2007 Elsevier Ltd. All rights reserved.