L10 Life (90% reliability) model based on two-parameter Weibull distribution was introduced by Lundberg-Palmgren in 1947 and subsequently became a de facto industry standard. But, American Gear Manufacturers Association is now specifying gearbox with 95% and higher levels of reliability. A significant barrier to estimate bearing reliability analytically is the poor current understanding of the processes of running-in and of the interactions between plastic deformation, wear, lubricant chemistry and damage accumulation. For this reason, semi-empirical approach is preferred and this needs extremely meticulous and time consuming fatigue experimentation and fault -tolerant experimental apparatus. The author discusses critical design issues of experimental apparatus, judicial selection of sensors and fault-tolerant instrumentation, and robust algorithms for bearing health monitoring. The various models and estimation methods for predicting bearing reliability beyond 90% are discussed and compared with standard models. This book also deals with Artificial Neural Network based incipient fault detection and residual prediction models for rolling element bearings.