Predictive Maintenance (PdM) is usually thought of as the use of condition monitoring technologies to detect machinery faults at an early stage, allowing planned corrective maintenance on an as-needed basis.These technologies include vibration, thermography, ultrasound, motor current, and oil analysis. Of these, Vibration-based PdM programs have proven their worth in managing rotating machinery, and the techniques and technology have developed to a very mature state. So successful is this technology that it is common for vibration-based PdM programs to provide a Return on Investment (ROI) of less than one year when the savings in unplanned downtime, reduced machinery damage, and lost production are contrasted against the hardware, software and manpower training costs. PdM programs typically use portable data collectors to acquire our spectral and waveform data on a periodic basis. The data is generally taken during steady state operation, and is usually not phase-referenced. This process achieves the intended goal of providing data that can be trended to identify arising problems and providing data that can be analyzed for frequency content and amplitude severity. And it is the frequency content that allows us to begin our analysis process and identify possible fault mechanisms. Because of their effectiveness, vibration based PdM programs are often a plants first step into PdM, the identification and resolution of machinery reliability problems, and moving from a reactive to proactive maintenance environment. And because of that, considerable focus is often placed on the training and technology that is required up-front to produce an effective, efficient analyst that can carry out the required job functions.