The number of preventive maintenance work orders completed from the daily/weekly schedule divided by the total number of preventive maintenance work orders on the schedule. Proactive Reliability Maintenance TM (PRM) SKF defines PRM as a strategy that addresses failures and implements the processes necessary to prevent recurrence.  At the process foundation is a systematic method to benchmark asset productivity and implement corrective actions that reduce total life cycle costs.  In short, PRM enables an organization to take complete control over what is happening on the plant floor.  The SKF Proactive Reliability process is based on four key steps:  (1) Predictive Maintenance, (2) Diagnostics and Root Cause Analysis, (3) Key Performance Indicators, and (4) Operational Review. In industry, PRM is partly compared to design-out maintenance.  For example, reactive maintenance only takes action when a pump breaks down, and in a preventive maintenance setting, the pump is cleaned, re-lubricated, etc., at regular intervals (x operating hours).  In a predictive maintenance setting, the pump may be monitored on-line.  When vibration levels increase, maintenance actions are initiated.  Applying design-out maintenance means the pump is "redesigned" with a different type of lubricant or bearing. Probabilistic Risk Assessment (PRA) A "top-down" approach used to apportion risk to individual areas of plant and equipment, and possibly to individual assets to achieve an overall target level of risk for a plant, site, or organization.  These levels of risk are then used in risk-based techniques, such as reliability-centered maintenance, risk-based maintenance, and Hazop, to assist the development of appropriate