Condition Monitoring

A maintenance strategy that uses condition monitoring data, analytics, and failure prediction models to determine the optimal timing for maintenance intervention. Predictive maintenance aims to perform maintenance just before failure is expected, maximizing equipment life while minimizing unplanned downtime. It goes beyond condition monitoring by adding prediction — estimating the remaining useful life based on degradation trends.

The time between the point at which a potential failure is first detectable (P — the onset of detectable degradation) and the point of functional failure (F — the point at which the item can no longer perform its required function). The P-F interval determines the maximum inspection interval for condition-based maintenance — inspections must occur at intervals shorter than the P-F interval to detect the developing failure before functional failure occurs.

A graphical representation of the degradation trajectory of an item from the point of initial potential failure (P) to functional failure (F). The P-F curve shows how condition deteriorates over time and where different inspection or monitoring techniques can detect the developing failure. The area between P and F represents the window of opportunity for planned intervention.

A measurable parameter that provides information about the current health or degradation state of an equipment item. Condition indicators include vibration levels, temperature, pressure, flow rate, electrical current, oil quality parameters, thickness measurements, and any other quantifiable parameter whose change indicates a developing failure. Each indicator has defined alert thresholds (warning and alarm levels).

A qualitative rating of the probability that an inspection activity will correctly identify and characterize the damage present in the inspected equipment. Inspection effectiveness is categorized from A (Highly Effective — high probability of detecting the damage) through E (Ineffective — virtually no chance of detection). The rating depends on the inspection technique used, the skill of the inspector, the coverage area, and the damage mechanism being sought.