Full definition
Set of techniques for assessing bearing health during operation without stopping the machine, enabling early defect detection and optimal replacement planning (predictive maintenance). Main methods: spectral vibration analysis (FFT, acceleration envelope), temperature (thermography, RTD sensors), structure-borne ultrasound (30–50 kHz), oil analysis (ferrography). Integrated systems: SKF IMx-8, SKF Enlight Collect. ISO 13373 standard. Savings: up to 40% vs preventive maintenance.