Glossary · Maintenance and diagnostics
Condition-based maintenance
Also known as: CBM, Condition-oriented maintenance
German: Zustandsorientierte Instandhaltung
In maintenance engineering, condition-based maintenance is preventive maintenance that is triggered by the assessed physical condition of an item rather than by a fixed interval. It combines condition monitoring, analysis of the measured data and the maintenance actions that follow from it.
- Maintenance
In one sentence
Condition-based maintenance is preventive maintenance triggered by the measured condition of an item instead of a fixed calendar or operating-hour interval.
Example
A gearbox on a packaging line is serviced when its vibration level exceeds an agreed limit, not every 2,000 operating hours.
How it applies
- Engineering: Condition-based maintenance needs measurable wear indicators such as vibration, temperature, current draw or cycle counts, and a defined limit for each. Sensors and data paths have to be planned into the machine and control software.
- Operation: The control system or a monitoring platform compares the values against limits and raises a maintenance request when a limit is reached.
- Maintenance: Technicians act on the request, record what they found and feed the findings back so that limits can be adjusted.
- Documentation: The maintenance manual should name each monitored parameter, its limit, the message the operator sees and the action to take. Where a safety function depends on the component, the documentation must still state any fixed proof-test or replacement interval that the safety analysis requires.
Condition-based vs. predictive maintenance
Condition-based maintenance reacts to the current state crossing a limit. Predictive maintenance goes a step further and forecasts the remaining useful life from trends, so the intervention can be scheduled before the limit is reached. Both are forms of Preventive maintenance; neither replaces the intervals stated in the Maintenance manual for safety-related parts.