Types of Preventive Maintenance
There are many different types of preventive maintenance, including time-based, usage-based, condition-based, predictive, and risk-based maintenance.
Ideally, a variation of these different types of preventive maintenance should be scheduled for all equipment to help prevent unplanned failures.
Time-based maintenance (TBM)
Time-based maintenance is one of the most common types of preventive maintenance. The time-based method schedules a preventive maintenance task using a predetermined time interval. This could be, for example, every month.
Other examples include regular inspections of important equipment on the first day of every month or once every 90 days. This approach is great for equipment that doesn’t operate nonstop but still requires regular maintenance to prevent deterioration.
There is also calendar-based maintenance, which is similar, but more specifically based around the 12-month calendar year.
Usage-based maintenance (UBM)
The usage-based preventive maintenance schedule signals a maintenance action when equipment usage hits a certain benchmark, like after a certain number of kilometres, hours (of operation), or production cycles.
An example of UBM is routine maintenance being scheduled on a vehicle every 10,000km.
Condition-based maintenance (CBM)
Condition-based maintenance is a strategy that monitors the real-time condition of an asset to determine what maintenance tasks need to be completed. CBM maximises uptime and minimises unnecessary maintenance tasks.
CBM is a form of proactive maintenance that dictates that maintenance should only be performed when specific indicators show signs of upcoming failure or decreasing performance.
For example, CBM will be scheduled when vibration on a component reaches a certain predefined threshold. Once that threshold is reached, it indicates that the part should be replaced or serviced.
Predictive maintenance (PdM)
Perhaps the most sophisticated form of preventive maintenance, predictive maintenance uses advanced condition-monitoring tools and techniques to track the condition of equipment.
Maintenance is performed when certain thresholds or parameters are breached. Examples of this include monitoring vibration in bearings or checking for thermal hotspots in electrical systems.
Risk-based maintenance
This type of maintenance combines condition-based and predictive maintenance elements to prioritise maintenance tasks based on the risk of failure. It weighs an asset’s risk factors and the potential consequences of failure to determine maintenance schedules.
Equipment with higher risk factors will receive more monitoring and maintenance than lower-risk equipment. While it requires a decent amount of knowledge of the risk associated with the equipment, it is a good way to allocate resources efficiently to protect the most important and vulnerable assets to your facility’s operations.