It is not uncommon for people to use the terms Preventive Maintenance and Predictive Maintenance interchangeably. Although they are similar in that they describe maintenance measures that are designed to address failures or operating problems from occurring, the ways with which these steps are planned and then executed are very different. Read on to find out what the differences are.
First of all, what is preventive maintenance?
Preventive maintenance measures are planned and performed on equipment with the purpose of ensuring that failures do not occur and to mitigate the consequences of breakdowns. These are routine measures that are completed regardless of the current operating condition, i.e. whether it is working well or not.
These measures are usually determined by time (e.g. every 6 months), events (e.g. every 500 uses) or meter readings (e.g.every 3,000 miles) with parameters that are based on statistics gathered on the expected or average life of the equipment.
This type of maintenance has many advantages compared with Corrective Maintenance which is only performed after equipment failures or breakdowns are reported. Check out our article on the advantages of Preventive vs. Corrective Maintenance for more information.
One problem with Preventive Maintenance is that reports are not based on the actual condition of the equipment. This can lead to some unnecessary maintenance steps being organised which can cost time and money.
What about Predictive Maintenance?
Contrary to Preventive Maintenance, this approach, also known as condition-based maintenance, is based on the current operating condition of an asset at the given tie of maintenance rather than on statistics and previously defined schedules.
The idea is to predict the occurrence of a failure before it ever even happens. This is done by constantly monitoring and testing the condition and performance of the asset in question using techniques such as vibration analysis or oil analysis. When unwanted conditions such as general wear are detected, a repair is scheduled before any actual failure occur. By doing this, you can guarantee that the repairs are both required and on-time which isn’t always the case with Preventive or Corrective Maintenance.
However, the implementation of a Predictive Maintenance strategy is usually more costly than Preventive as there is a need to invest in specific monitoring equipment and to train staff to use it and to interpret the data collected.
So which strategy should you use?
The best strategy is to have a maintenance program incorporating both of these types of maintenance according to each scenario. Remember that considering Corrective Maintenance is still (albeit less) necessary when adopting these strategies.
Maintenance Management Software tools, such as Infraspeak, exist precisely to help you define, perform and monitor your maintenance strategy. If you’re in doubt about investing in this kind of system, check out our article on 5 signs you should invest in a CMMS.