Compare Preventative vs Predictive maintenance

 
 

Maintenance strategies can largely be divided into two categories: reactive and proactive. Reactive (also referred to as run-to-fail) maintenance repairs equipment once failure has already occurred. Proactive maintenance focuses on avoiding repairs or asset failure via performing maintenance tasks on equipment prior to failure. Proactive maintenance can then be further divided into two sub-categories: preventive and predictive.

What is Preventive Maintenance?

Preventive maintenance involves conducting regularly scheduled inspections and repairs in order to ensure that failure never occurs. The scheduling of these inspections is based on either time (a period of weeks, months or years) or usage (such as the number of miles a car has been driven). Common tasks carried out during preventive inspections include lubrication, oil changing, replacement of individual parts, adjustment and cleaning.

Preventive maintenance is based on the fundamental principle that the failure chance of any piece of equipment gradually increases as it ages. Later in the equipment’s life cycle, inspection and repair will occur ever more frequently to counterbalance the increased risk. When a piece of equipment should be inspected is often calculated using either a software program or an equation to determine mean time between failures (MTBF). As the MTBF decreases, the frequency of maintenance increases.

Advantages of Preventive Maintenance

A preventive maintenance strategy is often more cost-effective than a reactive one, as it is typically cheaper to perform upkeep than after-the-fact repairs. In addition, preventive maintenance removes the unplanned downtime, loss of production and frequent employee overtime required when a piece of equipment breaks down and must then be repaired.

While preventive maintenance tasks require some training, they can often be carried out by hourly employees, especially the routine tasks such as cleaning and lubrication. This makes preventive maintenance a resource-efficient process as well.

Lastly, preventive maintenance has been shown to successfully increase the life cycle of equipment when compared with reactive or run-to-fail tactics. Companies which utilized a balance of 80% planned maintenance to 20% unplanned have reported the greatest increases.

Disadvantages of Preventive Maintenance

The time-based approach utilized by preventive maintenance strategies can frequently cause either “too much” or “too little” maintenance to occur. When equipment is maintained too frequently, it is considered to be a waste of time and money, and when it is maintained too infrequently, failures can occur and force the more expensive reactive maintenance to be used instead.

In addition, preventive maintenance tasks must be carried out while the machine is not operating. While it causes less overall downtime than run-to-fail tactics, some loss of production and occasionally unnecessary employee downtime does occur.

What is Predictive Maintenance?

Predictive maintenance focuses on observing the actual condition of the machine, so as to carry out maintenance and repair tasks only when performance has degraded and failure is about to occur. A variety of tests, known as condition monitoring, can be carried out either periodically or continuously in order to collect data on the state of the equipment.

Some of the most common tests include vibration monitoring, infrared monitoring, ultrasonic monitoring, and analysis of lubricating oil. These tests can identify a wide range of failures both mechanical and electrical in nature via the analysis of sound, temperature and oil quality. Recently, due to innovations by ProAxion® in the field of vibration and temperature monitoring technologies, it has seen increasing use in comparison to other tests.

Many predictive maintenance programs store data via software, such as a computerized maintenance management system (CMMS) in order to predict future failure and performance trends. Predictive maintenance acknowledges that not all equipment experiences a correlation between age and rate of failure.

Advantages of Predictive Maintenance

Like preventive maintenance, predictive maintenance has been shown to dramatically increase the lifespan of equipment when compared with reactive strategies. However, predictive maintenance has also been found to be more cost- time- and labor-effective than preventive maintenance, which is often performed too frequently. Predictive maintenance will save manufacturing companies a significant amount of money throughout the entire lifespan of the equipment.

In addition, predictive maintenance tasks can be carried out while the equipment is still operating, meaning that no downtime – planned or unplanned – need occur. This is ultimately more cost- and time-efficient in the long run than any maintenance strategy which requires downtime.

ProAxion®’s revolutionary technology, the Tactix™ vibration and temperature monitoring device, is easy to install, easy to use, and the gathered data is easy to understand and interpret. This eliminates the need for lengthy, expensive training, and allows employees at all levels of experience to perform tasks such as data interpretation or the scheduling of maintenance tasks.

Disadvantages of Predictive Maintenance

In the past, predictive maintenance was considered to have several disadvantages. It required expensive, complex testing equipment and featured high up-front costs for both purchase and installation. Interpretation of the data provided by testing equipment also required skilled professionals – it was necessary either to train existing employees extensively or hire a trained contractor.

Now, with ProAxion®’s vibration and temperature monitoring technologies, those disadvantages have been eliminated. Tactix™ is easy-to-use, easy-to-install and, best of all, cost-effective. It provides 24/7 real time data while the machine is still running and detects potential failures early enough that a time- and money-saving maintenance can be scheduled.

Preventive vs. Predictive Maintenance

Both preventive and predictive maintenance offer advantages when compared with traditional run-to-fail methods. Predictive maintenance is more cost-effective and widely usable, but preventative maintenance can still be a viable solution in certain situations.

Therefore, it is best to use both varieties of proactive maintenance in tandem as part of a larger reliability centered maintenance (RCM) strategy. RCM analysis identifies critical failure modes, causes and consequences and then selects the ideal maintenance method for each piece of equipment based on this data. It is the most well-rounded and thorough maintenance solution, incorporating both preventive and predictive maintenance where each is necessary. Contact ProAxion® today to learn more about incorporating RCM strategies into your maintenance process.