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What is preventative maintenance?
Homyze discusses what preventative maintenance is - different types of preventative maintenance and the benefits of each
What is preventative maintenance?
Preventative maintenance is a maintenance strategy that attempts to anticipate maintenance issues and undertake servicing before failures occur. The objective with preventative maintenance is to keep assets functioning and in a good state of repair so that unscheduled downtime can be minimised.
This strategy is often used by businesses where the costs of downtime can be high, such as manufacturing plants. Because of the interlinked value add nature of these companies, having a fully operational supply chain on premise is of paramount importance.
Preventative (or preventive) maintenance is similar to predictive maintenance in that it should anticipate, rather than respond to, equipment failure. The primary difference between the two is that the servicing frequency is based on intervals of time rather than other data or metrics. In reality, predictive maintenance can be thought of as a subset of preventative maintenance.
For more details on the difference between the two strategies, see this article: What is the difference between preventative and predictive maintenance?
The workflow under a preventive maintenance strategy
Below is an example of the workflow that occurs under a preventive maintenance strategy.
Summary: Preventative maintenance
Preventative maintenance looks at the cost of maintenance in the context of overall business costs. For example, rather than just running an asset until the point of replacement - which could be 1, 2 or 3 years away - and then needing to shutter operations whilst the asset is replaced, preventative maintenance replaces the asset (or component of the asset) after 1 year to try and maximise its uptime.
As you can tell, the cost effectiveness of this strategy is dependent on the variability around useful life of parts and equipment. However, in many instances this is outweighed by the costs of downtime and therefore is still the superior strategy. Preventative maintenance typically includes all servicing and replacement functions such as lubrication changes, filter cleans, parts repairs or replacement.
Preventative maintenance is part of an overall PPM strategy (Planned and Preventative Maintenance). As part of the creation of a PPM schedule, intervals are selected between service visits based on either historical data, the maintenance company’s assessment, or suggested intervals or usage as outlined by independent bodies, for example SFG-20.
Types of preventative maintenance
As detailed above, preventative maintenance relates to all maintenance undertaken in advance of an issue occurring. The means by which a decision is made on when to undertake maintenance differs from one asset to another as well as one company to another. There are, however, four primary types of preventative maintenance strategy.
Time based maintenance
A time based maintenance strategy undertakes maintenance visits at predetermined intervals e.g. monthly or quarterly. Work orders are issued by the computerised maintenance management system (CMMS) such as Cleverly in advance of the upcoming visits.
Usage based maintenance
Usage based maintenance schedules maintenance visits on the basis of the amount of use that assets have experienced, rather than a time interval. This is often done on the basis of meter readings on equipment.
Predictive maintenance uses either data or knowledge to determine when maintenance visits are required. Often this can be done on the basis of a preceding visit where either visual inspections or quality control feedback indicates a need to change service frequency.
Prescriptive (Rx) maintenance
Prescriptive maintenance (sometimes called RxM in the US), is designed to use big data to determine the correct maintenance programme. By using e.g. Internet of Things (IoT) sensors to provide real-time feedback on the assets, this allows for more dynamic decision making on service frequency.
What are the advantages of preventative maintenance?
The primary advantage of preventative maintenance should be reduced downtime of assets, plants and equipment. Often the equipment used by companies is highly complex and needs to be maintained in order to operate efficiently. Particularly where companies are focused on the residual value of their assets, ensuring that they are maintained and that documentation or readings are kept to this effect is critical to the business operations.
The degree to which a preventative maintenance strategy can provide benefits varies from one company to the next and is a function of the costs of downtime, the type of equipment and the expense incurred in increasing the frequency of visits.
What type of assets require preventative maintenance?
As you can likely guess from the preceding paragraphs, preventative maintenance can essentially be applied to all asset types but is particularly appropriate where the cost of downtime is high or where there are health and safety implications from failure of the asset.
This may include assets such as production machinery at a manufacturing plant in the case of the former or emergency lighting in a residential building in the case of the latter. There are of course other, perhaps less obvious situations where a preventative maintenance strategy is appropriate for example in the cleaning of filters in HVAC systems or the scheduled cleaning of high traffic areas to reduce fall risks.
In some instances, preventive maintenance may be a regulatory requirement. More information on best practices for maintenance can be found at the Health & Safety Executive website which provides detailed outlines across all sorts of machinery and asset maintenance.
Any holistic maintenance programme for buildings, plant and machinery will likely include elements of preventative maintenance.
Preventative maintenance refers to any maintenance that is undertaken proactively rather than reactively. The objective of preventative maintenance is to ensure that business costs are minimised by for example increasing asset uptime or ensuring a safe environment for occupants.
Preventative maintenance can be undertaken on a wide range of asset types and on the basis of different determinants.
When considering a preventive maintenance strategy, you must balance the costs of increased maintenance frequency versus the costs of asset failure.
It may be that the first step in implementing a preventative maintenance strategy is to conduct a survey of all assets and equipment and put them into an asset register. From there, you can create a preventive maintenance schedule for each asset based on either the guidance of your facilities manager, manufacturer recommendations, regulatory requirements or independent assessments.