Preventive vs Reactive Maintenance

What is preventive maintenance?

In contrast to reactive, preventive maintenance (sometimes written as preventative maintenance) is where maintenance is carried out before an asset goes wrong. In theory, this proactive approach allows your organisation to avoid issues by nipping them in the bud, thus extending your assets’ lifespans and minimising downtime.

There are a few different types of preventive maintenance; each strategy uses a different factor to determine when maintenance should be carried out.

Types of preventive maintenance

Usage-based maintenance

This maintenance strategy is where maintenance is scheduled after a specified number of hours of use or number of units of work.

For example, a vehicle may undergo an oil change after every 4,000 miles, or a conveyor belt may be maintained after 5,000 hours of operation.

Time-based maintenance

Somewhat simpler than usage-based maintenance, time-based maintenance is a strategy where maintenance is performed at regular intervals. This preventive strategy is also sometimes called calendar-based maintenance.

For example, maintenance on a conveyor belt may occur once every six months, or air conditioning filters may be changed on the first day of every month.

Note: the key feature that differentiates usage-based and time-based maintenance is that usage-based maintenance is based on how much the asset is actually used, whereas time-based maintenance is always carried out after the same time interval regardless of how much the asset is used.

Predictive maintenance

A predictive strategy of maintenance uses asset data and usage information to predict when problems will occur and schedules maintenance before then.

For example, predictive maintenance may involve using sensors to track the temperature of a motor to identify potential issues in advance. Condition-monitoring is a more costly approach to maintenance as it requires more technology and labour, however, it can be a highly effective and proactive way to optimise maintenance.

Prescriptive maintenance

Similar to predictive maintenance, prescriptive maintenance seeks to anticipate when assets will require maintenance so schedules can be optimised. However, the key difference is that it goes a step further than predictive maintenance by collecting data about the asset’s condition and then using artificial intelligence (AI) to anticipate future maintenance needs.

For example, while predictive maintenance will monitor the temperature of a motor and alert you to future maintenance needs when it surpasses a particular temperature, indicating that it may break in the next few weeks, prescriptive maintenance means analysing all the temperature data to predict the asset’s lifespan and schedule maintenance accordingly.

While prescriptive maintenance is the most intelligent solution, it also requires the most data and the most technologically advanced tools to work effectively.

Pros of preventive maintenance

• Reduces equipment downtime: By anticipating equipment maintenance and repair needs and handling these before an asset failure, preventive maintenance reduces unexpected downtime. This means organisations can avoid major disruptions that damage productivity and reduce customer satisfaction.
• Minimises emergency repair costs: In the long run, it can be cheaper to carry out minor repairs frequently instead of waiting for a major equipment failure that is costly to fix. This makes budgeting easier as employing maintenance staff and purchasing replacement parts is more regular.
• Can boost equipment lifespan: With an effective preventive maintenance schedule, your team can optimise asset use and keep equipment in great operational shape for longer. By boosting the assets’ lifespans, this helps you get the best value from assets.
• Improves safety: Preventive maintenance reduces the risk of unexpected and potentially dangerous failure in asset-intensive organisations. With frequent inspections and repairs, you can ensure a safer working environment for employees who use the equipment.

Cons of preventive maintenance

• Can be costly to carry out frequent maintenance: In the short term, preventive maintenance can seem like a costly or unnecessary expense, especially when carrying out non-critical repairs. However, the improved productivity and reduced risk of major breakdown is often seen to be worth this expense.
• Possibility of over-maintaining equipment: With poorly planned preventive maintenance, there’s a risk of over-maintaining equipment, leading to unnecessary costs or downtime, or even in some cases causing damage to the asset. For this reason, it’s important that the preventive maintenance strategy finds the right balance.
• Requires an effective system to track and schedule maintenance: Planning, scheduling, monitoring asset condition, creating work orders, and assigning maintenance tasks can make your equipment maintenance complicated and time-consuming. For this reason, it’s important to use a CMMS or maintenance software to streamline and ensure accuracy in all equipment maintenance.