What is the difference between preventive and predictive maintenance?

Preventive and predictive maintenance both aim to act before failure occurs. The main difference is how maintenance timing is decided.

Preventive maintenance is scheduled routinely
Predictive maintenance is scheduled based on actual asset condition

What is preventive maintenance?

Preventive maintenance is planned in advance and performed at regular intervals, typically based on time, operating age, or service recommendations.

The goal is to keep equipment as close to ideal operating condition as possible.

Challenges of preventive maintenance

maintenance may be done when it is not actually needed
maintenance may still happen too late if wear progresses faster than expected
planned downtime increases because tasks are tied to a schedule

What is predictive maintenance?

Predictive maintenance focuses on actual equipment state rather than fixed time intervals.

It is used to predict failure before it happens and gives teams time to plan service in advance.

Challenges of predictive maintenance

may require new technology and sensor infrastructure
may require more training
is more complex than preventive maintenance
can be costly to implement initially

How preventive maintenance differs from predictive maintenance

Approach

Preventive maintenance focuses on preserving the asset through routine intervention.

Predictive maintenance focuses on preventing breakdown by observing actual machine condition and using that information to decide when to act.

Maintenance trigger

Preventive maintenance is triggered by:

time
age
schedule
service intervals

Predictive maintenance is triggered by:

actual asset condition
measured performance changes
sensor signals
risk of failure

Requirements

Preventive maintenance is more schedule-driven and often requires repeated labor and recurring offline maintenance windows.

Predictive maintenance relies more on monitoring, analytics, and targeted action.

Maintenance techniques

Predictive maintenance can use methods such as:

vibration analysis
oil analysis
infrared thermal imaging

Preventive maintenance generally uses scheduled inspection and replacement work.

Intervals

Preventive maintenance happens on a fixed cadence.

Predictive maintenance happens when data indicates it should.

Reactive, preventive and predictive maintenance compared

Reactive maintenance, also called run-to-failure, fixes an asset only after it breaks. It looks cheapest, because little is spent before a failure and the team can be small, but the price is unscheduled downtime, costlier repairs, lost production and safety risk.

	Reactive	Preventive	Predictive
Acts	After failure	On a schedule	When data says so
Trigger	Breakdown	Time, age, service interval	Condition, use, failure risk
Upfront cost	Lowest	Low	Highest
Unplanned downtime	Highest	Medium	Lowest
Best for	Cheap, non-critical assets	Assets with predictable wear	Critical assets where failure is expensive

Run-to-failure is still the right call when an asset is cheap, easy to replace, has low consequence when it stops, or has a spare or redundancy elsewhere in the system. Light bulbs are the classic example. Choose predictive maintenance when failure is expensive, downtime hits production, safety matters and the asset's condition can be measured. Usage-based and condition-based triggers are the usual way in.

Final takeaway

Preventive maintenance is simpler and easier to organize, but it can lead to unnecessary work. Predictive maintenance is more precise, but it requires better data, tooling, and process discipline. The right choice depends on asset criticality, cost, and operational maturity.