Reactive maintenance means acting after a failure or defect interrupts normal function. Preventive maintenance means performing planned work at defined intervals or triggers to reduce failure exposure. Neither label alone proves that the strategy is appropriate.
When reactive maintenance may be reasonable
Run-to-failure can be acceptable for low-criticality, inexpensive, non-safety items when failure is obvious, replacement is available, and the operational consequence is small. Even then, the decision should be deliberate.
When preventive work is justified
Planned maintenance is stronger when a failure has safety, quality, production, environmental, or high-cost consequences and when an inspection or task can meaningfully control the risk.
The task must be specific. “Check machine” is not a useful preventive-maintenance instruction. The technician needs the inspection point, condition, method, acceptance limit, evidence, and required action.
Avoid maintenance that creates failure
Excessive disassembly, poor lubrication practice, incorrect parts, contamination, and rushed reassembly can introduce defects. Planned work should be reviewed using history and operating evidence.
Use a mixed strategy
Most factories need a combination of:
- run-to-failure for selected low-consequence items;
- time- or usage-based preventive work;
- condition monitoring;
- failure-finding tasks for hidden functions;
- redesign or defect elimination for recurring problems.
The strategy belongs to the failure mode, not the machine name alone.
Scope note: This general information does not replace a site-specific engineering assessment, manufacturer instruction, statutory requirement, or competent specialist advice.