In brief
Preventive maintenance is a strategy in which components are serviced or replaced at fixed time or usage intervals before they fail.
Contents
What is Preventive maintenance?
With preventive maintenance, maintenance intervenes before damage occurs. In common usage, the term refers to the time-based or usage-based variant: parts are changed according to calendar time, operating hours, switching cycles or quantity produced, regardless of their actual condition. EN 13306 defines the term more broadly and also counts condition-based maintenance as preventive; fixed-interval maintenance is called predetermined maintenance there.
The advantages lie in predictability: work can be scheduled during production breaks, staff and materials can be prepared, and unplanned breakdowns become less frequent. The disadvantage is that parts are often replaced even though they would last much longer. This increases material consumption and labour. In addition, rigid intervals do not prevent failures whose cause does not depend on age, and every intervention carries the risk of assembly errors.
Preventive maintenance is particularly suitable for components with predictable, age-related wear and for components whose failure would have serious consequences but whose condition is difficult to measure.
In practice: maintenance and procurement
Because intervals and quantities are known, the parts required for preventive work can be secured well through annual quantities or call-off orders. It makes sense to review the intervals regularly based on the condition of the parts removed.
Synonyms and abbreviations: PM · planned preventive maintenance (PPM) · predetermined maintenance · time-based maintenance · interval-based maintenance
Frequently asked questions
What is the difference between preventive and condition-based maintenance?
Preventive maintenance in the narrower sense replaces or services parts at fixed intervals, regardless of their condition. Condition-based maintenance, by contrast, measures parameters such as vibration or temperature and only intervenes when limit values are exceeded. It makes better use of the parts' service life but requires measuring equipment and analysis.
What are the advantages and disadvantages of preventive maintenance?
The advantages are good predictability, fewer unplanned stoppages and a foreseeable demand for spare parts. The disadvantages are the replacement of parts that are still intact, higher material and labour costs, and the risk of introducing new faults through frequent interventions. Failures that do not depend on a part's age are hardly prevented by fixed intervals.
Is planned preventive maintenance the same as preventive maintenance?
Yes, the terms are used interchangeably. Under EN 13306, preventive maintenance covers all measures carried out before a failure, including condition-based maintenance. In everyday usage, it usually means the interval-based variant, which the standard calls predetermined maintenance.