Preventive maintenance vs reactive maintenance is not a contest one side wins; every site does both, and the question is the mix. Reactive maintenance is repair after failure; preventive is work before it. What reactive maintenance vs preventive maintenance looks like on a work order history is a share, and the share is the single most telling figure about how a maintenance function is run. This page puts numbers on each, from this site's worked example, and says where the right mix sits and how a site moves towards it.
What a breakdown costs against a planned job
This site's worked example puts a breakdown at 3.4 hours of a technician and the same work done as a planned task at 1.1 hours. The difference is diagnosis under pressure, waiting for access and parts, and the disruption of an unplanned job. At a $48 loaded rate it is $110.40 a breakdown. On the example's 84 breakdowns a month that is $9,273.60 a month and $111,283.20 a year of technician time alone; the lost output is on top and is usually larger.
What the share says
The example's 240 work orders a month with 35% reactive is a site in the middle: a schedule exists and is partly done. A site above half reactive is running behind its equipment, and its preventive tasks are being deferred to fight fires. A site below a fifth has a schedule that runs and a history that is being read. The share is read from the work order type, which is why every work order has to say which it was.
Where the mix should sit
Not at zero reactive, which would mean over-maintaining assets whose failure is cheap. The right mix has the preventive work on the assets where a breakdown costs more than the task, and accepts reactive work on the rest, with spares. For most sites that is a reactive share well below a third, reached by moving the assets that break most onto inspection or interval tasks, one class at a time, and reading the share each month.
Moving the share
Record the type on every work order, so the share is known. Sort the reactive work orders by asset and find the repeaters. Put a task against each repeater with an interval from its history. Level the schedule to the hours available so the tasks get done. Read the share monthly. The example's preventive programme, 60 jobs and 66 hours at $3,168 a month, is bought against the $9,273.60 of avoidable reactive hours, and that ratio is what a site checks its own figures against.
Questions people ask about preventive maintenance vs reactive maintenance
Is reactive maintenance always bad?
No. On an asset whose failure is cheap and unpredictable, repair after failure with a spare on the shelf is the right strategy. It is bad when it is the strategy for everything by default.
What reactive share should I aim for?
Lower than it is, on the assets that matter. A figure is only meaningful against your own history, and the arithmetic above is how to price the move.
How do I record the type?
A field on the work order: preventive, corrective, reactive. The maintenance log worksheet on this site has it, and a CMMS reports the share from it.