Preventive or breakdown: the arithmetic most workshops never do

Everybody agrees preventive maintenance is better. Most operations still run on breakdown, and not because the managers are foolish. The schedule loses to the urgent, every week, and nothing in the process makes it win.

The comparison is worth doing properly, because it is less obvious than it looks.

What breakdown actually costs

The repair bill is the visible part and usually the smaller one. The rest: the vehicle is off road for longer because parts were not anticipated; the work happens at whatever rate is available rather than a negotiated one; the trip it was committed to either fails or gets covered at cost; and the failure often damages something adjacent that preventive work would have caught.

Against that, preventive maintenance costs a scheduled slot, parts consumed slightly earlier than strictly necessary, and planned downtime at a time you chose.

Where the obvious answer stops being obvious

Preventive is not free, and servicing everything on a fixed interval wastes money on components that had life left.

The sensible position is somewhere in between, and it depends on what failure costs for that unit. A vehicle on a committed daily route justifies tighter intervals than a spare that sits in the yard. Treating the whole fleet identically is the cheap answer, not the right one.

This is where consumption and downtime history earn their keep. With a year of data you can see which units fail unpredictably and tighten those, rather than tightening everything.

Why the schedule loses

A service is due and the vehicle is needed. The vehicle wins, every time, because the cost of missing the trip is immediate and visible while the cost of deferring the service is neither.

Three things change this. The schedule raises the job automatically rather than relying on someone noticing. Deferral requires an authorisation rather than simply happening. And deferred services stay visible as a list, so the backlog is a number somebody owns rather than an accumulating silence.

None of that is technology. The technology just makes it cheap enough to actually do.

Trigger on both distance and time

A vehicle covering high mileage needs servicing by distance. A vehicle sitting idle still degrades and needs servicing by elapsed time. Systems offering only one of these will under-service part of your fleet, and it will be the part nobody is watching.

Whichever comes first is the right rule, and it requires reliable odometer capture — which is the same gate discipline that everything else in fleet costing depends on.

Common questions