Reactive work: how much of the week gets hijacked by emergencies

It is Tuesday morning and the planner has the whole week mapped out. Then the packaging line trips, and within the hour three technicians have been pulled off scheduled jobs to deal with it. By Friday the planned work is barely half done, and nobody can quite say how the week got away from them.

That pattern of interruption has a name and a number. Reactive work measures how much of your maintenance effort is consumed by work that breaks into the week rather than reinforcing the plan you started it with.

What it actually measures

Reactive work is the percentage of your total maintenance labour hours spent on work that broke the weekly schedule, regardless of the reason. Usually that means emergency repairs and urgent jobs thrown up by unexpected breakdowns, but the definition is deliberately broader than "breakdowns": anything that forced its way into a committed week counts, including the last-minute priority change that bumps a planned job to make room. This is the scheduling-disruption view of reactivity. It does not ask whether a job was planned in advance, but whether the plan survived contact with the week, or whether the week ran straight over it.

How to work it out

Reactive work (%) = (Hours that broke into the weekly schedule × 100) / Total maintenance labour hours

Last month the team worked 1,000 hours, of which 350 were emergencies and urgent jobs that broke into the schedule.

Reactive work = (350 × 100) / 1,000 = 35%

More than a third of the month went on fire-fighting. That is expensive on its own terms, since a reactive repair typically runs two to three times the cost of the same job done on a plan, but the deeper cost is everything it displaces: the preventive work that would have stopped the next breakdown never gets done, so next month brings more of the same.

Why a reactive plant stays reactive

A high reactive figure is the clearest single sign that a plant is being run by its equipment rather than the other way round, and it is self-perpetuating. The hours lost to today's emergencies are the very hours that should have gone into the prevention that stops tomorrow's, so reaction feeds on itself: the busier the crew is firefighting, the less time it has to remove the causes of the fires. The cost compounds, too. One of the most quoted findings in the field is that for roughly every ten percentage points you shave off reactive work, you hand back about two points of uptime, because the breakdowns you stop are the ones that were quietly stealing production. Reactive work, in other words, is not just a maintenance problem; it is a production problem wearing maintenance overalls.

There is a human cost the percentage only hints at as well. A crew that never finishes what it starts, that is pulled off one job to chase another all week, is a crew that wears down and eventually leaves, taking its knowledge of the plant with it. And the firefighting climbs the organisation: when managers and planners spend their days reacting, the strategic work that would break the cycle is the first thing postponed, which is why a reactive plant so often stays reactive not from ignorance but from sheer lack of time to climb out.

What good looks like

Best-in-class is under 10%, and it is worth knowing how hard-won that figure is: in large surveys of maintenance practice, reactive work is the one category where even otherwise excellent plants routinely fall short. What separates the ones that get there is not, as you might expect, the size of the budget. It is management support and culture, the discipline to protect planned work and keep investing in prevention exactly when the temptation is to throw every available hand at the latest fire. You cannot simply forbid reactive work or order the number down; you have to remove the failures that create it, which is slower, less glamorous, and the only thing that actually works. Many plants on the way down treat twenty per cent as a realistic interim milestone rather than leaping straight for single figures.

Where it can mislead you

• Reactive work cannot fall sustainably unless proactive work rises to take its place, so always read the two together; a drop in one should show up as a rise in the other.
• The metric catches anything that breaks the schedule, not only breakdowns. A last-minute priority change counts too, which is intentional, since it disrupts the plan just as surely.
• A single large breakdown can spike one month, so judge the trend on a rolling average rather than reacting to one bad week.
• A low figure can hide a fragile truce. Check that planned work is genuinely completing, not simply being quietly rescheduled out of the week to keep the reactive number looking respectable.
• Not every unplanned job is a failure of strategy. Deliberately running a cheap, low-consequence item to failure can be a sound, costed decision; the reactivity to worry about is the kind you did not choose.

Reactive work turns the daily feeling of fire-fighting into a percentage you can track, benchmark and steadily reduce. It measures the same trouble that unplanned work and corrective work see from other angles, but it asks the most operational question of all: when the week actually happened, how much of the plan was left standing?