Unplanned work: the honest measure of how reactive you still are

A bearing seizes at two in the afternoon. Nobody has the right part on site. A supervisor starts ringing round vendors, a planner is pulled off three jobs in progress to help expedite, and two mechanics stand idle while the right seal is hunted down. By the time the machine runs again, five people's afternoon has been swallowed whole.

That is what unplanned work actually costs. It is never just the repair; it is the entire cloud of scrambling that forms around it, and unplanned work is the metric that measures how often your team lives inside that cloud.

What it actually measures

Unplanned work is the percentage of your total maintenance labour hours spent on jobs that were not formally planned before they began. A job is unplanned when work starts before a planner has assembled the labour, materials, tools and safety requirements into a plan. Emergency call-outs, reactive repairs and jobs done straight off a verbal request all count. It is simply the mirror of planned work, and the two together always make 100 per cent.

How to work it out

Unplanned work (%) = (Unplanned hours × 100) / Total maintenance labour hours

In the same week as the planned-work example, of 1,115 total hours, 448 were unplanned.

Unplanned work = (448 × 100) / 1,115 = 40.2%

Set beside the 59.8% planned figure, the two sum cleanly to 100%, and the message is plain: there is a great deal of work still to move out of the reactive bucket.

Why it is expensive twice over

A high unplanned share is the clearest single sign of a reactive culture, and it costs you on two separate counts. First, the work itself is dearer: a reactive repair typically runs two to three times the price of the same job done on a plan, once you count the overtime, the parts shipped in at a premium, and the collateral damage of a failure caught too late. Second, it bleeds production, because the disruption ripples outward; crews wait, planners abandon planning to chase parts, and uptime slips by roughly two points for every ten points of extra reactive work. So unplanned work is not one cost but a whole ecosystem of them, which is why it sits at the heart of what people mean by a "firefighting" plant.

What good looks like

Best-in-class performance is less than 10%, and reaching it is a story of conversion rather than heroics. One utility, once better scheduling freed up the capacity to get ahead, brought its reactive share down from around 95% to 65% and kept going. The mechanism is always the same: catch the work earlier, through preventive and predictive routines, so it can be planned before it becomes an emergency. Driving the number down is not about banning urgency; genuine emergencies will always exist. It is about removing the conditions that manufacture the unnecessary kind.

Where it can mislead you

• Planned and unplanned must always total 100%, so track the two together.
• Keep overtime and operator-maintenance hours consistent in both the top and bottom of the fraction.
• A stubbornly high figure usually points upstream. The cause is often weak preventive-maintenance compliance or poor defect elimination, not simply a planning office that cannot keep up; treating the symptom by adding planners alone will not move it.
• The single number hides which work is driving the reactivity. Break it down by asset class or work type to find the real sources.

Unplanned work is the most honest measure of how reactive your operation still is, and the most direct lever if you want your team's time back. A plant stuck near half its hours unplanned is not short of effort; it is trapped in a cycle, and watching this number fall, week after week, is exactly what climbing out of that cycle looks like.