In our article on the corrective maintenance trap, we quoted a discussion between maintenance professionals on r/assetmanagement. One detail of that thread deserves an article of its own: the diagnosis offered by u/eWorkOrders-CMMS, who says they work on the CMMS vendor side, about the indicator most teams track — and that misleads them. (These comments were written in English; we quote them in our own words from our French article, so the wording may differ slightly from the originals — see the thread for the exact text.)
“Teams load all their preventive maintenance into the system, but they never block out the time to actually do it. On paper everyone looks busy because lots of work orders are getting closed, but PM compliance is quietly dropping.” It's a sentence that should give pause to any managing director of an industrial SME who steers maintenance by the number of closed interventions.
The indicator that fools everyone
The number of closed work orders is the most natural indicator to look at — it's simple, it rises with activity, it's reassuring. The problem is that it says absolutely nothing about the nature of that work. A team that spends the month firefighting can close as many work orders as, or even more than, a team calmly following its preventive maintenance schedule. The figure goes up in both cases. Only the reality on the shop floor is different.
That is exactly the mechanism described in the rest of the comment quoted in the introduction: “A few months later the same machines start breaking down again, and everyone wonders why they're still firefighting.” The dashboard, meanwhile, won't have seen it coming — because it wasn't looking at the right figure.
The real figure: the preventive/corrective ratio
In the same discussion, u/MYK_Maintenance offers the direct remedy for this trap: “It's also worth tracking reactive vs planned as a percentage, so you can actually see whether it's moving. Hard to improve a number you're not looking at.” The idea is simple to state: out of all the interventions in a month, what proportion was planned in advance, and what proportion was a response to a breakdown that had already happened?
This ratio has a quality that a raw count of work orders lacks: it can't be inflated artificially. If the reactive share goes up, it shows. If it goes down, that's real progress, not a volume effect. It's an indicator that tells a story, where a simple total tells none.
Why this figure is hard to get without the right habit
There is nothing mathematically complex about calculating this ratio. The difficulty lies upstream: every intervention has to be recorded with its type, including — above all — the reactive interventions done in a rush, the ones you are most tempted to jot down on a sticky note before moving on to the next. A paper notebook or a spreadsheet updated only in the evening, if at all, almost never captures this data reliably.
It's the same observation we go into in our article on managing field interventions: what isn't recorded at the time is rarely recorded correctly later. A reliable preventive/corrective ratio requires systematic recording, not occasional recording.
A figure that can't be measured easily always ends up not being tracked. And a figure that isn't tracked can, by definition, never improve.
Record every intervention from the field, ratio included.
See the demoHow to track it without complexity
Tracking this ratio doesn't require a sophisticated dashboard. All it takes is for every intervention to carry one minimal piece of information — planned or reactive — at the moment it is created, not reconstructed after the event. Once that data is reliable, calculating the ratio becomes a simple reading, month after month, rather than a manual reporting exercise.
That is what Rotor-FSM makes possible: every intervention is categorised and logged against its machine at the moment it is carried out in the field, with no re-keying step that would lose this information along the way. Plan details are on the pricing page.
The practical corollary of preventive maintenance is the schedule that supports it: building the periodic inspection schedule for your equipment base.
Why is the number of closed work orders a poor indicator?
Because it says nothing about the nature of the work done. A team can close a large number of work orders while letting its preventive maintenance slide in favour of emergencies, and the indicator will still give the impression that all is well.
Which indicator should you track instead?
The ratio between planned and reactive maintenance, tracked over time. That figure shows whether a team is genuinely getting out of corrective mode, or simply documenting its emergencies better.
How can you calculate this ratio simply?
By systematically recording the type of every intervention — planned or reactive — and then tracking the share of each category month after month. The difficulty isn't the calculation, it's recording the data consistently in the first place.
Can Rotor-FSM track this ratio?
Rotor-FSM records every field intervention with its type and its history for each machine, which makes this tracking possible without having to build extra manual reporting on the side.
The number of closed work orders gives the reassuring impression that everything is moving forward. The preventive/corrective ratio tells the truth — even when it's less comfortable to look at. That is precisely why it is worth tracking.