This article is for maintenance managers, production managers, plant managers and continuous improvement leaders whose preventive maintenance plan slips week after week because “the line can’t stop”. It addresses one specific question: how to use the stops the plant already suffers (waiting for material, an upstream breakdown, a missing operator, a run finishing early) to bring forward preventive tasks prepared in advance, based on the actual history of machine stops.
- Preventive work often slips because no equipment shutdown is confirmed.
- Recurring unplanned stops are windows, if their duration is measured.
- Prepared task packages can start without delay.
- The CMMS records, stop measurement helps pick the windows.
Why preventive work slips even though machines stop every day
Enearis, a French CMMS software publisher, published Planification des interventions de maintenance : reprenez le contrôle de vos opérations (in French) on its blog. The article explains why maintenance schedules fall behind (emergencies, technical preparation, team capacity, operating constraints) and offers a five-step method, a priority grid and tracking indicators. It points to a gap many shops know well: “Une opération peut disposer d’une date sans que les pièces, les moyens techniques ou l’arrêt de l’équipement soient confirmés.” (in other words: an operation can have a date without the parts, the technical resources or the equipment shutdown being confirmed).
The equipment shutdown is often what is missing. The schedule plans an intervention for Tuesday, production refuses to stop the line, the task is postponed. Yet the same line stops several times a week for other reasons: waiting for material, a breakdown upstream, a missing operator, a run ending early. These unplanned stops are lost time for everyone. Opportunistic maintenance means recovering part of that time, provided you know in advance which stops are usable and have tasks ready to start.
What machine stop history reveals about available windows
An unplanned stop is only useful to maintenance if it is long enough, frequent enough and somewhat predictable. Only measured history can tell you that: manual logs round off durations and miss short stops. The table below is a reading grid to fill in with your own data.
| Type of unplanned stop | What to check in the history | Possible preventive tasks |
|---|---|---|
| Waiting for material or upstream | Median duration, time of day, days affected | Visual checks, lubrication, retightening, technical cleaning |
| End of run or format change | Real time between two runs, consistency from one format to the next | Replacing accessible wear parts, inspection adjustments |
| Missing operator or uncovered break | Frequency per shift, usual duration | Short tasks without heavy lockout |
| Breakdown on a neighbouring machine | Typical duration of the induced stop | Longer tasks, if the stop often exceeds the task duration |
These matches are leads, not rules. Every task must remain compatible with site safety rules, equipment lockout and the skills available at the time of the stop.
Setting up opportunistic maintenance, step by step
- Measure stops over several weeks. For each machine, collect the list of stops with start, end and reason. Without reliable durations, you cannot know whether a 30-minute task fits into a stop of “about half an hour”.
- Identify recurring unplanned stops. Group them by reason and by time slot. For example, a line that waits for material almost every start of shift offers a more predictable window than a random breakdown.
- Prepare task packages. Apply the principle Enearis defends: a prepared intervention has a known duration, parts and resources. Sort preventive tasks by duration (under 15 minutes, under 45 minutes, longer) and store parts and procedures close to the machine.
- Define a trigger rule. For example: if an unplanned stop with a given reason exceeds 10 minutes, the available technician starts the planned short package. The rule is written down, known to production and approved by management.
- Record what was done. A task completed during an unplanned stop is closed in the CMMS like any preventive intervention, so it leaves the backlog.
- Review the grid every month. If a stop reason disappears thanks to production actions, good: the window disappears too, and the preventive task needs a planned slot again.
Indicators to track on the maintenance and production sides
Opportunistic maintenance must not become an excuse to stop planning. It complements the schedule, it does not replace it. Three indicators are enough to stay on course: the number of preventive tasks completed during unplanned stops, the volume of overdue preventive work (which should go down), and the total duration of planned maintenance stops (which can go down for the same workload).
On the production side, OEE must not suffer: a task started during an unplanned stop must never extend that stop. If the line is ready to restart before the intervention is finished, the package was too long for that type of stop. Measured history shows it and lets you adjust.
What TEEPTRAK brings to maintenance planning
TEEPTRAK measures OEE, stops and micro-stops in real time. A module wired into the electrical cabinet and a sensor at the line record each machine’s activity automatically, with no connection to the PLC. Installation takes about one hour per machine and OEE is available within 48 hours. Every stop is timestamped and given a reason, which gives the maintenance manager the real duration and frequency of unplanned stops, machine by machine. The CMMS remains the tool that schedules and records interventions; TEEPTRAK provides the stop measurement that helps choose the right windows. The solution is deployed in more than 700 plants in over 30 countries.
Further reading
- Planification des interventions de maintenance : reprenez le contrôle de vos opérations (Enearis, in French)
- Planning maintenance windows around real machine stop patterns
- MTBF and MTTR: measuring unplanned downtime
FAQ
Does opportunistic maintenance replace planned stops? No. Long, regulatory interventions or those requiring full lockout remain planned. Opportunistic maintenance is for clearing the short, prepared tasks that slip for lack of a window.
How many weeks of history do you need to spot windows? There is no universal duration. You need enough data to see the same stop reasons come back across several shifts and run types. Start with what you have, then refine the grid every month.
Who decides to start a task during an unplanned stop? The rule is agreed in advance between maintenance and production. In the moment, the technician applies the rule and informs the team leader. What matters is that the decision is not renegotiated at every stop.
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