Three years ago I watched a packaging line go down because a $40 bearing seized. The replacement took forty minutes. The cleaning, recalibration, and missed production window took six hours. The worst part: the vibration data that would have warned us was sitting in a historian database nobody looked at.
That was the project that got me into predictive maintenance with machine learning. And I'll be honest, the ML part was the easy bit. The hard stuff was everything around it.
We started simple. Pulled vibration and temperature data from the PLCs on six critical motors, fed it into a random forest classifier, and trained it on six months of historical data where we knew exactly when failures occurred. The model flagged anomalies about two weeks before the next bearing failure. Two weeks. That's enough time to order the part, schedule the swap during a planned stop, and never lose a minute of production.
But getting there was messy. Half the sensor data had gaps because someone had configured the logging wrong and we were dropping samples during network congestion. The labels were a nightmare too. Maintenance tickets said things like 'motor noisy' and 'fixed it' with no standard terminology. I spent more time cleaning data and arguing with the maintenance team about what counted as a 'failure' than I spent writing model code.
The real lesson was this: the model is maybe twenty percent of the work. You need reliable data pipelines, sensors in the right places, and a maintenance team that trusts the output enough to act on it. We had a false positive in month two that made everyone nervous. The model flagged a pump as likely to fail. Maintenance opened it up and found nothing wrong. Took us a week to discover the sensor mounting had loosened and was picking up ambient vibration from a nearby compressor. Fixed the mount, added a data quality check, moved on.
After a year, our unplanned downtime on monitored assets dropped by about sixty percent. Not because the model was brilliant, but because we were catching things early and scheduling fixes instead of reacting to disasters.
If you're thinking about this, don't start with deep learning. Start with the data you already have, pick one asset, and prove value. The algorithms are commoditized now. The integration work is where careers are made.