Unplanned Downtime
Unplanned downtime is time a process or line is stopped unexpectedly due to equipment failure or faults. It is one of the largest hidden costs in manufacturing — lost production, restart costs and quality losses — and the main target of predictive maintenance.
Unlike planned maintenance windows, unplanned downtime strikes without warning and is expensive: lost throughput, scrap from restarts, overtime and missed orders. Quantifying the true cost per hour of downtime is the foundation of any predictive-maintenance business case, because it sets the value of avoiding a single failure.
Related terms
Predictive Maintenance (PdM) · OEE (Overall Equipment Effectiveness) · MTBF (Mean Time Between Failures) · MTTR (Mean Time To Repair)
Related guides
Software
Augury
Machine health monitoring for rotating equipment using vibration and AI.
Siemens Senseye Predictive Maintenance
Scalable predictive maintenance that learns from existing condition data.
Where this applies
Rolling out structured root-cause analysis · Setting up an OEE measurement programme · Criticality-based spare parts stocking · Planning a shutdown or turnaround · Running a bad-actor review meeting · Conducting an OEE loss-tree analysis