In heavy industries that rely on large-scale, continuous production processes—such as mining, fertilizer manufacturing, and chemical processing—the consequences of unplanned downtime can be catastrophic. While some production downtime is inevitable, how and when that downtime occurs can make the difference between a quick resolution and a costly disaster.
This article explores the true cost of unplanned downtime, the differences between planned and unplanned downtime, and how a well-executed preventive maintenance program can significantly reduce operational risk for process equipment like rotary dryers, kilns, agglomerators, and material handling systems.
Planned vs. Unplanned Downtime
Planned downtime refers to scheduled maintenance, inspections, and process optimization activities. These are expected events, often performed during off-season periods or lower demand cycles, when production losses are minimal and labor and parts can be scheduled efficiently. Planned downtime is part of a preventive maintenance or total productive maintenance (TPM) strategy, allowing plant managers to optimize their maintenance program for efficiency and minimized costs.
In contrast, unplanned downtime is unscheduled and typically results from equipment failure, deferred maintenance, or external disruptions. Because it’s unexpected, it leads to reactive maintenance and can trigger a cascade of costs—lost production, wasted material, emergency labor, missed orders, and even long-term equipment damage. Because it occurs unexpectedly, unplanned maintenance is often characterized by “patch work” – fast fixes with limited resources performed under time constraints, leading to poor quality repair.
The Real Cost of Unplanned Downtime
A run-to-failure approach—where equipment is operated until it breaks—is still common in many plants, especially those facing tight margins or limited staff. However, this method is risky and ultimately far more expensive than investing in preventive maintenance.
According to a 2024 ABB survey, unplanned downtime in the industrial sector costs companies an average of $125,000 per hour, with 23% of facilities experiencing unscheduled outages at least once a month.1 Even more concerning, Siemens reports a 319% increase in downtime costs across heavy industry in recent years due to more complex systems and supply chain pressures.2
Unplanned downtime can expose facilities to:
- Lost production revenue—every hour offline directly reduces production capacity and throughput
- Scrap and rework—materials in process when a failure occurs often can’t be salvaged
- Emergency labor and overtime—technicians may need to be called in after hours or redirected from other tasks
- Increased wear and reduced asset life—emergency restarts and rapid shutdowns accelerate equipment fatigue
- Supply chain and customer penalties—missed shipments damage relationships and may incur financial penalties
- Safety risks—emergency maintenance increases the chance of injury due to rushed or improvised repairs
In facilities where uptime directly impacts overall equipment effectiveness (OEE)—unplanned downtime translates into substantial financial and operational losses.
Consider the following example: Lack of tire reshimming on a rotary dryer at a processing plant leads to excessive wear on tire keepers, putting the tire and tire-mounting system at risk.
With a revenue stream of $10,000 per hour, the plant owner incurs a loss of $80,000 per shift ($240,000 per day) associated with troubleshooting and resolving the issue before the equipment could be restarted. This is in addition to the costs associated with emergency labor, overtime, and expedited parts orders, assuming these resources are available. Were the outage to last a full week waiting on parts, the plant would have experienced production losses of $1,680,000.
By incorporating tire reshimming into their preventive maintenance program, the plant can avoid this type of failure in the future, while also extending the life of their equipment.
The Risk of Deferred Maintenance
While it may be tempting to defer maintenance in the name of short-term productivity, the long-term consequences of this strategy are steep. When maintenance is delayed due to budget cuts, labor shortages, or time pressures, issues that could be addressed easily and affordably become costly emergencies. Deferred maintenance not only increases the likelihood of equipment failure but can also void warranties, inflate repair costs, and shorten equipment lifespan.
How Preventive Maintenance Helps Reduce Downtime
A structured preventive maintenance plan targets the root causes of equipment failure and extends the useful life of equipment. This often includes routine inspections, lubrication, calibration, and replacement of worn parts before failure occurs. Unlike corrective maintenance, which is reactive, or predictive maintenance, which relies on condition-monitoring technology, preventive maintenance is typically calendar- or usage-based.
The U.S. Department of Energy estimates that in addition to increased equipment reliability, facilities relying strictly on a reactive maintenance program could likely save around 20% in costs by instituting a preventive maintenance program.3
Here’s how preventive maintenance helps reduce unplanned downtime:
- Identifies wear early: Prevents catastrophic breakdowns of critical components like trunnion wheels on a rotary kiln or idler bearings on a belt conveyor.
- Improves mean time between failure (MTBF): This metric, combined with mean time to repair (MTTR), helps track and improve reliability and maintenance performance.
- Supports spare parts inventory management: Knowing what parts wear out and when allows for a smarter parts management plan and avoids costly overnight freight charges for emergency replacements.
- Enables efficient scheduling: Planned downtime can be coordinated with production slow periods or included in a preventive maintenance schedule to minimize disruption.
Final Thoughts: The Case for a Facility Maintenance Plan
Avoiding unplanned downtime is less about fixing machines when they break, and more about preventing those failures in the first place. A well-structured facility preventive maintenance program—one that incorporates reliability maintenance, asset inventory management, and a thoughtful parts inventory program—is essential for maintaining uptime, improving process reliability, and maximizing production capacity.
FEECO offers extensive service support to not only inspect your equipment, but also to provide parts and assist in maintenance planning that help to minimize unexpected downtime.
For producers operating in continuous production environments, these tools aren’t optional; they’re fundamental to staying competitive.
Need help developing a preventive maintenance strategy for your process or handling equipment? Contact us today!