Beyond the Symptoms: The Root Cause Behind 10 Critical Failures

From the presentation given at CMC (Congreso de Mantenimiento y Confiabilidad), Conference of Maintenance and Reliability in Cartagena, Columbia in June 2025 and Chile November 2025.

Equipment failure is often treated like a mechanical mystery. When a bearing overheats, a gearbox leaks, or a motor vibrates itself into early retirement, the focus immediately lands on the physical symptom. Teams investigate the component, the hardware, the environment, or the lubricant. They run down lists of potential causes, focusing on the heat, contamination, or lubrication, and usually assign blame to the most visible issue. While this approach is understandable, it is incomplete. Behind the scenes, deeper, more common threads connects these failures, and almost every plant struggles with them.

To uncover those common threads, you have to look past the symptoms. You must repeatedly ask why rather than settling for the first answer that surfaces. Only then does the real story emerge. 

Survey Says… (and Why It’s Only the Surface) 

Across the hundreds of assessments and responses I’ve reviewed, there are a few failure modes consistently rising to the top as the most common contributors to equipment breakdown. These categories appear so frequently that many organizations assume they represent true root causes. In reality, they are often only the outward mechanical expressions of deeper maintenance and reliability issues. Still, these offer a useful starting point because they reflect what people experience is causing failures. 

Failure Mode #1: Overgreasing (and Undergreasing)
Plants often assume more grease equals more protection, but survey data tells a different story. Overgreasing causes excessive heat, forces seals to fail, increases energy consumption, and ultimately shortens bearing life. The physical consequence is visible, but the underlying reason it happened is rarely mechanical.

Failure Mode #2: Contamination
This includes particles, moisture, and debris that compromise lubricant quality, accelerate wear, and destroy seals and surfaces. It’s one of the easiest problems to prevent, yet it remains one of the most widespread across industries.

Failure Mode #3: Using the Wrong Lubricant
Mismatched viscosity, incorrect base oils, incompatible additives, and seal incompatibility cause countless failures. When the wrong lubricant enters a system, the domino effect is almost predictable: heat rises, surfaces deteriorate, and component life drops significantly. This can also include overuse of degraded lubricants. 

Failure Modes #4 and #5: Imbalance and Misalignment
These two appear in nearly every reliability analysis. Imbalance generates excessive vibration, accelerates fatigue, and amplifies other failure modes. Misalignment adds structural stress, increases wear, consumes more energy, and often results in coupling failures or shaft fatigue. These problems often show up in trending data long before a machine fails, but often aren’t corrected when they’re detected – why is that?

Failure Mode #6: Seal failure
This is a contributor to lubricant leakage and contaminant ingress. Seals often fail prematurely not because of design flaws, but because of improper installation, incorrect lubrication, contaminants, or inadequate verification practices.

Failure Mode #7: Recurring Incorrect Installation
This includes improper torque, contamination during assembly, missed clearances, and the absence of verification steps. Many machines are effectively “born” with defects simply because installation practices lack structure or training.

Rounding out the top 10 failure modes are corrosion, overloading, and electrical faults. These were common survey responses that describe the physical failure observed in the field. Each can cripple equipment, shorten life, and create unnecessary maintenance cycles.

At first glance, these ten failure categories seem like a complete explanation of why equipment fails. But they aren’t. They describe what failed, not why. They document symptoms, not the root cause. And if you follow that thread deeper, you’ll find that all ten ultimately point in the same direction.  

Ask “Why?” Until the Mechanical Answers Run Out 

The turning point in most investigations comes when you stop accepting the first answer. Why was the bearing overgreased? Why was the wrong viscosity selected? Why did contamination enter the system? Why wasn’t imbalance corrected? Why did the seal leak in the first place?

Each time you ask “why,” the responses inch closer to a human factor: an action, a decision, an assumption, a gap in knowledge, or a missing expectation. Rarely does the final answer point to a hardware flaw, a vendor defect, or a design limitation. Nearly every path leads back to people.

This is not a criticism of maintenance professionals. Quite the opposite: it’s an acknowledgement that reliability lives and dies by human behavior. Lubrication excellence, precision maintenance, inspection quality, contamination control, route discipline; none of these succeed because machines ask for them. They succeed because people understand them, value them, and consistently execute them.

This philosophy has shaped Noria from the beginning. The core principles are simple: 

• Maintenance is the most controllable expense in a plant.
• Every plant has a “hidden plant” locked behind preventable losses.
• Lubrication is the No. 1 cause of wear and failure.
• Nothing influences lubrication more than human behavior and training.

The more you peel back mechanical failures, the clearer the pattern becomes: the machine failed, but the failure started with the decisions surrounding the machine. 

The Human Element: The True Root Cause Hidden in Plain Sight 

One of the most telling statistics comes from decades of research: 70% of production losses are directly tied to human error. The number is consistent across industries—chemical, automotive, mining, food and beverage, power generation, and more. Yet many plants still invest more in sensors, hardware, and diagnostics than they do in the people who operate them.

When people feel unprepared or unsupported, their work reflects that reality. When they are trained, empowered, and given clear expectations, their performance rises and so does the reliability of the machines they maintain.

Hear me clearly: Human error isn’t the enemy of reliability.
Lack of training is.
Lack of clarity is.
Lack of structure is.
Lack of accountability is.

People want to do good work. When they do, they feel better about their job and their contribution. Reliability improves when the workforce is confident in what it’s doing, not when machines are simply monitored more aggressively.

The economics of education reinforce this. A plant that avoids spending on training is not saving money. It is borrowing failure from the future. A dollar withheld from training can cost hundreds in unplanned downtime, repeated component replacements, excessive lubricant consumption, and reactive firefighting.

In other words, training is not an expense. It is a multiplier.  

When Good Intentions Meet Weak Execution 

Most plants don’t fail because no one cares. They fail because execution breaks down somewhere between intention and action. You can see this in real-world examples every day. 

1.  A plant installs high-quality breathers but they never saturate (or dry the headspace they were intended to) because airflow patterns were misunderstood. Someone did the right thing on paper, but the core objective wasn’t understood. That is not a hardware issue. It is a training issue.
2. Lube lockers show signs of effort with labels, shelves, product storage, but dates don’t match, delivery times are unclear, and quality checks are missing. Again, the problem isn’t the equipment; it’s the lack of standardized practices.
3. Oil analysis programs suffer from inaccurate samples, even when plants have invested in good valves, sample points, and tools. Why? Because training on sampling technique was never reinforced. Good sampling hardware can’t make up for inconsistent or substandard human execution.
4. Lubrication routes often rely on generic procedures that lack detail, condition-based decision points, or verification steps. Without training and a centralized system to track compliance, tasks devolve into “check-the-box” activities done by uninvested techs rather than precision procedures done by people who understand why what they’re doing matters.
5. Lube rooms sometimes show impressive investments into tanks, racks, color-coding, and filtration, yet airflow paths, contamination controls, and cleanliness standards reveal no quality control. The effort is there, but the structure is not. 

These cases show a consistent pattern: equipment doesn’t fail in a vacuum. People, processes, and culture dictate outcomes. The mechanical symptoms simply reveal where the process broke down. 

Culture: The Missing Link in Sustained Reliability 

Industry veterans often say that reliability is “80% culture and 20% everything else.” They are not exaggerating. Even plants with strong reliability programs experience failure when leadership, staffing, or priorities shift. The cycle is predictable: management invests in reliability, performance improves, new leadership arrives, budgets tighten, training is cut, and reliability collapses. Years of progress evaporate overnight.

Experts have often referred to this phenomenon as the Reliability Cycle of Despair, a repeating loop that undermines long-term success. Without a “corporate memory”, an institutionalized commitment to training, standards, and practices, plants are vulnerable to the same failures every few years.

Sustained reliability isn’t built on tools. It’s built on consistency. And consistency comes from culture.  

Breaking the Cycle: Training as the Central Strategy 

The turning point for most organizations comes when they recognize that technical excellence begins with human excellence. Investing in training shifts the mindset from reactive repairs to proactive care. It brings clarity to lubrication practices, inspection techniques, contamination control, and condition monitoring. It fosters ownership. It transforms maintenance from a cost center into a competitive advantage.

To break the cycle and eliminate the true root causes of failure, organizations must: 

• Provide intentional, ongoing training.
• Create clear, visual standards for lubrication and maintenance practices.
• Establish quality checks and verification routines.
• Treat lubrication as a precision task, not an afterthought.
• Align maintenance, operations, and leadership around shared goals.
• Reward consistency and craftsmanship.
• Reinforce behaviors that drive machine health.

 As stated earlier, every plant has a hidden plant within it. An untapped reserve of reliability, performance, and capacity. That hidden plant is unlocked not by new machines, but by the people who operate and maintain them.

Machines don’t fail themselves. People don’t fail on purpose. But people cannot execute what they haven’t been taught, empowered, or equipped to do.

The real root cause behind equipment failure isn’t the grease, the bearing, the seal, or the alignment. It is the absence of training, structure, and culture that gives people the ability and the confidence to care for machines correctly.