When OEM recommendations fall short: Rethinking maintenance for real-world reliability

In the world of power generation, especially in mission-critical settings, manufacturers’ maintenance recommendations are just the starting point. When I first got into endurance sports, I thought just running a few miles and lifting a few weights would cut it, but real progress took more than that. I had to dial in my nutrition, recovery, and training strategy to perform and not break down. It’s the same with reliability, just following the manual isn’t enough if you want top-tier results. Original equipment manufacturer (OEM) guidelines provide a critical foundation, ensuring equipment warranty compliance, safety, and minimal maintenance standards. However, in practice, these recommendations often fail to reflect the operational realities that affect generator reliability, especially when site conditions push equipment beyond design assumptions. I’ve experienced those real-world challenges first-hand, and I want to share a few best practices that can keep small issues from becoming major failures.

The role of OEM recommendations

OEM maintenance schedules are built around assumptions of standard operating conditions: ambient temperatures, duty cycles, fuel quality, elevation, and load profiles. The recommendations from the OEM are essential, particularly during warranty periods or initial commissioning phases, and they serve as the default for many operators when developing their preventive maintenance (PM) plans.

But that’s where the challenge (or opportunity) begins.

Conditions change- Your maintenance plan should too

In the field, equipment often operates in environments far more aggressive and unpredictable than those assumed by OEMs during the design and testing. Here are just a few of the situations where performance can be impacted:

• When diesel generators run at low loads, wet stacking can occur, causing unburned fuel buildup that degrades performance and could lead to failure.
• Coastal and industrial environments introduce high levels of particulates, humidity, and salt air, which accelerate corrosion and strain filtration systems.
• Microgrid and peak applications frequently involve load transitions or prolonged idling, both of which increase mechanical wear and reduce efficiency.
• Inconsistent fuel quality, such as lower-grade natural gas or diesel in remote or off-grid locations, can compromise combustion and engine reliability.
• Urban and rooftop deployments often face elevated ambient temperatures and restricted airflow, impairing cooling and reducing component life.
• High cycling frequency, with frequent start-stop sequences, places additional stress on mechanical and electrical systems, increasing the risk of early failure.

Under such conditions, the standard OEM PM intervals often prove too infrequent or insufficient, causing key degradation modes that develop over time to go undetected. This is further proof that what works in a lab or test cell doesn’t always deliver the reliability you expect and need in the field.

Failure doesn’t care about your checklist

Strictly adhering to OEM recommendations without regard for site-specific demands can lead to:

• Unexpected failures between preventative maintenance cycles
• Premature component wear, especially in the cooling, fuel, and electrical subsystems
• Misalignment with uptime guarantees, particularly in Service Level Agreement (SLA) based environments
• Underinvestment in condition monitoring or predictive maintenance, which can extend asset life

For generators supporting mission-critical assets like data centers, hospitals, or industrial loads, the cost of failure far exceeds the cost of optimizing the maintenance program.

Standards are a starting point—adaptation is the difference

The solution to maintenance challenges lies in bridging OEM guidelines with Reliability Centered Maintenance (RCM) principles and Failure Modes and Effects Analysis (FMEA). This hybrid approach allows operators to:

• Identify failure modes specific to their site and application
• Adjust intervals and inspection methods based on operating hours, environment, and failure history
• Implement condition-based maintenance (e.g., oil sampling, vibration analysis) for critical components
• Move from time-based to consequence-driven maintenance, focusing resources on what matters most

This enables teams to tailor maintenance strategies that honor OEM intent while being precisely adjusted for real operating conditions, thereby enhancing reliability and lowering lifecycle costs.

If you run it, you own its reliability

OEMs build the equipment that powers your operation. But no OEM knows your site, your fuel supply, or your load profile as well as your operations team does. Relying solely on standard recommendations is like using a one-size-fits-all training plan for an ultramarathon; you’ll start strong, but you may not finish.

Asset owners and operators must take ownership of reliability, building proactive programs that go beyond compliance. That means reviewing OEM schedules regularly, integrating site data, and investing in maintenance strategies that align with your performance expectations, not just design assumptions.

Strategic maintenance: Where reliability meets reality

OEM recommendations are necessary, but not always sufficient. When site conditions exceed design standards, reliability can suffer unless maintenance programs evolve. The most successful operators are those who treat maintenance not as a checklist, but as a strategy, combining OEM expertise with field intelligence to ensure performance where it matters most: in the real world.

You don’t need to have every answer in-house. The key is to turn to your trusted advisors, the people who know the equipment, understand the systems, and have lived through the edge cases and near misses. These are the individuals and partners who can translate experience into action, bridging the gap between textbook expectations and field realities.

Success in complex environments comes from leveraging those relationships, your vendors, technical consultants, and hands-on reliability experts, who’ve seen what works, what fails, and how to make things happen when it counts. With the right approach, even under nonstandard and demanding field conditions, reliability doesn’t just survive, it thrives.

 

This article was originally published on LinkedIn.