A Plain-English Guide to the Six Common Predictive Maintenance Methods

You've probably heard the pitch for predictive maintenance more times than you can count. Less downtime. Lower repair costs. Fewer 2am surprises. It sounds great until you start looking into the details of actually implementing predictive maintenance (PdM). And then it starts to get very technical, very fast.

At its core, predictive maintenance is about translating equipment data into plant floor decisions to maximize uptime and labor. But you can get to that end goal in dozens of different ways. Choosing the one(s) for you can quickly get overwhelming. That’s why this article focuses on the six most common and effective methods and technologies for predictive maintenance.

This guide breaks down each strategy in plain English. You’ll learn what each method is, what technology it relies on, the situations it’s most effective in, and how to get started. Once you have this foundation, the path to a world-class predictive maintenance program becomes a lot less intimidating.

Key takeaways

• Predictive maintenance isn't a single technology — it's a toolkit of six distinct methods, each designed to catch different failure modes on different asset types.
• For most plants, vibration analysis and oil analysis are the right starting point: broad coverage, low barrier to entry, and fast time to value.
• The barrier to entry for predictive maintenance has never been lower — what once took a year and millions of dollars can now be up and running in weeks.

The six most predictive maintenance methods and technologies

1. Vibration analysis

Vibration analysis is the oldest and most widely used diagnostic tool available to maintenance teams, particularly for any equipment that spins.

How it works

Every rotating machine, like a motor, pump, or gearbox, produces a unique vibration signature. That signature starts to change when something is off with the component. A sensor picks up those changes and analyzes it to identify what is wrong and how severe it is. For example, it can determine if there’s an outer race flaw on the inboard bearing of a motor and estimate that you have eight weeks before it leads to a breakdown.

How to get started

Vibration analysis used to require a highly trained specialist to interpret vibration data. These days, advances in AI and machine learning have encoded that expertise into software. Modern vibration vendors offer programs out of the box. Wireless sensors go on equipment, data streams to data historians, which analyzes readings automatically and creates work orders in maintenance software if an anomaly is picked up.

This combination of diagnostic depth and a low barrier to entry is why vibration analysis is usually the recommended starting point for predictive maintenance.

Best for: Rotating machinery, like motors, pumps, fans, compressors, and gearboxes

Primary failures it catches: Bearing faults, imbalance, misalignment, looseness, and gear wear

Why start here: Broad coverage, highly mature technology, and quick deployment

2. Thermography

Thermography is one of the most intuitive predictive maintenance tools available. If something is running hotter than it should, a thermal imaging camera will find it.

How it works

Any machine with friction or poor lubrication will generate excess heat. A handheld thermal imaging camera detects that heat by capturing the infrared energy that surfaces radiate. The resulting image makes problem areas immediately visible, whether it’s a bearing running hotter than others, a belt wearing unevenly, or an electrical connection starting to fail.

How to get started

Thermography has a relatively low barrier to entry. A technician with a handheld camera can walk a facility and conduct a survey without taking any equipment offline. Many plants start by scheduling periodic thermographic inspections before deciding whether to invest in a more continuous monitoring setup.

Best for: Electrical panels, bearings, belts, motors, and mechanical drive systems

Primary failures it catches: Overheating components, lubrication issues, misalignment, and electrical faults

Why use it: Data is straightforward, requires no contact with equipment, and can be deployed immediately with minimal disruptions

3. Oil analysis

Oil analysis is a very cost-effective predictive tool, although one of the most underutilized by maintenance teams.

How it works

Most rotating and hydraulic machinery relies on oil to lubricate moving parts and carry heat away from critical components. When something starts to wear or break down, evidence of that shows up in the oil, like metal particles, contaminants, and changes in viscosity. Oil analysis works by drawing a small sample from a reservoir or sump, analyzing it, and understanding what the oil contains as well as what it means for the health of that asset.

How to get started

The process is straightforward and requires very little upfront investment. Sample collection kits are inexpensive, and most labs charge between $20 and $40 per sample. Results are typically returned via a report or API, which can feed directly into maintenance software to trigger work orders when a problem is detected. Sampling a few times per year per asset is usually enough to maintain a meaningful picture of equipment health.

Best for: Hydraulic systems, gearboxes, compressors, and any oil-lubricated rotating equipment

Primary failures it catches: Bearing wear, contamination, dirt intrusion, and lubricant degradation

Why use it: Very low cost per data point, no capital equipment required, and easy to get started with minimal technical expertise

4. Ultrasound

Ultrasound is one of the most versatile tools in the predictive maintenance toolkit, capable of detecting both mechanical faults and energy waste in a single device.

How it works

Ultrasound tools detect high-frequency sound waves that can’t be heard by humans. A technician can press the device against a bearing housing and listens through headphones for irregularities. A healthy bearing sounds smooth while a worn or under-lubricated one produces a distinctive rumbling sound. The same device can be pointed along pipework to detect compressed air or gas leaks.

How to get started

Ultrasound is one of the more accessible tools on this list. Handheld devices are relatively affordable, and the learning curve is short. A good starting point is a compressed air leak survey, which tends to deliver fast, measurable ROI by identifying energy losses that can be addressed immediately.

Best for: Bearings, compressed air systems, steam traps, and pneumatic equipment

Primary failures it catches: Bearing wear, lubrication deficiencies, compressed air leaks, and valve leaks

Why use it: Dual-purpose capability, low cost of entry, and fast time to value

5. Motor circuit evaluation / motor current signature analysis

Motor circuit evaluation (MCE) and motor current signature analysis (MCSA) refer to the same family of technology. Together, they make a natural companion to vibration analysis for any facility with a lot of motors powering its equipment.

How it works

Every induction motor draws electrical current as it runs. When something goes wrong, mechanically or electrically, the frequency spectrum of that current changes. MCE/MCSA detects and analyzes those changes using a method similar to vibration analysis, allowing it to identify a comparable range of faults.

How to get started

MCE/MCSA can be implemented through periodic testing with portable equipment or through continuous online monitoring. For most plants, the logical starting point is to layer it onto an existing vibration program, using it to fill diagnostic gaps and add confidence to findings. Vendors in this space typically offer both the hardware and the analytical software needed to interpret results.

Best for: AC induction motors across any industry or application

Primary failures it catches: Rotor bar faults, stator winding issues, bearing defects, and mechanical looseness

Why use it: Strong overlap with vibration analysis makes it a natural add-on, and it can detect electrical faults that vibration alone would miss

6. Motion amplification

Motion amplification is the newest of the big six and solves a class of problems the other five often can’t.

How it works

Every machine moves slightly as it operates, but most of that movement is too small and too fast for the human eye to detect. Motion amplification uses a special high-speed camera to capture that movement, then uses the footage to detect the displacement of every pixel in the image. The result is a visual representation of how a machine, and everything connected to it, is moving during operation. This makes it particularly effective at identifying structural issues like resonance, pipe strain, and piping vibration.

How to get started

Motion amplification is typically deployed as a specialist service rather than an in-house capability, given the cost of the camera equipment and the expertise required to interpret results. For most plants, the best entry point is bringing in a service provider to investigate a specific problem other diagnostics haven't been able to explain, like an unexplained vibration or recurring pipe failures.

Best for: Piping systems, structural components, foundations, and machinery with suspected resonance issues

Primary failures it catches: Resonance, pipe strain, structural looseness, and piping vibration

Why use it: Uniquely capable of visualizing whole-body motion and structural behavior that no other tool on this list can reliably detect

The path to predictive maintenance success: Focus, excel, then evolve

Predictive maintenance can feel like a big, complicated undertaking. But the core idea is simple: the earlier you can detect a problem, the more options you have for fixing it on your terms rather than the machine's.

The six methods covered in this guide create a toolkit. Like any toolkit, you don't need every tool to get started, you just need the right ones for the job in front of you. For most plants, that means beginning with vibration analysis and oil analysis, establishing a foundation of diagnostic coverage, and building from there as your program grows and your team's confidence develops.

The question is no longer whether predictive maintenance is within reach. For most facilities, it is. The question is simply where you decide to start.