Breaking Down The Main Types of Maintenance

There is a lot of confusion about maintenance types. People often mistake different types of maintenance actions for different maintenance strategies and methodologies.  

This can cause various communication or policy-level misunderstandings within your maintenance team.  

Let’s look at some definitions and examples to set the record straight and get everyone on the same page.

The overview of all maintenance types

When we talk about “maintenance types,” we are broadly referring to types of:

• Maintenance approaches: Refers to the point at which maintenance work is triggered in relation to an equipment malfunction.
• Maintenance strategies: Refers to the overall way a team organizes, initiates, or prioritizes maintenance work.
• Maintenance actions: Refers to the actual tasks completed as part of daily maintenance work. 
• Maintenance methodologies: Refers to the way an organization evaluates its maintenance needs and determines an appropriate maintenance strategy.

In the following sections, we will quickly break down each of these categorizations.  

The two overarching approaches to maintenance: Reactive vs Proactive

Every equipment maintenance task you ever assigned was either reactive or proactive. 

Reactive maintenance is maintenance work that is performed after a problem has been identified, be it a full-blown equipment failure or a minor malfunction. Its purpose is to bring equipment back to an optimal operational condition. Examples include:

• Changing a broken lightbulb
• Fixing a conveyor belt slippage
• Finding where and why a pipe leaks and fixing or patching it
• Troubleshooting a misbehaving CNC machine

In contrast, proactive maintenance is maintenance work that is done before equipment failure, in an effort to prevent it. Examples include:

• Performing a visual inspection to look for rust, cracks, and other signs of deterioration 
• Changing an air filter on your HVAC device
• Performing oil analysis and oil change in your motor
• Applying corrosion-inhibitor coatings to metallic surfaces
• Lubricating dry machine parts to prevent wear and tear.

By default, most of your Work Orders will be reactive (performed to solve a problem that has already occurred), while PMs will be proactive (performed to prevent a problem from occurring).  

Five main types of maintenance strategies

When using the phrase “maintenance types”, this is what maintenance professionals are most often referring to.

There are five main types of maintenance strategies:

• Run-to-failure maintenance strategy (RTF): The maintenance team purposely leaves the asset to run until it fails, then replaces it. Suitable for cheap, disposable, short-life, and non-repairable assets, as well as those with high MTBF.
• Preventive maintenance strategy (PM): Puts equipment on time-based or usage-based maintenance schedules. Suitable for most repairable assets.
• Condition-based maintenance strategy (CBM): Uses condition monitoring technology (like vibration sensors and oil analysis) to check asset conditions and trigger maintenance actions. Suitable for important assets with expensive failure modes.   
• Predictive maintenance strategy (PdM): Uses maintenance history, real-time condition-monitoring data, FMEA analysis, and other inputs to create a complex data model that can predict equipment failures and lifespan. Suitable for critical assets that are expensive to repair or replace.
• Prescriptive maintenance strategy (RxM): An improved version of PdM, this strategy uses algorithms not only to predict failures but also to present you with “what-if” scenarios based on different actions you might want to take. Suitable for critical assets that are expensive to repair or replace. 

What is the right strategy for your facility? That’s a simple question with a complicated answer. 

We recommend applying a mix of maintenance strategies, based on asset criticality and the available internal resources.

Learn more in our in-depth guide: Head-to-head Comparison of 5 Best Maintenance Strategies. 

Six main types of maintenance activities

As we mentioned earlier, the maintenance work you are doing on a daily basis will be either reactive or proactive.

Reactive maintenance actions can be roughly divided into three categories:

• Emergency maintenance: These are  “all hands on deck” situations that happen when you need to fix a critical asset (unexpected failure of electrical power generator) or perform repairs to remove a safety issue (gas leak, steam boiler explosion, fire hazard…). 
• Corrective maintenance: Describes work performed to correct minor issues on (partially) functional equipment to return it to normal operating conditions. Some use the phrase as a synonym for performing any type of repair. 
• Other repair work: Includes all other reactive maintenance activities that aren’t covered by the above two categories.

Broadly speaking, proactive maintenance actions are all those routine maintenance tasks you perform to keep failures at bay. They can be categorized based on how they are triggered:

• Time-based maintenance actions: These tasks are performed on a daily/weekly/monthly/etc. basis, regardless of the condition or usage of the equipment, and include things like daily inspections, changing a filter every two months, or lubricating a piece of equipment every Monday.
• Usage-based maintenance actions: These are triggered by asset use, regardless of its condition, and include tasks like changing the oil in a vehicle after X miles/kilometers.
• Condition-based maintenance actions: These are typically triggered by a condition-monitoring sensor that notices that a certain asset part is deviating from a set threshold or level of functioning. 

Regardless of the maintenance strategy you are using, you will always find yourself carrying out every type of maintenance action above at some point or another.

Hopefully, proactive maintenance actions will significantly outnumber their reactive counterparts.

Maintenance methodologies you should know about

Maintenance methodologies represent a set of actions and principles that can be applied on top of any maintenance strategy.

In many cases, you can actually use them to find the ideal maintenance program for specific assets.

Reliability-centered maintenance (RCM)

Reliability-centered maintenance provides a method to identify critical organizational assets, understand the impact of their failure, and find the most cost-effective ways to minimize those impacts.

RCM forces you to gain a deep understanding of your maintenance processes. 

The results of the analysis leave you with invaluable information you can use to select the best-fitting maintenance strategy to predict and prevent equipment failures.

Risk-based maintenance (RBM)

Risk-based maintenance provides a framework you can use to determine the most economical use of your maintenance resources. 

It is based on Probability of Failure (PoF) and Consequence of Failure (CoF) factors which are used to plot a criticality matrix. You can see an example below.

In essence, RBM helps you find the critical/problem assets and dedicate your maintenance resources to them — while diverting resources from non-critical assets.

For an A+, you can run RBM to identify critical assets, and then run FMEA and RCM on those assets to determine their optimal maintenance program. 

Total productive maintenance (TPM)

Total productive maintenance is often referred to as a maintenance strategy. However, that’s not really correct since you still need to select maintenance strategies to use within your TPM framework. 

TPM is a unique philosophy that is applied in manufacturing facilities in an effort to create an ideal production environment with zero defects, zero equipment breakdowns, zero accidents, and zero waste. 

TPM extends way beyond the maintenance department. The whole organization has to be involved in a years-long continuous improvement effort to get close to that ideal. It includes initiatives like autonomous maintenance which can be implemented as a standalone improvement to your maintenance operation.

Simplify your maintenance management with Limble CMMS

CMMS solutions exist to help you organize, automate, and streamline maintenance work.  Whether it is a strategy, approach, or methodology, a CMMS will be instrumental in the success of whatever type of maintenance you are using.

For a small monthly fee, you get the ability to completely digitalize your maintenance operations. Maintenance history, work orders, SOPs, assets, parts, vendors, invoices, and more — all in one place, easily accessed with a couple of taps on your mobile device. 

In other words, CMMS software is the foundation you can use to build and run a cost-effective maintenance program based on any combination of maintenance strategies.  

To learn more about Limble CMMS, schedule a free product demo, start a free trial, or spend a few minutes in our online self-demo.