Preventive Maintenance: What It Is, Types, Examples and Benefits

It could be useful, for example, to understand the difference between preventive vs predictive maintenance in more depth.

Types of preventive maintenance

Many people use preventive, predictive and prescriptive maintenance interchangeably. But while all of them fall under the preventive scope, they differ in execution. We divide the different types into six categories: time-based, usage-based, condition-based, risk-based, predictive and prescriptive, starting with the simplest.

Time-based (calendar-based) maintenance (TbM)

As the name implies, this strategy is based on fixed intervals. It could be daily, weekly, monthly or yearly, depending on the asset and your production cycle. It is easy to implement and helps keep work organized, especially when handled through preventive maintenance scheduling tools. CheckProof's Planning Tool, for example, is designed to simplify scheduling and give full visibility of all your teams and tasks at hand. Servicing your conveyor belt every three months is an example of calendar-based or time-based maintenance. Essentially here, time is the trigger.

This is maintenance that will be carried out regardless of what the state of your asset is. Although a common method, it's also a process that is resource-heavy, as it can involve superfluous checks or, at the other extreme, result in insufficient maintenance and equipment breaking between scheduled maintenance dates.

However, time-based maintenance is still preferred over reactive care and acts as a minimally viable level of maintenance for heavy industries.

Example: Heavy machinery and OEM equipment often have set dates and time intervals for checks. It fulfills a function as it still ensures a check happens with continuous intervals.

Usage-based maintenance (UbM)

Usage-based maintenance is the practice of employing triggers based on the usage of assets. The method enables you to set up routines and schedules around actual use and predefined parameters, facilitating just-in-time maintenance that reduces costs and prevents asset failure. For example, you can set up triggers that activate after a specific amount of active running time or production.

When the trigger is the actual condition of the asset rather than how much it has been used, it is condition-based maintenance, covered in the next section.

Example: An example is tracking the tonnage that passes over a conveyor belt. After the conveyor belt has handled 10,000 tons, you will want to set a trigger to ensure a maintenance check is done.

Usage-based maintenance is especially beneficial when you implement a CMMS or preventive maintenance software that tracks asset use and automatically creates a task or set of actions for your employees to complete when a threshold is triggered. In CheckProof, routines can run on nine interval types, including odometer-based intervals.

Condition-based maintenance (CBM)

Condition-based maintenance (CBM) means doing maintenance when the measured condition of an asset shows it is needed, instead of at a fixed date or usage count. You set a limit for a measurement, such as temperature, vibration, wear or oil quality, and the work is triggered when a reading crosses it.

The condition data can come from two places:

• Sensors and connected machines: continuous readings such as bearing temperature, vibration or hydraulic pressure, streamed from telematics or the control system.
• Inspections and rounds: readings your frontline team takes and records, such as liner thickness, belt wear or oil sample results.
  That second source matters. Condition-based maintenance does not have to start with sensors. Many sites begin by recording measurements during routine inspections and setting limits on them.

Example: A crusher's manganese liners are measured during a monthly inspection. When the thickness falls below the limit set from OEM guidance, a liner change is planned for the next scheduled stop. Another example is a conveyor drive gearbox: if its oil temperature rises above a set level, it is checked before the bearing fails.

Condition-based maintenance avoids replacing parts that still have life left, which is the main weakness of time-based maintenance. The trade-off is that you need reliable measurements and clear limits for each asset.

Condition-based vs predictive maintenance: the two are closely linked. Condition-based maintenance acts when a reading crosses a set limit today. Predictive maintenance analyzes trends in the same data to forecast when that limit will be reached, so work can be planned further ahead.

In CheckProof, data streamed from connected machines can be checked against set limits. When a value is out of range, it is flagged and turned into a work order for immediate action

Risk-based maintenance (RBM)

This is the practice of prioritizing maintenance routines towards your most valuable assets. If key machinery or assets break down, it could put a strain on resources, such as time and the bottom line. Risk-based maintenance categorizes your maintenance tasks based on the risk each asset poses to entire production lines if it is left unchecked.

Example: Typically, in a processing plant, the most expensive and more complex parts, such as crushers, will need specialists to come in and fix an issue. So, this type of equipment often has risk-based maintenance applied to it, as the cost of unexpected downtime and rushing out specialist personnel to resolve sudden issues will be high.

A failure mode and effects analysis (FMEA) is a practical way to rank which assets carry the most risk. Read more in Why your FMEA is sitting in a binder.

Predictive maintenance (PdM)

The concept of predictive maintenance itself is not new. But the advancement in technology and the Internet of Things facilitates a new way of working predictively where sensors, algorithms and data help you anticipate when servicing is due. And when you create routines based on data, you enable your frontline team to carry out maintenance exactly when needed: not too early nor too late. According to the U.S. Department of Energy, predictive maintenance provides savings of up to 40% over reactive maintenance.

To get the most out of modern predictive maintenance using IoT, you need to adopt preventive maintenance software, or a CMMS system that collects historical data from assets and makes it accessible to employees. Your site managers can review the data to identify upkeep trends and patterns, enabling them to predict when downtime will occur, and schedule maintenance to prevent or minimize it.

PRO INSIGHT: Curious about how predictive maintenance works in practice?

Construction material supplier Swerock wanted to perform their preventive maintenance inspections on time, but not too early or more of it than necessary. To achieve this, they implemented automatic monitoring of predefined parameters for vibrations and temperature of their assets to detect maintenance needs in time. They already see a great cost and time-saving potential: "Our employees no longer need to physically go out to each machine and make a subjective assessment of its status. This gives us more time for tasks that require hands-on effort." Swerock has reduced its maintenance costs by 33%.

Prescriptive maintenance

Prescriptive maintenance is the most sophisticated type of maintenance. On top of using data to predict downtime and breakdowns, prescriptive maintenance leverages machine learning and artificial intelligence software to pinpoint optimally timed maintenance and provide an outcome-focused suggestion based on the asset's analytics. The software is developed to be able to detect deviations and irregularities in a machine's behavior. When detected, the system flags the anomaly for maintenance. And over time, it learns more and more about the specific asset, creating better recommendations and more specific maintenance schedules.

An example of this would be a preventive maintenance system that collects data, forecasts machine failure, and then automatically schedules the appropriate preventive maintenance checks and services with your technician. Prescriptive maintenance combines technology and strategy to help your team work smarter.

Which preventive maintenance strategy is best for your business?

When evaluating the strategies above, the best preventive maintenance strategy for your business will depend on specific operational needs, asset criticality, and resource availability. It will often boil down to the size of your business including the range of assets you have.

Calendar-based maintenance might incur costs due to potentially unnecessary servicing of low-risk assets but tends to be the more common maintenance method preferred by small to medium-sized companies.

Usage-based maintenance needs reliable meter readings, such as operating hours, odometer values or tonnage. It suits sites that already log equipment use, and costs rise when those readings come from sensors rather than manual entry.

Condition-based maintenance suits assets where wear varies a lot with load or material, such as crusher liners and conveyor components. It can start with measurements taken during inspections and grow as more machines are connected.

Risk-based maintenance offers a midway solution regardless of company size, as it ensures your most valuable assets don't come to a standstill.

Predictive and prescriptive maintenance need sensors, connected systems and clean data. Most sites add them once their time-based and usage-based routines are running well.

With CheckProof, regardless of the maintenance strategy you choose, the platform will accommodate your business. The customizable platform supports real-time integration for usage-based maintenance, scheduled reminders and checklists for calendar-based maintenance and tools for prioritizing tasks in risk-based maintenance, ensuring efficient execution and monitoring of all maintenance activities from one single platform.

What is planned preventive maintenance (PPM)?

Planned preventive maintenance is a structured approach where activities are scheduled in advance, often on a regular basis. Unlike reactive maintenance, which responds to problems as they occur, PPM aims to avoid failures and reduce downtime by maintaining equipment before issues arise.

Implementing planned maintenance often involves a detailed schedule, predefined inspection lists, and trained staff or contractors. Many businesses use preventive maintenance software to ensure these activities are completed on time and recorded consistently.

How to create a preventive maintenance program

To create a preventive maintenance program, set your goals, list your assets and rank them by criticality, write job plans for each task, build long- and short-term schedules, train your team, and review the results. The seven steps below cover each stage.

To implement a successful preventive maintenance program, you need to identify what tasks need to be performed, how often, and by whom. A well-thought-out preventive maintenance program needs to be balanced, protect your company's assets, reduce upkeep costs and ensure a smooth operation. And this requires planning, scheduling, and coordination across several departments. Whether you're overhauling an existing program or designing a new one, consider starting with these key steps:

1. Set your goals and priorities

First you need to define your plan's purpose. What do you hope to accomplish? To save money or prevent accidents? You must design tasks, methods and priorities in accordance with organizational goals. If you want to maximize uptime, you might devise your plan in ways that reduce unplanned downtime and breakdowns. If your organization's end goal is to eliminate accidents in your workplace, you might focus on increased planned maintenance and safety tracking.

2. Do an inventory of assets and determine their hierarchy

What assets are most critical to your operation? The second step of your preventive maintenance plan is to take stock of all your assets and map out their hierarchy (the relationship between essential and non-essential units).

Your team must first determine the total cost of ownership for each asset and the impact on safety should a component break down. Secondly, divide equipment into families and establish parent-child (mindmap) relationships between them. When creating an asset hierarchy, you should include information such as location, type of equipment (e.g. hot water boiler), and the parts that make up the asset.

Example:

• Location: Building 8
• Equipment Family: Hot Water Boilers
• Asset: Hot water boiler #1
• Brand/Manufacturer: Boilers Manufacturers, Ltd.
• OEM recommendation: general maintenance one month before the cold season. A general inspection is recommended every three months at the time of most significant use.
• Last inspection: date of the most recent inspection
• Legal requirements: n/a

In CheckProof, this structure maps to a Site, Section, Round and Unit hierarchy, so every asset sits in the right place from day one.

3. Define Tasks & Job Plans

Job plans are lists that contain the scope of work and the tools needed to do the job and should be part of every preventive maintenance plan. They help organize employees and keep them efficient and accountable. Planning and scheduling are the most vital parts of preventive maintenance.

Your job plans should therefore include:

• A step-by-step instruction on how to complete the task
• A list that specifies what tools are required
• A list that specifies what skills are required
• A list of materials and parts
• Visuals (e.g. photographs or diagrams)
• Operating procedures for the task at hand
• Safety instructions for the task at hand

4. Schedule for the long-term

Use a preventive maintenance scheduling tool to oversee a yearly maintenance schedule for each asset based on the data you collected from your hierarchy sessions and mapping, maintenance history, and OEM recommendations. Divide the yearly schedule into daily, weekly, monthly, and quarterly tasks. A CMMS will help you automate processes and keep track of your schedules.

You want to include as many critical assets as possible in your long-term schedule. This ensures minimal error and that the main components of your organization are always covered.

5. Schedule for the short-term

You've now established your long-term schedule, which includes the most vital maintenance work throughout the year. Now you can start planning for the foreseeable future, such as weekly tasks. To ensure thoroughness, layer your short-term maintenance schedules with your long-term ones.

Tips for a short-term schedule:

• Prerequisites: How many people are needed to complete a job plan? How many person-hours does it require? And how long will it take (full day, three days, etc.)?
• Scheduling success factors: Measure the performance of job plans by analyzing the scheduling process. Are tasks completed on time? Are your tasks contributing to your end goals? Always strive for continuous improvement by reviewing and improving your scheduling over time.

6. Train your employees

Having a great preventive maintenance plan in place means nothing if your employees can't or won't follow it. Hence, ensure that each employee knows how to perform their tasks and follow their maintenance schedules, and understand why preventive maintenance is essential. In addition to performing tasks correctly, you prevent wasting time on trial and error, accidents that come from ignorance, and wear and tear due to improper handling of equipment.

7. Documentation & Review

Track every action taken using a preventive maintenance system to monitor performance over time. Then, regularly analyze the collected data to identify improvements or cost savings.

Sample preventive maintenance schedule

Below is a sample schedule for a typical aggregates crushing and screening plant. Use it as a starting point and adjust intervals to OEM recommendations, operating hours and site conditions.

Preventive maintenance software and tools

The best preventive maintenance software for heavy industry combines scheduling, mobile checklists, deviation and work order tracking and full asset history in one platform that also works offline on site.

To be able to utilize preventive maintenance to the fullest, you need modern technology, primarily analytical and integrative software. This type of software will help you automate processes and enable the collection of real-time data and establish traceability and communication between assets. Preventive maintenance software keeps a detailed and centralized record of all maintenance activities for each asset in your facility and allows you to manage and automate tasks, checklists, reporting, processes and documentation. An effective CMMS tool will allow you to:

• Control your maintenance calendar by automatically creating tasks based on triggers and parameters such as usage or time. You can also program it to produce detailed instructions and how-to documents required to execute tasks correctly.
• Monitor multiple assets and facilities from anywhere through a centralized platform. It also enables you to monitor real-time information about your assets, such as temperature, fuel usage and quality output.
• Track and analyze maintenance data over time to continuously improve and optimize your routines. The data gives you actionable insights into when the optimal time for maintenance for a specific asset is.
• Connect your frontline teams with a system that allows them to access routines, documentation, checklists and reporting on-site.
• Integrate existing systems and stream their data directly into your CMMS, giving you full control over several systems through one platform.

When integrated with sensors and IoT technology, this software can provide real-time insights and trigger tasks before faults develop.

Benefits of using CheckProof for your preventive maintenance program

CheckProof is a platform uniquely designed for heavy industries that helps teams move away from reactive fixes and into proactive, preventive operations. Here's how it supports your preventive maintenance program:

• Mobile app: Perform inspections and register maintenance tasks from your phone or tablet.
• Custom checklists: Standardize preventive maintenance inspections for consistent quality.
• AI Checklist Builder: Create new checklists quickly and roll them out across sites with Master Checklists.
• RFID tags: Verify that the inspection was done at the asset itself.
• Deviations and work orders: Issues flagged during rounds can be tagged and turned into work orders, so nothing gets lost between shifts.
• Digital documentation: Keep track of all checks, routines, documentation, reporting and maintenance logs in one place.
• Alerts and reminders: Get notified when tasks are due, reducing missed inspections.
• Data analytics: See trends over time and improve scheduling and resource allocation.
• Connect your machines and existing systems to one platform. This also allows you to stream assets' real-time telematics data straight into CheckProof.
• Keeps your assets in optimal condition: increasing their lifespan and improving your facility's productivity by conducting maintenance at the optimal time for each piece of equipment.
• Use the data from your assets to define usage and value parameters, and set relevant triggers that automatically flag deviations, create tasks and notify you when maintenance is due (and with checklists on how to perform it).

Whether you're a quarry operator, cement plant manager or asphalt producer, CheckProof gives you the control and visibility to implement a truly effective preventive maintenance program.