What is Preventive Maintenance? A Complete Guide to Preventative Maintenance
No piece of equipment lasts forever. Constant wear and tear will eventually result in equipment failure or compromised operational efficiency. Preventive maintenance is a popular solution for postponing that point of failure and increasing the useful life of your assets. According to Plant Engineering’s 2019 Maintenance Study, 78% of manufacturing facilities follow a preventive maintenance strategy to some degree.
Despite that encouraging statistic, many organizations are still hesitant to switch from reactive to preventive maintenance. They have a preconceived notion that the change will be hard or expensive or just not worth the trouble. The goal of this guide is to dispel those myths and show how anyone can implement and run a successful preventive maintenance program.
We do that by focusing on the details and by using examples and custom graphics to explain all of the intricacies of the preventative maintenance process.
To give you a quick preview, in this ultimate guide, we discuss types of preventive maintenance, how it compares to other popular maintenance strategies, when should you apply it, how to set up and run a PM program, how to maximize the value of preventive maintenance, and much more.
This is a lengthy guide so pour yourself a cup of coffee, find a comfortable position, and let’s get this show on the road.
What is preventive maintenance? / What is preventative maintenance?
Preventive maintenance (commonly abbreviated as PM) is a proactive maintenance strategy. It is performed at regular intervals to address signs of equipment deterioration before they can lead to equipment breakdowns.
Some prefer to use the term preventative maintenance instead of preventive maintenance. Both are correct and can be used interchangeably, as we do in this article.
Preventive maintenance was one of the first responses to rising maintenance costs. Plant owners realized that it is more cost-effective to invest in routine maintenance and spare parts (like filters and belts) than it is to constantly deal with equipment breakdowns and replacements.
Even in cases where assets were cheap to repair or replace, production delays, safety issues, reputation damage, and employee dissatisfaction were reasons enough to look into ways to reduce the number of unexpected machine failures.
Over the years, preventative maintenance proved to be an effective remedy that can be applied in any industry that relies on physical assets and infrastructure. While it sees more use in asset-heavy industries like manufacturing, aviation, and construction, it is regularly applied in both industrial maintenance and facility management.
There are two types of preventative maintenance
As we mentioned earlier, preventative maintenance is performed at regular intervals. Naturally, those intervals are not decided willy-nilly. You can’t just arbitrarily decide that Thursday is the day for visual inspections or that oil changes are to be performed only on Friday the 13th.
Based on how we define those intervals, we can differentiate between two types of preventative maintenance: calendar-based and usage-based maintenance.
Calendar-based maintenance is performed at fixed time intervals, regardless of the condition or usage of the asset. If time-based maintenance had a motto, it would be: it’s better to be safe than sorry.
The time intervals can be set based on the guidelines provided by the equipment manufacturer and maintenance techs personal experience, as well as company and state regulations. Here are a few examples of time-based maintenance:
Changing the filter every couple of months.
Changing oil every three weeks.
Monthly visual inspection of the conveyor belt.
Testing the fire protection system every six months.
Lubricating pumps every other week.
The main downside of time-based maintenance is the risk of excessive maintenance. In other words, performing maintenance way before it is actually needed, wasting resources that could be better utilized elsewhere. One way to solve this problem is to adjust the maintenance calendar based on maintenance data recorded in your CMMS software.
Usage-based maintenance strives to be more precise. We know how much mileage we can get out of certain parts. Similarly, we can make an accurate estimation of how much resources (oil, lubrication…) an asset spends on average. When you have this data readily available, scheduling work based on usage is trivial. You can schedule maintenance after:
X amount of miles/kilometers
X amount of working hours
every X production cycles
If it is superior, why didn’t usage-based maintenance completely replace time-based maintenance? Well, there are several factors at play. The main reason is the inability to accurately track the usage of all assets (or track it at all). For example, you can’t schedule an inspection of a fire extinguisher based on mileage or working hours.
You do as best as you can, based on the data you have. If you run CMMS software, you can use it to periodically review your maintenance records and, if needed, adjust your preventive maintenance calendar.
Reactive maintenance vs preventive maintenance vs predictive maintenance
There seems to be a lot of confusion about the relationship between reactive, preventive, and predictive maintenance. They are the three most commonly used types of maintenance strategies. You can see their relationship on the graphic below:
Preventive and predictive maintenance are two out of several proactive maintenance strategies used today. You can think of predictive maintenance as a more efficient version of preventive maintenance where the work schedule is based on predictive algorithms. Those algorithms use data from condition monitoring sensors to predict failure points and enable you to schedule maintenance work just before that happens.
In both preventive and predictive maintenance, the majority of the performed maintenance work is spent on preventing breakdowns, rather than addressing them.
Reactive maintenance (a.k.a. breakdown maintenance; run-to-failure maintenance) is diametrically opposite. This strategy incorporates some level of routine maintenance work, but the majority of time is spent addressing breakdowns.
As teased on the graphic below, each of these strategies has different benefits, challenges, requirements, implementation costs, and potential ROI.
Preventive maintenance comes with a lot of different benefits. Here are some interesting stats to consider:
The true cost of unplanned equipment downtime can range from a few hundred dollars per hour to a few million dollars per hour, based on the industry and the size of the organization. Preventive maintenance is here to minimize the number of costly machine breakdowns.
Run-to-failure maintenance can cost between three and 10 times as much as a good maintenance program. In other words, every dollar invested in preventive maintenance will save you $5+ on average by avoiding future expenses.
Some of our clients used Limble CMMS to implement preventive maintenance schedules and reduce reactive maintenance by over 70%, saving over 3 000 hours of productivity in just a first few months.
Now, you might be the person that doesn’t pay much attention to numbers as every organization has its unique needs and characteristics. In that case, let’s establish a clear causal relationship between doing preventive maintenance and the ensuing benefits.
Preventive maintenance reduces the number of unexpected breakdowns
It is only natural that the machines you care about and regularly maintain have a lesser chance to unexpectedly fail. Preventive maintenance facilitates that in two major ways.
The first way is by ensuring that the basic maintenance needs of the asset are met. Tasks like oil and filter changes are something that even reactive organizations try to cover, but the problem is that they are usually very unorganized. Hence, even core maintenance tasks are not performed on time or even end up on the list of deferred maintenance tasks. That is a failure waiting to happen. The solution comes in the form of CMMS and preventive maintenance. Preventive maintenance forces you to create a maintenance schedule, CMMS makes sure you stick to it.
The second way is by scheduling regular inspections to spot signs of deterioration. Preventive maintenance schedules often rely on equipment manufacturer’s guidelines to define intervals for preventive maintenance tasks. However, OEM guidelines presume that you are running their assets in certain conditions. In reality, your plant might suffer from things like increased humidity or dust levels. You can have inexperienced machine operators that are misusing and consequently damaging the equipment in the process. Maybe you are even cutting costs by using cheaper replacement parts. Regular inspections are here to cover for such scenarios and help you spot potential problems as early as possible.
While regular inspections bring tangible benefits, they can be time-consuming. To offload their maintenance teams, some organizations take a note from the autonomous maintenance playbook. They train machine operators to look for and report the usual signs of equipment deterioration. If they are able to do that, maintenance technicians can focus on more complex maintenance tasks.
There are many ways in which preventative maintenance can help you lower your overall maintenance costs. A lot of them are actually indirect (stem from preventing expensive breakdowns), which is why they are easily overlooked.
Improved asset lifespan. Unexpected breakdowns rarely happen without serious damage to the equipment. Preventive maintenance means less of those breakdowns, which increases the useful life of your assets. It can be a difference between needing to replace a $100k asset in 5 instead of 10 years.
Reduced spare parts inventory costs. Lots of unplanned work means that you either have to hold a large inventory of replacement parts or risk expensive emergency shippings. Preventive maintenance brings a dose of stability and predictability which helps you do more accurate inventory forecasts, especially when supported by maintenance software with the inventory management module.
Reduced labor costs. Reactive maintenance inevitably leads to overtime work. Overtime work increases your labor costs. Over time, a sound preventive maintenance program should keep overtime work to a minimum.
Reduced energy consumption. Assets that are kept in peak operating condition tend to use less energy to run. By some estimations, facilities with proper HVAC maintenance can use up to 20% less energy than systems that are allowed to deteriorate. Moreover, in a manufacturing setting, assets in peak operating condition will produce fewer defects, improving your Overall Equipment Effectiveness (OEE) score.
Improved compliance and safety. Some systems have to be tested from time to time to ensure regulatory compliance. Assets that unexpectedly malfunction can pose a safety risk. If negligence is the cause for either scenario, the whole organization can be sued for compensatory damages. Don’t be negligent, schedule preventive maintenance.
Depending on how important the asset is for delivering your product or service, equipment problems can range from minor inconveniences to the complete halt of the production process. In a highly optimized production line, you only need one underperforming asset to start having idle time and other productivity issues. Heck, even a broken HVAC in the middle of the summer can reduce productivity in your office.
Once again, preventive maintenance shows its benefits by keeping the asset healthy and operational.
Potential downsides of preventative maintenance
Before we move on, there are a few potential downsides of preventative maintenance that are worth mentioning. The image below has a nice summary of pros and cons of running preventative maintenance.
Big proponents of advanced maintenance strategies like predictive and prescriptive maintenance often cite “excessive maintenance” as the main argument against preventive maintenance.
Since preventative maintenance schedules aren’t based on the real-time condition of the asset, some resources are inevitably going to be wasted. You will lose some man-hours doing unnecessary inspections and some spare parts will be replaced even though they could endure additional wear and tear.
If push comes to shove, wasting a few hours every week is worth it if that is the price you have to pay to save dozens of hours of unplanned work and associated costs.
If you do not want to waste any resources, you would have to opt-in for predictive maintenance. However, predictive maintenance has high upfront costs and is more complicated to implement and run, which makes it inaccessible to some organizations.
This begs the question “when is preventive maintenance the best approach?” and makes an excellent segue into our next section.
When should you apply preventative maintenance?
Questions about running preventive maintenance need to be answered as a part of a larger discussion about the applicability of different maintenance strategies. So, before we go any further, we need to frame this discussion by saying that focusing on a single maintenance strategy is neither feasible nor cost-effective.
Think of it this way. Every facility features a broad range of assets. Some are critical to production, some are kinda important, and some are on the chopping block. Different maintenance strategies incur different implementation and running costs. There can’t be one maintenance strategy that acts as a one-size-fits-all solution.
We believe that the best approach to maintenance involves a mix of different maintenance strategies. For example:
you use run-to-failure maintenance for low-priority assets, non-repairable assets, and soon to be replaced assets
you use preventive maintenance for medium to high-priority assets
you use predictive maintenance for critical assets that are responsible for main business processes and/or are very expensive to repair or replace
In general, preventive maintenance is great for all businesses which:
have important assets which functionality affects business performance
Does that sound like you? If so, be sure to continue reading as we discuss how to implement and run a preventive maintenance program.
The requirements for implementing an effective preventative maintenance program
The amount of work that needs to be put in to implement preventative maintenance depends on where your organization is right now and how many assets you want to include in your PM plan.
If you are already doing a lot of routine work and are just looking to be more organized, embracing preventive maintenance is a walk in the park. On the other hand, if you’re constantly running around putting out fires, the implementation will require some additional effort.
In both scenarios, there are two core requirements:
1. Getting buy-in from relevant parties
This is a point you will find in many of our articles that talk about implementing CMMS or maintenance strategies. What it boils down to is that, if you want your preventive maintenance program to succeed, you better get all relevant parties on-board with the project. Relevant parties being top management and maintenance techs.
It is always nice to have the blessing from top management if you plan to push any major changes. Moreover, while preventive maintenance is not expensive, that doesn’t mean it’s free. You will want to secure some budget to implement CMMS software (if you do not have one already) and allocate enough time to gather data, create a preventive maintenance calendar, and adjust your existing maintenance workflows.
Even though it is in their best interest, convincing top management that such a change is needed can sometimes be an issue. This is because of the sad reality where over 60% of decision makers think of maintenance simply as a cost center and necessary evil. With that in mind, your best argument is to focus on ROI (return on investment). Show how preventative maintenance leads to cost reduction and increases equipment uptime. You can take inspiration from our CMMS ROI calculator as the cost-saving areas are basically the same.
When it comes to maintenance technicians and mechanics, you want to get them excited about the changes because the success of the program ultimately depends on them. They will have to follow new procedures and use suggested software solutions. If the maintenance team is not able to switch from the reactive to preventive mindset and follow new procedures, the project is unlikely to bring significant benefits.
What seems to work great is to include them in the process. Discuss the changes you plan to implement. Explain which problems you are trying to solve and how will this benefit them. Work with technicians when establishing new workflows and selecting your CMMS software. It’s simple psychology. When people have a say in the process, they are more motivated to see it succeed.
2. Supporting the implementation with a maintenance software
Implementing preventive maintenance without any kind of software support makes the process way harder than it needs to be. It doesn’t take much to see why.
What is easier, writing tasks every week on the chalkboard or having a maintenance calendar where you can just select an interval and let the software schedule tasks for several months ahead?
Do you want to call technicians every time there is a new PM task or change in priority or would it be more efficient to let your mobile maintenance software send an automated email and push notification to assigned technician(s)?
Do you really want to spend time checking inventory or would it be nicer if you got a notification when certain spare parts are low in stock?
How do you expect to stay organized if you have no overview of your maintenance workload, the status of the assigned tasks, and all of the different metrics and KPIs CMMS allows you to track?
Computerized maintenance management systems started as a way to keep track of your maintenance schedules, but have since evolved into centralized digital platforms that hold and manage all of your maintenance information. They are designed specifically for businesses who want to take a proactive approach to maintenance. Considering the relatively low cost of running CMMS software, it is hard to find a good excuse for not using it.
How to create a preventive maintenance program
You do not have to be a genius to set up a preventive maintenance plan. However, you should be ready to roll up your sleeves, figuratively speaking.
Those that do not like to rush things should start with a pilot project. You can select one or two problematic assets to put on your PM plan. After running it for a while and getting the proof of concept, you can expand the program to other assets.
The implementation process can be split into 4 distinct steps:
Select assets that are going to be on your PM schedule. Those are usually assets important for organizational success, often expensive to repair/replace, and need regular maintenance in general.
Gather necessary information. You should look at OEM maintenance recommendations, review maintenance history, and talk with the machine operators and maintenance techs about any lingering issues that need to be regularly addressed.
Create the initial preventive maintenance schedule. With all of the data from the previous step, you should be able to create the initial preventive maintenance schedule. You should have everything written down in a maintenance tool (preferably CMMS but something like Excel can work as a temporary solution for smaller teams).
Track and adjust. Your first schedule is not going to be perfect. Track how much preventive vs reactive work you are doing. Look more closely at problematic assets and work hard on identifying the exact causes of failures. Adjust your PM schedule based on your findings.
Here is a video that shows how the above concepts are applied to create a simple PM task and schedule inside Limble CMMS.
For everyone that is seriously considering preventive maintenance, we recommend you also read our guide on how to start a preventive maintenance plan, as well as download the checklist below. The guide goes into more detail over all of the steps mentioned above.
7 tips for squeezing maximum value out of your PM efforts
To help you keep the focus on the right areas, we decided to make a compilation of preventive maintenance best practices.
1. Commit to change and keep everyone on the same page
Half-assed implementations lead to half-assed results. If everybody on the team puts in the effort, the results will follow. However, real change can’t be achieved overnight. Be sure to manage expectations and keep a close eye on the execution of the plan.
Pay special attention to the individuals that might be struggling with adjusted procedures and new tools. For example, if you’ve recently implemented a new CMMS solution, it is important to check if technicians are using it properly – logging their work, tracking used spare parts, leaving important notes, and similar. The goal is to spot and correct bad habits as early as possible.
Letting everyone do their own thing goes directly against the idea of streamlining maintenance work. The procedures are here for a reason, and they should be followed. Make sure everyone knows their role and their responsibilities.
2. Define and track relevant metrics
You can’t improve what you don’t measure. You are implementing preventive maintenance for a reason. Do you want to reduce maintenance operational costs? Lower your inventory costs? Reduce the number of unexpected breakdowns? Improve productivity?
Define your maintenance KPIs and then see which maintenance metrics you can use to track your progress towards those goals. If your records are a mess, you might need to run your CMMS for a couple of months to first see what is your starting point. After that, you can work on defining your maintenance goals.
Tracking important metrics is vastly simplified if you are using a CMMS. The software can automatically calculate a wide array of metrics like MTBF, MTTR, maintenance costs, planned vs unplanned work, are PMs getting completed on time, etc. Here is a screenshot from Limble’s custom dashboard that illustrates this in practice:
With a deeper insight into these metrics, it is much easier to identify what is preventing you from reaching your goals, as well as where you have the most room for improvement.
3. Use preventive maintenance checklists
A majority of preventive maintenance work are tasks that need to be carried out on a regular basis. A great way to streamline these tasks is to create informative maintenance checklists which technicians can follow to execute the assigned work.
Checklists are a great way to speed up the process and keep a consistent work quality. They can be especially helpful to less experienced technicians and those that do not have a lot of practice with particular assets.
Limble CMMS users can attach preventive maintenance checklists and diagrams to their work orders. Checklists should include the list of steps in sequential order, alongside annotated pictures (if necessary). This way, technicians and mechanics can just turn on the app on their mobile phone and quickly access the instructions, even when they are out in the field.
Here is an example of a preventative maintenance checklist created with Limble PM builder:
When you switch to preventive maintenance, the current problems will not automatically go away. You have to keep in mind your limitations on budget, parts, tools, and manpower.
It would be nice to have all important assets on a PM schedule right away, but is that a realistic scenario for your current situation? If so, great! If it isn’t, you have to play with the cards you have been dealt with.
When limited, you should focus your PM efforts on the assets which breakdowns incur the most costs and problems month over month. This will ensure you reap the most benefits from the program, which should in turn free up enough resources to start expanding it. When combined with a CMMS, you will become very efficient in managing your costs and resources and driving further improvements.
“With Limble, I can track all of our supplies that come in, how they are getting used, look at the usage rates, and then also be able to forecast budgets for next year. It has dropped my budget tremendously; I was actually able to hire another guy because of what we were able to save.”
— Benjamin Scott, Facilities Supervisor, Intercontinental Hotels Group
5. Make a conscious effort to minimize excessive maintenance
This can be done in three ways.
The first way is by adjusting your PM schedule based on the asset usage rates and working conditions. An asset that is used less needs less maintenance. Additionally, an asset that is never pushed to its limits and is operated in ideal conditions might not need as much routine work as suggested in the manufacturer’s guidelines.
The second way is by reviewing assets you spend a lot of time on. If they haven’t had any malfunctions or breakdowns lately, maybe they could do with less preventive maintenance. When possible, you can test the same/similar assets by putting them on a different PM schedule and tracking what happens.
The third way is by focusing on the right failure modes. Most organizations will have a few stress-inducing assets that are constantly malfunctioning, no matter how much preventive work is being done on them. Excluding poor design and defective products, there are two common reasons for why that happens:
either you are addressing wrong failure modes (i.e. doing excessive lubrication instead of cleaning the gears more often)
or the asset is misused (asset is used outside defined operational parameters; equipment/parts are installed improperly so they cause equipment damage and deterioration)
In any case, you will need to do some investigative work on problematic assets in order to determine the exact failure causes. As a precaution, you can run assets that are going to be on your PM program through a reliability centered maintenance (RCM) process.
6. Follow best inventory management practices
It is hard to do preventive maintenance if you do not have the tools, spare parts, or other MRO supplies to do it with. Using CMMS or some kind of inventory software is the best way to ensure you have the right items when you need them, without holding a huge amount of inventory.
Software tools help you track the usage of your spare parts so you can make accurate inventory forecasts. For instance, when closing a work order or a PM task, technicians that use Limble are prompted to list spare parts they’ve used. This helps Limble accurately track parts usage and inventory levels, sending you alerts about items that are low in stock.
If it wasn’t clear so far, we really think you should use a computerized maintenance management solution to track, organize, and streamline your preventive maintenance operations. It reduces the number of human errors, increases work accountability, improves communication and productivity, and so much more. We will dive deeper into this in our next and last section.
CMMS is the ultimate preventive maintenance software
Throughout the article, we tried to showcase how a modern CMMS is indispensable for running an efficient and effective preventative maintenance program. We pointed to many different ways in which CMMS supports the preventive maintenance process.
Quickly set up preventive maintenance schedules for any asset based on time or usage.
Track and manage all preventive maintenance work with an easy-to-use maintenance calendar.
Create PM checklists and attach them to your work orders.
Automate the administrative part of maintenance by sharing electronic work orders and letting the CMMS automatically log performed work.
Get instant access to all maintenance data which technicians can access via mobile devices even when out in the field.
Improve control over your spare parts inventory through automatic parts usage tracking and low in-stock notifications.
Keep a close eye on your preventative maintenance program by tracking important metrics and KPIs.
For those that are not ready to implement a CMMS but still want to focus on preventive maintenance as much as possible, there is something we can offer to you too. We created a free maintenance ticketing system based on Google Sheets. We set the templates in a way that allows you to also schedule and track preventive maintenance work. You can download the templates below.
How to get started with Limble CMMS
If you are interested in giving Limble CMMS a try, you have 3 options:
try our self demo (clicking on this link will open a simulated environment where you can play around with different features)
Organizations are adopting proactive maintenance because that is the right thing to do. It makes sense on paper and it has been proven to work by the market. Here at Limble, we witnessed over a hundred success stories and they all have one thing in common: they regret not doing it sooner. What are you waiting for?
"Great experience. Solved our obvious PM tracking issues but also addressing our SHE&S requirements (safety audit task tracking), Environmental checks are being logged, Corporate Audit items tracked"
— Michael Babcock
A very simple and elegant CMMS system
"If you've had prior experience with CMMS systems, Limble is very intuitive. The ability to view and use the software on multiple platforms is very advantageous. I was able to become proficient and launched the system after only 2 weeks. Support from Limble is fantastic - very prompt and they work well with you to truly understand your questions."
— Robert Toth
It takes me about 10 seconds.
"Limble made my job easier pretty much right off the bat. Now I create Work Orders on the fly. It takes me about 10 seconds."
— Fraser Cockell
Best value for money CMMS
"Limble has all the features essential to maintenance management. It is very easy to use. Limble can connect with wireless sensors for Condition Based Maintenance. We are in Thailand, and Limble also supports the Thai language. Importantly, their customer support is fantastic almost 24/7. They reply within 10 minutes anytime. I am sure that Limble will really help your operations."
— Natee Singhaputtangkul
A must for any maintenance department
"The thing that I loved the most right from the start was the ease of use of the Limble software. The customization options available when setting up PM's are great. I love the flexibility it gives to tailor the PM to exactly what your needs are."
— Richard Dunaway
Wow. You guys are amazing...
"Wow. You guys are amazing... your software really one-up's the competition. I've found several with some of the functionality, but much clunkier designs. I reviewed 16 CMMS packages, and yours was an easy choice. Thank you again. Well done."