Mantenimiento Reactivo vs Mantenimiento Preventivo

For most companies, the idea of moving from reactive to preventive maintenance (PM) is out of the question, even before discussions start. Such a huge leap can sound very intimidating. However, for those who choose to take on the challenge, there is some good news. It's not an impossible feat. But before diving deeper into preventive maintenance, it's worth looking into the reasons for doing it in the first place.

The purpose of improving maintenance systems, such as moving to a preventive strategy, all boils down to increasing reliability. Reactive maintenance and high failure rates contribute to a lack of reliability. But be cautioned, you can't simply PM your way to reliability. There is no silver, or even gold bullet, that will grant you instant reliability. Instead, start by getting a grasp of how failures occur. Later on, you will get to see how a preventive strategy becomes beneficial.

Reducing Defects Faster Than You Are Adding Them

In a perfect world, performing maintenance tasks is rewarded with exceptionally high reliability. The problem is that we live in a world that's full of defects. In reality, faults and failures can come from countless sources that make them nearly impossible to wipe out.

Some failures come from neglected maintenance liabilities. Other cases of faults might be coming from different parts of the production process. If you look into your overall operation, you might even have some systems that attempt to remove these defects. For example, you could have quality checks to catch problems with raw material, operator training, or equipment condition. The point is, flaws are everywhere.

The next best thing to completely eradicating defects is to reduce the number entering your system faster than you're adding them. In turn, you are preparing yourself to improve your reliability. Here are a few points to keep in check:

1. Focus on Defect Elimination

This point is partly the role of preventive maintenance. You want your process to catch these defects and eliminate them whenever possible.

2. Focus on the Remediation of the Causes of the Defect

While the first step is crucial, it is not enough on its own. As an extension of your preventive strategy, you want to keep the defects from entering your system.

3. Focus on Doing Jobs Correctly the First Time

Performing tasks incorrectly can lead to costly rework or even added stress to your equipment. Examples of these mistakes are improper installations and substandard servicing.

4. Focus on Reducing the Incidents of Careless Work Habits

Wear and tear are some of the unavoidable causes of defects. However, a considerable percentage of things that would require reactive maintenance is due to some form of carelessness. These could be on the part of the technician, operator, or even the design.

5. Focus on Buying the Right Equipment for the Job

Getting the right equipment to suit your needs sets your company up for success. By having quality tools right out of the box, you can reduce unnecessary and time-consuming workarounds.

How Do We Achieve Reliability?

The quickest way to improve reliability is to catch events before they even happen. You want to perform corrective action even at the earliest signs of possible failure. In other words, you want to perform corrective maintenance diligently.

The term "corrective maintenance" is easily misunderstood as the act of fixing breakdowns. In this sense, corrective maintenance means that problems are detected by other means before failure even occurs. For example, inspections can identify the proper actions to prevent any potential breakdowns. You have people going around the plant, looking at equipment, sensing components, and using instruments to spot any issues.

These maintenance tasks are essential because they prevent defects that are just about to fail. Executing corrective action, rather than acting reactively, is a quick win in achieving reliability.

Three Big Ways Preventive Maintenance Can Help You

By now, you might be seeing how preventive maintenance can help an organization to increase reliability. Now that we have a good background of defects and maintenance, here are three main ways how PM can help you.

1. Extend the Life of an Asset

There are methods of preventive maintenance specifically designed to extend the life of an asset. Some would argue that corrective action, by inspection, works just as well to increase the length of service of a machine. However, there are distinct PM practices that can further improve what corrective actions can offer.

Straightforward routines in PM can go a long way for the longevity of an asset. Think TLC: tightening bolts, lubrication, and cleaning. How many pieces of equipment have failed due to a poorly lubricated bearing? How often would you encounter a mechanical component that's stuck from debris or dirt? These seemingly basic things - TLC - can prevent disastrous incidents from happening when done early and habitually.

2. Inspection to Detect Deterioration Problems

The second way of how preventive maintenance helps is by detecting problems of deterioration early on. Through scheduled inspections, you can identify areas that are not looking right. This activity can be someone visually examining components or even feeling the vibration of equipment. In these examples, you can get a good idea of the balance and alignment of rotating materials by sensing vibrations or hearing rumbling.

When done correctly, inspections can bring out valuable insight about your equipment. An inspection task that reads "Inspect Equipment X" is a bad example of a line on a procedure list. You want instructions that specifically tell you what to look for, or in this case, what characteristics to note down. If the inspection requires you to read a meter or a gauge, then you must indicate the acceptable range of values to the task. By providing good instructions, you can expect more useful results.

3. Short Repair Time

Think of a short repair as a reward on its own. It's a situation where you have the opportunity to fix a defect quickly and effectively. It could be a loose wire, a screw that has backed out, or maybe a pill block that needs to be tightened and torqued up. Short repairs might take 15-30 minutes to complete. But to do these tasks, you'll need to make sure that tools and spares are readily accessible to the assigned technicians.

In industries working in dangerous environments, you are usually not allowed to do quick repairs without the proper clearance. In some cases, servicing tasks might require more time, effort, and longer lead times to execute work. If you can't complete what you need through a short repair, you can instead initiate a corrective maintenance work order. In this case, the assigned individual can write up a work order to perform the required maintenance activity.

The benefit of short repairs is all about addressing the fault right there and then. You have an unsound machine in your control, while in a safe state, that allows you to work on it. This high level of productivity reduces your wrench time to increase your availability and reliability.

Preventive Maintenance Systems

Virtually all preventive maintenance systems work in a cycle. While companies might have varying details in their PM steps, they would typically resemble the following pattern:

PM Task List

Carrying out any preventive maintenance activity starts with a task list. A task list is a collection of tasks, arranged in a particular order, that ensures the completion of a job. You can think of task lists as procedure manuals that describe the steps to perform maintenance. These procedures allow you to detect failure modes and action them accordingly. Most CMMS systems are capable of integrating task lists to enable more seamless transactions.

Inspection Procedures

Once a task list is activated, inspection procedures look into the specific details of an issue. This stage collects information about the incident or the condition of the equipment. The inspector might not have the right parts for the job at this stage yet.

Corrective Work Order

After having a clear picture of the situation, the inspector can then write up a work order. This document, mostly filled out electronically nowadays, lists the required spares and specific actions to do.

Planning, Scheduling, and Execution

The required jobs in the work order then enter the backlog of the system. These jobs are then scheduled and planned according to the availability of parts and resources. Eventually, the maintenance team picks up the work and executes the required tasks to close out the work order.

Await the Next Task List Run

There is a particular set of criteria that initiates a task list to kick off. One of the most common ways to initiate PM tasks is through a time-based schedule. You can set your CMMS to execute tasks according to a periodic, calendar-based plan. For example, you might schedule the replacement of wearable parts after 12 months. In some cases, you might take a usage-based approach using the same concept. You could set task lists for your fleet to refresh every 3,000 miles, for example.

A more modern, high-tech approach to triggering maintenance tasks is through detecting deterioration. In this age of the Internet of Things, sensors can give you all sorts of information about your equipment. You can install sensors that check on the condition of your equipment 24/7. All that data goes into artificial intelligence (AI) software that prescribes whether you should send out a maintenance team to check on your equipment. While this can be a whole other maintenance approach on its own, you can see how it relates to a PM strategy.

Face Up to the Sins of the Past

Maintenance people are the ones down in the trenches, seeing the reality of everyday operations. They are the ones that have gained real experience with machines and hold priceless insights about their history. Part of this history includes the sins of the past. These pertain to the pieces of machinery that were running fine for the longest time. But these machines are deteriorating in various ways, and missing out on proper care will make them worse.

At some point, you will need to put money back into your equipment to keep it in tiptop condition. Think of it as an investment that allows you to maximize the potential life of your assets. If you miss this opportunity, it becomes an unfunded maintenance liability. Part of the design of a preventive maintenance strategy detects and reports these kinds of problems.

It can take a while to appreciate the effects of a PM system. The benefits of moving toward a preventive strategy typically show around 18 months after implementation. Recall that a PM approach tries to remove existing defects while avoiding more of them from creeping up. And it takes some time to prove that PM is picking up. In parallel to preventive processes, it would be a good idea to boost your corrective performance. This way, you can expect short- to mid-term results in reducing defects.

Types of Defects

One of the main benefits of moving to a preventive strategy is reducing defects and preventing them from happening. To effectively do that, it helps to know the various ways that defects can sneak up on you. Here are some types of defects that maintenance teams need to look out for:

1. Defects in raw materials

2. Defects from the operation or mishandling of equipment

3. Defects from craftsmanship issues of your tools and equipment

4. Defects from faulty spares

5. Defects from design flaws

Think of these defects as little bugs that can slip past you. Your best bet against these nasties is to work with precision in everything you do.

Using Precision to Keep Defects Out

When working within the precision domain, you eliminate failures by doing the repairs right. Reactive, preventive, and predictive maintenance are all based on something that happened. But when applying precision maintenance, there won't be any incidents in the first place.

Working with precision has a lot to do with the culture in maintenance. You want to apply precision in all tasks from lubrication, assembly, installation, repairs, and even procuring spares. By employing a precision maintenance culture, you keep defects from appearing in your operations.

Tips on Jumping from Reactive to Preventive Maintenance

Preventive maintenance provides a concrete plan to reduce defects and increase your productivity. But it's understandable to have some apprehensions when coming from the opposite side of the spectrum. Here are a few practical tips that might help put your mind at ease with preventive maintenance and ways to get it off the ground.

How to Overcome Putting Out Fires From Inherited Systems

The only way to start is by taking that first step. You can resolve any challenging task by taking it piece by piece. Take some percentage of your free time and dedicate that to getting rid of defects. You can tap into your team and find interested individuals in the area that you need to resolve. Record your successes, and present them to your management. That way, you can gain some traction to get the support you need.

Good Practices for Corrective Maintenance

The big question is when to perform corrective maintenance. Is it right after you detect a defect? Or do you need to wait for a shutdown or a scheduled activity? Well, the answer depends on your environment. If you have the tools and you can carry out tasks safely, then go for it. It's a different scenario when working in factories that have strict schedules to meet production requirements. If you can perform corrective action, then great! If you can't, then you'll have to prepare for contingencies and assess the situation.

Applying Preventive and Corrective Maintenance to Multiple Branches or Locations

Some barriers to preventive maintenance could be that you are operating in multiple locations. It becomes more challenging when you spread yourself thin across all plants. If you can, you want to standardize your equipment as much as you can. That way, you can focus on the components you have and prepare more efficiently.

Conclusion

Preventive maintenance is part of a broader effort to reduce defects, keep them out, and ultimately increase your overall reliability. Companies that have embraced reactive maintenance might find it hard to move towards a more proactive approach. However, seeing how a PM strategy works and considering its benefits can go a long way to achieve reliability.

Note: This article is based on a webinar “Jumping From Reactive to Preventive Maintenance” with Joel Levitt. To view the recording of the webinar, visit this link.