Complete Guide to Preventive Maintenance

Preventive Maintenance Definition

Preventive maintenance is maintenance routinely performed to monitor the condition and the status of assets in order to prevent unexpected downtimes and equipment failure. It is a planned process that requires proactive scheduling and detailed documentation of past reports.

Types of Preventive Maintenance

Think of preventive maintenance as similar to preventive action. If preventive actions eliminate potential nonconformities through early intervention, preventive maintenance applies that same concept to preventing performance issues in assets. In short, preventive maintenance is a type of preventive action.

Preventive maintenance requires consistency. It involves systematic inspection of identifying potential problems or failures and correcting them ahead of time. These include anything from simple cleaning, lubrication, oil changes, adjustments, and repairs, to more substantial fixes such as replacing parts, and partial or complete restorations.

Archiving Maintenance Data

Just as important as the maintenance itself is the bookkeeping of maintenance data. Detailed documentation of past records is crucial to improving processes and future maintenance plans. The collection of these data points can provide insights into equipment effectiveness and efficiency, and prevent costly losses from machine breakdowns and unplanned downtime. This data can be used to guide your decision-making process when purchasing new assets.

Preventive Maintenance Looks Different on Every Shop Floor

The preventive maintenance procedure will be different for every piece of equipment, every operation, and every industry.

Many shops, however, follow the recommended standards outlined by the American National Standards Institute (ANSI). These standards are tools for determining which inspections and maintenance techniques are appropriate for which equipment. Since the ANSI was written with the health and safety of customers in mind, it helps align maintenance activities with quality.

Benefits of Preventive Maintenance

There are several reasons to conduct preventive maintenance:

• Reduction of equipment downtime and failures
• Lower repair costs and fewer large-scale repairs
• Increased life expectancy of assets
• Longer asset lifecycle
• Smoother day-to-day operations
• Improved reliability of equipment
• Reduced risk of injury
• Reduced overall costs on labor and electricity due to the increase in equipment efficiency
• Reduced scrap caused by defective equipment

Although Preventive Maintenance can be a heavy carry from an administrative perspective, the long-term benefits outweigh the time spent organizing and conducting routine maintenance.

Creating a checklist is helpful for preventive maintenance procedures. However, there is no ‘one-size fits all’ - every shop floor has different assets, and the maintenance protocol for each of the assets varies across production and industry.

The checklist should always be tailored to each shop floor.

That said, some foundational elements frequently make it onto the checklist across the board. Here is a rough structure of what that checklist looks like, and how you can custom-fit it to your shop floor.

Questions to Ask Before Creating the Checklist

Before creating a preventive maintenance checklist, ask these questions to ensure that you are taking the correct approach.

1. Which assets need preventive maintenance?

Come up with a list of equipment and tools that absolutely need to be on the checklist. This doesn’t mean listing items that are already being maintained on the shop floor but reevaluating what truly needs maintenance to optimize production based on past performance.

2. What do the OEM manuals recommend?

Gather documentation that came with the assets and review which preventive maintenance procedures can happen in accordance with the manufacturers’ recommendations and specs.

3. How were the equipment and tools actually used on the shop floor?

Review the relevant production history for the assets and tools in question. Look for any record of past failures, part changes, or other unique updates that could potentially impact the way that the device needs to be maintained.

You should keep a good record of all of the information you collect while going through these steps (and it’s one of the reasons why documentation is so important in the first place). Make sure that the documentation is accessible across the organization so that anyone can review and make edits if necessary.

Other Considerations

Keep in mind these components before creating your checklist:

• Engineering: Understand whether the tasks involved with the checklist are strategic and appropriately timed.
• Worker Capacity: Are workers trained enough to perform preventive maintenance? If not, you may have to consider carving out training times and financial resources.
• Economical: Make sure that this process is worth tackling financially. Does it cost less to maintain it than to fix or replace some of your assets?
• Management: Is preventive maintenance built into the operations as a whole? Is it a part of the company’s business goals?

Elements of a Good Preventive Maintenance Checklist

Preventive maintenance checklists incorporate existing maintenance protocols. Checklists simply gather all of that existing information and give more structure to the maintenance process.

If you remember to incorporate these elements into your new checklist, you will have an easier time maintaining a consistent structure:

Safety

Safety should always be the first and last step in any preventive maintenance. Ensure that the appropriate safety equipment is used and worn by the maintenance personnel and that the area is clear of debris and sanitized thoroughly, if necessary.

Give It a Time Structure

Record how long each task should take and how long it actually took. Use this information to understand whether the overtime or undertime was due to equipment failure, lack of proper training, or misguided planning.

Ordered Checklist

As intuitive as this sounds, make sure that the checklist is in order. The checklist should be in sync with the preventive maintenance journey.

Be Concise

Try to use keywords and key actions, and keep the descriptions short and to the point. Try to use bullet points if you need to expand on specific points, but keep it to a minimum.

Supplement with Images and Diagrams

Incorporate images and diagrams to minimize errors and the misinterpretation of instructions. They will make it easier to stay concise.

Building the Preventive Maintenance Checklist

Every preventive maintenance checklist should include the following components. If the checklist is missing any, make sure to have a clear reason for why it was left out, or consider adding back the missing elements.

1. Inspection – This is the foundational step of all maintenance. Inspect and evaluate the current state of the machines, equipment, and tools. Look for signs of wear or damage and identify causes and services for repair. The quality of your inspection will determine the success of your preventive maintenance.

2. Servicing – Servicing includes cleaning, lubricating, charging, and other actions to prevent early wearing and failures.

3. Calibration – Compare the value of an asset’s characteristics to the expected standard set by the manufacturer (in the OEM) or by experts. Make sure that the value displayed stays within the recommended range or standard.

4. Testing – Test run machines, equipment, and tools to make sure they are serviceable.

5. Alignment – Align the specified variable elements of an asset to the goals of production to achieve optimum performance

6. Adjustment – If need, make adjustments to the specified variable elements of an asset so that it better fits the needs of your shop floor

Preventive Maintenance Checklist Example (Guide)

The checklist can be largely divided into three categories:

• Equipment, machines, and tools
• Buildings and Facilities
• Vehicles and fleets

These are not necessarily the names of each of the checklist categories but the general groupings of how you should structure them.

For Machines

1. Make sure that the machinery is clear of debris, before and after every shift
2. Lubricate Machines according to their schedule
3. Regularly inspect tools for sharpness or damages
4. Check for worn or damaged tools and record them for replacement or repair
5. Inspect fluid levels and air filters
6. Calibrate assets

For Facility Infrastructure

1. Make sure the assets have enough physical space to operate safely
2. Check if the caution and safety areas are properly marked
3. Keep exits, entrances, and walkways clear of debris and storage
4. Make sure there are no broken braces or wires
5. Check building systems such as electrical, plumbing, and network

For Safety

1. Make sure gas leak detectors, smoke detectors, and fire alarms are all working properly
2. Make sure evacuation lights work
3. Check that emergency first aid kits are fully stocked

For Network and Data Systems

1. Check the strength of your firewall and other network security systems
2. Regularly check for any data breach
3. Make sure employees change their password every couple of months
4. Check in with your colleagues in IT to see what items they think should be on this list

Just as important as creating a solid preventive maintenance checklist is knowing when to schedule the maintenance. This helps efficiently allocate time, energy, and resources, and it reduces net waste over time.

First off, the schedule must be structured based on how the priorities are determined. For example, will there be a higher priority placed on equipment, tools, or devices that:

• Take the longest to perform preventive maintenance?
• Require workers with certain expertise?
• Are more expensive or have high repair costs?

Depending on the priorities of production, you should determine the priorities of which equipment should go through preventive maintenance first.

Here are some common examples of how companies set priorities based on the questions above:

• Equipment that requires longer preventive maintenance hours
  Completed during large plant shutdowns, or heating/cooling season
• Equipment that requires a certain set of expertise schedule the rest of preventive maintenance based on when the workers with certain expertise can run preventive maintenance or when their workload is the least
• Equipment that is expensive—More frequent maintenance or more spending on the preventive maintenance budget

Unplanned Maintenance (Corrective vs. Emergency)

Preventive maintenance won’t always go as scheduled. Unexpected breakdowns can happen, and changes in equipment usage can prompt unplanned maintenance. Therefore, shop floors should always schedule with corrective and emergency maintenance in mind.

To ensure that proper repair or replacements can follow maintenance, sufficient time should be reserved for conducting corrective and preventive actions.

Fixed vs. Floating Preventive Maintenance

What is Fixed Preventive Maintenance?

Fixed preventive maintenance is when maintenance is scheduled at a set time, regardless of when the previous maintenance was performed. For example, even if corrective or emergency maintenance occurred between set times, the scheduled preventive maintenance will still happen. The fixed schedule only accounts for what is planned, not for what happened in the past.

Fixed Preventive Maintenance Example

Let’s say a machine is scheduled for preventive maintenance every 500 units it produces. However, an order of 300 units is placed after the machine has already produced 400 units. To meet the demands of the customer, the machine runs up to 700 units. In this case, the fixed maintenance would still occur at 1,000 units, instead of 1,200 units.

What is Floating Preventive Maintenance?

Floating preventive maintenance is based on when the maintenance was last performed. The maintenance will occur routinely, but not at a steady interval. It depends on previous maintenance records, performance, and past usage.

Floating Preventive Maintenance Example

Let’s use the same example from fixed preventive maintenance. After running maintenance on the machine at 700 units, floating preventive maintenance will run the next one at 1,200 units. Unlike fixed, floating is scheduled based on when the last preventive maintenance was performed.

Preventive Maintenance Scheduling Tip

Most equipment manufacturers have robust product-related data from in-house testing to user feedback. Therefore, the manuals often include recommended schedules for maintenance, which can serve as a guideline when planning preventive maintenance.

Predictive and preventive maintenance have the same purpose: to inspect shop floor assets and prevent unexpected downtime or failure. Both of their goals are to prevent all possible equipment breakdowns from occurring.

However, their differences lie in how that maintenance decision is made.

Preventive Maintenance relies on:

• Industry Averages
• Standard Practices
• Original Equipment Manufacturer (OEM) Manuals

Predictive Maintenance relies on:

• Asset’s Utilization
• Historical Performance Data
• Current Performance Data

To sum that up, preventive maintenance is scheduled based on some sort of time or set quantity interval, whereas predictive maintenance is based on the status of the assets. The trigger for preventive maintenance is time, and the trigger for predictive maintenance is asset condition.

Predictive vs. Preventive Maintenance Example

Suppose preventive maintenance is maintenance performed every 400 units or 30 hours of runtime. In that case, predictive maintenance is only performed when the status of the asset begins to fall below (or rise above) a certain threshold. For example, a machine starting to overheat close to 180°F may trigger maintenance, regardless of the industry standard or the OEM manual recommendation of running a maintenance every 400 units.

To further break it down, think of preventive maintenance as a regular health checkup. It happens twice a year, scheduled in advance. On the other hand, predictive maintenance is similar to seeing a doctor when you show early (perhaps not quite diagnostic) signs of a condition—like high blood pressure or cholesterol.

Preventive focuses on preventing problems before they occur, while predictive maintenance predicts problems to increase asset reliability, longevity, and performance.

Technology as Predictive Maintenance Enabler

Since predictive maintenance relies heavily on measurement and analysis, collecting data points on the criteria that trigger maintenance activities is crucial.

The collection of these data points is largely enabled by IoT devices and maintenance software that track the utilization and the performance of the assets. Capturing real-time data on the status of the assets provide strong evidence for when maintenance should be run.

If set up correctly, IoT devices can measure the status of assets against the predetermined threshold for key performance indicators like temperature, vibration, and sound. Any variants found between the set condition and performance can trigger maintenance by prompting supervisors or workers on the shop floor.

Benefits of Predictive vs. Preventive Maintenance

There are different uses for each type of maintenance.

Preventive maintenance is more appropriate for assets that are used in daily operations and require some sort of steady maintenance. Since these are used frequently, it does not make sense to wait until there are signs of a potential breakdown.

Predictive, in contrast, is more appropriate for assets that are dependent on the success of a certain component based on set standards. This helps maintain a custom standard of asset conditions so that maintenance on the shop floor can be optimized to its function.

Cost

Preventive maintenance is routine maintenance that costs far less than predictive maintenance. Since predictive requires the consistent collection of data on the performance of assets, it involves monitoring of asset conditions.

Efficiency

Since preventive maintenance is reliant on a steady schedule, it runs the risk of over-maintenance. This can cost over time and labor and cause assets to deteriorate faster than expected. Although preventive maintenance reduces overall maintenance time, it still takes longer to set up and implement when starting out.

So which one?

Different assets call for different maintenance protocols. As mentioned above, depending on the frequency of use and its function, an asset will require either preventive or predictive maintenance. However, with Tulip, you can achieve both. Tulip provides the flexibility of choosing the maintenance protocol that works best for your assets, not the protocol that is the easiest to deploy uniformly.

Whether it is preventive or predictive maintenance, it can be challenging to manage all the different requirements and procedures for various assets on the shop floor.

Tulip can help you stay on top of whatever maintenance you wish to execute.

Let’s look at how this would work for preventive maintenance.

Capabilities:

1. Create your asset with the Tulip app
2. Set up asset requirements
3. Schedule maintenance

Create Your Asset with Tulip App

The first step is to create the asset you would like to schedule maintenance for. Fill in the name, the location, and asset type.

Next, mark whether it is single-use. This will remind you to dispose of certain assets that have a shelf life.

If the asset needs recurring maintenance, add procedures along with frequency. You will be able to add more details to these procedures later on.

Manage Maintenance Procedures

Now let’s add more details to the maintenance procedure you have created above. Select the asset type and the procedure you want to edit further.

In the box under ‘selected asset type – Procedure,’ add subtasks that make up that procedure. Once you have added all of the action items, you can move them up or down the sequence and adjust their order.

When you click on the individual procedure sequence, you can add images and instructions to better guide the shop floor workers.

Maintenance Schedule Board

Let’s look at what the maintenance person will interact with on the shop floor.

This schedule board will give all the list of assets and procedures sorted by due date and frequency.

Once they click on a specific procedure for an asset, they can see the entire work sequence needed to complete the maintenance. Once the tasks are complete, the maintenance person can click the ‘finish procedure.’

Single-Use Asset Checkout

For single-use assets that have to be thrown out after the duration of its shelf life, this single-use checkout screen can trigger an alarm or alert the line leader when the asset expires.

Predictive Maintenance with Tulip

Predictive maintenance must be tailored to the condition and the function of your assets. Therefore tracking the health of those assets throughout their life cycle is crucial to planning predictive maintenance.

You can easily do this by connecting your industrial IoT devices to the Tulip app and triggering maintenance when any variants are detected. From our extensive collection of supported devices, you can directly feed the data from connected scales, calipers, thermometers, and sensors into the app and notify the maintenance personnel or the line leader when that data prompts predictive maintenance.

The trigger conditions would be different, but the maintenance procedure would use the same app interface as the one introduced above for preventive maintenance.

In this guide, we’ve covered:

• What Preventive Maintenance is and its benefits
• How to create a Preventive Maintenance Checklist
• Elements of a Good Preventive Maintenance Checklist and examples
• Preventive maintenance scheduling
• Predictive vs. Preventive Maintenance
• How Tulip can help realize the maintenance process

Digitizing the maintenance process is a no-brainer. Instead of having to manually follow a maintenance checklist or a schedule, you want to minimize the administrative work and optimize the maintenance practices, leaving only the kinds of work that can be done by humans for the shop floor workers.

If you’re interested in how Tulip can help you digitize maintenance, get in touch.