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How Maintenance Will Revolutionize the World (Chapter 3)

*For the next 4 weeks, UpKeep will be releasing chapters from our upcoming publication, How Maintenance Will Revolutionize the World. This is the first installment and includes chapters 1-3. Chapter 2 can be found here.

UNDERSTANDING THE DIFFERENT TYPES OF MAINTENANCE

“Anyone who stops learning is old, whether at twenty or eighty. Anyone who keeps learning stays young. The greatest thing in life is to keep your mind young.”
-Henry Ford

Chapter 3: Getting Started

This section is all about understanding the 4 broad types of maintenance. Yes, there is a whole suite of different terms in the industry, and they all serve important functions in the world of maintenance. This does not cover all maintenance and reliability philosophies and should be used as a great starting point into maintenance strategies! Ready? Let’s go!

For ease of understanding, we are going to break out maintenance strategies into 4 different groups:

  • Breakdown maintenance
  • Time based preventative maintenance
  • Condition based maintenance
  • Predictive maintenance

 

Chapter 3.1 BREAKDOWN MAINTENANCE

 

 

The Breakdown Maintenance Workflow

 

BREAKDOWN MAINTENANCE

Breakdown maintenance (also known as Run-To-Failure maintenance) is a maintenance strategy that is sometimes more appropriately called “Fit and Forget” because there is no maintenance plan beyond complete replacement upon failure. It is an essential technique in certain industries. Take, for example, the space program where satellites are beyond human reach and simply cannot be serviced. 

In essence, breakdown tells you that no amount of maintenance will refill a toothpaste tube. When it’s empty, it’s at the end of its useful life. Buy a new one so it is ready to go when the other fails.

However, breakdown maintenance should not be misconstrued as unintended failure replacement (UFR) which is failure from neglect or ignorance without a plan to cope. Breakdown maintenance is a very deliberate strategy where the item is intended to run until it fails and owners are prepared to take remedial action instantly upon failure

Types of breakdown maintenance

There are two types of breakdown maintenance: planned and unplanned.

Planned

Planned breakdown maintenance means that the organization is prepared for a breakdown and even expects it to happen. The equipment runs until it breaks, which initiates a breakdown trigger. While breakdown triggers can be unplanned, breakdown maintenance is a way of lowering the cost of maintenance.

This kind of plan needs to be rigorously documented and controlled. Employees should be clear on exactly which parts will break down and which parts will be maintained normally via preventive maintenance. Without these checks, a breakdown maintenance plan can be exploited or run awry.

Unplanned

Unplanned breakdown maintenance, on the other hand, occurs when a piece of equipment fails or breaks unexpectedly—also called an unplanned downtime event. While some facilities may not utilize a planned breakdown maintenance plan, nearly every facility needs resources in place for unplanned breakdown maintenance. After all, every piece of equipment will break or fault at some point in its life.

Examples of breakdown maintenance

Breakdown maintenance is unique in its applications because it cannot be used with certain industries or products, especially ones that involve health and safety. This means that breakdown maintenance is most frequently used when parts are inexpensive or nonessential.

Here are some examples in which breakdown maintenance is applicable:

  • Equipment can’t be repaired at all (inaccessible, designed to not be repaired)
  • Asset consists of inexpensive or easy-to-replace parts
  • Non-critical pieces of equipment (like hand tools)
  • Objects/equipment that are disposable or meant to be replaced at the end of their lifespan
  • Short-life assets (batteries, high flow pumps)

As you can see from these examples, breakdown maintenance becomes viable when there’s no inherent safety risk to letting a part or piece of equipment break. As an example, consider a facility’s light bulbs. If a light bulb is not linked to a safety feature, it doesn’t make financial sense to replace it before it has burned out.

However, breakdown maintenance is absolutely not viable when peoples’ lives can be endangered by a part or product breaking. For example, the aviation industry cannot rely on parts breaking down to fix them because doing so could threaten the personal wellbeing and safety of people on planes. This is also true for tire manufacturers who are responsible for road safety. When it comes to peoples’ lives, preventive and predictive maintenance are the right choice.

Benefits of run to failure maintenance

There are two possible beneficial outcomes while using breakdown maintenance: economizing costs and enhancing productivity. Ideally it is a mixture of both.

Breakdown maintenance can save money by eliminating the impact of regular maintenance. Inspecting and cleaning all of the sprinkler heads on a farm or golf course would have a huge time impact, driving up costs. It’s much simpler to note the occasional failure and replace the whole unit. The same could be said about drop ceiling tiles; or other damage are simply replaced since it is impractical to repair them.

To streamline and enhance operations to improve productivity, a facility with dozens of people assembling electronics will probably have replacement parts in bulk. Soldering irons, magnifying glasses, multimeters, and so on, are too inexpensive to maintain, and too labor intensive to service.

Examples

Run to failure maintenance requires good judgement. Knowing when to declare wholesale failure as opposed to initiating repair is part of the skill set. Here are a few examples of ideal breakdown maintenance scenarios. 

It is also ideal for short life assets that are not robust or particularly durable in design. This includes incandescent light bulbs, overhead door motors, circuit pumps, water heaters, air-traffic warning lights on radio towers, or anything that is typically replaced 5 or more times in the lifetime of a building.

This also applies to disposable assets are items which are generally inexpensive or single use. These could include car shock absorbers, automobile tires, signage, pneumatic pistons on assembly lines, most printer cartridges, all the way down to brooms and mops.

Conclusion

At its worst, breakdown maintenance is referred to as crisis maintenance because the status of equipment is unknown and the company faces unpredictable downtime when something breaks. Once implemented on appropriate assets, with intelligent planning for dealing with the inevitable failures, it saves time, saves money, and contributes to enhanced productivity.

 

 

Chapter 3.2 TIME BASED PREVENTIVE MAINTENANCE

Fun Fact: 80% of manufacturing plants use some form of preventive maintenance.

The Preventive Maintenance Workflow

Preventive maintenance, also spelled preventative maintenance, is a type of proactive maintenance that keeps assets in good order and reduces unscheduled downtime and major repairs.There are many different types of preventive maintenance that require different technologies and expertise. 

Preventive maintenance is carried out with the goal of increasing asset lifetime by preventing excess depreciation and impairment or untimely breakdown. This maintenance includes, but is not limited to, adjustments, cleaning, lubrication, repairs, and parts replacements.

Time-based preventive  maintenance

A recurring work order is scheduled for when a specified time interval is reached in the computerized maintenance management system (CMMS).

Benefits of preventive maintenance
There are more benefits of implementing a preventive maintenance program than merely reducing the amount of unplanned downtime. Other benefits include:

Think about it in simple terms such as with your car. Oil changes and regular servicing are part of a preventive maintenance schedule that ensures your car runs properly and without unexpected failure. If you ignore that maintenance schedule and miss service intervals, your car will depreciate in value and utility. The same goes for machinery in manufacturing plants and equipment in facilities.

With a PM schedule in place, maintenance managers can decrease downtime. This schedule is usually automated with a CMMS that comes with PM scheduling software. However, managers are always cautious of over-maintaining assets. There’s a point where preventive maintenance starts costing too much in relation to the amount of downtime it prevents.

“EMIT Optimisation – Getting More out of Existing Equipment for Less.” Risktec – The Newsletter of Risktec Solutions, 2017, www.risktec.tuv.com/risktec-knowledge-bank/asset-integrity-management/emit-optimisation-getting-more-out-of-existing-equipment-for-less/.

There are more benefits of implementing a preventive maintenance program than merely reducing the amount of unplanned downtime.

Other benefits include:

  • Extension of asset lifetime
  • Increased safety and reduced risk of injury
  • Optimized maintenance planning and resource allocation
  • Less expensive corrective repairs
  • Better margins and profits due to less downtime
  • Perhaps the greatest benefit is increased safety, especially for a company that owns heavy machinery. The price of employee safety is never too high and organizations such as the Occupational Health and Safety Administration (OHSA) rigorously enforce government policy.


Examples of preventive maintenance

Some aspects of a solid preventive maintenance program are obvious. Production line equipment should be suitably maintained to prevent breakdown, and infrastructure elements such as heating, ventilation, and air conditioning (HVAC) should be routinely inspected, cleaned, and updated as required. However, there may be other systems that also need routine maintenance to prevent failure.

How about your water systems? Do you have appropriate filtration? Are you running warm water systems that may be a breeding area for serious bacterial infections such as Legionnaires Disease? How about your electrical systems and the need to ensure that they not only comply with legislation but do not degrade over time? Doors, stairways, lighting, and flooring all need periodic inspection and maintenance, too.

The list of what needs to be included in your preventive maintenance plan can be bewildering, but there are certain guidelines that give you at least a basis to conform too. The American National Standards Institute (ANSI) carries a lot of information on preventive maintenance and is a good place to start if you are unsure as to the extent of the program that you need.

Important questions to ask yourself

Preventative Maintenance is the most common form of maintenance, but time based maintenance schedules only capture about 20% of issues. This means 80% of the time, maintenance teams over-PM or under-PM your assets, so be sure to ask yourself, “Do I have the right metrics and KPI’s to make sure I selected the right time based interval”?

Conclusion

Preventive maintenance is often seen as an overhead cost that is difficult to justify. But it takes just one period of downtime or a single notifiable accident to demonstrate how important it is to undertake a program of forward-looking maintenance.

To start implementing a PM program, choose a few critical assets, make a preventive maintenance checklist, then schedule the PMs in a CMMS.


To help you get started, we’ve collated some helpful sample checklists below from the U.S. Department of Energy’s Operations & Maintenance Best Practices – A Guide to Achieving Operational Efficiency:

Sullivan, G. P., et al. Operations & Maintenance Best Practices A Guide to Achieving Operational Efficiency. FEDERAL ENERGY MANAGEMENT PROGRAM, 2010, Operations & Maintenance Best Practices A Guide to Achieving Operational Efficiency, www.energy.gov/sites/prod/files/2013/10/f3/omguide_complete.pdf.
Sullivan, G. P., et al. Operations & Maintenance Best Practices A Guide to Achieving Operational Efficiency. FEDERAL ENERGY MANAGEMENT PROGRAM, 2010, Operations & Maintenance Best Practices A Guide to Achieving Operational Efficiency, www.energy.gov/sites/prod/files/2013/10/f3/omguide_complete.pdf.

 

Chapter 3.3 Condition-Based Maintenance

Fun Fact: 10% (and maybe even less) of industrial equipment ever actually wears out, meaning a very large portion of mechanical failures are avoidable

Condition-based maintenance workflow

Condition-Based Maintenance 

Condition-based maintenance (CBM) uses sensor devices to collect real-time measurements (ie. pressure, temperature, or vibration) on a piece of equipment. This data allows maintenance personnel to perform maintenance at the exact moment it is needed.

Condition-based maintenance uses meter measurements to perform maintenance only when that equipment may fail or needs repairs. You determine the precise maintenance point via visually inspecting a piece of equipment, performing tests on equipment specs, or gathering data and diagnostics. CBM allows maintenance personnel to act on a by-need basis, optimizing the amount of time spent on maintenance tasks.

This type of maintenance uses both condition monitoring and condition measurements. Condition monitoring measures specific equipment parameters (like vibrations in a system), taking note of drastic changes that could be indicative of a fault. Maintenance personnel take regular condition measurements from these parameters, which provides the current view of the equipment’s health. As equipment health dips, maintenance personnel perform work and return the equipment to its working state.

Condition-based maintenance uses equipment measurements to perform maintenance only when that equipment may fail or needs repairs. You determine the precise maintenance point via visually inspecting a piece of equipment, performing tests on equipment specs, or gathering data and diagnostics. CBM allows maintenance personnel to act on a by-need basis, optimizing the amount of time spent on maintenance tasks.

This type of maintenance uses both condition monitoring and condition measurements. Condition monitoring measures specific equipment parameters (like vibrations in a system), taking note of drastic changes that could be indicative of a fault. Maintenance personnel take regular condition measurements from these parameters, which provides the current view of the equipment’s health. As equipment health dips, maintenance personnel perform work and return the equipment to its working state.

Benefits

By monitoring equipment parameters in real time, CBM systems reduce downtime (and can even eliminate downtime as a whole). For example, your system measures the amount of noise produced by a motor, and a higher noise level indicates that the motor needs to be replaced. Because the equipment runs on a condition-based maintenance system, maintenance personnel will know exactly when to replace that motor because of this noise measurement. The moment the noise reaches an unacceptable level, the motor will be replaced.

That means you don’t need to wait until the machine faults out or the motor breaks and causes a massive downtime event. The unplanned downtime goes away, and in its place is maintenance work that takes place at a defined, measured point in time.

Examples of condition-based maintenance

Condition-based maintenance works similarly to the warning lights in your car. For example, the oil light doesn’t pop up when your car is running on its last few drops. Instead, it conditionally measures the oil content of your car and lets you know when you need to change or replenish the oil. This information allows you to make an informed decision to maintain your vehicle.

This is true of manufacturing environments as well. If a machine produces a certain amount of heat under normal conditions but heats up quickly when an energy problem exists, an infrared camera can detect the change in heat and the system can dispatch a maintenance technician.

Another example is pressure readings. When a large amount of water flows through pipes, the water produces considerable pressure; fluctuations in this pressure can cause problems when water is needed (low pressure) or too much water is flowing (high pressure). Reliably diagnosing pressure issues can save a lot of headache in any industry that relies on water cooling systems.

Conclusion

Condition-based maintenance may seem too expensive for too little benefit. However, in any organization with critical equipment, a CBM system can prove its worth twice over when it comes to reducing or even eliminating unscheduled downtime.

 

Chapter 3.4 PREDICTIVE MAINTENANCE

Fun fact: PdM can lead to a 25 to 30% decrease in maintenance costs!

The Predictive Maintenance Workflow

Predictive maintenance (PdM) is the most advanced type of maintenance currently available. With time-based maintenance, organizations run the risk of performing too much maintenance or not enough. And with reactive maintenance, maintenance is performed when needed, but at the cost of unscheduled downtime. Predictive maintenance solves these issues. Maintenance is only scheduled when specific conditions are met and before the asset breaks down.

PdM relies on IoT devices that monitor conditions of assets. Different assets are monitored in different ways (vibrational analysis, acoustical analysis, infrared analysis). This data is used to predict when the asset will require maintenance to prevent equipment failure. A continuous or online approach is used to monitor conditions of assets. Remote monitoring is also possible by connecting an IoT sensor device to maintenance software. When specific conditions are met, a work order for an inspection is triggered.

Types of predictive maintenance

A) Vibrational analysis

Machine Speed: High | Machine Type: Mechanical | Cost: Medium

This is the go-to type of analysis for predictive maintenance inside manufacturing plants with high-rotating machinery. Because it’s been around longer than other types of condition monitoring, it’s relatively cost-effective. In addition to detecting looseness like in the example above, vibrational analysis can also discover imbalance, misalignment, and bearing wear.

B) Acoustical analysis (sonic)

Machine Speed: Low, High | Machine Type: Mechanical | Cost: Low

This type of analysis requires less money to implement and is used for low- and high-rotating machinery. It’s particularly popular among lubrication technicians.

According to an article by Machinery Lubrication, “Acoustic analysis is similar to vibration analysis; however, its focus is not to detect causes for rotating equipment failure by measuring and monitoring vibrations at discrete frequencies and recording data for trending purposes.

Instead, acoustic bearing analysis is intended for the lubrication technician and focuses on proactive lubrication measures.”

C) Acoustical analysis (ultrasonic)

Machine Speed: Low, High | Machine Type: Mechanical, Electrical | Cost: High

While sonic acoustical analysis borders on the line of proactive and predictive maintenance, ultrasonic acoustical analysis is solely used for predictive maintenance efforts. And because it can identify sounds related to machine friction and stress in the ultrasonic range, it’s used for electrical equipment that emit subtler sounds as well as mechanical equipment. It’s argued that this type of analysis predicts imminent breakdowns better than vibration or oil analysis.

D) Infrared analysis

Machine Speed: Low, High | Machine Type: Mechanical, Electrical | Cost: Low

This type of analysis is not dependent on an asset’s rotational speed or loudness. Therefore it’s suitable for many different types of assets. When temperature is a good indicator of potential issues, infrared analysis is the most cost-effective tool for predictive maintenance. It’s often used to identify problems related to cooling, air flow, and even motor stress.

Example of predictive maintenance

A centrifugal pump motor in a coal preparation plant is a vital asset for day-to-day operations. To prevent unscheduled downtime, the maintenance team decides to use predictive maintenance technology. Because it’s a large piece of mechanical equipment that performs heavy rotations, the obvious choice is to monitor vibrations with vibration meters.

The team attaches a vibration meter close to the pump’s inner bearing and establishes a normal baseline measurement, visualized through a waveform graph (below, left). A few months later, the vibration meter identifies a spike in acceleration (below, right). The maintenance team reviews this new data remotely and schedules an inspection. The technician who performs the inspection finds a loose ball-bearing and repairs it.

Moving forward, the team connects the vibration meter to its CMMS. Now, when the same spike is identified, a fault with the ball-bearing is predicted and a work order is automatically triggered to perform the repair.

Conclusion

Predictive maintenance is not for every organization, especially those that have yet to implement planned maintenance. But for larger organizations that have outgrown traditional PMs and have additional budget, predictive maintenance can provide an ROI that turns the maintenance department into a source of cost-savings and higher profits.

Some helpful sample checklists below:

Sullivan, G. P., et al. Operations & Maintenance Best Practices A Guide to Achieving Operational Efficiency. FEDERAL ENERGY MANAGEMENT PROGRAM, 2010, Operations & Maintenance Best Practices A Guide to Achieving Operational Efficiency, www.energy.gov/sites/prod/files/2013/10/f3/omguide_complete.pdf.

 

STAY TUNED FOR CHAPTER 4 NEXT WEEK!