MTTF allows you to know when to dispatch maintenance technicians before equipment is likely to break down
MTTF allows you to know when to dispatch maintenance technicians before equipment is likely to break down

How To Use & Improve Your Facility’s MTTF

Your assets and their lifespan are incredibly valuable. When they contribute to the revenue of your business, it’s vital that you get an accurate snapshot of your equipment’s worth for accounting purposes. Any downtime, disruptions or incidents will impact the overall productivity of your facility. Therefore, it’s important to determine your equipment’s reliability so you can be prepared for the expected and unexpected. There’s some math involved, but it becomes much simpler with a proper understanding of how to calculate the life and value of your assets.

One key metric for calculating asset life is mean time to failure (MTTF). Let’s take a deeper look at how to use and improve your facility’s MTTF and how maintenance management software can help.

What is mean time to failure?

By definition, mean time to failure (MTTF) measures the amount of time a piece of equipment will last before it fails. In these cases, it would calculate the entire lifespan of an asset if it’s considered part of a non-repairable system. Otherwise, repairable items measure the time between breakdowns – known as the mean time between failures (MTBF) – which is averaged out to provide a value to the asset owner or maintenance employee.

A diagram illustrates the mean time to failure. MTTF equals the number of operational hours divided by the number of failures of non-repairable equipment.

MTTF is usually calculated by dividing the total number of working hours by the number of assets in operation. The higher the number of a particular type of asset you have, the longer your MTTF will be. MTTF is measured in hours. Here’s an example:

Let’s say you manage a large facility that has 50 tube light bulbs and you want to calculate the MTTF. Not every light bulb will have the exact same run time. Some might get used more than others because they’re always in use. Others might be from another, lower-quality brand. This is why, when we add them all together, we may not get to a whole, easy-to-calculate number. But, for simplicity’s sake, we’ll say they have a total run time of 10,000 hours.

MTTF = Total number of hours / total number of an asset

MTTF = 10,000 hours / 50 assets

MTTF = 200 hours

MTBF, on the other hand, is calculated by dividing the total number of hours the assets have been operating by the number of failures that have occurred.

An illustration shows how MTTF transitions to MTBF after the first equipment failure. MTBF includes the MTTR repair period before MTTF begins again after a repair.

Determining an asset’s MTTF can be tricky, but having a way to track equipment usage as part of your maintenance KPIs is helpful to prevent unnecessary downtime.

But, wait, how can we possibly know the MTTF value of an asset if we need to know the total hours of use? Consider your MTTF as a working average that continues to get more precise over time. If you’re calculating the lifespan of a replaceable light bulb, every time one burns out or is broken, you can then input those hours into your tracking to improve your accuracy.

MTTF only measures how long it takes for a system or asset to fail based on the average from a total of previous occurrences. It doesn’t measure how often failures happen, the time between failures or whether an unexpected system outage might occur. Therefore, tracking MTTF is important, but it shouldn’t be the only metric you use when evaluating asset reliability.

There will be other variables that could potentially affect your facility’s various MTTF hours.

What impacts a facility's MTTF?

For maintenance managers, ensuring that a facility’s operation is productive and seamless is a top priority. You’ll likely spend a considerable amount of time gathering data and insight into your activities to track and prioritize tasks. While incident metrics like MTTF, MTBF, and others can all be useful, especially when used together, there are some factors that can impact the actual life of your assets that an equation can’t automatically foreshadow.

What is considered a good MTTF?

The ideal MTTF for your organization will be unique to your circumstances. It’s impossible to benchmark a universally “good” MTTF that you should strive toward. Instead, you can determine your own goals by taking several factors into consideration.

Environment

The physical location where your asset is being stored and used will impact its life and durability. A light bulb being used outdoors, for example, can be subjected to extreme weather conditions, humidity and ice. It’s going to fail much sooner – and have a lower MTTF – than an asset used in a temperature-controlled utility closet. Therefore, because you expect the MTTF of an outdoor asset to fail sooner, you won’t anticipate it to be as high as one kept indoors.

Usage

Similar to the above, how often an asset is used will also impact its MTTF. If we consider tube light bulbs again, we know that those used in low-traffic areas will have a longer lifespan than ones in the lobby of a busy organization. If you’re grouping every light bulb into the same MTTF, those left on 24/7/365 are going to leave a mark on the total number of hours used in your calculation.

Economic value

An asset’s initial cost is going to influence your MTTF in two ways: First, if you’re purchasing bulk light bulbs for a very affordable price but sacrificing the quality of the bulb, and second, the number of light bulbs bought. Your MTTF will be influenced by whether you purchase more bulbs at a lower price or fewer, longer-lasting bulbs at a higher expense.

While the above factors can be analyzed and interpreted in your calculations relatively easily, there may be some unpredictable variables. For example, if your asset is installed or used improperly, the usage will impact when it will fail. It’s important to use your MTTFs when planning repairs or evaluating new purchase decisions, but not to use them strictly to determine when an asset will fail.

Once you have an MTTF for a particular asset or group of assets, you can then factor it into your maintenance routine, inventory management, and more. You can also take measures to improve the MTTF to limit the need for costly repairs and replacements for as long as possible.

How to use and improve your MTTF

Once you’ve calculated an asset’s MTTF, you can use it to help you with maintenance management. As MTTF is an estimate, it can be used to determine the probability of failure at any given point in time. For example, a MTTF of 2 years means that there is a 50% chance of asset failure in any given year. You can ensure you have the right repair products on hand, spare parts, or a replacement readily available to reduce the amount of possible downtime and maintain productivity.

To improve your MTTF, one of the top goals should be to reduce the number of failures that occur. If a piece of equipment has a high failure rate, it’s necessary to understand why this is happening.

There are many possible causes for this problem, which may include:

  • Poor quality materials
  • Lack of maintenance
  • Improper handling or operation
  • Scarcity of operator training
  • Shortage of safety measures in place
  • Poor design
  • Improper installation or setup
  • Dirty environment or unfitting storage conditions

Therefore, the key to reducing failure rates is to try to solve the possible issues which may be contributing to your assets’ breakdowns. This also includes making sure that equipment has been properly calibrated, maintaining a clean work environment, and regularly checking for any signs of wear and tear.

Improve the MTTF of your equipment even further with some of the following best practices:

Preventive maintenance

Take the necessary precautions by scheduling preventive maintenance and inspecting all your assets. Yes, even the light bulbs. This will prolong their usage and limit reactive maintenance while also ensuring parts remain safe and in good working condition.

Setting up your small assets such as fans and motors with sensors that predict when preventive maintenance is needed and send alerts to your management software will come in handy.

Quality over quantity

It may seem economical to purchase low-quality parts and equipment to decrease upfront costs. However, in the long run, you’ll need to replace and reorder more often, which adds up to more money over time – and a lower mean time. Think about it like buying a pair of really good shoes: they’re going to last longer and be able to survive the weather much better than something that’s poorly made.

Analyze unexpected failures

When early failures occur with no recognizable cause, it can be useful to complete an analysis to see what exactly happened. Even if you can attribute it to “wear and tear,” there may be some underlying cause that, with a quick fix, could expand the life of your assets even further. Once you’ve distinguished what the reason for the unexpected failure was, you can then gather the data and use it to better predict and prevent the problem from occurring again.

When should MTTF not be used?

If the equipment life you’re measuring could potentially last for years, failure metrics such as MTTF probably won’t work. It’s a much better method for assets with a shorter lifespan. Take industrial-sized electric push floor scrubbers, for example. Your maintenance facility may have four or five of them to keep up with the high traffic of busy hallways. These are intended to last for years and can easily crack an MTTF calculation. How?

MTTF = Total number of hours / total number of an asset

MTTF = 50,000 / 5

MTTF = 5,000 (or the equivalent of almost 7 months of continued use).

Is it likely that one floor scrubber could be used for 5,000 hours before breaking down? We’ll leave that for you to decide.

How can maintenance management software improve MTTF?

It’s important for facility managers to keep their machinery and equipment in good condition. Through the use of technology, we can automate many manual tasks and keep updates and maintenance top of mind.

The main purpose of maintenance management software is to organize and manage all information related to equipment maintenance. It can also help with tasks such as scheduling, tracking, planning and budgeting. The data gathered is used for statistical analysis, which helps identify trends and improve MTTF. The more efficient the maintenance management software, the higher the mean time.

Why choose FMX?

The world of facilities management technology is changing more and more every day. We’re here to ensure you have a system that can keep up with this pace of change, so you don’t have to worry about it slowing you down. We pride ourselves in providing only the highest quality software to our clients – for both their equipment as well as their team.

You can integrate the number of usage hours into FMX software, and include notes and tracking that will make calculating MTTF and other failure metrics more organized and easier to manage. By scheduling preventive maintenance and other necessary functions into the software, you can extend the life of your assets and decrease the number of random failures and unplanned downtime.

FMX maintenance management software tracks equipment maintenance in three components: two charts to display cost and count of work order by equipment type, and one maintenance equipment summary.

Our software is designed to meet the needs of a wide variety of maintenance service teams, from small contractors to large enterprises with multiple locations. Whether you’re managing a single site or an entire network, we’ve got your back.

Keeping track of documents, work orders, schedules, and time sheets has never been this easy! With our dashboard, you’ll have access to all the information about your organization’s maintenance management operations in one place.

Ready to implement your MTTFs into a dependable, customizable and easy-to-navigate maintenance management software? Reach out for a demo today.