Tracking asset maintenance KPIs is a great way to better understand what your facilities management is doing well and where it’s struggling. Performance metrics give you the power to analyze asset maintenance through a diagnostic lens, allowing you to isolate and solve problems before they become major issues.

These 7 asset maintenance metrics were curated to give you a well rounded snapshot of your facility’s performance, providing you with the knowledge to help your facility improve.


MTBF—Mean Time Between Failures—is a bit of a celebrity when it comes to facility management metrics, but a list of valuable asset maintenance KPIs would be amiss without it. Tracking MTBF allows you to anticipate future breakdowns by looking at your asset’s failure and maintenance history.

Successful tracking will allow you to intervene before your asset’s next failure with preventive maintenance. Over time you’ll be able to create a preventive maintenance schedule with a specialized plan for each asset based on the model’s life cycle, extending the asset’s life, improving efficiency, and cutting costs.


MTBF = (time asset has been in use – unplanned downtime due to breakdown) / total number of breakdowns

For example, an HVAC system that runs 24/7 for a year would have an asset uptime of 8,760 hours. In one year, the system faced 2 breakdowns, once for 12 hours and once for 23 hours, for a total unplanned downtime due to breakdowns of 35 hours. 

MTBF = (8,760 hours – 35 hours ) / 2 breakdowns
MTBF = 4,362.5 hours

What this means:

On average, the HVAC unit goes 4,362.5 hours before breaking down, or 181 days and 18.5 hours. In this scenario the technicians should check in on the HVAC unit twice a year to perform preventive maintenance as needed in an effort to prevent future breakdowns.


MTTR—Mean Time To Repair—is the flip side of the MTBF coin. MTTR analyzes your technician’s response time to resolve breakdowns. MTTR is a powerful metric in planning and scheduling preventive maintenance because it gives you an estimate of the required downtime for repairs.

This KPI also allows you to compare the performance of different technicians by calculating each staff member’s unique mean time to repair a common asset and issue. Evaluating how your technicians are performing is important to understanding your facility as a whole. 


MTTR = total maintenance time / total number of repairs

Total maintenance time is a count of time that starts as soon as the asset breaks down, and stops when the asset is repaired and in use again. To continue with the example used in MTBF above, the sum of the 12 hour breakdown and the 23 hour breakdown accounts for the total maintenance time of 35 hours. The number of repairs is 2. 

MTTR = 5 hours / 2 repairs
MTTR = 17.5

What this means:

On average, the HVAC unit takes 17.5 hours to repair. This information will be useful when planning scheduled downtime for preventive maintenance initiatives.

3. OEE

OEE—Overall Equipment Effectiveness—is a measure of an asset’s effectiveness based on three categories: availability, performance, and quality. A perfectly efficient piece of equipment will earn an OEE score of 1, and a piece of equipment that doesn’t work at all will earn a 0.

Determining an asset’s effectiveness is useful in decisions like replace or repair, and in determining the optimal preventive maintenance schedule.


OEE = availability x performance x quality

Availability = true operating time / planned operating time
Performance = actual cycle time / planned cycle time
Quality = valid pieces / total pieces produced 

This OEE formula is crafted with manufacturing machinery in mind, but it can be adapted as needed to suit other assets. For this example, however, we’ll analyze a manufacturing machine that produces lightbulbs. 

Calculating availability: 

The lightbulb manufacturing machine is supposed to run 12 hours a day, but today it broke down for 3 hours, meaning it was only usable for 9 hours. 

Availability = 9 hours / 12 hours
Availability = .75

Calculating performance:

The machinery is supposed to produce 50 lightbulbs every hour, but today it averaged 45 lightbulbs per hour. 

Speed = 45 lightbulbs per hour / 50 lightbulbs per hour
Speed = .9

Of the 540 lightbulbs produced in one day, only 515 lightbulbs met quality expectations. 

Calculating quality:

Quality = 515 lightbulbs / 540 lightbulbs
Quality = .95

To find the total OEE score, multiply the scores calculated above. 

OEE = .75 x .9 x .95 
OEE = .64

What this means:

While no individual category seems terribly inefficient, a score of .64 is considerably lower than the target score of 1. Using OEE to calculate your asset’s efficiency will help you get an accurate reading on your facility’s performance.

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4. Cost of Asset Maintenance

Cost of Asset Maintenance is a bit of a blanket term—there’s a lot of different aspects and systems for analysis that go with this KPI. 

One way to analyze costs is by comparing the cost of planned maintenance to unplanned maintenance. Understanding where your funds are going is crucial to forming an effective budget. If you see you’re spending a lot of money on preventive maintenance for an asset but see no decrease in the cost of unplanned maintenance, that may be a sign preventive maintenance is not working effectively. Catching discrepancies like this should prompt you to revisit your preventive maintenance plan and reevaluate before moving forward. 

Another effective way to track costs is by calculating asset maintenance cost variance. Cost variance is the difference between the budgeted cost allocated to a project and the actual cost of performing the maintenance. This asset maintenance KPI gives you feedback on the quality of your budget and can help you plan more effectively for future budgets.


Asset maintenance cost variance = expected cost of maintenance – actual cost of maintenance

For this example, imagine a budgeted cost of maintenance of $300 and an actual cost of maintenance of $250.

Asset maintenance cost variance = $300 – $250
Asset maintenance cost variance = $50

What this means:

The maintenance performed cost $50 less than expected. That extra money can be saved to go towards padding in the budget. Oftentimes, maintenance cost variances are negative, meaning that the actual cost of maintenance exceeds the expected cost. Setting extra funds aside from a positive cost variance will help to offset negative cost variances later on, keeping your budget balanced.

5. Cost to replace vs. cost to repair

Performing maintenance –both planned and unplanned– can get very, very expensive. When you’re in a consistent routine of performing asset maintenance, especially if you often opt for a cheaper quick fix as a response to breakdowns, it might be easy to lose sight of the true value of your asset. Any time you are planning to pump more time and money into a deteriorating asset, it’s important to consider the cost of a replacement instead.

Replacements are expensive, there’s no denying that, but at a certain point it will be a cost saver to bite the bullet and purchase new equipment. Keep a log of the cost of expected future repairs (with a buffer for unplanned maintenance), a reference cost for a replacement, and the expected routine repair costs of said replacement on hand.


Cost to repair = annual expected cost of maintenance on existing equipment

Cost to replace = (cost of replacement / replacement asset’s lifetime) + expected annual cost of maintenance

For example, you currently have an asset with annual maintenance costs of $200. A replacement for this asset costs $1000. The new asset is predicted to last 15 years with annual maintenance costs of $100. 

Cost to repair (annually) = $200

Cost to replace (annually) = ($1000/ 15 years) + $100
Cost to replace (annually) = $166.67

What this means:

Since the annual cost to replace, $166.67, is cheaper than the annual cost to repair, $200, it makes sense to invest in a new asset for $1000 upfront and save money over time.

6. Unplanned maintenance percentage

Tracking unplanned maintenance gives you an idea of the success of your facility’s preventive maintenance plan. Even in a fully optimized facility, unplanned maintenance is inevitable. A healthy amount of unplanned to planned maintenance falls at a 10-20% unplanned to 80-90% planned ratio.

If your current ratio is favoring unplanned maintenance, use the asset’s MTBF to help you implement a preventive maintenance plan that schedules preventive maintenance before the next breakdown is expected.


Unplanned maintenance percentage = unplanned maintenance / total maintenance 

If you perform 17 total hours of maintenance on an asset, of which 3 hours are due to a spontaneous breakdown, then your unplanned maintenance percentage is 18%.

Unplanned maintenance percentage = (3 hours / 17 hours) x 100

Unplanned maintenance percentage = 18%

What this means:

18% is a healthy unplanned maintenance percentage, but there is still room for some improvement!

7. Work order resolution time

The clock starts on this KPI as soon as a maintenance request is filed and stops once a technician has addressed and solved the issue. This asset maintenance metric gives you a picture of the functionality of your team and the complexity of specific maintenance issues. The shorter the work order resolution time, the better, meaning your technicians are quickly solving issues shortly after they occur. 

Work order resolution time can be shortened by optimizing several functions, many of which relate to the asset maintenance KPIs listed above. Focusing on planned preventive maintenance will decrease the amount of work orders for reactive maintenance that are submitted. The less work orders, the less backlog, meaning your team will stay on top of maintenance requests and resolve work orders faster.

Specialized software is a great way to further improve work order resolution time. Work order software manages, organizes, and prioritizes tasks to increase time spent working in the field, ultimately decreasing average work order response time.

Using KPIs to track asset maintenance and ultimately optimize asset performance will take your facility to the next level. In order to better track and manage these facility management KPIs, consider implementing asset and equipment management software. Asset and equipment maintenance software manages and tracks the asset maintenance KPIs listed above, as well as many more, and provides you with detailed analytics and reports that can help you optimize your facility.

Learn asset tracking best practices and how asset and equipment maintenance software can help you track the KPIs listed above.

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