Improving performance with motor-system KPIs

Previous posts discussed why you need a motor management plan and listed the various steps involved – inventorying your motors, establishing a motor failure policy, motor purchasing policy, creating repair guidelines, and right-sizing your maintenance program. This post describes why it’s important to manage motor-related KPIs and identifies motor-performance metrics to track.

The old axiom teaches that you can’t manage what you don’t measure.

Key performance indicators (KPIs) are quantifiable measures that demonstrate the degree to which an organization is meeting its stated goals and objectives. Additionally, KPIs — especially the following motor-related metrics — elucidate opportunities to improve your operations. Tracking these motor-related key performance indicators can help you identify and fix recurring problems with particular motor applications.[i]

  1. What is the value of your motor portfolio?

A new motor easily costs several thousand dollars, depending on its size, and you likely have scores of motors in your facilities. In total, that adds up to a significant capital investment. To quantify this investment, ask your asset manager or facility maintenance supervisors

– How many motors do you have at each of your facilities?

– What is the total size (horsepower) of your motor portfolio?

– What is the value of your motor portfolio as capital assets?

These statistics help you communicate motors’ importance to your organization. In addition, you may find it helpful to calculate what percentage of your capital assets your motors comprise. This value helps others in your organization to compare your motors’ value relative to your other capital assets.

  1. How much of your motors’ value has been depreciated?

Your motors’ depreciation ratio — the amount already depreciated divided by your motors’ total value as capital assets — indicates the average age, and often, health, of your motor portfolio. Management best practices recommend keeping your depreciation ratio below 0.50[ii][iii]

A ratio greater than 0.50 indicates that your utility has older motor assets than newer ones, creating three challenges: First, you’ll likely hit a period when you’ll need to replace a high percentage of motors in your operations, inflating your capital costs through that period. Second, motors (as with most equipment) become somewhat more likely to fail as they age, making it more likely that you’ll experience unscheduled downtime. Third, since appliance standards have increased motor efficiency by 4 – 7% over the past 20 years, your older motors probably incur higher energy expenses than newer motors.

  1. What are your annual energy expenses?

And how does energy rank compared to your other major cost centers, such as personnel and contracted services? Many organizations hide their energy expenses as operating costs within operational divisions. While allocating energy costs to your divisions makes it easier to calculate the cost to produce your products, it obscures your energy expenses’ total impact on your bottom line.

  1. What percentage of your energy expenses do your motors consume?

Motor-driven loads consume more than 90% of the energy required to produce and distribute drinking water, nearly 70% of the energy required to collect and reclaim wastewater, and up to 50% of the energy used in other industrial and manufacturing processes. What’s the percentage at your facilities? Used in combination with total annual energy expenses (#3) and its rank against other cost centers, this metric provides context to understand your motors’ importance as a cost center.

  1. What does motor-related maintenance cost you?

Over a motor’s approximately twenty-year life, its maintenance costs will rival its initial purchase price. In addition to considering direct motor maintenance costs, such as what you’re spending at motor repair shops, this category includes your maintenance-related labor costs and maintenance supplies, such as grease. Add to these direct maintenance costs any lost revenue or regulatory fees incurred by motor failures in the past year. The number and duration of unscheduled downtime events, and the costs related to this downtime, are key performance indicators for any maintenance program. I also recommend tracking the mean time between failure as well as the results of the root-cause analyses performed on your failed motors to see if there are trends that indicate opportunities to improve your maintenance program.

  1. What is the availability and capacity of your motor-driven systems?

Operational KPIs to track include motor run-hours, load-duration curves, mean time between motor failures, number of unscheduled outages, and duration of motor-related downtime. These measures feed into your availability, capacity, and overall equipment effectiveness metrics. For example, load-duration curves can help you understand whether capacity calculations actually indicate spare capacity vs. over-sized motors.

Want to know more on how our solution can help track your motor performance metrics? Contact us at to get the full picture.

[i] Motor Decisions Matter / CDA

[ii] Caveat: This indicator is only as good as your depreciation schedule and historic pricing.

[iii] Environmental Finance Center at the University of North Carolina, NC Water & Wastewater Dashboard: Financial Benchmarks: Asset Depreciation.

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