Key Downtime Metrics for Operations Management


Minimizing downtime is one of the most important -- if not the most critical -- function for maintenance teams and technicians. But measuring how effective you are in minimizing downtime goes beyond simply the time it takes from breakdown to repair. Understanding key downtime metrics is essential to building sustainable, effective maintenance operations.


It’s important to grasp the distinction between downtime minimization as a company-wide key performance indicator (KPI) and the specific metrics that feed into achieving that overarching goal. Different metrics measure various aspects of the repair and maintenance process, from a machine’s overall uptime effectiveness to how long repairs actually take.


Here, we’ll pin down the specific downtime metrics that every facilities management team needs to improve. We’ll also cover industry benchmarks for those metrics and strategies for improving them. Finally, you’ll learn about specific technology tools that can help you reduce downtime and improve those metrics on a regular basis.

Most Important Downtime Metrics

First, let’s dive into the specific downtime metrics you need to know about, how they’re measured and how they contribute to your overall success. These metrics are closely related to Maintenance Effectiveness metrics, but with a greater focus on asset reliability and repair process efficiency. 


The most well-known downtime metric is Mean Time to Repair (MTTR). The MTTR metric reflects the average time it takes to troubleshoot and repair a failed piece of equipment. The MTTR calculation typically includes the time from when a technician is first notified about an issue to the moment the machine is spun back up for operation and/or production. MTTR effectively measures both the effectiveness of your maintenance operations and a machine’s ability to be repaired or maintained.


For example, the technician may be knowledgeable, skilled, and efficient when deployed to a job. But if certain lines of equipment are outdated or overly complex, it can be the asset dragging down MTTR and therefore increasing overall downtime. The basic calculation for MTTR is as follows:


𝑴𝑻𝑻𝑹 = 𝑻𝒐𝒕𝒂𝒍 𝑴𝒂𝒊𝒏𝒕𝒆𝒏𝒂𝒏𝒄𝒆 𝑻𝒊𝒎𝒆 ÷ 𝑵𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝑹𝒆𝒑𝒂𝒊𝒓𝒔


The next metric that has a huge impact on downtime is Overall Equipment Effectiveness (OEE). This metric focuses solely on the piece of equipment’s overall functionality and reliability, and thus its impact on downtime. The OEE calculation factors in machine availability, performance, and quality. Availability is defined as the percentage of time an asset functions when needed. Performance is how much of the time the asset is operating at top speed, and quality the percentage of time the machine is producing without any defects. In a perfect world, your OEE would be 100%, and is calculated as follows:


OEE = Availability × Performance × Quality


Another important metric is Mean Time Between Failures, or MTBF. Measured in hours, MTBF reflects the average time an asset is functioning properly in between breakage or failure events. The higher the MTBF, typically the less downtime. You can calculate MTBF using this equation:


MTBF = (Uptime Hours Per Day × Total Days of Operation) ÷ (Number of Breakdowns)


However, when it comes to getting the most clear picture of downtime and how it’s impacting your business, Lost Time is the most effective metric. Lost Time provides a single number showing, well, how much productivity time you’re losing on a piece of equipment over a specific time period.

Lost Time = (Time Asset is down ÷Total Time) ×100


So, if your machine is down 5 hours out of a 40 hour workweek, then 12.5% of the potential productivity time of that equipment is reflected as Lost Time.  


But what’s important to remember is that we measure asset reliability because it directly impacts cost. Lost time can also be interpreted as lost revenue, whether it’s paying for replacement parts or not manufacturing enough products. The good news is you can actually do something about it.

Industry Benchmarks and Improvement

When it comes to benchmarks, best in class organizations average an OEE of roughly 82 percent. Top companies average an OEE of more than 96 percent, while the bottom tier performers have an OEE of 31 percent or lower. Most organizations should target an OEE of 86 percent or better.  


Reaching these OEE targets -- and improving other metrics like MTTR -- requires a mix of technology and business strategies. Addressing asset reliability and performance issues with assets themselves is certainly part of the solution. Use machinery that breaks less frequently and is easier to repair. Plus, share your data with your equipment manufacturers for improvement you can benefit from when you upgrade.


From a business strategy approach, move your maintenance operations from a reactive stance to a planned preventive or predictive model can also reduce Lost Time and improve OEE.


“A robust predictive maintenance program can direct and focus repairs to the proper fail point,” writes Graham Immerman of MachineMetrics. “Introducing faster response to equipment failure, equipment fallout ranges can be reduced, saving money for the entire operation through increased efficiency and production of more first quality goods.”


By implementing Internet of Things (IoT) sensors and smart devices, you can collect data in real-time from equipment for analysis and planning of maintenance on a predictive basis. You can then integrate that technology with Sigga solutions to help with things like planning and scheduling to reduce downtime.

How Sigga Reduces Downtime

Sigga’s EAM solutions can prove pivotal in helping you reduce downtime though increasing asset reliability with preventive maintenance and increasing team responsiveness to sudden downtime events.


Sigga’s Planning and Scheduling solution can help you move from reactive to planned maintenance through more efficient use of technicians. As more planned, preventive work gets accomplished, fewer breakdowns will occur leading to a higher OEE.


Technicians can complete their work faster and improve MTTR by using Sigga’s Mobile Enterprise Asset Management (EAM) solution, giving techs the ability to report a problem immediately for the organization to react faster. They can also log their hours and exact time spent on jobs so your metrics calculations will be even more accurate.


Reducing downtime is all about saving money, maintaining quality, and using technicians smartly and efficiently. By understanding key metrics like MTTR, OEE and Lost Time, you’ll be able to get a handle on exactly where you stand and how far you need to go to achieve industry standards. Once you have a clear picture of where you need to go, you can begin employing the right technologies to enable a planned approach that will keep you up and running longer than ever.


Learn More


See how Sigga Solutions can help you reduce downtime.