In manufacturing, system failures and unplanned downtime can have a significant impact on operations, profitability, and customer satisfaction. To manage these issues effectively, maintenance teams rely on key performance indicators known as reliability metrics and one of the most important among them is Mean Time To Repair (MTTR).
In this article, we’ll explain what MTTR means, how to calculate it, how it differs from other metrics like MTBF and MTTA, and how you can use it to drive efficiency improvements.
What is Mean Time To Repair?
Mean Time To Repair (MTTR) is a maintenance metric that tracks the average time required to restore an asset or system following an unexpected failure. It includes every stage of the repair process—from the moment the fault is reported to the point at which the system is back online and operating normally.
Although MTTR usually stands for Mean Time To Repair, you may also encounter other interpretations, including:
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Mean Time To Recovery
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Mean Time To Resolution
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Mean Time To Respond
Each term focuses on slightly different aspects of the repair process, but for clarity in manufacturing, MTTR generally refers to the time spent diagnosing, fixing, and restarting a failed machine.
What does MTTR include?
The MTTR metric covers the following activities:
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Alerting maintenance or engineering staff
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Diagnosing the cause of the failure
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Executing the repair work
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Calibrating and reassembling the asset
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Testing and restarting production
However, it does not include lead times for sourcing replacement parts or scheduled maintenance windows.
Why is MTTR important?
In manufacturing environments, every minute of unplanned downtime costs money. MTTR is a critical measure of how efficiently your team can react to equipment breakdowns and restore productivity.
Benefits of tracking:
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Minimise operational disruptions
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Improve customer satisfaction by reducing delays
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Support service-level agreement (SLA) compliance
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Inform equipment purchasing and replacement decisions
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Identify bottlenecks in your repair and alerting process
By consistently monitoring and reducing MTTR, businesses can achieve faster recovery times and optimise plant performance.
How to calculate MTTR
To calculate MTTR, you’ll need two key figures:
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Total unplanned maintenance time for a given asset
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Total number of unplanned repair incidents during the same period
MTTR formula:
MTTR = Total Maintenance Time / Number of Repairs
Example:
Let’s say your team spends 20 hours on unplanned maintenance for a machine that fails five times:
MTTR = 20 hours ÷ 5 failures = 4 hours
This means it takes an average of 4 hours to get the asset fully operational after each failure.
Always exclude scheduled or preventive maintenance from this calculation—it’s all about measuring reactive repair time.
What is a good MTTR?
There is no universal MTTR benchmark, as acceptable times vary depending on asset type, industry, and operational criticality. However, in manufacturing, a good general rule is to keep MTTR under 5 hours for most production equipment.
The more critical a system is to production output or customer fulfilment, the faster it needs to be repaired.
Common issues
Reporting inconsistencies
Different team members may define or report failures in inconsistent ways. Ensure everyone understands which incidents count toward MTTR and follow a unified process.
Incomplete repair Logs
Incomplete or delayed data entry in maintenance logs can lead to inaccurate MTTR calculations. Digital tools like Maintmaster OEE help standardise and automate this process.
How to reduce MTTR
Reducing MTTR requires process improvement, better tools, and ongoing training. Here’s how to get started:
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Streamline fault reporting – Ensure your alert system is fast and reliable
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Automate diagnostics – Use digital systems to identify root causes quicker
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Train your maintenance team – Skilled technicians fix issues faster
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Improve spare part availability – Keep essential components on hand
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Use predictive analytics – Tools like Maintmaster OEE can help detect patterns that lead to failure
How Maintmaster OEE helps reduce MTTR
Maintmaster OEE enables real-time performance tracking, automated fault logging, and instant notification of breakdowns—empowering your maintenance team to act fast.
With Maintmaster OEE, you can:
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Track downtime and repair time automatically
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Get alerted the moment performance drops or thresholds are breached
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Analyse root causes and failure patterns
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Integrate with CMMS, ERP, and QMS systems for full visibility
By giving you actionable insights into every step of the fault resolution process, Maintmaster OEE helps you shorten your repair cycles and boost equipment uptime.
Mean Time To Repair (MTTR) is one of the most valuable metrics for maintenance teams. It reflects how prepared, equipped, and responsive your organisation is when failures occur. Reducing MTTR leads to less downtime, lower repair costs, and greater operational efficiency.
Maintmaster OEE gives you the visibility, speed, and data needed to improve MTTR and enhance the performance of your entire maintenance operation.
