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Mean time between failure (MTBF) and mean time to repair (MTTR) are essential failure metrics every maintenance team should track.
These metrics tell you how well your maintenance strategy is working and how healthy your equipment is.
Predicting downtime, the time between failures, and the time your team needs to repair failures will help you to maximize uptime.
The most important metrics to track are:
- MTBF (the average duration before a failure occurs)
- MTTR (the average time required for recovery, repair, response, or resolution)
- Mean time to failure (MTTF) (the average time until a failure happens), and
- Mean Time to Acknowledge (MTTA) (the average time taken to acknowledge an issue)
These measures show teams how often failures happen and how fast they can fix them.
This article will show you how to calculate and improve both metrics.
Key takeaways
- Mean time between failures measures the average uptime between failures for repairable assets and indicates reliability.
- Mean time to repair measures the average time it takes to complete a repair after a failure occurs, indicating maintenance efficiency.
- Improving Mean time between failures involves proactive strategies like preventive maintenance and root cause analysis, while reducing mean time to repair focuses on streamlining repair processes and technician training.
- Tracking both metrics in a computerized maintenance management system provides a complete picture of asset performance, helping you balance reliability improvements with operational efficiency.
The difference between mean time between failure and mean time to repair
The key difference between MTBF and MTTR lies in what each metric measures. MTBF tracks the average uptime between failures, while MTTR measures the average amount of downtime during repairs. In short, MTBF tracks uptime and MTTR measures downtime.This distinction matters because you need both metrics to run effective maintenance.
Mean time to failure
MTBF measures the average time between two instances of fixable failures. It factors in the time spent on unscheduled maintenance. Time spent on routine maintenance tasks, like inspection and recalibration, is considered part of the total life of the asset.
MTBF essentially measures equipment and system availability (or total uptime). This metric provides insights into:
- Equipment efficiency: How well assets perform during operation
- Reliability patterns: Frequency of unexpected breakdowns
- Failure rates: Statistical probability of future issues
While you should aim to maximize this metric, a high MTBF doesn't guarantee your equipment won't ever break down.
Mean time to repair
MTTR measures downtime. It gives insights into the average time spent troubleshooting and fixing failures.
MTTR has several variations that maintenance teams use:
- Mean time to recover: Complete restoration to full operation
- Mean time to resolution: Problem solving and root cause elimination
- Mean time to restore: Basic functionality is returned
- Mean time to reply: Initial response to failure alerts
Related incident management metrics include:
- Mean time to acknowledge: Time between failure alert and action start (like creating a service ticket)
- Mean time to detect: Time to identify issues requiring corrective action
We’ll focus on mean time to repair in this article.
MTTR shows how fast your team can get equipment back online. A high MTTR can indicate many issues, but most prominent are inefficiencies or obstacles in your maintenance team’s operational workflows.
How to calculate mean time between failure and mean time to repair
The formulas for these critical metrics help maintenance managers calculate reliability and efficiency:
Calculation example
Suppose a machine runs 24 hours a day for 10 years. It has four outages per year. The repair time on each of these outages is 10, 15, 20, and 25 hours, respectively.
- Total operation hours (uptime) = 86,900 hours (24 hours x 365 days x 10 years) - (700 hours of unscheduled downtime)
- Number of failures = 40
The MTBF calculation is: 86,900 hours÷ 40 failures = 2,172.5 hours
The MTTR calculation is: [700 hours ÷ 40 failures] = 17.25 hours
What are good mean time between failure and mean time to repair values?
Defining ’good’ values for each metric depends on your industry, equipment type, and operational goals. Each industry, including manufacturing facilities, oil and gas operations, and food processing plants, has different benchmarks based on their unique requirements.
Industry-specific considerations include:
- Manufacturing: Critical production assets typically target MTBF of 3,000+ hours
- Food and beverage: Processing equipment often aims for sub-4-hour MTTR due to spoilage risks
- Oil and gas: Safety-critical systems require both high MTBF and rapid MTTR
- Facilities management: HVAC systems balance comfort with maintenance costs
Set benchmarks based on your own equipment rather than industry averages. Calculate current metrics for critical assets, then set realistic improvement goals. Increasing MTBF by 10% or reducing MTTR by 15% over six months represents significant capacity gains.
How to improve mean time between failure
MTBF often isn't consistent throughout the asset's life. As time passes and the asset depreciates, this metric will likely start to fall. However, several tactics can minimize this reduction:
Use high-quality parts
Use the manufacturer's recommended replacement parts whenever possible during repairs. Alternatively, you can source high-quality replacement parts from third-party vendors. Poor-quality parts often wear out quickly and, in some cases, cause further damage.
Stick to your maintenance schedule
Consistently being on time with your predictive or preventive maintenance techniques minimizes unscheduled downtime. Maintenance teams often detect problems during routine maintenance that could lead to failure in the near future.
Study the root cause of failure
Study the root cause after troubleshooting equipment or system failure. Over time, you'll develop a playbook that informs your maintenance schedule and helps prevent these root causes from occurring.
Proper operation of equipment
Train employees on proper equipment operation. Rough handling shortens equipment lifespan. Using equipment as intended goes a long way in increasing its MTBF and useful life.
How to reduce mean time to repair
Reducing MTTR directly impacts productivity and revenue. The right strategy can get equipment back online faster.
Here's how to cut repair time:
- Real-time monitoring: Use sensors and Internet of Things (IoT) devices to identify problems before they escalate
- Standardized procedures: Create repair checklists for common failure modes
- Mobile documentation: Give technicians instant access to standard operating procedures
- Skills training: Develop technician expertise in efficient repair methods
- Parts availability: Stock critical components based on failure history
- Data collection: Track each failure event to identify improvement opportunities
A computerized maintenance management system is the best way to manage mean time between failure and mean time to repair
A computerized maintenance management system (CMMS) logs and stores data on asset performance and work orders throughout the asset's lifecycle. These systems automatically calculate metrics like MTBF and MTTR using the collected data.
MaintainX is a mobile-friendly CMMS designed to improve maintenance efficiency. You can use the platform as a central control system to manage maintenance processes. It auto-collects data you can use to improve your maintenance and repair processes, which in turn helps improve asset reliability.
Turn maintenance metrics into operational excellence
MTBF and MTTR aren't just numbers to track. They help you shift from fixing broken equipment to preventing failures. These metrics provide the foundation for data-driven decisions that reduce unplanned downtime and improve asset reliability across your operations.
You need tools that collect this data and help you act on it immediately. MaintainX was built specifically for frontline maintenance professionals who need mobile-first solutions that work in industrial environments. The platform connects asset performance data with work order management, giving you the insights needed to optimize both metrics simultaneously.
Ready to see how your maintenance metrics stack up? Sign Up for Free and start tracking the data that drives operational excellence.
FAQs
What mean time between failure targets should manufacturing facilities set for critical production equipment?
Manufacturing facilities typically target values of 2,000-5,000 hours for critical production equipment, depending on asset type and production schedules. Focus on your most expensive downtime scenarios first, then work toward industry-specific benchmarks for your equipment category.
How do maintenance managers calculate mean time between failure for repairable assets versus replaceable components?
Use MTBF calculations only for repairable assets where you restore functionality after failure. For components that you replace entirely (like filters or belts), track MTTF instead, which measures total lifespan from installation to disposal.
When should facilities prioritize mean time between failure improvements over mean time to repair reduction in their maintenance strategy?
Prioritize MTBF improvements when you experience frequent short breakdowns that disrupt production flow and employee productivity. Focus on MTTR reduction when failures are rare but create extended, costly downtime periods that impact customer delivery commitments.
The MaintainX team is made up of maintenance and manufacturing experts. They’re here to share industry knowledge, explain product features, and help workers get more done with MaintainX!
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