Mean Time Between Failures (MTBF) & How to Calculate it

What is MTBF?

Mean Time Between Failures (MTBF) is a metric that helps teams quantify system reliability and predict failure rate. MTBF measures the amount of time systems or equipment are operating between downtime or stoppages. Teams need reliable equipment to operate efficiently and stay productive; MTBF helps companies anticipate maintenance needs, reduce costs, and minimize unplanned downtime. 

While MTBF measures the time between failures, it’s helpful to understand how it differs from related metrics like Mean Time to Repair (MTTR) and Mean Time to Acknowledge (MTTA):

• MTBF measures equipment reliability by calculating the average operating time between failures.
• MTTR is the average time it takes to repair equipment after a failure.
  MTTA is the average time required for a team to acknowledge an incident after it’s reported. 

Why is MTBF important?

MTBF data helps businesses measure equipment reliability and ensure optimal business operations. Analyzing this data can help teams make data-driven decisions to improve performance and operational efficiency. Calculating MTBF helps organizations plan an effective maintenance strategy, enhance productivity, boost customer satisfaction, and reduce costs. 

• Reduced downtime and preventive maintenance schedules. Tracking MTBF allows organizations to anticipate repairs and schedule maintenance accordingly to reduce the risk of unexpected failures. 
• Increased customer satisfaction. Frequent failures can frustrate customers. Reliable equipment leads to better service and fewer disruptions for users.
• Cost savings. Regular maintenance keeps systems running, helping teams avoid costly repairs or replacements.
• Quality control. Measuring MTBF allows organizations to compare products based on quality and reliability. Teams can make better-informed decisions about equipment or suppliers. 

Essentially, MTBF indicates how long a team’s equipment or systems operate before experiencing issues or stoppages, and it’s used in a variety of industries, including healthcare, technology, and financial services. 

• Healthcare: Healthcare providers must have access to medical records, treatment plans, and patient data. Unexpected downtime in a medical monitoring device can pose serious risks to the patient’s health. Measuring MTBF helps teams track equipment performance, ensuring continuous operation and patient safety.
• Technology: Tech companies use MTBF to anticipate maintenance needs, predict failures, and identify potential design flaws. 
• Financial services: Professionals in this field need uninterrupted access to customer accounts, market and trading data, and financial systems. Understanding system dependability can help them prevent costly downtime.  

The MTBF formula

Calculating MTBF requires the total uptime, the amount of time the equipment or system was running, and the number of times the equipment broke down over a specified period.

MTBF = Uptime / # of breakdowns

MTBF calculation example

Consider this example to calculate MTBF:

A tech company provides cloud storage solutions and monitors the performance of its servers. It wants to calculate the MTBF of its storage servers over the past year.

• Number of servers: 50 
• Total operational time over the past year: Each server operated 365 days per year, 24 hours per day.
• Number of failures: 25

Operational time or uptime = 365 * 24 * 50 = 438,000 hours

MTBF = Uptime / # of breakdowns

MTBF = 438,000 / 25 = 17,520 hours

 This means that, on average, the servers fail once every 17,520 hours of operation. 

 To calculate MTBF for individual servers, divide by the number of units:

 17,520 / 50 = 354 hours

How to improve MTBF

Understanding the importance of MTBF is the first step, but knowing how to improve this metric can help companies minimize downtime, extend the lifetime of their equipment, and improve operations. 

• Maintenance management: While MTBF helps predict downtime and upkeep, a consistent maintenance schedule ensures systems stay operational and addresses minor problems early to prevent potential issues or critical failures. Tools like PagerDuty provide monitoring and system alerts to help teams implement a preventive maintenance strategy
• Identify the cause: Understanding the reason for equipment failure helps teams address issues, implement solutions, and prevent future problems. PagerDuty’s incident response capabilities allow teams to quickly investigate and resolve root causes to minimize downtime
• Make process changes: Teams can implement process changes, such as enhanced monitoring and testing, to better understand equipment reliability. With an automated alerting system, teams can identify issues before they impact users or systems

Understanding MTBF can help teams optimize equipment reliability, minimize downtime, and make better-informed decisions about equipment and processes. By prioritizing and improving MTBF, businesses can reduce maintenance costs, enhance productivity, and boost customer satisfaction.

PagerDuty helps teams anticipate and resolve issues fast, minimizing disruption for systems and users. Discover how our incident management platform helps teams mitigate risk and build resilient operations.