What Is Mean Time to Detect (MTTD)? And How to Calculate It

Mean time to detect (MTTD) is an essential key performance indicator (KPI) for measuring the average time it takes to identify an equipment failure or cybersecurity threat after it occurs. This metric helps in understanding how quickly an organization or system responds to issues related to hardware malfunctions or operational failures.

In short, a low MTTD correlates with a more efficient incident response process. This means that outages and failures are caught quickly, and response teams address problems before they lead to extended equipment downtime. 

This metric is critical for enhancing operational efficiency, reducing downtime and improving business continuity. You can improve your organization’s MTTD by using real-time monitoring tools, automations, effective incident management training and proactive incident detection strategies. By continuously refining your incident response plan, your business can optimize system reliability and security for key stakeholders. Read on to learn how.

MTTD vs. MTTR

MTTD indicates the average time between a problem’s first occurrence and when it is identified, while mean time to repair (MTTR) calculates how long it takes to fix the problem once it’s detected. Since MTTD is specifically focused on the amount of time until detection, it is representative of how effective teams are at spotting problems before they lead to failure. Reducing MTTD can significantly reduce downtime by encouraging faster detection times.

MTTR, on the other hand, has more steps for calculating the time taken to diagnose the issue, to source parts or qualified experts, to fix the issue and to confirm that the repair was a success. As a result, MTTR tends to be more complex and influenced by multiple variables. 

Of course, there are two other failure metrics — mean time to failure (MTTF) and mean time between failure (MTBF) — that maintenance teams use to determine equipment performance. MTTF measures the amount of time an unrepairable asset (for instance, a light bulb) works before it fails, while MTBF measures the average time between asset breakdowns. 

How Is MTTD Calculated?

MTTD is calculated by dividing the total time between failures and detection, divided by the total number of incidents.

Let’s imagine a factory that uses a computer numerical control (CNC) machine as a key part of its production line. It experiences an issue like overheating that’s detected by a sensor set to a specific threshold. However, the sensor didn’t detect it until after several faulty parts were produced. You realize that it’s been four hours between when the faulty parts started being produced and when someone was able to determine what the root cause was. But the next time this machine has an issue, the sensor catches the outlier issue right away, making that four hours total for two failures.

Here’s how that calculation would look:

Total Time Between Failures & Detection / Total Number of Failures = MTTD

4 hours to detect / 2 total failures = 2 hours 

Benefits of Tracking MTTD

MTTD is an important maintenance KPI for managing unplanned maintenance effectively. By calculating your MTTD and improving your team’s incident management processes, you can reap the following benefits:

Improved Maintenance Strategies

Your business can refine its maintenance protocols before problems escalate by spotting problems quickly. Having a proactive maintenance strategy is a major positive that improves machine uptime, uses resources more effectively and strengthens maintenance teams and organizational leaders to make better, data-backed decisions. 

Reduced Asset Downtime

Maintenance teams can schedule preventive maintenance to ensure that assets perform as efficiently as possible, limiting production halts by catching issues way before they turn into excessive equipment downtime.

Reduced Maintenance Costs

A lower MTTD means catching problems before they turn into major breakdowns that come with expensive repair bills. Faster identification reduces labor costs, part allocations and brings costs down overall. 

Better Product Quality

Spotting possible abnormalities quickly within the production cycle ensures product integrity. Manufacturing plants can continue hitting consistent outputs and produce fewer defects, resulting in better user experience or higher overall satisfaction for the end user.

Enhances Compliance & Safety

Fast detection ensures malfunctioning equipment remains operational, meets compliance standards and keeps employees safe. 

Challenges in Measuring MTTD

Measuring MTTD can be difficult, as various factors can impact how you determine when a failure first started like a lack of accurate data to system issues. The following challenges make it difficult to calculate accurate and consistent maintenance time to detect data:

Limited Access to Data on a Failure Occurrence

Measuring MTTD accurately requires a full understanding of when a failure first began. In many cases, problems start to arise gradually, making it challenging to recognize the exact moment a piece of equipment or system started malfunctioning. Relying on estimates will lead to inconsistencies in the calculation; teams need precise timestamps for a fully accurate MTTD score.

Hidden or Intermittent Failures

Oftentimes, failures remain hidden from detection for extended periods of time with less than obvious symptoms. Intermittent issues specifically can be difficult to spot since they sometimes fail to trigger immediate system alerts or alarms.

Variability in Detection Methods

Using the vast array of available management tools and methodologies for detecting failures can result in inconsistencies in how MTTD is measured. Standardized detection protocols are needed to effectively compare mean time to detect across systems and machinery.

Human Delay

Automated systems can report an issue that goes undetected by humans, but humans still need to determine that it’s accurate to avoid artificially inflating your MTTD score and making it difficult to improve.

How to Improve MTTD

The following tactics can help to improve your MTTD score and ensure you’re finding and addressing issues before they lead to failure and unplanned downtime.

• Implement advanced monitoring systems: Leveraging maintenance AI to monitor systems in real-time ensures you improve your MTTD score by detecting abnormalities immediately without the need for constant manual inspections.
• Set up automated alerts: Receiving automatic alerts ensures that you’re made aware of potential issues quickly and can have maintenance technicians respond faster to mitigate risk of failure. 
• Enhance employee training: Properly trained maintenance teams can detect early warning indicators of failure with precision. Ongoing education on new technologies, system behaviors and troubleshooting techniques is integral to improving detection speed and accuracy.
• Create a proactive maintenance strategy: Preventive maintenance procedures like routine inspections and data-driven maintenance reports help in catching minor issues before they worsen. By reducing your dependence on reactive repairs, you can lower MTTD and prevent costly downtime.

How a CMMS Can Help

Using a computerized maintenance management system (CMMS) like Coast can streamline your maintenance workflows to reduce MTTD by:

• Providing real-time maintenance reporting: Use data-driven analytics to identify recurring issues, monitor detection trends and refine maintenance strategies.
• Automated system monitoring: Track asset performance constantly and receive instant notifications whenever anomalies or failures occur.
• Simplified work order scheduling: Schedule routine maintenance tasks well in advance and quickly assign unplanned repairs as soon as issues arise. 
• Enhanced inventory management: Have critical spare parts and maintenance tools readily accessible to perform repairs quickly.

To learn more about how Coast can help to reduce your MTTD and enhance your productivity as a whole, book a demo today!