Mean Time to Dangerous Failure (MTTFd)

What is Mean Time to Dangerous Failure (MTTFd)?

Mean time to dangerous failure (MTTFd) is a reliability metric that calculates the average expected time until a component or system experiences a failure that could potentially lead to hazardous conditions. The MTTFd is particularly vital in critical safety systems in which a single event could lead to serious consequences for health and safety, such as valve mechanisms in chemical plants or heavy industrial machinery. In facilities management time to dangerous failure is crucial for understanding the reliability of safety systems and functions, planning preventive maintenance activities, and risk-management responsibilities.

Relevance of MTTFd in Facilities Management

In several industries, facilities management involves involves overseeing complex systems where safety is the top priority. MTTFd provides insight into the reliability of these systems. Monitoring MTTFd and tracking the metric over time helps facilities managers identify components that may pose a safety risk ahead of any critical failures. MTTFd is a proactive approach to safety that can help prevent accidents, reduce unplanned downtime, and ensure compliance with industry safety standards and government regulations.

Factors Affecting MTTFd

While safety-critical assets and equipment may vary between industries and companies, these factors commonly influence the time to dangerous failure across all types of facilities:

Quality of Components

In facilities where safety and safety function is a primary concern, the reliability and longer life span of quality parts more than makes up for the higher cost of components. Higher quality parts and equipment generally have a longer MTTFd, which can significantly reduce the cost of operations and maintenance over time.

Operating Conditions

The conditions of a facility and the surrounding environment have a significant impact on mean time to dangerous failure. Extreme conditions, continuous vibrations and other factors can reduce the MTTFd of vital equipment.

Maintenance Practices

In an environment where one mishap can mean serious health and safety concerns, it’s vital to stay ahead of potentially dangerous failures. Proactive preventative maintenance practices help to head off potential safety hazards before an issue even arises.  If an event occurs that requires reactive maintenance or repairs, it could already be too late.

Lowering the failure rate through reliable and regular diagnostic coverage means implementing a control system that monitors the performance level and safety functions to prevent system, component and asset failure.

How to Calculate Mean Time to Dangerous Failure

MTTFd is typically calculated based on historical data or predictive models and is expressed in units of time. Divide the total number of operational hours (T) of an asset by the total number of dangerous failures that the asset has experienced in that time (D). The result gives you the MTTFd score.

When written as an equation, the MTTFd calculation typically looks like this:

[MTTFd = T / D]

For example, an overhead hoist has seen 2,500 hours of operation since its installation. Over those 2,500 hours, the hoist has experienced four failures that have or could have led to a safety incident. The 2,500 operating hours divided by the four incidents comes to a MTTFd score of 625. With this information, maintenance teams know to inspect and perform upkeep every 600 hours of operation or so to ensure that the hoist continues to function safely over its expected lifetime.

Utilizing MTTFd Data

Integrating a computerized maintenance management software (CMMS) platform with current industrial systems can enhance data-gathering and MTTFd monitoring efforts. Its tracking provides helpful details that facilities managers and company leadership can use to inform a variety of implementations and activities, including:

• Planning: Monitoring operation times and knowing the MTTFd measurements for safety-critical equipment and components gives organizations ample time to organize maintenance schedules and plan down time.
• Design Improvements: Facilities managers can present low MTTFd scores to encourage approval for design improvements and selection of high-quality, more dependable components to reduce the risk of dangerous failures.
• Compliance: Understanding MTTFd enables companies to comply with safety standards and regulations that may require specific MTTFd values for certain systems.

Strategies for Improving MTTFd

To maintain a dependable facility safety system, managers can adopt several strategies to improve MTTFd. Taking these steps can help maintain confidence that your equipment will function safely, enhancing your compliance and risk-management efforts.

Investment

Select high-quality equipment and components with a proven track record of dependability and long MTTFd scores. Trust in their equipment empowers personnel to work with confidence, and dependable equipment has a long-term positive impact on company budgets.

Redundancies

Select equipment with redundant components or build redundancies where able. Integrating backup components into systems when feasible provides a crucial safety function that ensures failures won’t lead to a potentially dangerous situation. This enables crews to continue to operate until the maintenance team can replace a crucial safety-related part.

Maintenance

Schedule regular inspections and preventive maintenance of vital assets and equipment. Establishing a thorough preventive maintenance process lets you identify and remedy potential issues before they result in hazardous failures

Education

Provide training to operators and maintenance teams on the equipment they’ll be handling. Training should include proper operations, shutdown protocols, maintenance procedures, and action items for emergency situations. By understanding what they’re dealing with empowers workers to remain vigilant and operate safely.

Challenges in Managing MTTFd

MTTFd is crucial for environments where a single failure can compromise an asset’s functional safety. However, managing this metric within a facility does provide some inherent challenges. 

• Data Accuracy: Obtaining precise data to calculate MTTFd can be difficult, especially if the failure modes aren’t simple to understand.
• System Complexity: Elaborate systems may have multiple potential failure points, which can complicate MTTFd calculation and interpretation.
• Resource Allocation: Providing the appropriate supplies, labor, and funds between maintenance tasks while considering MTTFd requires careful planning.

Addressing MTTFd Challenges

While MTTFd may present its share of challenges, facilities managers can take steps to meet these obstacles head-on and overcome them.

• Monitoring: Invest in software platforms that employ condition monitoring and predictive maintenance technologies to gather accurate equipment-performance data and perform in-depth analysis.
• Risk Analysis: Bring leadership, engineers, maintenance teams, and safety professionals together to perform collaborative risk assessments and address areas of concern.
• Resource Management: Develop a flexible plan for managing personnel, supplies, and third-party vendors to adapt quickly to changing conditions and new equipment reliability data.

Mean Time to Dangerous Failure in Conclusion

Mean Time to Dangerous Failure is a vital metric for facilities management, particularly in systems where safety is a concern and the failure rate needs to be minimized. By understanding and improving MTTFd, facilities managers can enhance the dependability and safe operation of potentially hazardous systems, prevent dangerous conditions through a safety system that prevents dangerous failures, and ensure a safe environment for occupants and employees.

Effective MTTFd management calls for a strategic combination of equipment selection, diligent maintenance practices, and an ongoing commitment to safety improvement. By addressing the challenges associated with MTTFd managers can ensure that a facility operates efficiently and securely, with a reduced risk of incidents that could compromise human safety and operational continuity.