Five Minute Facts  

The Relationship of Equipment Reliability, Failures, Potential Failure (P-F) Curve and Human Safety

Tod Baer | Production Specialist IV - Reliability, Minnkota Power Cooperative Inc.

This is the last of a three-part series on Understanding the P-F Curve.  The last article will be a brief review of the two earlier articles and ending with a focus on an article and presentation published by Dustin M Etchison, CMRP with Elanco Global Engineering that brings all the aspects of equipment reliability and safety together.  Mr. Etchison has been so kind to allow us to use his article titled “The Impact of Equipment Reliability on Human Safety” to make the point that there is a direct correlation between reliability and safety at the Young Station.

Equipment Mechanical Failure Probability Patterns

In the first article, explained that over the course of time equipment failures will occur.  Studies performed by United Airlines, the US Navy, Bromberg and RCM by Nowlan and Heap have provided evidence that there are different patterns relating to failures and time intervals. A majority of failures in industry have been determined to be randomly (specifically infant mortality pattern F) and not age related.

In the same article, we demonstrated that the understanding of how these failures occur could help establish the methods for early detection using condition monitoring.  This early detection of a failure mode is helpful in applying the appropriate priority to corrective repair work orders, allows for planning and scheduling of resources to make repairs before a catastrophic failure occurs.

Potential Failure (P-F) Curve | Proactive Domain | Predictive Domain | Protective Domain

The type of condition monitoring technology used to detect the problem and the level of energy the problem is emitting – along with the P-F Curve Interval – is helpful in applying the appropriate priority to corrective repair work orders.

The second article describes two programs that are capable of reducing and/or eliminating the random failures patterns and thus extending the proactive domain timeline on the D-I-P-F curve (D-I-P-F Curve developed by Doug Plucknett CRL, modified by Brian Heinsius CRL and permission to reprint provided by the Relaibilityweb).  This increase in reliability and the value it creates is a huge advantage in helping an organization sustain its competitive edge.  These benefits can be recognized by implementing a comprehensive reliability, precision maintenance and precision operations program. Items within these programs include:

  • Life Cycle Asset Management Plan
  • Design for Precision/Reliability
  • Procure Quality
  • Precision Assembly, Alignment and Balancing
  • Precision Installation
  • Precision Commissioning
  • Operator Care
  • Work Processes, Procedures and Standards
  • Asset Condition Management
  • Lubrication Reliability
  • Clean and Inspect (5S)
  • Operate for Reliability

D-I-P-F Curve developed by Doug Plucknett CRL, modified by Brian Heinsius CRL

The Impact of Equipment Reliability on Human Safety

Dustin M Etchison, CMRP

To understand the connection between reliability and safety, we need to look at the Heinrich Safety Triangle.  The safety incident pyramid is a broad focus on human safety in an industrial organization.

Safety Incident Pyramid | Heinrich Safety Triangle

There is a direct correlation in the importance of human safety to the importance of equipment reliability.  The understanding of both are critical in driving an injury-free culture.  Keep in mind that the probability of an injury is significantly increased with non-routine maintenance activities resulting from equipment failures (reference the DIPF Curve with Safety Incidents).

D-I-P-F Curve with Safety Incidents | RELIABILITY CONNECT

Human factors such as rushing, frustration, fatigue, and complacency have an impact on both human safety and equipment reliability.  These factors lead to unintentional, risk-increasing errors like eyes and mind not on task, being in or moving into the line-of-fire, or losing your balance, traction, or grip.  Similar to human safety, these factors can result in precision maintenance gaps like incomplete or improper precision alignment, PMs, or gaps in other maintenance related tasks.

Effectively managing these human factors will net positive results in both human safety and equipment reliability.

Please note this article reflects the views, thoughts, and opinions of the author only.  The author has been working in the fields of condition monitoring, precision maintenance, and reliability since 1983.

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About the Author

Tod Baer Production Specialist IV - Reliability, Minnkota Power Cooperative Inc.

Tod currently holds the position of Production Specialist IV – Reliability at Minnkota Power’s coal-fired generating facilities located at Center ND.  Minnkota Power Cooperative Inc, is a generation and transmission utility which serves 11 member-owner cooperatives located in eastern North Dakota and western Minnesota.  Tod has been working in the reliability centered maintenance field since 1983 at the facility.  His current responsibilities are managing and overseeing the facility’s Reliability Program which includes the PD/PM Program, Loss Elimination, RCA, Asset Control and Care Process.  He is very passionate about Pd, PM and RCM, as a practitioner, instructor and mentor in the fields of vibration, lubrication, ultrasonics, thermography, RCFA and precision maintenance.

In the mid 1980’s he was the driving force in the development and implementation of Minnkota Power’s Pd/PM program, and supervised Minnkota’s Pd/PM team.  In the 1990’s, using information obtained from the Pd/PM, CMMS and RCA programs Tod justified the need to adapt precision maintenance philosophies into the facility’s maintenance program.

Today, Minnkota Power’s, Asset Reliability Maintenance Program, incorporates most maintenance philosophies and technologies.  The evolving 40 year old maintenance program has been very successful and has played an important role in the power plants’ success as a cost effective, reliable energy producer.  The program and the individuals championing the program have served as a guidepost to others seeking similar results.