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Linking Reliability Concepts and Safety Performance

Linking Reliability Concepts and Safety Performance

Definition of Reliability

The concept of Reliability is often misused, misunderstood, and misinterpreted. Reliability in its academic root, is defined as the probability that a system will perform its intended function in a specified mission time and within specific process conditions. So, it is in essence a probability.

The time variable is crucial in calculating the reliability of a system. Reliability is the Probability of Success. And 1 minus the Probability of Failure.

$$ \displaystyle \large R\left(t\right) = 1 – F\left(t\right) \:\:\:\: (where \: F = Failure \: Probability) $$

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Power-law vs. Exponential Acceleration Models

Power-law vs. Exponential Acceleration Models

Making the Right Choice in Reliability Engineering

In reliability engineering, we often need to extrapolate test data collected under accelerated stress conditions to predict performance under normal operating conditions. Two mathematical models commonly used for this purpose are the power-law model and the exponential model. But which one should you choose when your data fits both models equally well? This article explores the differences between these models and provides practical guidance on making this critical decision.

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5 Reasons Rate of Change is Important

5 Reasons Rate of Change is Important

A simplifying assumption associated with using MTTF or MTBF implies a constant hazard rate. Some assume we’re in the useful life section of the bathtub curve. Others do not understand what assumptions they are making.

Using MTTF or MTBF has many problems and as regular reader here know, we should avoid using these metrics.

By using MTTF or MTBF we also lose information. We are unable to measure or track the rate of change of our equipment or system’s failure rates (hazard rate). The simple average is just an average and does not contain the essential information we need to make decisions.

Let’s explore five different reasons the rate of change of a failure rate is important to measure and track. [Read more…]

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FMEA Quality Objective 2: SCOPE

“If you don’t know where you are going, you’ll end up someplace else.” – Yogi Berra

As summarized in the first article in this series, “New Series – The Quality of FMEAs,” each month, I will write an article focusing on one of the 14 FMEA Quality Objectives. The intent is to provide insights and application tips for evaluating how well an FMEA meets the quality objectives. By learning to apply FMEA quality objectives, you can help to ensure that product designs and manufacturing processes are safe and reliable. If you didn’t read the introductory article, now is a good time to read it, since it explains FMEA Quality Objectives, and how they are used to create high-quality FMEAs.

In this article, I will outline how to evaluate an individual FMEA against the FMEA Quality Objective for Scope. [Read more…]

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Big Difference in Consequence Reduction Strategy and Chance Reduction Strategy

Big Difference in Consequence Reduction Strategy and Chance Reduction Strategy

The vital difference between using consequence or chance reduction strategies if you want operational excellence results, is consequence reduction requires repairs and maintenance, whereas chance reduction removes repairs and maintenance.

In reading “Enterprise Asset Management Success the Plant Wellness Way for CEOs and Senior Executives” I was interested in your table on page 15 that showed risk based inspection and condition based monitoring techniques as consequence reduction strategies.

My understanding is that both RBI and CBM are specifically designed to prevent failure through reducing the likelihood of failure i.e. by detecting failure before it happens within timescales that allow mitigation action to be taken. In the API 581 RBI standard, consequence is treated as a constant over time so the methodology specifically targets risk reduction through more effective inspection or design changes. [Read more…]

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Mental Risk: Solitude is Pleasant: Loneliness is Not

Mental Risk: Solitude is Pleasant: Loneliness is Not

Guest Post by Bill Pomfret (first posted on CERM ® RISK INSIGHTS – reposted here with permission)

Mental Health Awareness week is fast approaching. This year [2022] it is from 9th-15th May, and the theme is Loneliness, Anna Neagle is right, in her book Cultivating and being happy in our own company is important, but even the most introverted among us benefit from human connection and where increasingly people have started working from home, or in a hybrid home/workplace setting, we need to proactively seek that connection out.  Connection can be with our close circle, or even from small talk with strangers the research shows that both are helpful for our well-being. [Read more…]

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How Defining Functions Shapes Your Reliability Strategy

How Defining Functions Shapes Your Reliability Strategy

Understanding RCM

Hi everyone, I’m Nancy Regan, and in today’s video, I’m breaking down what makes Reliability Centered Maintenance truly “Centered.” Using a real-life example from my own vehicle—where my fan only works on level four, causing all sorts of noise issues—I explain how defining the function of an asset is the key to understanding its reliability needs.

I walk through how writing Functions is the foundation of the RCM process, ensuring assets are maintained to meet the specific needs of their operating context. From there, I explain how this noisy fan failure creates non-operational consequences in my case, and why, in this situation, it’s okay to run this particular Failure Mode to failure. What does the “Centered” in Reliability Centered Maintenance mean? Watch to find out!

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Distinguishing NPI Materials Management from Project Management

Distinguishing NPI Materials Management from Project Management

A sometimes overlooked function of production planning, is materials management for new product introduction (NPI).

In our previous article, we covered fundamentals of managing contract manufacturers (CM) value streams.  The goal for NPI is similar: we want NPI prototypes available per a prototype plan and (eventually) a production plan.

Below is a simplified value stream map for a managing a contract manufacturer using “plan, source, order, make, deliver” as major subprocesses.  The planning function “NPI Materials Manager” is shown with corresponding interfaces and is the focus of this article.

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The Answer That’s Clear, Simple, and Wrong

The Answer That’s Clear, Simple, and Wrong

H.L. Mencken, the sharp-witted satirist and critic of early 20th-century American life, once wrote, “For every complex problem, there is an answer that is clear, simple, and wrong.”1 Mencken, born in Baltimore in 1880, was known for his incisive critiques of societal norms and his skepticism of simplistic solutions to complex issues. 

Mencken’s wisdom applies to both everyday life and technical fields. His insights are particularly relevant in the engineering, manufacturing, and reliability disciplines, where the temptation to seek easy answers can lead to costly errors. We’ll start with a relatable everyday example before exploring documented cases in engineering and manufacturing that demonstrate the pitfalls of oversimplified solutions.

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The Origins and Power of the FINESSE Fishbone Diagram for Reliability Engineers

The Origins and Power of the FINESSE Fishbone Diagram for Reliability Engineers

You get a few raised eyebrows when you claim to be Communicating with FINESSE. Well, at least you do if the person on the other end does not understand that FINESSE stands for something. Or if they do not understand what a fishbone diagram is. Here’s a short review of the origins of FINESSE and how the FINESSE fishbone diagram powers the communication of reliability engineers.

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3 Recent Questions and Comments Concerning MTBF

3 Recent Questions and Comments Concerning MTBF

Trying to Respond to All Questions and Comments Concerning MTBF

Over the past couple of days, like most days, have received questions and comments concerning MTBF. I do try to respond to all questions and acknowledge the comments.

Glad to help in anyway I can, so please feel free to send me your questions. Certainly do appreciate the supporting comments, or any comments for that matter.

Let’s take a look a few such discussion that occurred over the past two days. [Read more…]