This is a two part series where I outline the basic elements of creating and supporting a reliability program. [Read more…]
Program Elements Part 2
Articles
Find all articles across all article series listed in reverse chronological order.
ALT Value
Here is an example of how to determine the future value of a specific reliability task. Many of us face the challenge of how to justify spending product development resources to provide insights and information to the rest of the team. Accelerated life testing (ALT) is particularly difficult: It is time consuming, expensive, and at times statistically complex. Having a clear method to estimate the value serves your career and the organization well, as both benefit from the right investments.
[Read more…]
Reliability Knowledge
A recent forum post included the notion that many engineers and managers developing products or maintaining equipment have knowledge apathy concerning reliability. “They don’t care!” was the poster’s words. Has this happened? Have we lost the ability to care about reliability?
Reliability Understanding
In a course I teach on reliability engineering management I ask my students to find an advertisement using reliability as a central theme or claim. This isn’t very hard to do, and I’ve regularly been surprised at the range of uses advertising finds around the concept of reliability. ‘Reliable Movers’ claims to reliably and safely move your belongings to your new home. A reliable shotgun ammunition-loading device suggests each shell will fire reliably. And, many other advertisements use the basic concepts of consistent, repeatable, safety, and trustworthy via the term reliable or reliability. There is a common and good association with reliability. [Read more…]
Program Elements Part 1
This is a two part series where I outline the basic elements of creating and supporting a reliability program.
Gather Requirements and Set Reliability Goals
Reliability Management Terminology
For Reliability Engineers to converse with one another and with non-technical people in an organization, it is necessary for the language of reliability to be widely understood. These terms form the backbone of a working vocabulary and should be well understood by Certified Reliability Engineers.
Availability: Fraction of time that a system is usable. Steady state Availability = MTBF/(MTBF+MTTR) [Read more…]
Reliability Predictions
If only we had a crystal ball or another device to predict the future. From the general wondering about the enemies next move, to the soldier hoping their equipment will work. In the corporate boardroom estimating the competitions next move, to the maintenance manager ordering spare parts, we have many uses for knowing the future.
We often look to past performance to provide an indication of the future. Has this mutual fund regularly provided adequate returns? If so, we predict it will going forward. And anyone that has reviewed mutual fund performance also has read or heard the admonishment to not use past performance to estimate future returns. Mutual funds, markets, business and battlefields all change and respond in sometimes unforeseen ways. [Read more…]
Weibull Distribution
A continuous distribution is useful for modeling time to failure data. For reliability practitioners, the Weibull distribution is a versatile and powerful tool. I often fit a Weibull when first confronted with a life dataset, as it provides a reasonable fit given the flexibility provided by the distributions parameters. [Read more…]
Reliability Value
What is reliability management? Reliability Engineering? Would a product design or an organization benefit with a focus on reliability management and engineering? What is the value of a focus on reliability?
Any organization, that develops and produces products, has resource limits. It may be talent, capabilities, time, funding, or some combination of these. Yet, the goal to create a product that meets customer expectations includes the concept of product reliability. The product should provide the expected functions over time, without failure. This expected product reliability occurs, even if the design requirements and advertising do not explicitly mention product reliability. [Read more…]
Reactive and Proactive
Do you let events happen to you, or do events follow your designs and expectations? Are you a spectator or actor? Do you wonder about your product’s future or do you control your product’s future? Are you reactive or proactive?
Every reliability and maintenance program is a system. Every program has inputs, such as product testing results and field returns. Every reliability program has outputs, such as product design and production. In the most basic terms, a reliability program includes product specifications for functionality including expected durability. The program includes some form of design, verification, production and field performance. Given this basic lifecycle description, it is possible for two types of approaches to executing the product lifecycle. [Read more…]
Good Mind
It is not enough to have a good mind; it is more important to use it well. — Descartes
Learning and Value
Over the past week, I’ve received a couple of questions about the pursuit of a graduate degree in reliability engineering and about preparing for the CRE. One question was particularly interesting – how will a reliability engineering graduate degree or CRE help my career? [Read more…]
Variance
In another post, I started the discussion about variability and interquartile range. This is part 2 of that discussion and will focus on variance.
With rare exception, most distributions or groups of data require more than one parameter (or statistic) to fully describe both the location and spread (scale and shape) of the group of data. Is the data clumped tightly about some value, or spread out over a wide range. [Read more…]
Reliability Culture
Years ago I had the opportunity to assess the reliability programs of two organizations. They made similar products for different segments of the market, and they both had about the same size an organization. Two years previously, both organizations lost the reliability professional from their staffs. Furthermore, both teams were located in one building, one upstairs and the other downstairs, which made scheduling the assessment interviews convenient.
Musings on Reliability and Maintenance Topics
I write quite a bit about reliability and have plans to write quite a bit more. I have looked to prolific authors in our field with admiration and respect: Wayne Nelson, Patrick O’Connor or Terrence O’Hanlon, they all share so much knowledge. They make the subjects and material clear and accessible. They have in large part helped me all throughout my career by enabling my ability to solve problems and create value.
Of course, there are many others that have contributed to my career and my approach to engineering. My colleagues, managers, and mentors have each helped to educate and develop my skills and approach. Every single client has also contributed. As many of you have heard from me, I learn from every encounter and feel very fortunate to have a career that enables such wonderful exploration and learning as part of my day-to-day work. [Read more…]
Degradation Hypothesis
This week I received a question from the ASQ Librarian concerning a person’s question about one of the CRE Question bank questions. It was a nice two-part question concerning a hypothesis test of a sample means value and degradation.
Here’s the question as sent over for consideration. [Read more…]
Binomial Cumulative Density Function
Last week I posted about the Binomial probability density function, and it is useful when calculating the probability of exactly x successes out of n trials given p probability of success for each trial.
Well, what happens if you want to know the probability of 2 or more successes for example? [Read more…]
