Your Reliability Engineering Professional Development Site
The design of a product includes the arrangement of all of the product elements. When considering the reliability of a system, the arrangement matters. Many systems are arranged serially. This means that with the failure of any one element, the system will not work. See the article on Series Systems for more details. [Read more…]
It’s always necessary to estimate the value of specific reliability activities. It is needed to justify the investment required to accomplish the task. Prototypes, diagnostics equipment, and environmental chambers are expensive. The difficulty is an inability to know what will be found, before conducting the experiment.
Not doing the test means the certainty of not finding anything. That is often not enough motivation to invest, to learn something about the reliability performance. The following scenario is just one situation, along with a few ideas to help you estimate the value of investments in reliability work. [Read more…]
Creating a product or maintaining equipment is actually about our ability to manage risk. The various risks are outlined below, and there are more to consider. This summary covers the basics related to reliability. [Read more…]
This example is based on a real situation. After a class on design for reliability, a senior manager declared that every component would be fully derated in every product (electronic test & measurement devices). Within a year the design team redesigned all new and existing products, with strict adherence to the derating guidelines provided in the class. A year after the class the product line enjoyed a 50% reduction in warranty claims. They learned about derating and a manager saw the potential value. [Read more…]
This is a two part series where I outline the basic elements of creating and supporting a reliability program. [Read more…]
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.
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?
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…]
This is a two part series where I outline the basic elements of creating and supporting a reliability program.
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…]
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…]
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…]
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…]
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…]
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…]
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…]