Your Reliability Engineering Professional Development Site
A histogram is a graphical representation of a set of data. It is useful to visually inspect data for its range, distribution, location, scale, skewness, etc. There are many uses for histogram, there you should know how to create one.
Let’s explore a set of data and create default histograms using a variety of methods. If you have a way to create a histogram using some other method or software package please send it over and we’ll add it to the article. [Read more…]
DFR has been a term in and out of fashion for some time—one of the many DFX type programs. DFR, unlike some of the other Design for X programs, has to exist within the overall culture of the organization to be successful. The premise that design occurs at the point of decision implies that each design may have the appropriate information to consider the decision’s impact on reliability performance properly. [Read more…]
In the situation where you have a sample and would like to know if the population represented by the sample has a mean different than some specification, then this is the test for you. In this case, you do not know the actual variance of the population, you just have a sample.
This test is often the second one in a textbook that describes hypothesis testing. It is a useful hypothesis test and applies in many situations as we rarely know the population variance. [Read more…]
The essence of creating a reliable product involves making informed decisions. Informed related to the implications of the various options on reliability performance. Yet, these decisions, made nearly every day during the early stages of a product’s lifecycle are fraught with uncertainty.
There is an approach that instead of making perfect decisions every time, we instead focus on making decisions that allow us and others to learn the necessary information to then make better decisions. [Read more…]
The more you understand the failure mechanisms, the easier it is to design an accelerated life test (ALT). Yet, we often do not have all the information we would like to draft an ALT. So, what do we do then?
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One of the key ideas behind the ASQ CRE certification is the need to learn enough to pass the exam. Then you are expected to continue to learn to maintain your certification. It is the key idea of ongoing professional development that central to the CRE program, and many other certification programs.
Over this past year of COVID-induced restrictions, the ability to attend local chapter meetings or conferences has changed. While many events are now done online, it’s another Zoom meeting after a day full of such online meetings.
A recent article by Anant Agarwal, the founder and CEO of edX titled, “What I’ve Learned About Learning – 5 Hacks for Success” caught my attention. Anant provides a few tips to improve your online learning – and I would say any learning. A little research on how to best learn online also found “Tips for Successful Online Learning” that helped inform this short summary. [Read more…]
The way we think and act concerning creating a reliable product or system defines the reliability culture of an origination. I trust your organization doesn’t complete the design then ask the reliability folks to ‘add the reliability element’ or ‘test to prove it’s reliable enough’.
Another ineffective approach is to perform many reliability-related tasks, like a design FMEA, HALT, ALT, derating, margin and environmental testing, life testing, demonstration testing, etc More is not better. If the focus is just doing the list of tasks, with little information acted upon, then this approach is little more than a waste of resources.
So, what is it that makes a wonderful design for reliability program? It’s not expecting the reliability team to do it on their own, nor is it checking off a long list of tasks. It is the focus across the organization, inside and outside the design and development team, that each decision made has an impact on reliability performance. As such, the work of the DfR program is to enable each decision to be well informed concerning the potential impact to reliability involved with the pending decision. [Read more…]
Nicholas W. Eyrich, Robert E. Quinn, and David P. Fessell published in the Harvard Business Review an article titled “How One Person Can Change the Conscience of an Organization”, dated December 27, 2019. In the article, they discuss how corporate transformations, while assumed to occur from the top-down, actually it is the middle managers and first-line supervisor that can make significant change happen.
They look at what it takes for one person to make a significant change within an organization. As reliability or quality professionals, we often have the opportunity to spot needed changes. It is then up to us to tackle those challenges to make the change happen. [Read more…]
One of the first things to do when faced with a set of numbers is to plot them. A histogram is often the first choice, maybe a dot plot. Up your data plotting skills and let your data provide a bit more information by using a box plot. [Read more…]
A common practice I’ve seen in organizations is to deal with field failures when they occur. This may occur when the mistaken assumption that no failure will occur due to ‘such an excellent design.”
Ben Franklin may not have been thinking about future product failures, yet his quote:
By failing to prepare you are preparing to fail.
implies we need to prepare ourselves and our organization to deal with field failures. Having clear processes to deal with field failures is a best practice. [Read more…]
As reliability professionals, we are in the business of estimating or forecasting the reliability performance of our product, equipment, or system. While we use a range of tools to analytically make these estimates, sometimes we do not have sufficient data or information.
One method is to ask another person that has knowledge of the particular technology, use conditions, or whatever is hampering our work. If you ask two people you most like will get two different answers. If you ask 10, 10 different answers.
One way to work with a group of subject matter experts is to conduct a structured communication technique called the Delphi Method. [Read more…]
At an early concept meeting discussing the technical strategy for the new product, the engineering teams were at an impasse. The decision matrix balanced out with three distinct options. Product reliability differed slightly with each option yet presented risks just as the considerations of cost, complexity, feature set, and time to market.
The project manager, the leader of the development program, asked a few questions, asked for input from the director of engineering, and selected a path forward.
The team accepted the decision. The project went well. Yet, I’ve often wondered how did she know which option to select. I also learned to trust her judgment on difficult decisions. [Read more…]
What if you knew all the possible outcomes for your product’s reliability performance due to component variations, for example? What if you knew the future with enough certainty to make a difference?
Building on brainstorming, what-if analysis involved using models or prototypes that allow you to change something and see how it alters the output or performance. What if we change this support bracket from iron to aluminum? What if we swap out this 100 ohm resistor for a 200 ohm one?
As a curious engineer you could spend many, many hours conducting what-if based experiments, so there is a bit more to this idea then just a random walk of changes. [Read more…]
Over the past week, I received a couple of interesting questions. One concerned assuming a Weibull beta value for an accelerated life test plan. The second involved assuming expected life models for elements within a reliability block diagram.
In both cases, we faced incomplete data and uncertainties, yet felt the need to assume some values in order for the math to work out. We do make assumptions in order to solve problems. We also can make mistakes that lead to unwanted consequences. [Read more…]
One of the enjoyable parts of reliability engineering work is the consistent need to learn. We learn how new materials, designs, applications, and systems work, and fail. Sometimes we learn through proactive characterization studies, sometimes via unwanted field failures.
Failures will occur, it is what we learn from them that matters. The ability to gather and remember the lessons learned is a common and ongoing need for every organization. We are not very good at it, in general. [Read more…]
