Your Reliability Engineering Professional Development Site
This is part of a short series on the common life data distributions.
The Pareto distribution is a univariate continuous distribution useful when modeling rare events as the survival function slowly decreases as compared to other life distributions. This short article focuses on 7 formulas of the Pareto Continuous Distribution also known as the Pareto distribution of the first kind (there are three kinds, apparently). [Read more…]
I was asked “Do you know about Singularity design?” I hadn’t heard the term in that context before.
It’s the concept of not approaching design from multiple disciplines. The design process is done with an approach and knowledge base of all needed disciplines at once and in conjunction. The electrical system isn’t designed by an electrical team and the mechanical by a mechanical team. The “Design Team” 
designs both simultaneously. Team members knowledge might be rooted in one discipline but there is clearly no boundary to their knowledge of other disciplines. This would be a mechanical engineer who has designed a PC board before.
In my prior article, Process Capability I – Overview and Indices, the process capability concept was defined for prototype samples and serial production. The data is assumed to be normally distributed and Pp, Ppk, Cp, and Cpk indices were defined. Its application to one-sided and two-sided tolerances was discussed. This article provides methods to estimate the percent defective.
The engineering tolerance for a critical characteristic is 10±0.2. So the lower specification limit (LSL) is 9.8 and the upper specification limit (USL) is 10.2. A sample of 30 parts provided measurements of the critical characteristic. The sample mean ($-\bar{x}-$) was 9.951 and the sample standard deviation (s) was 0.1825.
Assessing the occurrence ranking is one of the more challenging aspects of FMEAs. This article presents problems that relate to occurrence risk assessment, based on a fictitious case study, and highlights a common mistake.
Having visited hundreds of manufacturing plants in the last 17 years, someone recently asked me if there were any traits the most reliable plants all had in common. I have listed below the top 6 signs of a reliable plant. [Read more…]
To be innovative, you need to resolve competing requirements. How does someone do that through testing? Over 20 years ago, we created a process that has worked for us and countless others when applying Design of Experiments. These tidbits may help you accomplish more in your new product development.
This article covers the operation of steam traps and how they work. Steam is a greatly used medium. Its use ranges from heating process and domestic fluids through to driving turbines by the expansion of the vapour. Yet the steam trap at the bottom of a drop leg is easily forgotten. [Read more…]
Guest Post by Geary Sikich (first posted on CERM ® RISK INSIGHTS – reposted here with permission)
What is risk? Think about it before you leap to answer. Do we really know and understand risk? Some facts to consider:
Risk management requires that you constantly monitor recognized risks and continue to scan for new risks. This process cannot be accomplished with a ‘one and done’ mindset. Risk needs to be looked at in three dimensions and perhaps even four dimensions to begin to understand the “touchpoints” and aggregation of risk, potential to cascade, conflate and/or come to a confluence. [Read more…]
The quality triangle is an admission that every project has design constraints. Note that reliability is rarely listed directly within the triangle, yet reliability does impact each element of the triad.
In a world where the design team is beset with numerous design for X priorities, understanding how reliability related to the top three and most common set of constraints is imperative.
For any set of priorities, you should be able to convey how addressing reliability performance in the design and assembly process impacts those priorities. Addressing reliability can improve quality, reduce the risk of launch delays, and reduce the cost of a product. All this and improve customer satisfaction as well.
Let’s explore a few ways you can connect reliability priorities to the common quality triangle priorities. [Read more…]
While previous articles focused on requirements writing, another element of products requirements is design constraints.
A design constraint might not be a requirement in the purest sense, but must be accommodated in product requirements (and, ideally, identified as such). Design constraints almost always make their way into product requirements.
Let’s use a simple example whereby a specific housing material is specified (a polyester thermoplastic elastomer).
The requirement might simply be: “The housing material shall be made of a polyester thermoplastic elastomer”. The PRD is then provided to the designer, essentially telling him he must use this material.
I’ve teamed up with Skylar Wooden, a Technical Writer, and Katie Butler, a CPA, the ladies behind Pare and Flourish to bring you some technical writing tips for engineers. 
Engineers are incredibly knowledgeable people. You understand how to design and build the most complex of structures. You analyze and evaluate intricate data. But, many engineers miss one of the most important aspects of any profession—explaining your work to others. Whether it’s to tell someone how to perform a task, or report on a project to a superior, relaying information is just as critical as knowing the information.
As an engineer, you can offer your expertise in two ways: verbal or written communication. You likely deal with the verbal aspect of this on a daily basis when you answer questions, explain a process, or even talk about your job with your friends. So, how often are you writing? [Read more…]
Intuitively, the emphasis in reliability to achieve a reduction in warranty and in-service costs results in some minimal increase in development and manufacturing costs. However, use of the proper techniques during the proper life cycle phase will help to minimize total life cycle cost (LCC).
To minimize total LCC, your organization should do two things:
We make decisions every day. Our project teams and organizations have many individuals making decisions every day. Most of these decisions have little to do with product reliability, yet a surprising number of design, marketing, production, and customer care decisions that have a direct impact on product reliability performance.
As a reliability professional, do you work to make better decisions? Do you work to enable the individuals designing, producing, marketing, etc your organization’s products to make better decisions concerning reliability?
If not, why?
Let’s outline a few ways to estimate the value to you and your organization to improve decision making concerning reliability. [Read more…]
I’ve been told that humor, especially New York sarcasm doesn’t go over too well on LinkedIn. That as a regular contributor of articles, blog postings and hopefully useful updates one should try avoid attempting to use humor as a teaching tool.
Well those who know me well know I also don’t always follow the advice of those who somehow believe we all learn the same way, think the same way and therefore do things the same way. I’m a guy who believes that while common sense might not be that common, when you explain why something makes sense most of the audience will get it. For the others who still don’t understand I of course bring data.
Recognizing the heartbeat of product development will allow organizations to make the most of their resources. Using the right tools, at the right time, will lead to improved designs. This video talks in detail about what the heartbeat is made up of.
