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Prep notes for ASQ Certified Reliability Engineer exam ISSN 2165-8633
The CRE Preparation Notes series provides you with short practical tutorials on all the elements that make up the ASQ CRE body of knowledge. The articles provide introductory material, basics, how-tos, examples, and practical use guidance for the full range of reliability engineering concepts, terms, tools, and practices.
Keep your knowledge fresh by regularly reviewing topics and tools that make up reliability engineering.
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You will find the most recent tutorials in reverse chronological order below.
One approach for reliability improvement is to find the weaknesses or faults, then fix them.
This is best done before shipping to the customer.
You may hear this called the Test, Analyze, and Fix Method (TAAF). Or, you may have heard of it called a Reliability Growth Test program (RGT). Either way, the essence is evaluating prototypes to find specific faults. [Read more…]
Testing a new design is expensive and takes time to accomplish. During the design, process engineers make assumptions across many decisions. Unknown interactions and unanticipated events may lead to product failure.
Finding design weaknesses early in the design process permits the team to address and correct problems. [Read more…]
In Chapter 8 of The Basics of FMEA by Robin E. McDermott, et. al. discusses the ten steps for an FMEA. I find it to be an excellent summary for describing and conducting a failure mode and effect analysis.
Therefore based on the work of McDermott and others, plus my own experience here are the ten steps with my descriptions. [Read more…]
One of the most basic skills needed for the CRE exam is the ability to correctly read the Standard Normal Table.
Writing this short how-to article would be really easy if there were only one way to create the table. There isn’t. It seems every author has to create a unique way to tabulate the values. [Read more…]
An effective product reliability process requires a strong team, at every level.
The team of employees within an organization that participate and impact product reliability is a vast and widespread group of people. They include members of the design team, design managers, quality and reliability engineers and managers, procurement engineers and managers, warranty managers, failure analysis specialists, members of the marketing and sales staff, members of the finance and manufacturing teams, and field service and call center staffs. [Read more…]
For our use of the Weibull distribution, we typically use the shape and scale parameters, β and η, respectively. For a three parameter Weibull, we add the location parameter, δ. [Read more…]
My best CRE exam preparation tips
Over the past few years, we have been helping people from around the world prepare for and pass the ASQ CRE exam. Over this time, and from personal experience, I’ve learned a few things about what makes a difference.
Here are ten tips to help you prepare. [Read more…]
In a recent discussion in the Linkedin group ASQ Reliability Division, John Pagendarm replied with his recipe for CRE exam preparation. With John’s permission, I’m posting here.
For a stable process, nothing much happens. If the stable process is producing acceptable products, we should expect to continue to produce acceptable products.
Unless something changes. [Read more…]
Thanks to you all for a great year. The idea of the blog is to assist those preparing for the CRE exam or wanting to learn about reliability engineering. It seems to have found the audience.
The WordPress.com stats helper monkeys prepared a 2013 annual report for this blog.
Here’s an excerpt:
The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 21,000 times in 2013. If it were a concert at Sydney Opera House, it would take about 8 sold-out performances for that many people to see it.
Once you decide to monitor a process and after you determine using an $- \bar{X} -$ & s chart is appropriate, you have to construct the charts.
The $- \bar{X} -$ & R charts use the range as an approximation of the variation in the population. When feasible use the standard deviation, s, rather than the range, R for the improved efficiency in detecting meaningful changes in process variation. [Read more…]
Once you decide to monitor a process and after you determine using an $- \bar{X} -$ & R chart is appropriate, you have to construct the charts.
This is not difficult and by following the 8 steps below you will have a robust way to monitor the stability of your process. [Read more…]
The NASA Fault Tree Handbook with Aerospace Applications
This is a break from the usual format of this site. I’m highly recommending that as your review materials and prepare for the CRE exam or prepare to conduct an FTA, you read this NASA document as an intro to fault tree analysis.
For a review, I suggest the first chapter or two. If working in the aerospace industry, you should print and use a copy.
The following is an extended excerpt from the first section of the document. [Read more…]
What are Variables Control Charts?
From NIST Engineering Statistics Handbook, section 6.3.2, with edits and additions.
During the 1920’s, Dr. Walter A. Shewhart proposed a general model for control charts as follows: [Read more…]
