The CRE_Errata_9-26-2011_revised document is in pdf format and contains a couple of typos noted by John Cooper in the Indiana Council CRE prep materials – he has taught the CRE Prep course for Ops A La Carte and is a pretty good teacher and a CRE. [Read more…]
CRE Preparation Notes
Prep notes for ASQ Certified Reliability Engineer exam ISSN 2165-8633
The idea of the CRE Preparation Notes series is to provide you short practical tutorials on all the elements that make up the ASQ CRE body of knowledge. The articles provide introductionary material, basics, how-to’s, examples, and practical use guidance for the full range of reliability engineering concepts, terms, tools, and practices.
Keep your knowledge fresh with regular review of topics and tools that make up reliability engineering.
Sign up for the CRE Preparation Notes email list to receive weekly reliability engineering short tutorials.
- Improve your reliability engineering skills
- Learn about the wide range of tools available
- Enhance your resume with the ASQ CRE
You will find the most recent tutorials in reverse chronological order below. Below each article is the section and specific clause of the CRE Body of Knowledge that tutorial addresses. Click on those tags to find other articles on the same topic. To the right on the sidebar, there is a listing of the 7 major categories in the body of knowledge - it's a quick way to find groups of articles on each specific area. You can also use the search function to locate articles, podcasts, or tutorials on specific topics.
Series Reliability Question
Recently a colleague sent me a published copy of the first CRE exam. Scanning through the document suggests that a few things have changed and many have not changed at all. I often comment my enjoyment of the reliability engineering profession, as it doesn’t change too fast and even I can keep up. [Read more…]
RBD and Design Process
A reliability block diagram (RBD) for a product that has no redundancy or complex use profile is often very simple. A series system (reliability wise) implies that any one part or element of the product that fails the entire product fails. One might ask if an RBD is even necessary. [Read more…]
Top Tips for Probability Analysis
This is provided courtesy of Amanda at
Egerton Consulting Ltd
Visit our website at www.egertonconsulting.co.uk
<They have a great newsletter and worth subscribing. Fred> [Read more…]
Why HALT is not HALT
An excellent short white paper by Craig Hillman that is worth reading. It underscores why I claim HALT is the second-worst four-letter acronym in our profession. See the paper at http://www.dfrsolutions.com/uploads/white-papers/Why_HALT_Is_Not_HALT.pdf
How to Calculate Warranty Failures
Let’s say we have a product that most often fails for one major component. Let’s say a fan (it could be anything, and while I don’t have anything against fans, it’s easy to picture).
Ok, this fan has a data sheet with the classic reliability claim of 50,000 hours MTBF. For those that know about my disdain for MTBF (www.nomtbf.com) rest assured I’m not going to get into it here. The basic approach for estimating the number of failure during any [Read more…]
5 Books for a Professional Reliability Engineer
A part of the preparation for the ASQ CRE is experience and education. These, in my simple way of thinking, means applying what you have learned to solve problems and provide value. Reliability engineering is about two questions: [Read more…]
Life Testing Question
Hi Fred,
I would take this opportunity to ask the reliability guru about bathtub curve for hardware reliability. I am running 27 units for life test for a million cycles around 555 hours. I have one failure at 300,000 cycles, and the rest of the units are running fine. Would this be classified as an early life failure? Also, how do I make a determination of when the early life failure time interval ends and constant failure rate starts in this example based on failure rate of remaining units? Thanks. [Read more…]
CRE exam in May at WCQI
All attendees from the World Conference on Quality and Improvement, or Quality Institute for Healthcare Conference can take a certification exam listed.
Sunday May 20, 2012
Application Deadline: April 6, 2012
All exams will start at 10:00 a.m.
http://wcqi.asq.org/certification.html?WT.dcsvid=MzgyNjkwNzYwNgS2&WT.mc_id=EM118117
CRE Primer Error
Update:
I forwarded the note below to QCI for comment and asked if they have an errata available. They do.
The QCI errata is posted on [the] website. [Read more…]
Reading a Datasheet
Reading a datasheet to determine a reliability value may take some investigative work. Whenever I see a fit rate based on failure-free testing, I am curious about how they did the testing and the calculations. [Read more…]
Series System
During design and development, Reliability Engineers often receive reliability parameters in many forms. The most common reliability parameter is the mean time to failure (MTTF), which can also be specified as the failure rate (this is expressed as a frequency or Conditional Probability Density Function (PDF)) or the number of failures during a given period. [Read more…]
Parallel Systems
Speaking reliability-wise, parallel, means any of the elements in parallel structure permit the system to function. This does not mean they are physically parallel (in all cases), as capacitors in parallel provide a specific behavior in the circuit and if one capacitor fails that system might fail.
In this simple drawing, there are n components in parallel and any one component is needed for the system to function. [Read more…]
Value of CRE
The annual salary survey done by American Society for Quality (ASQ) is summarized in the December 2011 issue. And, the good news is a CRE certification provides approximately a $21k salary premium over those in similar positions without the certification. Based on Table 2. salary premiums for certification holders in the article, Land the Big One, indicated the largest premium is [Read more…]
Weakest Link
Each piece of gear used in rock climbing has the potential to be the weakest link. Often, based on accident reports, it the human decisions or lack of focus that is the most difficult to improve.
Ropes, anchors, harness, and carabiners and another equipment all have to work in the event of a fall. The design of each piece of equipment is to meet and hopefully exceed any possible load. And, to maintain the needed strength over years of harsh outdoor use. [Read more…]