Your Reliability Engineering Professional Development Site
A listing in reverse chronological order of articles by:
Can you take into account reliability or durability functions in an FMEA? How can this be done? A reader asks this question, and it is discussed and answered in this FMEA Q and A article.
“A prudent question is one-half of wisdom.”
Francis Bacon
When your engineering project struggles, how do you respond? This video provides a sports analogy to the situation. Get back to the fundamentals – and Design of Experiments can be part of that process.
www.PerrysSolutions.com [Read more…]
After years of consulting, what motivates us now? This video discusses those areas of interest for us. Constant learning and challenge keeps us going! [Read more…]
Why did we start the company – and why this specific company. This video provides the answer. www.PerrysSolutions.com [Read more…]
Many times, a complete analysis is not performed with DOE testing. However, the learning value is substantial for model building situations and only takes a small amount of additional time if you know what you are looking for. In this video, we give an overview of the key items we look for to develop break throughs in product and process development. This same process has been used for the majority of our 25+ years of DOE experience. [Read more…]
In this week’s FMEA problems and solutions article, the intermediate problem challenges readers to prioritize a series of RPNs (with their corresponding S, O, and D). In the advanced problem, readers are asked to weigh in on a fictitious debate between advocates of traditional RPN, and advocates of criticality assessment, using only severity and occurrence.
If you haven’t yet read the article titled “Prioritizing risk for corrective actions in an FMEA – Know before you go!“, you can access it by clicking on the link.
Reliability and durability are essential in today’s competitive market place. However, component reliability verification tests and system durability tests take a long time, cycles, or miles to complete. This puts these tests in direct conflict with program timing, product development budgets, and limited testing resources. To minimize this conflict, it is essential to accelerate these tests.
Taking Your Business to Next Level
A radio interview with Perry Parendo.
This video provides some of our learning and observations regarding renewing your business or renewing your career. www.PerrysSolutions.com [Read more…]
Needs and How to use an Expert for your Project
Finding an expert for your project is important. Knowing what traits they need and how to employ them will lead you to improved opportunity for success. We at Perry’s Solutions, Inc. have these key traits and exist as a business because we are often being used in this role – previously as a corporate employee and now as a consultant. [Read more…]
Extended bogy testing builds on test to bogy (TTB), discussed in a prior article. TTB focused on calculating the number (N) of parts tested to one life bogy, with 0 failures allowed, to a specified reliability (R) and confidence (C) levels.
Using TTB to verify conformance to high reliability and confidence targets requires very large sample sizes, increasing testing cost. The capacity to test large samples may require large facility capital expenditures. Also, the zero failures allowed paradigm removes the opportunity to learn about product failure modes and the opportunity to improve the product through design or manufacturing process changes.
This article focuses on extended bogy test plans as an alternative to TTB.
Design of Experiments classes always talk about Resolution III and higher designs. But what is a Resolution II design? We show what it is – and show that it is actually used quite a bit! Should be used with caution as it does not provide understanding.
www.PerrysSolutions.com [Read more…]
Innovative situations require strategic testing to reduce risk. The points reviewed summarize our approach when we have performed this activity. It ends up being the heart of the development plan. [Read more…]
This video gives some tips regarding networking. It applies to finding a job or for obtaining clients in a consulting business.
This was created for the large number of people I know who have been displaced from a job. Many wanted advice based on my experiences and with my daily effort to build my consulting business. Not being able to have lunch with everyone, I created this video to help them get started. It has been helping people, so hope you can find value. It may also turn into a book at some point.
[Read more…]
Note from author:
Since this article was originally published, there are subsequent articles in the “Inside FMEA” series that further describe better approaches than RPN to risk prioritization. Here are links:
Is There a Better Way Than RPN?
Risk Prioritization in FMEA – a Summary
Is There a Better Way Than RPN?
Text of the original article:
One of the most important steps in FMEA procedure is prioritizing risk for corrective actions. As soon as Severity, Occurrence, and Detection ratings have been determined for each failure mode and associated cause, the next step in an FMEA is to prioritize the risk and identify which issues need corrective actions. This step has been misapplied more often than any other step in the FMEA process.
“The perfect is the enemy of the good.”
Voltaire
Test To Bogy Sample Sizes
Introduction
Reliability verification is a fundamental stage in the product development process. It is common for engineers to run a test to bogy (TTB). What sample size is required for a TTB?
Reliability Testing
Reliability is the probability of a part successfully functions under specified life, duty cycle and environmental conditions. Many functions are specified during the design process. Each reliability test will be focused to validate a specific function. The targeted verification level depends on the criticality of the function and potential failure modes. The life could be specified as a count of cycles, an operating time, or perhaps a mileage or mileage equivalent. The duty cycle is a description of how the device is used. Environmental stresses are generally included in the test.
