Your Reliability Engineering Professional Development Site
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…]
It seems the forces of nature are working against our ideas.
I recall being frustrated as a child playing in the sandbox. I wanted to create a ramp of sand to race my cars down. No matter how much I pushed and patted the dry sand succumbed to some unseen force and did not hold the desired shape.
In business, we sometimes experience the same frustration. It’s not gravity.
Instead, we are facing organizational inertia.
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…]
Most agree that improving products or process reliability is a good thing. It’s good for customers, factories, and our business.
And, sometimes it’s difficult to answer the question,
What is the value of that reliability activity?
Years ago my boss asked me what value I provided the organization. Working as a reliability professional, I thought that my value was obvious. He asked me to show the value.
It was harder than I thought.
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…]
Failure modes and effect analysis (FMEA) is a tool that works to prevent process and product problems before they occur.
I like to define FMEA’s as an organized brainstorm. The process examines a product or process and asks what could go wrong. Then the team systematically determines and rank orders for each failure mode:
– the severity of the problem when it occurs
– the probability of the problem occurring
– the ability to detect the problem before it occurs
Good design engineers think about how the design could fail and improve the design. FMEA provides a structured team approach to further improve the design.
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…]
One of the primary questions we answer as reliability engineers is:
How long will it last?
Reliability prediction is the forecast or prognostication attempting to quantify either the time till failure, or expected future failure rate or warranty claims, or required spare parts.
We need to know as we make decisions today about the design or purchase.
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…]
Over the past week or two, I’ve received requests and comments that have given me pause. Why is it that I have time to answer questions and share information? Why do I spend the time to do so in the first place?
I have found that responding to questions or requests for assistance is rewarding.
Today I received a request for help in a job search. Last week it was an employer looking for a perfect candidate. I’ve received questions about graduate school in the US from a Chinese undergraduate. A question on accelerated life testing approaches. Another on maintenance practices and data analysis.
For each, I try to provide an answer or direct to find an answer.
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…]
When a product or asset works as it’s expected for as long or longer than expected, we often consider it reliable.
Consumers around the world look for reliable products and services. Some will pay a premium with the desire to obtain failure free value from the purchase. When designing a product or service we often want to create the most reliable item within the constraints of time, resources, and cost. Designers and engineers may add margin or safety factors into calculations and decisions to avoid failures.
Many of us have heard that fixing a design is orders of magnitude less expensive early the product lifecycle. Product recalled or major failures can damage profits and brand image.
Here are three ways you can invest in improving product reliability. [Read more…]