Your Reliability Engineering Professional Development Site
The Apex Ridge article series covers a diverse set of topics that relate to many of our reader’s work, interests, and experiences. The articles are inspired by industry experiences with the intent of sharing, educating and assisting you with your career challenges and growth. The content is targeted for a diverse audience with backgrounds even extending beyond engineering (Hmm talking to you project and business managers). My hope is that these topics inspire you to have discussions with your colleagues or right in the comments of the series. I look forward to seeing you on-line soon.
Understanding the reliability stakeholders in an organization is an interesting exercise.
Who are they?
It’s easy to look at each of those and say “They all could easily get by and appear successful even if a product has moderate to poor reliability”. You could also state that ” Reliability is a key factor to success in their role” [Read more…]
This is the bathtub curve we are often shown.
This is what a real bathtub curve looks like. [Read more…]
With all the complaints you hear about products rebooting and software crashing, do companies really practice Software Reliability? In fact, there are some companies that do, but they are mostly in the industries that require products to have high availability, such as telecom, defense, and space, or safety-averse industries, such as medical and industrial plant operation. Most other industries don’t pay as much attention to it. The best method to increase Software Reliability without significant increases to schedules or budgets is to use a Software Design for Reliability (SDFR) approach. These are the key steps. [Read more…]
The original windmills of Europe are feats of engineering. I was able to get inside of a few in Holland and see all the mechanisms that have been operating for hundreds of years. I was lucky that the wind was strong and the windmills had their sails out the days I was visiting. A few were grinding flax seed and others designed to pump water from a low basin to
a high basin to control basin water levels. Being inside of the windmill was like being an insect inside of a grandfather clock. It was so interesting seeing how they engineered the mechanisms to optimize the balance of the system needs in such a different manner than we do with many of our currently engineered products. [Read more…]
Many product programs ( actually all) are on a tight schedule. When Accelerated Life Testing (ALT) get’s it’s place in the process it is another mouth to feed. ALT is not a short process. Each round of testing typically takes weeks, and the results may drive design changes that prescribe additional testing. It is common to want to get the ALT process going as quickly as possible. In this haste the primary wear-out failure modes and it’s driving stresses are confidently stated, a model is created, and the test is started.
Mean Time Between Failure (MTBF) is one of the most well know reliability metrics. 
But to anyone who works with reliability, it seems like it was developed by some evil anti-reliability mastermind to undermine the possibility of connecting reliability to anything or anyone.
Mean Time Between Failure means what?
This is the process of understanding everyone goes through as they are introduced to MTBF, formally or informally. [Read more…]
You have been put in charge of a program to study failure rates of brake pads. The place to start is a testing program that will generate data for analysis.
Testing programs should begin with a specific intent. This may be to characterize quality based failures, use life, or wear-out failure modes. When a test is complete it is easy to take all observed failures and use them in the data set to characterize the failure mode. This is a mistake.
Each of the study intents I described above can be attributed to wanting to understand a specific section of the life curve that is commonly represented by the “bathtub” curve. [Read more…]
Design of Experiments (DOE) is a phenomenal way to identify key relationships between variables and effects. It fully leverages statistics to not only identify these relationships in a compressed time frame but any “interactions” between variables that cause a specific effect. These interactions would not have been observed if experimentation was limited to adjusted one factor at a time (OFAT).
Engineers have been applying Prognostics to mechanical components for many years.
For example:
However, most industries building systems with mechanical components choose not to use prognostics because of the cost of the instrumentation within the product. Products that have on board “smarts” can choose to include diagnostics with less effort or expense. With advances in technology, the cost of the instrumentation is dropping. This not only means that adding the hardware to support advanced metrology is more feasible but that many of these components/systems may have already been added for other functionality and controls improvements in the product. It doesn’t take much brainstorming to find creative ways to use these existing sensory systems. [Read more…]
Reliability goals are often communicated in Mean Time Between Failure (MTBF) 40,000 hrs, Failure rate 0.00035, or percentage still functioning over time 99.98%. If you are not familiar with actually calculating these numbers they really don’t mean a lot. Are any of those above numbers good? bad? something we will even measure before release?
Are any of those above numbers good? bad? something we will even measure before release? [Read more…]
HASS doesn’t break stuff like HALT. HASS is like a good physical examination from a doctor: It gives you the thumbs up or thumbs down on health based on a quick and thorough examination. But a good thorough examination is possible because of research, education, and practice.
[Read more…]
Why do so few product development programs make that connection between the product specification document content and the released product? It seems to be such a common thing that these two don’t connect that organizations don’t even bother to review or analyze this after release.
The mindset at that point seems to be:
I was in a meeting recently with a customer team. It was on-site with 12 people ranging from mid-level engineers to upper management. Someone defended me earlier in the meeting by saying “Well, he did write a book on it!” Which was nice and kinda cool to hear someone say. But this lead to a later comeback by a crusty, principle engineer, 40 years under his belt, boat captain from “Jaws” kind of guy. “If we can buy your book then why do we need you?”
I took a moment. I knew that not responding wasn’t what I wanted to do but had to tread carefully because a poorly crafted response could easily sound arrogant. This is what I responded with… [Read more…]
We are all familiar with the base of our car warranties being in both months and miles. 
Some of that is that they want a definitive end to all warranty periods. But another reason is you can’t just boil down all aging factors to one stress. In a product development program, we are always under pressure to keep all activities as short as possible. Accelerated Life Testing ALT can loose almost all of it’s value when not executed with care. [Read more…]
This video clip looks like a disaster but is actually a visualization of precision reliability engineering………. right after a disaster . [Read more…]