Your Reliability Engineering Professional Development Site
A listing in reverse chronological order of articles by:
Reliability engineers have traditionally been asked to answer a common question during development of a new device or system, and that is “How long will it last?”.
It is the eternal question in equipment reliability development, and it really comes down to “that depends on many factors”. One question that needs to be asked is how long do you need it to, or should it last? [Read more…]
Autonomous Vehicles (AVs) are still futuristic – but there are plenty of people are thinking about them and what they would mean – particularly as they relate to safety.
And when they do, they invariably think about how vehicles are currently regulated as a starting point. We envisage perhaps more regulation, standards and rules – because AVs are more complex and complicated. But for every regulation, standard and rule, we take responsibility away from the manufacturer.
Why?
Because all the manufacturer needs to do is ensure that their AV meets each regulation, standard and rule for them to not be liable for subsequent accidents (this is a simplistic interpretation to be sure … but satisfactory for the sake of this article).
Is this desirable?
Is this possible? [Read more…]
Weibull analysis is a tool that is used for characterizing the behavior of a data set. The value of characterizing a data set is being able to make predictions of failure rate for the same or a similar population. Input to the Weibull analysis is time to fail for all failed units and running time for operating units. The assumptions for the data set are critical to ensuring the right information is included in the analysis. This may include root cause analysis of the failures so they can be characterized as wear-out or use stress related. It would be beneficial to separate these two data sets because their characterization and behavior will be quite different Weibull factors. [Read more…]
If you had to section the history of reliability into only two periods I believe the dividing point would be around 1950. The first section, stone age to 1950, the “Robust” era; 1950 to today, the “Margin” era. In the robust, era reliability concerns were addressed by creating a design that was orders of magnitude stronger than required, “over-engineered”. This protected against the variability of fabrication, use, and environment. If it was made sloppily with low tolerances, it still worked; Used for an unintended purpose, still worked; Left out in the snow, dropped in the river, run over by a horse, buried in the sand; still worked. [Read more…]
I wonder how many product tests have been undertaken and nothing has been done with the results? Maybe development activities have moved on before any results are available? Maybe the test results didn’t provide the answers that were needed? Maybe the test wasn’t focused on the critical issues. In other words, cost, time and resources were wasted.
I will present a better way to ensure value is delivered and test results are acted upon. [Read more…]
Mission profiles are fundamental to any reliability prediction being valid. Without clearly defined environmental and use profiles there will be a long chain of inaccuracy that accumulates into significant errors within a product. 
This is what occurs at the following stages, or tools, if the mission profile or environment profile changes after its completion. [Read more…]
Do they design reliable products? Or Do they guide the development of reliable products?
It’s some mix of course. It depends on the process for the organization they operate in. I will point out that neither extreme works. I am often surprised with how many organizations I see that still have the 1950’s model of ” Design it and then give it to the reliability team to make it reliable.” I still don’t believe there is a single person in any engineering role in any engineering organization that believes that works.
That is what one of my old mentors used to call a “window dressing program”. No one believes it actually helps the product but you get to take your customers around your facility and show them all the great testing you are doing (SILENT END OF SENTENCE ” on out of rev parts and in a program phase where results can’t be implemented.”). [Read more…]
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…]
I posted an article recently by Bloomberg on the Defense Department’s recent disclosure of the escalating support cost of the F-35 Joint Fighter Jet. With over 3,700 views, it was the most read of my posts. The original article on escalating F-35 reliability costs can be read at this link
I posted the article with the comment: “Once a test engineer working for a large DoD contractor once told me at a reliability conference, ‘These new reliability development techniques of HALT and HASS would be a lot easier to implement if spare parts and service did not constitute 60% of the total program profits.’ That was not the first time I have heard a similar comment from a test or reliability engineer or manager working in the defense industry. I believe these engineers working on the reliability end of the programs said these concerns me out of frustration. [Read more…]
Talking is not the same as a discussion or conversation. Talking is one direction only. If two people are talking, they are talking at each other.
A discussion is two way. When two people have a discussion information passes both ways, both speak, both listen.
As an engineer, there is plenty to discuss. We work with others to find solutions, make compromises, determine optimizations, and finish projects. We need to share our knowledge and insights, as well as learn from others.
You can learn to foster true discussions and minimize simply talking at one another. You can take steps to enable the give and take exchange of a discussion. [Read more…]
Autonomous Vehicles (AVs) are still futuristic – but there are plenty of people are thinking about them and what they would mean – particularly as they relate to safety. And when they do, they invariably think about how vehicles are currently regulated as a starting point.
We envisage perhaps more autonomous vehicle regulation, standards and rules – because AVs are more complex and complicated. But for every regulation, standard and rule, we take responsibility away from the manufacturer.
Why? Because all the manufacturer needs to do is ensure that their AV meets each regulation, standard and rule for them to not be liable for subsequent accidents (this is a simplistic interpretation to be sure … but satisfactory for the sake of this article).
Is this desirable? Is this possible?
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…]
Have we gone through the introduction of autonomous vehicles before? In other words, have we gone through the introduction of a new, potentially hazardous but wonderfully promising technology?
Of course we have. Many times. And we make many of the same mistakes each time.
When the first automobiles were introduced in the 1800s, mild legislative hysteria ensued. A flurry of ‘red flag’ traffic acts were passed in both the United Kingdom and the United States. Many of these acts required self-propelled locomotives to have at least three people operating them, travel no greater than four miles per hour, and have someone (on foot) carry a red flag around 60 yards in front. [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…]
