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Find all articles across all article series listed in reverse chronological order.
To work our ways towards understanding Design For Test (DFT)applications I am taking you back to the Stuck at Fault model (S@).
In the article which introduced you to the S@ model you learned the S@ model at the logic gate level.
Let’s build on this by applying it to combinational logic circuits.
Combinational logic has no clocked circuitry; sequential logic has clocked circuitry. In a few articles you’ll learn about test and sequential logic circuitry. [Read more…]
Big dreams and ambition have always come pretty easily to me. Watching the Magnificent 7 compete for Olympic gold in 1996, 11-year old me was convinced that I could become a champion gymnast. Little did I know that these same dreams and ambitions would help serve as lessons learned in becoming an engineering subject matter expert.
My gymnastics dreams did not care that I only had a couple of years of tumbling training. No bother to my ambition that my parents could not afford our monthly bills, let alone specialized coaching. “No big deal!” said my heart when reminded that I was terrified of a back handspring – how would I ever be able to accomplish the death defying acrobatics an Olympic gymnast must complete? [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…]
After the sponsorship and training are in place and resourcing is defined, there is still no guarantee that any investigations will get done. (See the end of the article for links to the blogs about these needs) This is where the definition of insanity applies – “doing the same thing over and over – and expecting different results” – so something must change. If there is no reason to perform an investigation, then things will continue to happen as they always have. [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?
Reliability Centered Maintenance is a powerful tool that when applied and implemented correctly can provide numerous benefits including improved equipment reliability, a reduction in unplanned downtime and lower unit cost of product. One of the most impressive benefits of performing a RCM Blitz™ analysis is the identification of failure modes that could result in a health, safety and environmental incident or accident. While some would like to believe that in today’s world where most new designs and capital projects are subjected to numerous design reviews that would include process hazard analysis we still uncover a significant number of health, safety and environmental related failure modes in every RCM Blitz™ analysis. [Read more…]
Historically, it has been relatively easy to meet customer system requirements using basic testing techniques. Today, however, customers require faster changes in technology and requirements are getting more difficult to meet. Competitive cost pressures have made the achievement of goals an even tougher task. In some cases, customers have requested and in a few cases mandated tools for companies to “be more efficient and organized in testing”. These facts create the need for organized and effective testing methods to be incorporated in all phases of the development process. [Read more…]
You walk into the plant on Monday morning. You are immediately confront by the production manager stating “Press 201 is down. The mechanics are saying it is the clutch again.” You feel an overwhelming sense disbelief. You ran overtime last weekend and replaced clutch at a cost of $30,000. How is it the clutch is failing again?
This scenario may sound familiar. It happens all the time, across many different industries and plants. So what exactly happened? The root cause was not properly diagnosed, and the clutch was replaced. Based on the short life of the new clutch, the root cause was likely something else that is affecting the clutch. [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…]
Guest Post by Umberto Tunesi (first posted on CERM ® RISK INSIGHTS – reposted here with permission)
Mens Sana in Corpore Sano (A Sound Mind in a Sound Body).
It could also be translated that quality of life is more important than the span of life, the number of years you live.
Or that medicine’s task is not to add years to your life but the life to your years.
And it might also be that such a formula for life – originally a Juvenal’s wish or prayer – is much more ancient than its Latin transcription. [Read more…]
What readers will learn in this article.
Too much stress in metal will cause it to fail. Failure can occur by putting the metal under a once-only load greater than it can take or by continually loading the metal cyclically with a high load less than the breaking load (metal fatigue). [Read more…]
Last week we reviewed the 10+ topics removed from the CRE body of knowledge (BoK). This week, let’s look at the additions.
Three of the additions are new categories or groups of topics that in part contain new topics. There are five new topics, that in most cases included bits and pieces of concepts buried in the previous BoK.
Let’s take a look at each additions in a bit more detail. Some I agree with, some I wonder what the motivation is behind the addition, and some I question why it is included. [Read more…]
In the beginning– just test the specs.
Analog circuits have been around a long time. Consider a simple LRC circuit– the inputs and outputs are continuous wave forms.
This remains a key differentiator from digital circuits which operate on 1’s and 0’s.
Continuous waveforms require different test equipment and test techniques. Analog circuits have properties of impedance, 3Db points in the frequency domain, transform functions. They can be treated like a lumped circuit or a distributed circuit in which signal integrity and transmission line theory apply.
So testing is easy- you just test the specs. [Read more…]
The analysis of residuals helps to guide the analyst when analyzing data. It provides a way to select the model, analyze the data, develop parameter estimates, and to develop confidence in the results. [Read more…]
