Articles

Find all articles across all article series listed in reverse chronological order.

Is It Faster to Demonstrate Component Reliability at the System Level?

Here is a common situation that is considered when reliability testing is being planned. Let’s use letters to designate depth in a product component structure. The top level product is level “A” and a component in top sub assembly is “B”. A sub assembly, of a sub assembly, of a sub assembly, is at level “D”. So is it more efficient to test the component at level “E” or at level “B”?

Question: Is it more efficient to test the component at level “E” or at level “B” to demonstrate it’s individual goal? [Read more…]

by Greg Hutchins Leave a Comment

What is Risk Based Thinking?

We get this question weekly and sometimes daily it seems.

Why? ISO has not defined Risk Based Thinking? And, this is a hugely important question because ISO has elevated RBT to the same level as PDCA and Process in the Final Draft International Standard (FDIS) of ISO 9001:2015.

One of the things we know is the marketplace hates a vacuum. Someone will develop a product or service to fill in the vacuum. This is exactly what we did with RBT. [Read more…]

by Mike Sondalini Leave a Comment

Spherical Roller Bearings

Understanding the Basics of Spherical Roller Bearings

Spherical roller bearings (SRB) are popular because they can take very heavy loads and are self aligning. Their design allows them to take combined loads in both the radial and axial direction acting together. Each roller is loosely retained in place within a cage that goes full circle between the raceways. Figure 1 shows a simplified drawing of a spherical roller bearing on a shaft under deflection. [Read more…]

by Anne Meixner Leave a Comment

Labor Saving DFT: Built-In Self-Test

In honor of Labor Day, I thought I would jump over to the Built-In Self-Test (BIST) wing of the DFT Castle.

I will provide you with a quick tour. Then when you hear the term in a meeting you can follow along and ask a few questions.

BIST saves labor for the Automatic Test Equipment (ATE).

Though there’s no free lunch. BIST does require an engineer to labor—someone has to design it specific to the device under test (DUT). [Read more…]

by Fred Schenkelberg Leave a Comment

Mandate and Commitment to Manage Risk

Risk Exists; Therefore, Manage Risk

Every organization, business, and individual faces a relentless barrage of risk. Some risks are minor, while others may overwhelm.

We all deal with risk, manage risk, in our own way. For more than just yourself the management of risk is taking on a new level of organization and importance.

Risk exists whether or not we choose to plan, prepare, and mitigate.

The decisions concerning product reliability, and associated risks, require senior management (including the board of directors) engagement and commitment. While there is a wide array of business and societal risks the management team must address, the reliability performance of products and systems presents potentially catastrophic risks to any organization. [Read more…]

by Kirk Gray 2 Comments

What do you mean that my phone is obsolete?

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…]

by Dennis Craggs Leave a Comment

DOE Supports World Class Quality

This is an example of a practical DOE that was used in the development of a manual window mechanism for a truck application. A similar process can be used for current mechanical and electrical design and development projects. In this article, you will see that the DOE method:

is superior to the design-test-fix cycle
builds knowledge of which factors are important to product performance
quantifies the effect of a combination of factors
allows performance prediction

[Read more…]

by Christopher Jackson Leave a Comment

Autonomous Vehicle Regulation – Could Less Actually Be 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…]

by Perry Parendo Leave a Comment

The Basis of Design of Experiments is Comparison

A t-test Example

The basis of DOE analysis is comparing two samples. This methodology can be used just as well for changing one variable or more than one variable as in DOEs. Comparison of means is as simple as the t-test.

Some people initially feel intimidated considering the connection of DOE with statistics. Once they understand it in simple terms, the topic comes together for them.

So let’s see if we can accomplish that for you now. [Read more…]

by Doug Plucknette Leave a Comment

Clean, Green and Reliable – the book

Clean, Green & Reliable – Improving Equipment Reliability and Reducing Energy in Manufacturing Facilities

I first became interested in manufacturing reliability nearly twenty years ago working as a maintenance mechanic who had a personal interest in improving the reliability of individual assets by searching through our maintenance history for areas where we were spending the most time and money in regard to emergency/demand work orders. Using the history we had in our database we used the 80/20 approach to identify the 20% of our assets where we spent nearly 80% of our maintenance budget. Once we identified a system or asset to work on we would use a cause-map or root cause analysis to identify the potential causes of our equipment failures, understanding these causes we would then look to identify potential redesigns to eliminate or reduce the frequency of equipment failures. [Read more…]

by Carl S. Carlson 1 Comment

Understanding FMEA Functions – Part 1

The Essence of the Item

What is the essence of properly defined FMEA Functions? More than half of FMEA practitioners miss a key element when defining FMEA functions. This first article in the FMEA Definitions and Concepts Series will discuss functions and their application in FMEAs.

“A perfection of means, and confusion of aims, seems to be our main problem.”
Albert Einstein

[Read more…]

by James Kovacevic Leave a Comment

The Coach: The Maintenance Supervisor

The Roles & Responsibilities of the Maintenance Supervisor

The Maintenance Supervisor is known as the coach of the maintenance department. But what if they are pre-occupied with other tasks and unable to coach the technicians? It has the potential to increase overtime, increase rework and increase Mean Time to Repair. That is why this series continues with the Maintenance Supervisor. With the Supervisor clear on their roles and responsibilities, the technicians get the coaching they need to succeed. [Read more…]

by Anne Meixner Leave a Comment

A Primer on Design For Test

In a previous article I alluded to Design for Test (DFT) by mentioning a specific example.

The techniques have been around for decades. Just how long ago though?

I searched on “Design for Test” in the IEEE paper data base; the search resulted in 760 references the oldest being 1983.

Hmm there had to be earlier papers? So next I plugged in the key words “Design For Testability.” This time a list of 4,235 references appeared, the oldest one published in 1978. [Read more…]

by Adam Bahret 2 Comments

What is Weibull?

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…]

by Greg Hutchins Leave a Comment

What is ERM?

What is Enterprise Risk Management (ERM)?

ERM is a relatively new concept. There is a robust discussion among experts what it really means. Common ERM elements in most definitions include: [Read more…]