Fred Schenkelberg — Thought Leader

Author of CRE Preparation Notes, Musings", NoMTBF, multiple books & ebooks>, co-host on Speaking of Reliability>/a>, and speaker in the Accendo Reliability Webinar Series.

This author's archive lists contributions of articles and episodes.

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Using rain-flow counting methods for process wear out studies

Guest Post Prepared by Eugene Danneman, Wind Wear LLC

Introduction

Analyzing and visualizing data that is related to equipment wear-out (fatigue stage) over a specific time span is a challenge. Analyzing systems, equipment and components exposed to spectrum loading as opposed to uniform cyclical loading that span years or decades or centuries requires a special approach. Think of roads, bridges and other assets with long life spans that are susceptible to wear out mechanisms caused by external and internal loads, varying load durations, temperature swings and corrosion. [Read more…]

by Fred Schenkelberg 2 Comments

Taguchi’s 3 Fundamental Concepts

Taguchi may be best known for the variation of design of experiments that bear his name. Yet the impact of his work is felt across the product life cycle and all of the quality field.

Building on Deming’s observations that 85% of poor quality is due to faulty processes and only 15% due to the worker, Taguchi focused on creating robust processes.

A robust system is one that tolerates the daily and seasonal variations of the environment, machine wear, and equipment part-to-part variation, etc. A robust system operating in the range of real world conditions. [Read more…]

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You Are a Reliability Leader, Now Make a Difference

Your Reliability Engineering Leadership Role

Leadership is not a position or title within an organization. It is an attitude.

You’ve seen the internet meme’s about the difference between leadership and management. There is a difference and while not everyone is going to be in top management, everyone can (and should) be a leader.

As a reliability professional, you are conveniently looked to for leadership. You are expected to use your knowledge and skill to solve problems. To help teams solve problems. To improve the reliability performance of your system and across your industry. [Read more…]

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The Perfect Strength and Stress Concepts

Recently Peter Stuttard asked if I knew of a reference for the perfect strength and perfect stress concepts. I didn’t and asked for a bit of explanation of the phrases.

Here is his reply (via Linkedin, btw a great tool to get and stay in touch) posted with permission with minor formatting edits.

To learn more about Peter check out his Linkedin profile.

Fred

Thanks for responding so quickly, the concepts of Perfect Strength and Perfect Stress are related to your discussion re Parts Count and Parts Stress predictions and reading this on your web site prompted me to ask you about them. [Read more…]

by Fred Schenkelberg 3 Comments

Introduction to the Quality Triangle

Priorities and Balance

Have you ever worked on a project with no deadlines, unlimited resources, and boundless scope? Probably not.

Quality Triangle-1 — The Quality Triangle

You may have worked under the guidelines of a quality triangle, also known as a project management triangle, iron triangle, or project triangle.

Why is that? Why the limits to our ability to create a product or improve a system?

First, the world we work and live within has limits. We have only so much time for work, only the available resources, and limited knowledge. We do our best with what we have to work with at the time.

Second, as I once was told while working on an accelerated test design, ‘if there isn’t a deadline, you’ll happily tinker with the plan and get the testing done.’ My boss was right of course.

The set of constraints shape our projects and products. By understanding the set of constraints, specifically how they frame decisions, then we can complete complex projects. [Read more…]

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The Need to Improve the Reliability Narrative

Little Compromises and Future Costs

In a recent Seth Godin blog, Counting beans he talks about the eventual costs of little compromises. The immediate benefit may be celebration worthy, yet

But overlooked are the unknown costs over time, the erosion in brand, the loss in quality, the subtraction from something that took years to add up.

This certainly applies to reliability as well. Deferring maintenance just one more month, addressing one more software bug can be done after shipping, and similar small shifts erode reliability of your system. [Read more…]

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Using Reliability Goals to Set Requirements

Customers of your product would like the particular one they have to work. To work over time.

If a product meets the customer’s expectation by working as long or longer than they expected it to do so, then they may consider your product reliable.

We use reliability goals to discuss the customer’s reliability expectations. It is the establishment of requirements that converts the customer expectations to development and production obligations. [Read more…]

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Interviewing for Reliability Position with Senior Managers

Preparing for an Interview with Senior Managers for a Reliability Engineering Position

Organizations around the world are recognizing the value of reliability engineering. Or, they are realizing that creating a durable product that delights the customer is good for business.

Another contributor to the interest in reliable products is the news of recalls. One recall not only distrupts the normal course of business, it may alter the future of the company. It may cause the collapse of the organization. Some do better than others, yet a major, in the news, recall is something to avoid. Creating a reliable product helps.

So you made it past the initial round of interview and have been called back to talk to the senior folks. As with any job interview, being prepared helps you present your best self. Understanding the business drivers motivating an interest in reliablity is essential for your preperation. This is not how to prepare an accelerated test plan type question, rather it is about how the results of an ALT will provide relevant value to the organization. [Read more…]

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Uncertainty and Risk Management

We are rather good at being surprised when setting expectations for the future. This is the essence of risk. The difference between what we expect to occur or would like to occur, and what does occur.

The definition of risk in ISO 9000:2015 and ISO 31000 include the phrase “ effect of uncertainty”. Let’s remove some of the uncertainty around the term uncertainty in the context of risk and risk management. [Read more…]

by Fred Schenkelberg 2 Comments

The Connection of Reliability and Customer Expectations

Customers Experience Product Reliability in Real Time

In a customer’s mind, the product works or it doesn’t. If it doesn’t work as expected it has failed. This may or may not be a reliability problem.

A customer or someone using your product brings a set of expectations to the experience. The range of expectations may range from very little to very high functioning, value production, and durability.

Failures are defined by customers.

In part, this is the functional capability, the operating within specifications, and the durability. The customer’s definition of reliability may or may not follow the design specifications.

It is the comparison of what should happen to what does happen. [Read more…]

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Use and Environmental Profiles

Use and Environmental profiles

Did you know that hot air doesn’t rise when there is no or very little gravity?

The electronics used to steer an oil exploration drill head 5 miles deep in the earth experiences 200°C sulfuric acid immersion along with continuous 50,000G shocks.

I used to think the environment under the hood a car was difficult. [Read more…]

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Performing the Right Corrective Action

When something doesn’t work as expected, it is a failure. A common response to a failure by an organization is to restore the system or remedy the situation.

Each failure is unique to the product, industry, customer situation, expectations, etc. Selecting the appropriate response or corrective action when confronted with a failure may or may not be obvious.

Selecting the right corrective action depends on the business and legal factors, along with customer expectations.

For a given failure, thinking through the range of possible responses and selecting the right one takes care to meet the various stakeholder’s requirements or expectations. [Read more…]

by Fred Schenkelberg 2 Comments

The Environmental and Use Manual

Environmental and Use Manual

How well can you describe the use conditions your product will experience?

How well do you need to know the use conditions?

For some situations, the environment for your product is assessable, others are not. For some situations, we guess the range of expected stresses, others we measure.

The design process and the myriad decisions that impact product reliability rely on characterized environmental stresses.

A great place to consolidate how and where customers will use your product (including the relevant stress factors) is in an environmental manual. [Read more…]

by Fred Schenkelberg 4 Comments

Building and Using a System Reliability Model

From the simplest to the most complex system, building and using a reliability model permits the entire team to make better decisions.

Understanding and monitoring system reliability involves knowing both:

the reliability of elements within the system,
as well as how the elements relate to each other reliability-wise.

We use system reliability models to identify weak links, and focus resources, to meet our desired reliability goals.

Being able to build the right model to meet your team’s needs best is one of your roles as a reliability professional. [Read more…]

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The Many Ways We Use Variance

The term variance is a statistical concept related to the spread or dispersion of a set of data. Second to the mean, it a common value we may calculate.

We find standard deviation easier to understand and use (it uses the same units as the data) whereas variance uses the units squared.

We use variance in quite a few different ways. Let’s review just a few. [Read more…]