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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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Improve Decision Making with Statistics

Improve Decision Making with Statistics

We make decisions all the time. Often our decision making is with little more than a gut feeling.

When faced with a major decision we often look data to help us decide. Is the product reliable enough as designed? Which field returns indicate we should stop production?

Some decision may help us earn or lose thousands if not millions of dollars.

Deciding to delay a product launch by six months means we have no revenue for the duration. The delay may also permit us to address a design flaw that would cause half the products to fail within a few months.

The later may cause loss of market share, erosion of brand loyalty, not to mention the cost of warranty claims. [Read more…]

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Take Action to Deal with Part Obsolescence

Take Action to Deal with Part Obsolescence

Even products with relatively quick design cycles and short stays in the market deal with part obsolescence.

Long design periods along with long durations in service or in production simply increases the chance that one or more parts will become obsolete.

Designing systems with part obsolescence in mind helps. Working with suppliers to select parts with many sources, with long-term plans to produce, and with long term commitments, all may help. Even then, companies change priorities, go out of business, or simply discontinue the part you need. [Read more…]

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Understanding Reliability Across an Industry

Understanding Reliability Across an Industry

The Department of Energy (DOE) Office of Energy conducted an Energy Storage Reliability Workshop this week provide a unique glimpse at how the stakeholders across an industry view reliability.

The representatives from government and private sector, including national labs, large and small companies, insurers and consultants gather to talk about the reliability of large-scale stationary energy storage systems.

Specifically, the focus of the workshop was on helping the DOE identify the specific activities and focus for their involvement in this relatively new industry segment.
[Read more…]

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The “What” & “Why” of Weibull Analysis

The “What” & “Why” of Weibull Analysis

How to conduct a Weibull analysis and the questions the analysis will generate.

Part 2 of 7

Every failure is part of a puzzle. The equipment we are maintaining is trying to communicate with the use of each and every failure.

Often the message is not obvious.

There is the immediate failure. And, if we’re paying attention we can sort out the root cause of the failure along with replacing or repairing the damaged parts. Sometimes though the damage is caused by another issue with the system. [Read more…]

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Identifying Parts Obsolescence Early

Identifying Parts Obsolescence Early

One aspect of creating a new product or system is the sourcing of parts, components, and materials.

Gone are the days of your organization providing every element of the final product. Henry Ford’s supply chain for early Ford automobiles includes their own forests, rubber plantations, and iron ore mines. [Gelderman, 1981]

We increasingly rely on the supply chain to create the necessary parts for the design’s functionality. Then to continue to supply those same parts for decades, in some cases. [Read more…]

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How Do You Select Reliability Tasks to Accomplish?

How Do You Select Reliability Tasks to Accomplish?

As reliability engineers, we have a large number of tools available.

From project planning, system modeling, data analysis, test planning, to risk identification and defect discovery, we have techniques, procedures, algorithms to help us identify and solve reliability problems.

We also may ways to apply an individual reliability task.

We could do an exploratory drop test to see what happens if anything. Or, we could conduct a full characterization study of the force signature of drops onto different surfaces and faces from a range of heights. Or something in-between.

We have options and thus need to make choices. [Read more…]

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Basic Description of a Fault Tree Analysis

Basic Description of a Fault Tree Analysis

A fault tree analysis (FTA) is a logical, graphical diagram that starts with an unwanted, undesirable, or anomalous state of a system.

The diagram then lays out the many possible faults and combination of faults within the subsystems, components, assemblies, software, and parts comprising the system which may lead to the top level unwanted fault condition. [Read more…]

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Material Selection and Reliability

Material Selection and Reliability

Physical products are made up of materials.

The materials including metals, polymers, adhesives, and many others experience loads and stresses during assembly, transport, storage, and use.

Selecting the right materials such that they both meet the needs of the customer and are sufficiently reliable relies on understanding how the material will respond to the applied stresses over time.

As with parts selection, one way to determine if a material is suitable for your application and end use is to monitor the material’s performance over time in your products. The trouble is it also transfers the risk of failure (the unknown risk of failure) to the customer.

In many cases this is unacceptable. [Read more…]

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Field Data Analysis First Look

Field Data Analysis First Look

Field data analysis starts with the collection of data.

In a previous article, we used a Nevada chart to gather the counts per month of field failure data. The chart also provides the necessary data to account for how many units have not failed as of yet.

The Nevada chart on its own is just a table of numbers and does not reveal patterns of the changing nature of failure rates over time. Are we experiencing early life failures or wear-out related failures?

We need to conduct some data analysis to learn what message the data contains. [Read more…]

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Reliability Management & Risk

Reliability Management & Risk

What is reliability management? Reliability Engineering? Would a product design or an organization benefit with a focus on reliability management and engineering? What is the value of a focus on reliability?

Any organization, that develops and produces products, has resource limits. It may be talent, capabilities, time, funding, or some combination of these.

Yet, the goal to create a product that meets customer expectations includes the concept of product reliability. The product should provide the expected functions over time, without failure. This expected product reliability occurs, even if the design requirements and advertising do not explicitly mention product reliability. [Read more…]