All articles listed in reverse chronological order.

Selecting the wrong ALT model

Many product programs ( actually all) are on a tight schedule. When Accelerated Life Testing (ALT) get’s it’s place in the process it is another mouth to feed. ALT is not a short process. Each round of testing typically takes weeks, and the results may drive design changes that prescribe additional testing. It is common to want to get the ALT process going as quickly as possible. In this haste the primary wear-out failure modes and it’s driving stresses are confidently stated, a model is created, and the test is started.

[Read more…]

by Greg Hutchins Leave a Comment

Unaddressed Risk

Guest Post by Paul Kostek (first posted on CERM ® RISK INSIGHTS – reposted here with permission)

What’s the risk of not addressing a risk? What happens on a project when a risk is identified and not addressed/mitigated? There may be reasons not to correct it, e.g low probability of occurrence and minimal impact, but how do we document and track this decision? And if we’re delaying an implementation how do we insure the risk is addressed at a later date, e.g. next version release? How do we insure that if an audit takes place the project team can clearly explain the reasons for the decision? Is this even acceptable? [Read more…]

by Mike Sondalini Leave a Comment

Shaft Coupling Selection Issues

What readers will learn in this article.

The purpose of shaft couplings and how they work.
What to consider when selecting shaft couplings.
Maintenance issues with using couplings.

Couplings are used between shafts to connect them so power can be transmitted and to allow for axial expansion. Shafts can either be aligned or intentionally inclined at an angle to each other. When at an angle a universal joint is used to connect the shafts. When aligned a shaft coupling is fitted. [Read more…]

by Fred Schenkelberg 1 Comment

Waterfall Test Planning

A Waterfall Test Planning Approach to Product Reliability Environmental Testing

I may have the name, waterfall, used incorrectly here.

Years ago I learned from a former Apple reliability group manager how to organize reliability and environmental related testing where samples cascade through a sequence of stress conditions and evaluations. He called it waterfall testing. [Read more…]

by Anne Meixner Leave a Comment

Manufacturing Test Approaches and Product Expectations

Depending upon the type of engineer you ask the word test evokes a different notion of goals and expectations.

Engineers who work on the design of semiconductors test that their designs meet the specifications.

This can be done pre-silicon and naturally verified in-depth on silicon.

Engineers concerned with manufacturing of a product test to find defects and to verify performance.

Similar approaches can be taken by both engineers though there exist differences in the amount of time. To be cost effective, a manufacturing test must be completed in as short a time as possible. Let’s continue to compare and contrast design validation with manufacturing test. [Read more…]

by Fred Schenkelberg Leave a Comment

The Ability to Influence

The Ability to Influence Reliability Performance and Results

The role of a reliability engineer is to support the other engineers and managers as they make decisions concerning reliability.

Our ability may be well honed and effective. Or it may be fumbling or annoying. It is our ability to communicate along with our technical ability that determine our ability to influence well.

We may do analysis or testing. We follow up on failures and evaluate suppliers. What we actually are doing is influencing decisions. [Read more…]

by Doug Plucknette Leave a Comment

The Dangers of RCM Shortcuts!

When people first begin to learn about Reliability Centered Maintenance and methodologies like RCM Blitz, they get excited about the potential results that can come from performing a RCM analysis and implementing the resulting tasks. Shortly after completing their RCM Training some begin to understand that good RCM takes leadership, structure and discipline, others begin to think of ways to shortcut the process. [Read more…]

by Adam Bahret Leave a Comment

Why can’t we shake off MTBF?

Mean Time Between Failure (MTBF) is one of the most well know reliability metrics.

But to anyone who works with reliability, it seems like it was developed by some evil anti-reliability mastermind to undermine the possibility of connecting reliability to anything or anyone.

Mean Time Between Failure means what?

It’s the time between two failures? –
It’s when the first failure occurs? –
It’s how long the product is good for?
It seems way to big to be a reasonable goal! “How can an air pump have an MTBF of 4 million hours? That’s ridiculous these things are only supposed to last for five years!

This is the process of understanding everyone goes through as they are introduced to MTBF, formally or informally. [Read more…]

by nomtbf Leave a Comment

How to Judge a Reliability Book

How Do You Judge a Reliability Book?

By it’s cover no doubt. The title and cover are important, this is true. When you judge a reliability book we often first see and evaluate the cover.

The author? Do you buy the book based on who wrote or edited it?

Do you have a quick scan or check for key features before you add the book to your library? I’m curious how you select a book to use a reference for your work. The books we read and use for work shape our work, thus it’s important to have the right works at our disposal. [Read more…]

by James Kovacevic Leave a Comment

Fast Track RCM: Improving Plant Performance & Profitability

A Proven Framework to Improve Performance and Build Ownership of the Equipment

Understanding the how equipment failures along with utilizing a proven and effective approach to developing an equipment strategy is a winning combination for manufacturers everywhere. When combing the knowledge and the system, manufacturers can yield significant improvements in their operation, such as a reduction in PM workload of 22% with gain 4% in line efficiencies. Or how about a reduction of 42% of PMs, without a single loss in equipment availability. It is possible and required for manufacturers to become and remain profitable. [Read more…]

by Mike Sondalini Leave a Comment

Shaft Alignment on Pumps

Shaft alignment on pumps. Shaft misalignment is one of the most common reasons for bearing and mechanical seal failures. Rotating misaligned shafts produce vibration and complex fluctuating radial and axial loads that lead to breakdowns. Shaft alignment is a precision maintenance requirement that requires exacting care and detail and if not performed will cause much production down time.

Keywords: axial alignment, laser alignment, dial indicator, soft foot, shaft coupling. [Read more…]

by Greg Hutchins 2 Comments

What are the Risks of Self Driving Vehicles?

Guest Post by Paul Kostek (first posted on CERM ® RISK INSIGHTS – reposted here with permission)

You’ve no doubt read about Google’s driverless car and the effort at the state level to gain permission for its use on public roads.

Driverless Car Risks

There are the obvious concerns and risks with operating a driverless car, though Google does have someone sitting behind the wheel, just in case. Of course, can a person just along for the ride respond fast enough to a problem? This becomes one of the risk areas needing to be addressed before full adoption of driverless vehicles. Integrated with Intelligent Transportation Systems (ITS) we’ll see vehicles and roads sharing data with each other to produce safer travel and relief of congestion. [Read more…]

by Les Warrington Leave a Comment

How to Keep Sight of the Big Picture and Avoid being a Slave to Reliability

We have “reliability” in our job title? Therefore, we must promote reliability across all our company products as our first priority?

If you believe that, then I believe you are a slave to reliability.

A project manager or design engineer comes to us and makes a proposal that would adversely impact product reliability. We’d reject it, yes?

Well, I believe, on both counts, we should first take a step back and review the alternatives. [Read more…]

by Fred Schenkelberg 1 Comment

ALT Allocation of Test Units

One question that you should consider when planning multiple stress accelerated life test (ALT) is the allocation of test units to the various stresses.

We want to create a model detailing the relationship between stress and time to failure. We also want to project the time to failure estimates to use conditions. Ideally, we test at nominal conditions only and gather time to failure information. We do not have the luxury of time thus explore using ALT.

One method of allocation is to place an equal number of samples with each stress level. Is that the best approach? [Read more…]

by Anne Meixner 2 Comments

Introduction to Testing 1 2 3

Let’s Start At The Very Beginning

Before embarking on a complicated task one needs to have the basics understood.

In the musical “The Sound of Music,” Maria teaches the Von Trapp children to sing by first teaching them the musical scale.

She quickly discovers that the basics really do need to be learned one note at a time.

By the end of the “Do Re Mi” song she has them singing harmony while she sings a new melody with the words “When you know the notes to sing, you can sing most anything.” [Read more…]