Articles

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

Descriptive Models of the Design Process

I’ve often said, “reliability occurs at the point of decision.”

At the point of design during the design process. At each and every decision.

The design team of engineers establishes the bulk of the reliability capability early in the design process. The team’s decisions about materials or shape, concerning inventions or outsourcing, about how and where to build the product, and many more decisions impact the final product’s reliability performance.

Reliability is designed into the product right from the start. [Read more…]

by Mike Sondalini 2 Comments

Changing the Service Duty of a Pump

What readers will learn in this article.

Centrifugal pumps can be moved to a new service.
The impeller size, impeller speed, and motor power need to match the new service.
That Similarity Law formula is used in calculating the new impeller size, speed, and motor power.
Introduction to centrifugal pump curves and their use.

When there is a need to determine a new service duty for a centrifugal pump, and no performance curves are available, the recommended method is to use the Similarity Laws. These laws are derived by the use of [Read more…]

by Fred Schenkelberg Leave a Comment

Show me the Data

Early in my career, I worked for an unreasonable person.

He wanted us, his engineering staff, to show him the data. He wanted us to gather, monitor, analyze and display data regularly. Anytime we needed approval, funding, or resources he wanted to see the data. [Read more…]

by Kirk Gray 4 Comments

You May Often be Exceeding Operating Specifications!

HALT (Highly Accelerated Life Test) requires exceeding specifications

One aspect of HALT, (a test to find weaknesses and reliability risks empirically), is the difficulty for many engineers that are new to the HALT- that it guarantees that the maximum or recommended operating environmental specifications for the system and components under test will be exceeded, and failures beyond spec are potentially relevant to field reliability. [Read more…]

by Fred Schenkelberg Leave a Comment

Understanding the Design Process

Let’s start by understanding the difference between engineers and engineering designers.

The work we do as reliability engineers may require a different approach when working with these different types of engineers. [Read more…]

by Fred Schenkelberg 4 Comments

The System Effectiveness Concept

Reliability is not the only concern when building a system.

Let’s consider a passenger car. Reliability refers to how often the car in the shop. How often we need to perform preventative or corrective maintenance. How often it fails. [Read more…]

by Kirk Gray Leave a Comment

Required Case History for Reliability Engineers

One for the (Reliability) Books

The GM Ignition switch failure case history should be required reading for all reliability engineers.

It is rare to have insight into any internal company history of serious electronic and electromechanical failures. Failure analysis and the causes of electronics or electromechanical systems failure can be a difficult investigation for any manufacturing company. Disclosure of the history and data is rarely if ever published due to the potential liability and litigation costs as well as loss of reputation for reliability and safety.

[Read more…]

by Fred Schenkelberg Leave a Comment

Design for Assembly

The ability to assemble a system to meet the functional requirements is constrained by the design, the materials, and the tolerances.

Some designs are impossible to assembly. While other designs take little effort to build. The discipline of design for assembly, DFA, applied during the design process can enhance the manufacturing process. [Read more…]

by Fred Schenkelberg 2 Comments

The Environmental Test Manual

Let’s say you run across a lightweight, inexpensive, easy to manufacture metal that you are considering for a new bike frame. Beyond the functional considerations of strength, size, and finish options what else do you consider?

Is it durable? If it fails how does it fail (a shattering a bicycle frame would not be good, for example). You may also consider how the bicycle will be used and stored. What stress will the frame experience over its lifetime? [Read more…]

by Greg Hutchins Leave a Comment

How Six Sigma Can Help You?

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

Six Sigma is a powerful tool used to solve a problem or improve a process. The company (one of the 4 big defense companies) I worked for over 20 years lived, breathed and ate it every day. I became a six sigma specialist. For those readers not familiar with six sigma, I offer the following example to hopefully provide some insight into how it works and the benefits it offers. [Read more…]

by Fred Schenkelberg 2 Comments

General Human Factors Design Principles

People build, transport, use, maintain and dispose of equipment or products.

Thus the creation of these items should include consideration of the humans involved. In order to fully benefit from the functional capability of an item or system, we, as humans, have to interact with an item’s interface, displays, sounds, etc.

Whether a smartphone or bottling machine, the ability to provide commands or direction, the ability to recognize and understand responses, and the ability to correctly identify faults or outputs all combine to permit humans to place calls or fill juice bottles.

It is in the design stage that the elements of a piece of equipment (hardware or software) thwart or enable efficient human interaction. [Read more…]

by Fred Schenkelberg 1 Comment

Electronics Failure Analysis Done the Right Way

“Failures are gold”

Early in my career the engineering manager relished discovering equipment failure.

It didn’t matter if it was human, electronic, mechanical or software in nature, the glint in his eye soon gave way to a flood of possibilities. He enjoyed the process of investigating the fundamental reasons a failure occurred. [Read more…]

by Kirk Gray Leave a Comment

Eliminating early life failures

MTBF for electronics life entitlement measurements is a meaningless term. It says nothing about the distribution of failures or the cause of failures and is only valid for a constant failure rate, which almost never occurs in the real world. It is a term that should be eliminated along with reliability predictions of electronics systems with no moving parts. [Read more…]

by Fred Schenkelberg Leave a Comment

Comparing Human and Machine Capability

In 1968 NASA explored where machines and humans would best achieve tasks primarily during space missions. Many of the findings are true today, and in some areas, the differences are blurring.

Machines created by humans continue to improve and take on complex tasks, that once only humans could do. For example, parking a car, now a feature of newer car models. Autonomous driving is happening and continuing to improve. The ability to reason, to foresee and evaluate risks, once thought to be strictly in the domain of human capability is now being done by machines. [Read more…]

by James Kovacevic 2 Comments

What Can You Do to Improve Reliability?

Part 5 of 5

A Question & Answer Period with Fred Schenkelberg on the what can be done to improve the reliability of your operation.

So far in this series, we have had the opportunity to discuss the role of reliability engineering in today’s maintenance environments. In this final post of the series, I (James) had the opportunity to ask Fred Schenkelberg some questions related to this very topic. Fred, with his years of experience, was able to provide some great insights to the role of reliability engineering, and what those in the maintenance department can do to improve reliability. [Read more…]