Musings on reliability and maintenance topics

Short essays and thoughts (musings) on reliability and maintenance engineering topics. Let me know your reaction and thought, plus any questions.
ISSN 2329-0080

Purpose of a Reliability Program

March 22, 2015
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Purpose of a Reliability Program The reliable performance of a system is important. It is important to the customer, to our business and to us. Very few argue that we should ignore the reliability characteristics of a product. We also deem cost, time to market or feature set as important also. The trouble is we […]

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Duration and Reliability Goals

March 15, 2015
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Duration Coupled with probability is the duration over which the probability applies. For example, if we desire 99 of 100 to survive, we must state over which period of time this applies. It is proper to state the couple of 99% reliable over 1 year. It is not sufficient to define reliability as ‘5 year […]

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Probability and Reliability Goals

March 8, 2015
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Probability Roll the dice. It is about that simple if any one product will survive to a specific time. Every product has a chance not a guarantee. The time to failure for each product is a function of the use, stresses, assembly, latent defects or imperfections, and many other variables. The result is generally unknown.

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Environment Element of Reliability Goal

March 1, 2015
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Environment This element of a reliability requirement answers the questions of where and under what conditions the product should operate. It includes storage, transportation, and installation conditions too. One way to think of the environment is to consider the weather around the device. Temperature, humidity, preoccupation, etc.

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Use Profile and the Reliability Definition

February 23, 2015
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Use Profile How a customer uses a product matters. It matters in the amount and type of stress your product receives. It determines the life span. Someone that uses the product often isn’t necessarily going to have a short life span, it might be the lack of use that most damages a product.

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Function: A Reliability View

February 16, 2015
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Defining the product’s function well, allows us to define failures well, too.

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Understanding Customer Reliability Expectations

February 8, 2015
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Customer Expectations Once asked a customer what they wanted concerning product reliability. She fully understood that some units will fail, that it’s matter of chance. She seemed understanding of the difficulty creating every product such that none would fail. Then said confided that all that is fine, as long as the product she buys does […]

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How to Select Tasks for a Reliability Plan

February 5, 2015
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How to select tasks for a reliability plan There are a lot of reliability tools. From FMEA to FTA, from ALT to HALT, from derating to sneak circuit analysis. We also have a lot of acronyms. We cannot afford to do all the tasks, so which do we select and why? Each activity has some […]

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The Gold in Prototype Failures

January 28, 2015
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Meaning of a failure Every failure provides information. It provides time to failure, stress strength relationship, process stability and design margin types of information. In every case. Even failures directly related to human error. A hardware intermittent failure observed by a firmware engineer should not be dismissed. Rather recorded, explored and examined. A single intermittent […]

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3 Supply Chain Caused Failures

January 18, 2015
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3 Stories of Electronics Supply Chain Reliability Impact Some days are better than others. We sometimes run into failure when working to create a new product. With a little investigation we suspect the components are not working as expected. We’ll call the vendor and ask for an explanation. If this is normal production and variability […]

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