How Many Do We Need To Test?

In this episode we review sampling for design tests. We talk through a generic thought process for choosing a statistically relevant sample size and propose some basics that we can all learn about to better understand sampling. Our goal is for us to be able to better talk through a sampling scenario with our quality…

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5 Aspects of Good Reliability Goals and Requirements

Good reliability requirements are going to drive our design decisions relating to the concept, the components, the materials, and other stuff. So, the moment to start defining reliability requirements is early in the design process. But, what makes a well-defined reliability requirement? There are five aspects it should cover: do you know what they are?  We’ll describe…

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How to Handle Competing Failure Modes

If we’re not careful with or ignore failure modes, we can choose the wrong reliability model or statistical distribution. If our product performance is close to the required limits and/or we need a very accurate model, this could be a big problem. We talk about the importance of failure modes and step-through a tensile-test example…

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HALT! Watch out for that weakest link.

HALT (Highly Accelerated Life Test) uses the weakest link mentality. We apply stresses beyond what our designs would normally see in the environment to make something fail. It’s meant to be an iterative test program where you are testing, analyzing the results, determining the root cause, fixing the design, and then testing it, again.

This blog reveals more about its roots, why you should perform HALT (or not), when in the design process it’s best (hint: really early), and who likely needs to be involved. Also understand how HALT is different from ALT.

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A big failure and too many causes? Try this analysis.

We have identified a failure of our design. It’s a complicated failure that has multiple potential root causes, and some that are conditional. Is there a tool that can capture it all and help us prioritize our reactions to get rid of this problem? Yes, there is: Fault Tree Analysis! Learn what it is and…

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