Quality During Design Podcast Blog

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Statistical vs. Practical Significance

When we’re looking at results (like measures of a characteristic), we need to take care not to get too hung-up on what the statistics is trying to tell us. Yes, statistical tools are a good way for us to make decisions and the results can act as proof for us. But, there’s a practical, engineering side to results, too. We need to evaluate the statistical significance along with…

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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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Life Cycle Costing for Product Design Choices

It costs our customers to own our designed products. It costs them initially to purchase it, but it also costs them to use it, maintain it, repair it, and eventually dispose of it. And it costs our company in ways too, like processing, training requirements for customers, and warranty repair costs.  Life cycle costing can…

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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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Using Failure Rate Functions to Drive Early Design Decisions

We have good requirements for the reliability of our design. We also have a preliminary design with ideas of how we’re going to manufacture it. Is our design idea good enough? Are there things we should do to improve its performance and reliability? For a physical product, there are three general stages in its life…

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Types of Design Analyses possible with User Process Flowcharts

Flowcharting isn’t just useful for manufacturing processes. We can use them in lots of ways to help us with design of products and to identify quality characteristics. After all, products are used by people, and the way in which they use them is a process. compare ideal vs. actual flowcharts identify where there is disagreement…

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Design Tolerances Based on Economics (Using the Taguchi Loss Function)

Defining tolerances for our quality characteristics is sometimes not an easy task. If we set tight tolerances, it could be costly to make with a lot of rejects and rework in the future. If we’re too sloppy with our tolerances, then it can affect the functionality of our product, leading to unhappy customers, and also possible…

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How many controls do we need to reduce risk?

When we’ve identified a risk to our design or user process – and that risk can pose a potential harm – how many controls do we need to add? We discuss prevention vs. detection controls, ALARP, as low as possible, and some scenarios where we could (and maybe couldn’t) justify a risk as acceptable without…

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Solving symptoms instead of causes?

How we describe and approach the issues we need to solve can affect how we react to them.  We know we’re supposed to be solving for root causes. But are we, instead, really just addressing symptoms? Are we celebrating the quick fix and then moving on without addressing the root of our issue? “If you…

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Do you have SMART ACORN objectives?

Objectives are goalposts of what it is we’re trying to accomplish. Though they’re only a part of planning a project, if we don’t have well-defined and clear objectives, it could lead to us not having the stellar project results we want. Our objective should be a SMART ACORN.  We review these two, complementing acronyms as…

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