When it’s Not Normal: How to Choose from a Library of Distributions

When trying to fit a probability distribution to quantitative results, sometimes the normal probability doesn’t fit. Minitab has a wealth of distributions to pick from. Do you just pick whichever one Minitab tells you fits the best? Maybe not. Just because the distribution fits your data doesn’t mean it’s a good one to use. We review my top 3 distributions for product testing and some other ones that come up but may not be appropriate to use.

We’ll also share what you need to think about when picking a distribution:

1. think about your purpose of test
2. consider your failure mode and how you’re expecting your product to perform – does the typical use case of a distribution fit?
3. when you have options, the simpler the distribution the  better (i.e. choose a 2-parameter over a 3-parameter)

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What are TQM, QFD, Six Sigma, and Lean?

You may have heard of QMS but are not sure how your activities fit in. Or, you’ve heard of QFD, ISO 9000, Six Sigma, Lean…these cryptic names that you’re not sure what they’re about. You may be doing activities under one of your company’s procedures and asking, “Why am I spending time on this?”  Sometimes it’s good to re-orient to the big picture. That’s what we’ll be doing in this episode: reorienting to the QMS.

We’ll also talk about some of the standard QMS (Quality Management System) philosophies:

• TQM (Total Quality Management)
• ISO 9000
• QFD (Quality Function Deployment)
• Six Sigma
• Lean
• Malcolm Baldrige National Quality Award

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The Designer’s Important Influence on Monitoring After Launch

Because of your role as a designer in product development, you have great input into the planning for what field (or real-use) data should be monitored for your product. We talk about this as post market surveillance, which is a typical term used for medical devices. This episode talks about how the post market surveillance engine follows the PDSA (plan-do-study-act) continuous improvement cycle, some expectations of post market surveillance systems, and what inputs designers have in its planning.

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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 to explore these other topics:

• competing failure modes
• suspensions
• independent vs. dependent
• reliability block diagrams

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About Using Slide Decks for Technical Design Reviews

A danger of using slide decks for technical design reviews is loss of important technical information. In order to summarize something in a slide or slide deck, the presenter thins-out information without its raw data and divorces it from the plots, graphs, and other technical analyses.

Slide decks are useful to the presenter to pull together a meeting. Slide decks are terrible for the reviewers who need to review technical information and make decisions from it.

In this episode, I review some alternatives:

• eliminating slide decks all together; use the technical report with executive summary and a 10 minute study hall at the top of the meeting
• very sparse slide deck content, instead referencing the completed technical report
• a report formatted with all the details like Nancy Duarte’s Slidedocs®, a hybrid between a technical document and a slide

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Remaking Risk-Based Decisions: Allowing Ourselves to Change our Minds.

Recent news highlights an accident involving a product with tragic results. This podcast explores this as cautionary tale and example outside of our own design house. The goal is to shift our perspectives to let us gain a better understanding of risk-based decisions.

We also talk about allowing ourselves room to change our minds about risk acceptability when we learn new information, both during the design process and from the field.

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Need to innovate? Stop brainstorming and try a systematic approach.

When we’re trying to innovate, we can get trapped into the old thinking that the solution has to be out there somewhere. We need to think outside the box to find the solution to a problem.

We should stop brainstorming and, instead, think inside the box with Systematic Inventive Thinking. We use systematic approaches to do lots of things, and being innovative can be one of them, too.

This podcast blog talks about the shortcomings of group brainstorming sessions and a different approach to innovation.

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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.

Listen-in to the podcast or read the transcript to find out 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.

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The Designer’s Risk Analysis affects Business, Projects, and Suppliers

It takes a village to produce a design from concept to realization. Everyone along the way seems to think of risk a little bit differently. Designers are both directly and indirectly involved with all these risk management methods, but it’s important to understand who is looking at what type of information. Why? Because of communication. One group might think that risk management is covered in the way they’re thinking it should be, when in actuality it’s not.

This podcast will review risk management of other functional groups and how a designer’s risk affects them.

• Business/Marketing risk management
• Project Manager risk management
• Supplier Management

As a designer you have an important job and a unique perspective to analyze risk of your design and a responsibility to communicate it so everyone can help reduce risks.

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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 how it can help us get a handle on that big failure:

• all of our causes are mapped out in a visual diagram
• we can identify cut sets
• we can see where to prioritize resources where its best to eliminate or reduce causes

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Why Your Design Inputs Need to Include Quality & Reliability

You’re nearing the end of your project, getting cross-functional approval on your design, when your QE or RE friend comes running with a big, red STOP button! Let’s avoid that!

Quality and Reliability are INPUTS into the design process, much earlier than by the time we have a prototype in-hand (even at the black-box, input-output phase). Getting the QEs and REs involved early will help your design be a success with suppliers, manufacturers, and your cross-functional team.

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My product works. Why don’t they want it?

Have you ever designed a product that works but that customers just don’t want to use?

We’ve put a product to market only to find that the users just don’t want to use it. They’re buying it, so there’s perceived value in it. It’s functional, it does what we say it will do, it really works! But they’re not repeat buyers and not making good recommendations to others (it’s sort of making the company look bad).

What went wrong? In some cases, there’s warning signs to watch for during your design development. And, if looking to the design process for an answer, there’s some tools and strategies to help prevent that from happening before product launch, or to help as a starting point when you plan for your version 2.0.

This podcast will review the strategies and pitfalls and how to avoid them. [Read more…]

QDD 001 How to Choose the Right Improvement Model

You have a design you want to make better. Or you’re working within a designing framework that you think needs to be updated. Quality folks use and promote some standard problem solving and continuous improvement methods, and you’ll want to get started with the right one, or reference the right acronym when getting buy-in for your project.

You may have heard of PDCA, PDSA, and DMAIC. You vaguely know these represent improvement processes, but don’t really know what their differences are. When should you use which one, and for what? [Read more…]