Patrick Runkel’s picture

By: Patrick Runkel

The word “kurtosis” sounds like a painful, festering disease of the gums. But the term actually describes the shape of a data distribution.

Frequently, you’ll see kurtosis defined as how sharply “peaked” the data are. The three main types of kurtosis are shown below.

Lepto means “thin” or “slender” in Greek. In leptokurtosis, the kurtosis value is high.

Gary Phillips’s picture

By: Gary Phillips

For decades now, the measurement systems analysis (MSA) approach has been the predominant method for evaluating measurement systems capability. Although this method is widely considered to be an acceptable and comprehensive approach throughout most of the world, a growing number of specialized industries, both overseas and in the United States, have begun to adopt a different system based on the measurement uncertainty approach.

Abdallah Samaha’s picture

By: Abdallah Samaha

Lin Engineering is a California-based manufacturer of hybrid step motors that was founded in 1987 as a consulting company specializing in step-motor applications. Today, Lin Engineering is the largest manufacturer of 0.9-degree step motors in the motion control industry. As the quality and custom-product manager at Lin Engineering, I’d like to share how we experienced stepping into cloud-based quality control.

Jay Arthur—The KnowWare Man’s picture

By: Jay Arthur—The KnowWare Man

When looking at any existing process, people often have a hard time visualizing the enormous amount of delay, waste, and nonvalue-added work involved. That’s where a time value map comes in; it makes the invisible waste visible. A time value map shows value-added and nonvalue-added activities and delays.

Lean Math With Mark Hamel’s picture

By: Lean Math With Mark Hamel

Available time for changeovers per period (Ta∆), also called available time for (internal) setups, represents the time per a given period (e.g., day, shift, week) during which a machine, equipment, or resource can be changed over (i.e., from one product to another, prepared for a different medical procedure, cleaned for another customer). Ta∆, is foundational to every part, every interval (EPEI), changeover distribution, and kanban-sizing calculations.

David Muil’s picture

By: David Muil

Management systems are sometimes misunderstood as nothing more than a heavy administrative burden providing limited business benefit. In fact, many organizations with management systems in place haven’t effectively defined the processes they actually employ at all. Perhaps it’s because they think management systems only pertain to standards, and “ISO 9001 is separate from how we run the business.”

Donald J. Wheeler’s picture

By: Donald J. Wheeler

Why bother to plot your data? A simple shortcut is available that will allow you to do your analysis without the data getting in the way. How do you accomplish this breakthrough? Read on.

This marvelous advance in analysis is known as the “data-free graph.” As usual we begin with a collection of data as in figure 1.


Matthew J. Savage’s picture

By: Matthew J. Savage

Lori, a software customer, phoned to ask if Cpk is the best statistic to use in a process that slits metal to exacting widths. As a PQ Systems technical support analyst, I too wondered what index would be best suited for her application, a highly specialized one. Perhaps Cpk, Ppk, Cpm, or some other index offers the best means of reporting the capability of her product or process.

Bruno Scibilia’s picture

By: Bruno Scibilia

My main objective is to encourage greater use of statistical techniques in the service sector and present new ways to implement them.

Bob Emiliani’s picture

By: Bob Emiliani

Let’s get rid of value stream maps. I can hear it now: “Why would you say such a thing? Value stream maps are great. We can’t see waste without them.”


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