The first question we usually ask about lead times, inventory levels, critical dimensions, defective rates, or any other quantity that varies, is what it is "on the average." The second question is how much it varies, but we only ask … Continue reading
Averages in Manufacturing Data
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The meaning(s) of "random"
"That was random!" is my younger son's response to the many things I say that sound strange to him, and my computer has Random Access Memory (RAM), meaning that access to all memory locations is equally fast, as opposed to sequential … Continue reading
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The bell curve: "Normal" or "Gaussian"?
Most discussions of statistical quality refer to the "Normal distribution," but "Normal" is a loaded word. If we talk about the "Normal distribution," it implies that all other distributions are, in some way, abnormal. The "Normal distribution" is also called … Continue reading
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Tradition, Tradition, Data Visualization, and Pareto Charts
Some of the standard charts used in manufacturing for decades don't meet today's criteria for effective visualization. But using them is now a tradition; they are taught in school and their value is unchallenged, but it is time to challenge it. If … Continue reading
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Where Have The Scatterplots Gone?
What passes for "business analytics" (BI), as advertised by software vendors, is limited to basic and poorly designed charts that fail to show interactions between variables, even though the use of scatterplots and elementary regression is taught to American middle schoolers and … Continue reading
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The Value Of Surveys: A Debate With Joseph Paris
Joseph Paris and I debated this issue in the Operational Excellence group on LinkedIn, where he started a discussion by posting the following: “Riddle me this… If the Japanese way of management and their engagement with employees is supposedly the … Continue reading
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If Talk Of Probability Makes Your Eyes Glaze Over…
Few terms cause manufacturing professionals’ eyes to glaze over like “probability.” They perceive it as a complicated theory without much relevance to their work. It is nowhere to be found in the Japanese literature on production systems and supply chains, or … Continue reading
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Probability For Professionals
In a previous post, I pointed out that manufacturing professionals’ eyes glaze over when they hear the word “probability.” Even outside manufacturing, most professionals’ idea of probability is that, if you throw a die, you have one chance in six of … Continue reading
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There Is More To Data Than Just Numbers
Don Wheeler’s Understanding Variation starts with a chapter entitled “Data are random and miscellaneous” that contains no discussion of any part of its title. Implicit in Wheeler’s book, however, is the view that data consists of tables of numbers, representing … Continue reading
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Is SPC Obsolete? (Revisited)
Six years ago, one of the first posts in this blog — Is SPC Obsolete? — started a spirited discussion with 122 comments. Reflecting on it, however, I find that the participants, including myself, missed the mark in many ways: My own … Continue reading
↧
Averages in Manufacturing Data
The first question we usually ask about lead times, inventory levels, critical dimensions, defective rates, or any other quantity that varies, is what it is “on the average.” The second question is how much it varies, but we only ask … Continue reading
↧
The meaning(s) of “random”
“That was random!” is my younger son’s response to the many things I say that sound strange to him, and my computer has Random Access Memory (RAM), meaning that access to all memory locations is equally fast, as opposed to sequential … Continue reading
↧
The bell curve: “Normal” or “Gaussian”?
Most discussions of statistical quality refer to the “Normal distribution,” but “Normal” is a loaded word. If we talk about the “Normal distribution,” it implies that all other distributions are, in some way, abnormal. The “Normal distribution” is also called … Continue reading
↧
↧
Tradition, Tradition, Data Visualization, and Pareto Charts
Some of the standard charts used in manufacturing for decades don’t meet today’s criteria for effective visualization. But using them is now a tradition; they are taught in school and their value is unchallenged, but it is time to challenge it. If … Continue reading
↧
Where Have The Scatterplots Gone?
What passes for “business analytics” (BI), as advertised by software vendors, is limited to basic and poorly designed charts that fail to show interactions between variables, even though the use of scatterplots and elementary regression is taught to American middle schoolers and … Continue reading
↧
The Value Of Surveys: A Debate With Joseph Paris
Joseph Paris and I debated this issue in the Operational Excellence group on LinkedIn, where he started a discussion by posting the following: “Riddle me this… If the Japanese way of management and their engagement with employees is supposedly the … Continue reading
↧
If Talk Of Probability Makes Your Eyes Glaze Over…
Few terms cause manufacturing professionals’ eyes to glaze over like “probability.” They perceive it as a complicated theory without much relevance to their work. It is nowhere to be found in the Japanese literature on production systems and supply chains, or … Continue reading
↧
↧
Probability For Professionals
In a previous post, I pointed out that manufacturing professionals’ eyes glaze over when they hear the word “probability.” Even outside manufacturing, most professionals’ idea of probability is that, if you throw a die, you have one chance in six of … Continue reading
↧
There Is More To Data Than Just Numbers
Don Wheeler’s Understanding Variation starts with a chapter entitled “Data are random and miscellaneous” that contains no discussion of any part of its title. Implicit in Wheeler’s book, however, is the view that data consists of tables of numbers, representing … Continue reading
↧
Is SPC Obsolete? (Revisited)
Six years ago, one of the first posts in this blog — Is SPC Obsolete? — started a spirited discussion with 122 comments. Reflecting on it, however, I find that the participants, including myself, missed the mark in many ways: My own … Continue reading
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More Pages to Explore .....
