Math – AllAboutLean.com

Denso’s Way to Visualize BIG Data 3: Additional Quality Control Tools

November 4, 2025November 4, 2025 by Christoph Roser

In my last two posts, I talked a lot about the free Analysis Platform application, used by Denso and others to dig deeper into big data to understand what exaltiert is happening on your shop floor. I showed you the Digital Native Seven Quality Control Tools (DN7 or DN7QC7). But beyond these seven tools, there are a few more included in the application, which I also would like to show you briefly here.

And, on top of that, I will also briefly show you Seven New Quality Control Tools that are not really part of the application, but aim to dig deeper into problems that are hard to quantify, and many of these tools are more based on relations than on data.

Denso’s Way to Visualize BIG Data 2: The Digital Native Seven Quality Control Tools

October 31, 2025October 28, 2025 by Christoph Roser

In my last post, I started to talk about the free Analysis Platform application used by Denso and others (especially in Japan) to tackle big data. In this post I will go into much more detail on what Denso calls the Digital Native Seven Quality Control Tools (DN7 or DN7QC7). These data analysis tools go way beyond the usual things you can do in Excel, and are designed to tackle big data analysis for industry 4.0. Beyond that, this application also includes more tools, which I will also show briefly in my next post.

Denso’s Way to Visualize BIG Data 1: The Analysis Platform Application

October 31, 2025October 21, 2025 by Christoph Roser

A lot of problem solving is about understanding the current situation. Ideally this includes data. There are a couple of ways to analyze data. Denso uses seven traditional ways of analyzing data, which you are all familiar with. However, they expanded these tools with the goal to analyze big data. They call it the Digital Native Seven Quality Control Tools (DN7 or DN7QC7) …and of course I will share this with you. Even better, there is a freely available tool “Analysis Platform” that does these analyses for you (albeit it is not that easy to use).

Hard Math in Lean: Selected Equations

August 21, 2025July 1, 2025 by Christoph Roser

I am a scientist, and I try to understand how the world works, particularly in my field of manufacturing and lean production. (I also try to teach others about this, e.g., through this blog.) Hence, in this post I will look at different equations used in lean. Somehow, there are not that many…

Continuously Moving Assembly Line—Speed, Work Content, and Length

August 21, 2025July 11, 2023 by Christoph Roser

This second post on continuously moving assembly lines will look at the math behind the correlation between the speed of the line (line takt or customer takt), the length of the line, and the amount of work that has to be done on the line. Luckily, the calculations are not very tricky. And, different from a pulsed assembly line, it is perfectly fine to have a continuously moving line that fits not a whole number but a fraction of parts to save space. The tricky part on how to assign the work to the workers will be discussed in the next post of this series.

The Kingman Formula – Variation, Utilization, and Lead Time

August 21, 2025September 19, 2017 by Christoph Roser

The lead time of a system is heavily influenced by both the utilization and the variation. There are approximations available to estimate this relation, and one of them is the Kingman formula. In this post I would like to introduce you to this equation and describe the fundamental understanding of it. Luckily, you don’t really need the formula for your daily dose of lean. The equation itself has little practical use. However, this relationship is important for understanding the behavior of your production system. While you won’t use the Kingman formula to evaluate your production system, understanding the equation will help you in tweaking your system in the right direction.

On Running Changeovers

November 4, 2025June 6, 2017 by Christoph Roser

Changeover times and their reduction are popular topics in lean manufacturing. In this post I would like to introduce the idea of running changeovers for production lines. The idea behind it is simple, and probably many of you do it already. Nevertheless, I have found little info on it online. I also would like to go into more detail on the benefits of a running changeover in comparison to the alternatives.

The Many Different Flavors of the OEE

August 21, 2025September 20, 2016 by Christoph Roser

If imitation is the sincerest form of flattery, the OEE (Overall Equipment Effectiveness or Efficiency) is indeed one of the most appreciated measures in lean. I counted at least eight different variants and adaptions of the basic OEE – although let me tell you that I am not impressed with all of them. Many of them seem to be theoretical academic constructs with little meaning for your shop floor. Also, identical acronyms and similar terms are often used in a completely different way, adding quite a bit to the confusion. On top of that, I think the OEE is used way too much in industry where it does not make sense, and many OEE numbers are heavily fudged. Anyway, let me show you the many different flavors of the OEE.