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Paul Naysmith

Quality Insider

Seven Quality Tools of an Improvement Ninja, Part 1

The cause and effect diagram

Published: Monday, January 21, 2013 - 17:05

Writing articles for Quality Digest Daily has created some positive if unpredicted consequences for me. I’m fortunate that people read what I write and even reach out with feedback. Recently one such reader, just beginning her quality career in Chicago, emailed me, and we started a conversation about the “seven basic quality tools.” Initially she was unaware of these tools, but she was resourceful enough to do her own research and learn more.

This got me thinking about the quality of quality teaching, if you’ll excuse the pun, as well as the general awareness of the principles in our field. Are our quality colleagues across the world fully conversant with the history or the basics of our discipline?

So here I am, on a new quest to write about the seven quality tools (also known as the “old seven” or “first seven”) in my own particular style. Given the great deal of original and contemporary work to reference from, why would anyone bother to read my take on the subject? Well, in this series I will explore the origins of the tools and offer some insights based on my personal experience in applying them, and I’ll include some of the lessons I learned from their successful use.

The seven basic quality tools have separate and distinct births. However, according to Kaoru Ishikawa’s What Is Total Quality Control? (Prentice Hall Trade, 1991), they were brought together in Japan via the quality circles that Ishikawa claims credit with starting in 1962. Used independently, these tools are undeniably useful; however, combine them and you have a very powerful tool set to use in your daily challenges.

These are the seven quality tools, as recognized by the American Society for Quality (ASQ):
1. Cause and effect diagram
2. Check sheet
3. Control charts
4. Histogram
5. Pareto chart
6. Scatter diagram
7. Stratification

Some of the keen-eyed quality punks out there may disagree with my list. Certainly there are other quality tools to reference, but I think anyone beginning his ASQ or other quality professional development and education will benefit from understanding the old seven, and for that reason I’ll confine my discussion to them.

In this series I will also include hints and tips for using relevant software to your advantage. None of the programs I mention imply a preference, but I do use them nearly every day. I am aware of off-the-shelf programs that assist people in getting the most from the seven quality tools, but since I’m aiming at new quality professionals, I’m assuming that many may not yet have these “specialist” applications.

In the “Hints and Tips” section, I will share how I get the most from the tool. Granted, I may not be the world’s expert (I’m still waiting for the official ceremony lauding me with that title), but I can share my Improvement Ninja kata. And I certainly would like to hear about your own tips for success.

Tool 1: The cause and effect diagram, aka the Ishikawa or fishbone diagram

Figure 1: A blank cause and effect diagram produced with Minitab software

Cause and effect diagram tool ratings:
Difficulty to understand. I rate the cause and effect diagram a 3 on a scale of 10, with 10 being most difficult. With its various names, including the “Ishikawa diagram” and “fishbone diagram,” people have the understandable but mistaken impression that these are three different tools. However, they are one and the same. An advantage of the cause and effect diagram is its structured appearance of categories. This assists in collecting many ideas into “groups,” a visual logic that is quickly understood by the majority of people I have worked with.
Difficulty to use. I rate it a 2 out of 10, with 10 being the most difficult. Little teaching is required for the uninitiated to grasp the diagram’s purpose. There are more challenges with the brainstorming aspect of the diagram.
Difficulty to create on a computer. I rate it a 5 out of 10, with 10 being the most difficult. This is of course dependent on your proficiency with some of the software discussed below, not to mention your keyboarding abilities. Although my hands are as functional as anyone else’s with opposable thumbs, my fingers don’t always want to work together, particularly when it comes to the keyboard.

For background on the cause and effect diagram, you will need to plow through nearly a quarter of Kaoru Ishikawa’s What Is Total Quality Control? before you are introduced to the diagram and its approach. There you will find the author’s musings over the “Ishikawa diagram,” as Joseph M. Juran termed it. As I mentioned in an earlier column, I recommend sneaking into a bookshop just to read that section for a giggle. You’ll also find some amusing footnotes from the translator, who didn’t entirely agree with Ishikawa’s opinions.

When he designed the cause and effect diagram, Ishikawa hung the common themes of failure in a business around Taichi Ohno’s ideas of the 5Ms—i.e., man, method, material, machine, and Mother Nature—or the 5Ps—people, policy, procedure, process, and product. Collating these “tags” of information around the diagram’s “branches” assists organizations in deciding where to focus improvements efforts. You can read more about the 5Ms and 5Ps in Taichi Ohno’s and Norman Bodek’s book, Toyota Production System (Productivity Press, 1988).

How to create one

This is normally a 10-step process for me:
1. Identify the problem or solution.
2. Identify and invite appropriate key stakeholders.
3. Paper the wall with flipchart paper or use a nice big white board. Have lots of sticky notepads and pens on hand.
4. Draw the main branches of the diagram and the fish “head.” At the end of each branch, put one of the 5Ms or 5Ps. In the head, define the problem.
5. Explain the brainstorming rules, e.g., no such thing as a bad idea.
6. Ask everyone to brainstorm the causal factors and record them on the sticky notes.
7. Agree as a team where each note belongs on which branch, and stick it up there.
8. Keep going until you run out of ideas or questions.
9. Review the findings with the team.
10. Capture the cause and effect diagram on paper or via software.

Helpful software for using the tool

MS PowerPoint. One of the most common office programs, and the easiest when it comes to making simple line drawings. PowerPoint also has a nice little feature that makes the sub-branches (Insert tab > Shape button > Callouts). If you are going to use this software a great deal, I would recommend creating a blank template. This will help save time in the future. When including it in a report (such as a MS Word file), select all elements, and then copy and paste into your report. Nice and easy.

MS Word or MS Excel. A nightmare for me to use, and I’d suggest you use it only if you have incredible stamina and patience. These software packages are not always the best choice for creating “drawings,” and I would suggest looking elsewhere.

MS Visio. This software comes with predefined templates, and its drag-and-drop functionality makes building a cause and effect diagram quick and easy.

Minitab. You have to order your branches into a table before the software will render it into a nicely laid out diagram. However, you can create one within three to six mouse clicks. Figure 1 is a product of Minitab.

Hints and tips

Involve as many people as possible when creating a cause and effect diagram. I like to invite people outside the process or department to participate. Often they will see the issue slightly differently than key stakeholders will, and they usually aren’t afraid to ask the “obvious” questions.

You should not have to rush creating a good cause and effect diagram, and the pace will be dictated by the brainstorming activity, so take the time to revisit it again and again. After all, if you are attempting to trace a customer-related issue to its root cause, this can be your only priority.

During the brainstorming step, watch for natural pauses and ask open-ended questions to stimulate conversation or debate. I have found that there will be a moment where it all goes quiet, and nobody can think of anything to say. At that point I like to jog people along either by moving to the next branch, covering a previous comment idea, or even calling a halt to the proceedings. As for open-ended questions, the old Scottish proverb of the five wise men named “Who, What, Where, When, and Why” captures them succinctly.

It’s OK to have the same thing listed on different branches. I get asked this from time to time. “This would fit under equipment and people,” says the engineer holding aloft a pink sticky note with comments. I’m comfortable with a factor being placed in two or more different branches.

You don’t have to confine your main branches to the 5Ms or the 5Ps. Use definitions that are meaningful to your business. Also, you don’t necessarily need to stick with five branches; add more if you deem them appropriate. The more complex the problem, the more branches that will probably have to be added to your diagram.

Consider focusing first on the branch with the most sub-branches. I find this helpful because I can use this as a conversational tool with upper management: “Most of our issues are around our people or process. We need to fix this first.”

Different-colored stickies are a good idea. I like to use one color for known or established facts and another for questions to be answered. Once the team arrives at the answer to a question, you can easily place that sticky note over the original question.

You don’t have to build a cause and effect diagram on your computer. Why not take a picture of it instead? It may save you some time, especially if you are under a super-tight deadline. I do this frequently. The camera on my cell phone comes in handy, especially considering my employer’s 5S rules about white boards: They must be cleared after each meeting, before the next starts.

Last tip: Go do it. Making a cause and effect diagram can often help you understand a complex problem in a different way.

So there you have it, the first of the seven quality tools as seen by this Improvement Ninja. In the next installment, I will tackle check sheets. For now, if you would like to share your hints and tips, or even gripes about the tool or its related software, please add a comment below.


About The Author

Paul Naysmith’s picture

Paul Naysmith

Paul Naysmith is the author of Business Management Tips From an Improvement Ninja and Business Management Tips From a Quality Punk. He’s also a Fellow and Chartered Quality Professional with the UK’s Chartered Quality Institute (CQI), and an honorary member of the South African Quality Institute (SAQI). Connect with him at www.paulnaysmith.com, or follow him on twitter @PNaysmith.

Those who have read Paul’s columns might be wondering why they haven’t heard from him in a while. After his stint working in the United States, he moved back to his homeland of Scotland, where he quickly found a new career in the medical-device industry; became a dad to his first child, Florence; and decided to restore a classic car back to its roadworthy glory. With the help of his current employer, he’s also started the first-of-its-kind quality apprenticeship scheme, which he hopes will become a pipeline for future improvement ninjas and quality punks.



Dear Paul,

Not too long ago I read a book by William Zinsser titled "Writing to Learn". The title nicely summarizes why everyone should write. Writing forces you to understand the topic properly. It causes you to reconcile ideas you didn't know were in conflict as well as illuminating connections between ideas you thought were disparate. You exit the writing process wiser and more knowledgeable. So, cheers to you for writing and especially for writing about foundational tools of the quality professional.

The seven basic tools you outlined are not complex. Anyone can grasp them in a matter of minutes. Their power lies in their interactions with one another. They prod the problem solving process along. The factors you think up as causes with the Cause & Effect Diagram lead you to investigating their importance with a Pareto chart. You can then evaluate if the vital factors are in control with control charts. And so on. The tools form a system.

Looking forward to reading your experiences using these tools in your place of work (or even at home). I'm sure examples will be helpful to those new to the quality field.

Best regards,

Shrikant Kalegaonkar

twitter: @shrikale

A diversity of counter measures

A diversity of counter measures was taken to stop the behavior of the ninja. Precautions were often taken besides shooting, such as weapons covered in the lavatory, or under a detachable floorboard. Buildings were constructed with traps and trip ropes attached to alarm bells.

Cause and Effect is not for solutions


Thanks for an interesting article - everyone should know about these simple tools.

The purpose of a fishbone diagram is to capture the knowledge and experience of those working in the process and use this to narrow down the areas to gather data on. The solutions come out of the data analysis, not the brainstorming to create the fishbone. It is a great tool and there is no need to search for an alternative, as suggested by other commenters.

It does happen that teams suggest that human error is the cause of the problem. My advice is to ask them to gather data to prove this (while gently reminding them of Dr. Demings assertion that 99% of issues are due to the process and 1% due to the people). I have never found a case where the data confirmed their original idea, so they go back to the fishbone diagram and look for the next likely area to study. This is all part of the learning process that a team goes through. Using the fishbone to narrow down prevents the team from attempting to gather and analyse data on all aspects of the process.

It is snowing heavily in Scotland just now - thought that you would like to know.

Its +24C in Louisiana

Thanks for the comment Mike, I too love the question "what causes the human to make a mistake?" such a simple but powerful way to approach a systems failure, and I am sure you too ask this question all the time. Thanks also for the weather update, I see on the BBC Scotland website there are fantastic pictures of Scotland looking like the ice planet Hoth.

The Thirty-Nine Steps

Hi, Mr. Naysmith. I agree with you, writing for Quality Digest is a life-enriching experience. But, if you read my columns - I'm the white-bearded guy wearing a green shirt - and my comments, too, you'll notice that i'm rather more on the side of holistic, continuous approaches, than step-wise mechanisms. In my work career I've seen to many cases of 4M's and Evironment - based fish-bone charts happily ending with a "human error" root cause: what else is to be expected? Any- and every-thing we do is done by humans, it's only logical that any and every final cause has to be allocated to one or more humans. I much prefer - because I find it more effective - a free-wheeling approach; or - even better - "free-willing". You are surely familar with Run@Rate practices: I find more viable "Run@Risk" approaches. Thank you.

A journey of one thousand miles starts with a single step

To the white-bearded guy wearing a green shirt, from the flame haired improvement Ninja, I appreciate your sentiment on writing for QD and your continued pursuit of excellence. I'm not 100% conversant with Run@Risk and I would appreciate any articles you could send my way.

Fishbone diagram is useless

Hi Paul,

Hooray, it's not just me!  

The Fishbone Diagram has always been a crock, in my view.  

It yields half-baked fixes at best. It can't work because it requires guesses to be drawn up front about where the problems might lie.  Hence, it suffers from "Solutions First Syndrome", as I call it, the antithesis of systemic improvement.  So far as I can tell, Dr Deming did not include it in his 4 day seminars; I can well imagine he regarded it as tampering.

I have an alternative I call the Binary Model, based on Prof James Reason's Swiss Chese Model and Dean Gano's Reality Charting. The following link takes you to my paper at the World Business Capability Confrerence in Auckland NZ just before Christmas. 


I hope the paper is of interest.  Any probs drop me an email via LinkedIn.



Guess work

Thanks for your comment Ian, you are right in reference to the fishbone diagram having some limitations, however most tools and techniques in my experience do. The cause and effect through traditional teaching is a brainstorming exercise, however the benefit of the system is that it is an initiator to other investigation techniques. I am glad you are familiar with Reason et al, as these more advanced tools help us further ourselves in our Quality career, however, as I said at the start, I'm trying to enlighten our freshman colleagues. I do hope some go onto further study this area, and perhaps review your paper (which I have read - props). Keep up the writing and please send more over to me.