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Top 10 Improvement Tools Named After A Lean Sensei

1. Ohno Circle

Taiichi Ohno was the Toyota executive largely responsible for structuring and implementing the system known today as the Toyota Production System over four decades after World War II. Ohno was known for drawing a chalk circle around managers and making them stand in the circle until they had seen and documented all of the problems in a particular area.

Today the “stand in a circle” exercise is a great way to train one’s eyes to see waste and to provide structure for the team leader to do daily improvement or for the busy executive with limited time to go to gemba.

When you spend time in the gemba standing in the Ohno Circle, you will see the gap between the target condition and the actual condition. It’s time to decide where to start first in closing this gap, using the Pareto principle.

2. Pareto Chart

In 1906 Italian economist Vilfredo Pareto simplified the world for us with his 80/20 rule, or what is known as the Pareto principle. This is most often expressed in a Pareto chart. Identify the vital few that will give you the biggest impact towards closing the gap between current condition and target condition, and when that’s done, move onto the next tallest bar in the Pareto.

To focus on addressing the root causes of the top 20% factors that are keeping your from hitting the target, the next step is to dig deeper into the root causes using the Ishikawa Diagram.

3. Ishikawa Diagram

The Ishikawa Diagram (also called the fishbone diagram or cause and effect diagram) was introduced in the 1960s by Kaoru Ishikawa. Ishikawa pioneered quality management processes at the Kawasaki shipyards, and in became one of the founding fathers of modern management. The diagram shows the causes of a certain event or condition. The Ishikawa Diagram is one of the seven QC tools including the histogram, Pareto chart, check sheet, control chart, flowchart, and scatter diagram.

It is quite a flexible tool. Root cause analysis can be conducted for manufacturing or production-type processes using the 4M (man, material, machine, methods) or sometimes up to 6M (add mother nature, measurement) as well as 4P (price, promotion, place, product) for a marketing and sales kaizen.

Now that you have identified the root causes of your problem, you are ready to implement countermeasures. For that, you’ll need an action plan.

4. Gantt Chart

Henry Gantt was a management consultant who popularized the project management tool known as the Gantt Chart some time around 1910.

Anyone who has used Microsoft Project or who has used this classic project management tool has Mr. Gantt to thank. He revolutionized the managing of large, complex projects such as construction, worldwide when he introduced his Gantt Chart.

Gantt was a very early Lean sensei in that he set the foundation for later developments such as standard work combination sheet, scheduling a day’s work and work balancing. The action plan must not be limited to “plan and do” but also “check and act / adjust” according to the PDCA Cycle, also known as the Deming Wheel.

5. Deming Wheel

The Deming Wheel is also known as the PDCA Wheel. Edwards Deming is credited with teaching PDCA to the Japanese, but proper credit should be given to Walter Shewhart, the pionnering statistician and teacher of Deming, who originated the PDCA notion.

6. Taguchi Method

Genichi Taguchi took the notion of R.A. Fisher’s Design of Experiments and sought to understand the influence of parameters on variation, not only on the mean. In conventional DOE, variation between experimental replications is considered a nuisance that experimenters would rather eliminate, whereas in Taguchi’s mind, variation is a central point of investigation.

Using these tools, you will have the data to prove that your experiment is a success! But how do you motivate people to come around to your way of thinking and adopt a new way? It might be helpful to know something about human motivation and Maslow’s Hierarchy of Needs.

7. Maslow’s Hierarchy of Needs

Abraham Maslow was an American psychologist who is most famous for the hierarchy of human needs. Maslow’s model gives us the foundation for understanding how to motivate people to change.

Improvements made, you now need a way to check and audit the process regularly so that the process does not revert to the old way, and that new problems are discovered quickly. The Oba Gage is a useful means to enable a visual workplace for abnormality management.

8. Oba Gauge

A 4 foot tall Japanese Lean sensei named Mr. Oba was notorious for insisting that nothing in the factory be taller than his eye-level This resulted in the “Oba Gage” for a visual workplace. The idea is to avoid creating view-blockers in your workplace whenever possible. It is also called the “4-foot rule” or “1.3 meter rule”.

The workplace is more visual, many large problems have been solved and the process is stable. But how can we avoid complacency and keep continuous improvement going?

9. Heinrich Principle

H.W. Heinrich taught us through his Heinrich Principle that we must pay attention to even the smallest of safety incidents or so-called “near misses” if we want to find the root causes of what could become larger safety accidents. The same principle applies to 5S, the elimination of waste, and awareness of quality problems. Lean management means everyone is vigilant about even the smallest problems. This requires constant education and attention to maintain a heightened sensitivity and avoid habituation to the warusa kagen (condition of badness).

The first nine tools used properly will result in improved safety, quality, cost and delivery. This will also open up capacity in your company to develop and deliver new products and services. But which products and services will give you a market advantage? The Kano Model helps you answer this question.

10. Kano Model

When we go back to the beginning in the cycle of continuous improvement, we have to ask again “What does the customer want?” Professor Noriaki Kano gave us a model to answer this question more effectively. The chart below illustrates how there is the Voice of the Customer (spoken needs) as well as what is sometimes called Mind of the Customer (latent or unspoken needs).

Quality Function Deployment (QFD) makes effective use of the Kano Model, as does fact-based Hoshin Kanri (policy management or Lean strategic planning).

You might ask why to include a Professor who developed a model largely used for product development and strategic planning on this list of improvement tools named after Lean sensei. If we follow Pareto’s Law, 80% of the waste in a product is in the design phase and likewise 80% of the waste in management effort is probably in misdirected or unaligned strategy. So although the Kano Model ranked at #10 on the list because it is far less practical and hands-on useful on a daily basis than the other nine, one could say that it has the biggest potential impact on the overall system.

There are many tools in the world. Knowing how to use them is important, but even more important is knowing how to put them to use as an overall system in such a way that helps people see things in a new way, to change how they think and work.


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