Japanese and Modern Joinery

Konnichiwa Mina San!!

I'm very excited to share with you a very cool Kaizen throwback to making things using nature and habitation with the use of tools. The other day, I was speaking to my neighbor Jim who incorporates the Art of Japanese Joinery into his Artwork, and got me to thinking how we could use this technique more today! From the book, "Tsukuru Aesthetics at Work"; a craftsman's work is a process of discovering and extracting the beauty inherent in nature, using techniques and skills that were refined to incredible tolerances over generations.
The tongue and groove wood working, called Tsugite (splicing joinery) or Shiguchi (connecting joints),  are what these Japanese craftsman have been using for millennia and still use today.  There are over a 100 different methods of Shiguchi employed over dozens of different uses which have been going through the Kaizen process for thousands of years. 
While I lived in Japan, I would walk through these incredible Shinto and Buddhist shrines and temples and Castles that were made with the Shiguchi methodology of tongue and groove with no nails, screws, plates, or bolts. Some of these structures are over a 1000 years old and still in beautiful condition.
The craftsman that made these had to develop incredibly intricate tools to create these structures with the smallest of tolerances. These tools are thought to be the extension of the craftsman's limbs to which they help refine, strengthen, and make more efficient our manipulation of things and materials.

In most cases this way of building is completely dependent on the skills of the craftsman. Since Japanese Joinery is so intricate with using chisels to chip away at wood to very small tolerances, the risk of error is great so much emphasis is placed on the craftsman to be nearly perfect.
As an industrial engineer, I would like to take this beautiful art of Japanese Joinery and make the process more efficient and common place in today's society. With the use of metal incorporated with the Japanese Joinery methodology we could bring in the best of both worlds to continue with making the process of building better.
For example, the Tsugite joints of traditional Japanese timber buildings are made without screws, bolts or plates; with the method involving cutting away of parts of the structural section. This reduces the structural strength of the wood because the stress of the woods is reduced the strength of the joints, which if small, could be considered a shortcoming to this ancient art of Tsugite Japanese timber structure making.
Since the strength to weight ratio of timber as a structural material is lighter and more durable (tensil, compressive, flexural) than steel or concrete, the use of tongue and groove that's reinforced with steel would seem ideal.
One company that I researched uses such a system called the KES System in which metal plates of the KES System are integrated into the beams and columns without cutting away large sections of the timber. This creates frames that are far more rigid than traditional or conventional timber structures.
 
 http://structure.kes.ne.jp/KesTechnicalArchitecture/architecture/index.html

 I look forward to watching the growth of this matrixed form of taking the traditional Japanese Joinery process and complimenting it with the newest advances in building technology.
From an Industrial Engineers and a Japanese Traditionalist art of building stand point, this could be the way of the future by keeping costs down, increasing quality, and increasing the artistic form of building western structures.

Hope you found this interesting and I look forward to any questions or comments you may have below or via e-mail.

Ja Mata Ne!!!

Scott 

Kaizen Margin Analysis

Konichiwa mina san!!

Its been a while since I have posted because I have been very busy living the Kaizen Kaikaku Life!

This post is very important in the area of engineering and can help businesses improve and sell there products by proving quality!

First I want to give you the background to be able perform a robust margin analysis then I will show you how to apply it to Kaizen which will ultimately lead to Kaikaku.

There are many ways to perform margin analysis but my favorite is using K-Factor because most things in life are natural and random and fall to the central limit theorem; thus, using the Normal Distribution (Guassian) would make sense.



Equation above: Gaussain Distribution

The K-Factor Equation is K=M/U or simply stated Margin over Uncertainty.

M=Mean - Lower Performance Requirements (LPR)  and U = Sigma

If you arrive at K equaling 1 than you are 1 standard deviation (sigma) away from the mean or 68.3% of the numbers will fall within this range within the full distribution; if you obtain a K of 2 then you are two sigma away from mean or  95.4% and 3 sigma is 99.7 %.

Now here is the tricky part that most people have a hard time understanding when I explain this to them.

The higher the K is better!

I often hear but 3 standard deviations away from the mean is worse than 2. Which is false.

I understand where a person might say that but what we as engineers do here is put limits, tolerances, boundaries on numbers and those limits are the lower and upper performance requirements. Therefore, the more Sigma that fit within those customer imposed limits the better our margin.

Lets perform an example together by first looking at this histogram/bell curve below:

From the histogram we see there we have an initial population size of 150 units in which all were tested. We can see the mean is 4.065, a standard deviation of 0.726, and an observed 99th percentile of 5.59 (estimated by the average of the two largest values in the observed dataset). The performance characteristic has an upper limit of 7.1

Example Calculation:

First Step: Find a tolerance bound that contains 99% of the population with 95% confidence. We can do this by taking the upper performance requirements (7.1) and subtracting the approximate 99th percentile figure (5.6) to obtain our margin of M=1.5
Second Step: Using the K-Factor equation from above we get:
K= 1.5/.73 = 2.05
Note: We have a K-Factor of 2.05 which tells us 2.05 SD fit within the boundaries with 95% confidence.
Third Step: The K-Factor is considered to be "large enough" when its a greater number than that specified of the normal distribution i.e. .995. .995 is equal to a  2.576 (2.58) Z Score. You can look this up on the internet. For our problem we want a 95% confidence with an alpha tail of .05 would give us a z-score of 1.645.
Fourth Step: Is our K factor larger than 1.645 to say with 95% confidence we will meet requirements? Yes. However, if we used the 99.5% confidence we would be short.
Optional Fifth Step: If you didn't have a population (N) but a sample (n):  If its a sample, this does not take into account the relative error rate which is a function of sample size.  See the equation and subsequent chart derived from the equation for your K bounds that was derived from the CpK equation (capability index):

Therefore we have a sample of say 100 instead of the population of 150 we would have to calculate the Lower and Upper Relative Error Rate:
If our K- Factor is 2.05 we multiply by the error rate
2.05*.86 for Lower and 2.05*1.14 for Upper giving you 1.7663 and 2.337.
Which would still be higher that the 95% confidence rate you were after.
Conclusion: We can claim now that there is sufficient margin to conclude that 95% of the units will meet performance requirements.

Note: Judging by the analysis of the Sample step, if we had a sample size of 10 which would give 2.05*.53 giving a Lower Relative Error Rate K-factor of 1.08, we could not say with 95% that we will be within margins. Basically the more we sample the better within reason cost wise.

So how does this relate to the Kaizen Kaikaku Life?

By knowing your margins in meeting requirements, you can have a very good baseline for improvement. Remember what Taichi Ohno said, "Where there is not standard, there can be no Kaizen!"

Let me know if you have any questions or you want to get into some Margin Analysis that is less dependent on the Normal Distribution like the Tolerance Bound Approach.

Let me know in the comment section or e-mail me.

And as always stay improving my friends! Below I'm improving my skating skills!!

Kaizen Problem Solving

Konichi wa mina san,

First I want thank all my readers. We now have over 4,000 views in 37 different countries!

One thing that is certain in any engineer or non-engineer’s life is that there will be problems along the way. These problems could be as simple as a shipment of parts that’s always arriving wrong or late to the malfunctioning of a multi-million dollar satellite. In keeping with Tiachi Ohno’s teaching of, “without standardization there is no Kaizen”, there should be a systematic way to go about problem solving. This system needs to be more involved than the simple DMAIC (Define, Measure, Analyze, Improve, Control) and PDCA (Plan, Do, Check, Act) methodologies. This problem solving system, developed by TOYOTA, involves both DMAIC (Six Sigma) and PDCA (Lean) and takes it to another level! Here is how it works:

There are 8 steps that one should follow to a “T”. Do not skip any steps because if this does not work you do not want to have to double back and wonder what you missed. One can move on to another option to solve the problem and proceed to Kaizen.  These are the 8 steps:

1.       Background

•  Relevant background information
•  Ease in communication (Can a typical 3rd party relate to the contents?)

2.      Clarify the Problem (Problem Definition)  

• Clarify the “Ultimate Goal” of your responsibilities and work. 
• Clarify the “Ideal Situation” of your work.  
• Clarify the “Current Situation” of your work. 
• Visualize the gap between “Current Situation” and the “Ideal Situation”
• When identifying a gap; be analytical, quantitative, and detailed (AQD).  

Once you have a good idea of what the gap is, form your team. The reason why I like to form my team so early is because having experts in the field help with step 1 before moving to step 2 can save a lot of pain and aggravation down the line. Properly identifying the problem is one of the most important steps! Make sure your team agrees with your problem definition. 

3.       Target (Goal) Setting 

• Make the commitment.
• BE SMART (Specific, Measurable, Attainable, Relevant, and Timely).                                        I like to use the from what, to what, and by when method of goal setting.

PEER GATE: Have peers that are not a part of your problem solving team look at what you’re doing up to this point and get any feedback before moving to the next step. If management should be kept apprised this is the time to do it.

4.       Analysis and Action Items 

• Break Down the Problem
• Specify the point of cause by checking the process through “GENCHI GENBUTSU”;                which is translated at “GO SEE FOR YOURSELF”.
• Measure how the process is currently as a baseline.
• Measure how the process is after to see if gap is closed. 
• Analytic, Quantitative, and Detailed. 
• Use Benkei's 7 QC tools as needed. (Data Collection/Check Sheets, Cause and Effect                Diagrams, Graphs/flow charts, Pareto Chart, Control Chart, Histogram, and Scatter  
•  Diagram) 
• 5 whys or some type of interview analysis.  
• Make sure you can point to the root cause(s)

PEER GATE

5.       Develop Countermeasures

           Type 5A: Temporary Countermeasures 

          Can occur anytime in the process to keep process moving or contain the problem to avoid 
          costly delays but its important to never lose sight of the permanent countermeasure.)

           Type 5B Permanent Countermeasures

• Develop as many potential countermeasures as possible. (lifecycle Fault Tree)
• Narrow down the countermeasures to the most practical and effective.
• I like to use the Kepner Tregoe Analysis to make the decision more data driven.                    (You can e-mail me or ask me in a comment if you need more info)
• Build consensus with others within the team. I like to get a commitment from                      each member here so there is buy-in. I like to do this to avoid the naysayers later.
• Create a clear and detailed action-plan.

PEER GATE - Have peers that are not a part of your problem solving team look at what you’re doing up to this point and get any feedback before moving to the next step. If management should be kept apprised this is the time to do it.

6.       Implement Countermeasures 

•  Quickly and as a team, implement the countermeasures chosen from the options.
•  Share the progress by following the correct reporting, informing, and consulting.
•  Never give up! Proceed to the next step quickly.

7.       Check (Monitor Results)

• Evaluate the overall results and process used, then share the evaluation with involved               members.

PEER GATE – This one is a little different because the processes have been implemented and it is time to evaluate before standardizing through the company/center/organization.

          a. Evaluate from the three key viewpoints: Customer, Key Stakeholders, and your own.

8.       Standardize Successful Processes  

•  Structure the successful processes (Standardize)
•  Share the new precedent through YOKOTEN (a process for sharing/learning laterally across an organization. It entails copying and improving kaizen ideas that work.
• Reflect on any LESSONS LEARNED during this process.
• Start the next round of KAIZEN.

This problem solving method works and I do not recommend skipping any steps even if your problem solving seemingly doesn’t require a step like step 2. Do it anyway because you will be surprised what comes up in these steps.

This problem solving methodology is kind of a mix of the formal rigid toll gating style of DMAIC but also has some informal steps like PDCA. Its important to point out that one shouldn't be a slave to the process because the point of this methodology is the result not completing the methodology.

Remember, these problem solving methods can be used in one’s personal life as well! For example, my roof was leaking about a month ago and I went through the steps through to completion and now my roof doesn’t leak! This might sound silly but my team included: my wife, a former structural engineer friend, an Insurance Inspector, and my dog.  The Peer gates included my mother and a couple friends. Just if you do use it in your personal life, most of these steps should be informal. Trust me.

Ja Matta Ne!

Scott Lager