Sigma Method for Process Capability | Green Belt 2.0® Lean Six Sigma | fkiQuality HD
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- Опубликовано: 10 сен 2024
- The Sigma method is used to measure how capable or "satisfying" a process is.
Sigma tables display sigma values and their associated yield (in percentage) and defective proportion (in defects per million opportunities - DPMO).
The table used in this video is derived from the standard Normal distribution N(0,1) and is free of the arbitrary 1.5 sigma adjustment featured in many books. The 1.5 sigma shift implies that the process is not stable, in which case the calculation of capability value makes no sense at all.
Assumption for using this method: the process is normally distributed with a known average and standard deviation.
Appreciated seeing the visual representations of a company that initially performed on a mediocre scale in terms of average delivery times to performing much better after improvements. Really helps to solidify the fundamentals of Six Sigma, why it matters, and how the data can be charted.
great visual representation of how much satisfaction a customer will get from an improved process.
I’m in awe as to how this complicated process was broken down in an easily digestible format with the Six Sigma methodology. It appears that when there is data to show facts, and all else fails your numbers (data) will always be tried and true. Yee-haw!
Having the graphical depiction of the different sigma values was very helpful in seeing how changes in the the average and/or the standard deviation affect the shape/position of the curve.
This was a good explanation of how the signal method gives us a way to compare processes to make improvements.
This was a great walkthrough on how to calculate the sigma of a process. It also helps that they give the 'estimated defects per million' to give a better representation of what these almost 100% numbers mean.
This was a great video displaying how a couple of minutes can make a huge difference. It also effectively shows how to calculate the sigma of a process.
Thank you for showing the visual representation of the effect of lean processes. I also appreciate this being the same example you used in class, this really helps it stick and helps me best understand the concept.
Showing the graphs with the sigma calculation makes the approach very apparent. Thanks!
Putting the data into a graphical term for me is very helpful to me, it helps me understand it much better.
Great way of explaining the sigma method. The sigma method helps identify process improvement opportunities by highlighting change in variance.
By the end of the video I felt that I understood sigma and process capability much better. When I have more time I would like to re watch this video to understand it even better.
Very concise rundown of how reduced variability and improved process time improve yield. Thanks!
Its a useful tool to see how satisfy our customers are and what are capabilities are. The calculations are helpful to reiterate what we did in class. I like how he explained how the graph helps reiterate results.
Another concise explanation of Sigma scores and why it helps to present data in a visual format. The concepts of reducing the average and variability (standard deviation) are much easier to understand when visualized on the graph. It is easy to show how a shift to the left means process improvement. This also highlights how challenges increase as one tries to achieve a higher and higher Sigma score.
Good explanation on the Sigma Method for process capability. Useful tool to see your progress when running Lean Six Sigma projects to increase process capabilities, which results in a higher yield and reduced DPMO.
A good example of how changes to a process can be measured using sigma.
Good explanation. Smaller variation in a work process => smaller standard deviation=> higher sigma value, higher yield and lower defective rate
Useful tool for describing where you are at and for tracking results after improvements are made
This is a great video to explain and show how a process is doing, and to reach a number as high as 6 sigma could be hard to achieve.
The Sigma Method is a great tool for tracking a processes performance and figuring out ways to improve on the process.
Very good way to represent data sets and understand likelihood to achieve upper spec limit.
Thank you! A great example I can adopt to the needs of my students!
Homero Cardoso: This sigma method is a great visual tool. It really helps in understanding the continuous improving process.
That's right, Homero -- this is one of the concepts I wanted to explain visually.
Pizza delivery time a good example to illustrate the concepts. Thanks!
Thanks helped visualize six sigma better.
This video does a great job of highlighting what changes in mean and variance can do to your process capability. Sigma methodology is a great tool that is applicable to all different types of processes depending on the yield you can realistically achieve/the yield you need to reasonably achieve to remain competitive.
Good guidance through the problems.
Great video that demonstrates the main goal (in this case orders delivered in 30 minutes) and the variance whether orders are early or late. The pizza company is a perfect example as it helps put a real life scenario that everyone can relate to that clearly displays this lesson.
This is a good representation of a utilizing data to understand real life scenarios and how we can calculate variance and putting together what we have learned this far sigma z score, yield etc.
Looking forward to reviewing this further.
I understand the benefit but will need to watch this vid about 5 more times to really get it, maybe more… What I am very curious about is how we calculate process capability where I’m at. Will definitely be looking into that.
It is always beneficial to be able to graph something for visual effect but to be able to calculate a quantifiable number that means something too takes it another step further. It adds a rating to your process so you know exactly where you are and where you need to set your goals.
Great in depth example on sigma values!
John, subscribe to the channel and you'll get notices whenver I upload a new video.
understanding the process is good to know, applying to your every day work schedule will give you uniformity
Make data visual. Tells the story way better than equations or data sets. In this example, by reducing your average AND your variability, you can exponentially increase your acceptable deliveries, as deemed by the customer. A simple shift in the graph, or a compression of the curve, will show you where you need to be, so that you can allocate resources and gameplan accordingly.
Utilizing the Sigma method compliments the Yield process. A better managed process displays a smaller STD DEV possible through the Sigma capability method.
Very informative
I like all the breakdowns and the visualizations from the graphs. I'd like to see the formulas written out in addition to plugging in the numbers right away to help with correlating the symbols and formulas with the data.
Makes sense, now I need to do the math and calculate where my facility stands from a sigma method pertaining to quality.
Average outcome meeting goal or specification is not acceptable -reducing steps in process is necessary to narrow the bell- PC is a great tool to chart changes
Interesting how only 3 minutes can make such a major difference.
This video shows how critcal it is to be consistent with the product. Meaning having a very small standard deviation. How do we calculate if we have more than one specification?
I feel like I am missing something; how do we identify the "standard deviation" number? In order to determine the Z-score we need to know the customers specification, we then deduct our average against the specification, but how do we identify the standard deviation?
In using the pizza delivery example, do we take "X" amount of deliveries and then calculate STDEV.S in order to obtain the standard deviation? That would be the number we input in order to obtain our Sigma/Z score?
Through this analysis reducing the mean results in higher sigma score
That is right, and also reducing the variation increases the sigma score.
Good visuale of continuously improving the process through data.
Will there ever be a reason to go beyond 3 SD for the denominator?
"Six Sigma Champions are con men "
“All you have is smoke and mirrors ...”
- Creator of Six Sigma, Mikel Harry
Interesting video. Going by the DPMO, it seems to hint that reaching 6-sigma levels of quality can be quite difficult. Is that a fair assessment?
That is correct, Rafael; Motorola used to talk of the "4.5 sigma barrier" which required new thinking/designs to be surpassed and improvement alone won't do it -- according to their statement.
Is there a quick, verified tool that we can use to automatically look up the z tables?
Use Excel. For instance to find the cumulative probability (what we call yield) of a z value of 1 in a process normally distributed with mean 0 and std dev 1, use =NORM.DIST(1,0,1,TRUE)
And you can get the famous 99.99966% yield of "six sigma" with this formula:
=NORM.DIST(4.5,0,1,TRUE)
By the way, it is really a z-value of 4.5 or 4.5 standard deviations instead of 6, but that's for an in-person discussion.
I would really like to know, in practical terms, what those pizza delivery guys did to increase the yield on their on-time deliveries. Thinking about buying some stocks in this pizza delivery company. 🤣🤣🤣