Deming's Red Bead Experiment Simulator
- The low yield of work is attributed to the incoming material. The workers are helpless to improve quality. They will continue to produce defects so long as there are defects in the raw material.
- The variation between workers is random. It is the result of the System, and not based on the workers’ skills.
- The performance of a worker on any one day cannot be used to predict his performance in the longer term. I cannot be taken as the basis of making a judgement about his abilities.
Dr. W. Edwards Deming
Why a Simulator ?
In his book, Deming has expressed apprehension that mechanical sampling may distort the process average of colored beads. The reason for this is attributed to the mechanical differences of colored beads from the white ones. Red pigment is different from the white one. The colored beads may be of a slightly different size and weight due to pigment coating.
A safer option would be to use random numbers. These do not have the bias that colored beads have over white ones as described above. Random numbers would however make the experiment more mathematical, and lack the visual appeal that the mechanical experiment may have.
This simulator attempts to overcome this shortcoming. It does use random numbers to do sampling. The visual appeal is also maintained intact.
David Slattebo:
Very Well done! now I would be able to simulate Dr. Deming’s roleplay.
Georges Van Cauwenbergh:
This highlights an aspect of our work that we sometimes forget. Humans being Human, we tend to blame the worker. In doing so we forget about the process and the inputs which help to produce the defects at the output.
Christopher Cleveland:
Excellent work, easy to use and understand, a good paring with the funnel experiment as it shows how uncontrolled operator influence of the process on the one end and the inability of the operator to affect the quality of the process on the other.
Kevin Mader:
I’m glad that you created a tool like this for folks to move to and check out. OOTC provides a reasonably good reference, but I think that your visual explanations would surely be beneficial to neophytes to the SOPK who want to understand variation with some psychology and systems appreciation. The Red Bead Experiment demonstrates that errors caused by workers operating a process are more on account of the System than the fault of the workers.
Dr. W. Edwards Deming describes the experiment in his book titled “Out of the Crisis”.
This simulator is a soft simulation of the Red Bead Experiment.
To run the simulation:
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- Specify the number of beads of each color (Total 10000)
- Name four Willing Workers by typing their names.
- Give specific names to the defects (instead of Red, Green, Blue).
- Select a worker and click “Draw Sample” button.
- Click “Show Chart” to view the control chart.