Six Sigma is a philosophy that underlies efforts to improve business performance and customer satisfaction using facts and data to eliminate defects and variation.

2. 1
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The term “Sigma” is a measurement of how far a given process
deviates from perfection – a measure of number of “defects”.
“Six Sigma” implies near zero defects.
“A quality improvement methodology that applies statistics to
measure and reduce variation in processes.”
A management system that is “comprehensive and flexible for
achieving, sustaining, and maximizing business success.”
A philosophy that underlies efforts to improve business
performance and customer satisfaction using facts and data to
eliminate defects and variation.
Subhodip Pal

3. 2
Source:
The
Six
Sigma
Handbook,
McGraw
Hill
Education
D e f i n e , M e a s u r e , A n a l y z e , I m p r o v e , C o n t r o l
D - Define the goals of the improvement.
M - Measure the existing system.
A - Analyze the system to identify ways to eliminate
the gap between the current performance of the
system or process and desired goal.
I - Improve the system.
C - Control the new system.
Subhodip Pal

4. 3
Source:
The
Six
Sigma
Handbook,
McGraw
Hill
Education
Observe some important aspects of the marketplace or the business.
Develop a tentative explanation or hypothesis consistent with the observation.
Based on the hypothesis make the predictions.
Test the prediction by conducting experiments or making further careful
observations. Record the observations. Modify the hypothesis based on the new
facts. If variation exists, use a statistical tool to help separate signal from noise.
Repeat the 3rd and 4th steps until there are no discrepancies between the
hypothesis and the results from experiments or observations.
Subhodip Pal