Lets define two terms before going forward:

- In Six Sigma, a defect is defined as anything outside of customer specifications.
- In Six Sigma, an opportunity is the total quantity of chances for a defect.

**Defects Per Unit (DPU):**

DPU = (total number of defects)/(total number of product units)

The probability of getting 'r' defects in a sample having a given DPU rate can be predicted with the Poisson Distribution.

**Total Opportunities (TO):**

TO = total number of product units x opportunities

**Defects Per Opportunity (DPO):**

DPO = (total number of defects)/ (total opportunity)

**Defects Per Million Opportunities (DPMO):**

DPMO = DPO x 1,000,000

Defects Per Million Opportunities or DPMO can be then converted to sigma values using Yield to Sigma Conversion Table given in Six Sigma - Measure Phase.

**According to the conversion table:**

6 Sigma = 3.4 DPMO

**How to find your Sigma Level**

- Clearly define the customer's explicit requirements.
- Count the number of defects that occur.
- Determine the yield-percentage of items without defects.
- Use the conversion chart to determine DPMO and Sigma Level.

**Simplified Sigma Conversion Table**

__Yield DPMO Sigma__

30.9% 690,000 1.0

62.9% 308,000 2.0

93.3 66,800 3.0

99.4 6,210 4.0

99.98 320 5.0

99.9997 3.4 6.0

62.9% 308,000 2.0

93.3 66,800 3.0

99.4 6,210 4.0

99.98 320 5.0

99.9997 3.4 6.0

**Six Sigma - Summary**

- Six Sigma is a philosophy of quality improvement.
- Six Sigma is 3.4 defects in one million opportunities (DPMO).
- Components of Six Sigma are Customer, Process, and Employees.
- Six Sigma implementation requires the following roles:
- Business Leader
- Sponsor
- Black Belt
- Master Black Belt
- Green Belt
- The generic cycle of Six Sigma includes the following phases: Define, Measure, Analyze, Improve, and Control.
- Six Sigma is dedicated to 'Customer focus'.