2. Six Sigma

3. What is Six Sigma? Philosophy: We should work smarter, not harder.
Business strategy: We gain a competitive edges in Quality, Cost, Customer Satisfaction.
Statistical measurement:
We measure defect rates in all processes through an expanding statistical concept.

4. What is Six Sigma?
Sigma is a statistical measure of variation from the average
For a manufacturing process, the sigma value is a metric that indicate how well that process is performing.
The value of 1 sigma is one standard deviation from the mean.

5. Six Sigma Approach
Combines some of the best technique of the past with recent breakthroughs in management thinking and plain old common sense.
The term ‘Six Sigma’ is a reference to a particular goal of reducing defects to near zero.

6. Benefits:
The goal of Six Sigma is to increase profits by eliminating variability, defects and waste that undermine customer loyalty.

7. Goals of Six Sigma
To achieve Zero Defect (3.4 PPM) in all outputs of the company through:
Measurement of defects in six sigma scale
Process re-design to improve capability
Involvement of all Employees

8. Six Sigma Belts:
Black Belt: Someone who either coaches or actually leads a Six Sigma team.
Master Black Belt: A person who coaches a large number of Six Sigma teams.
Green Belt: Employees who have received basic Six Sigma training.

9. Calculating Sigma Step 1: Calculating Defects per Unit (DPU)
DPU = Total number of defects
Total number of units

10. Calculating Sigma
Step 2: Calculating Defects Per Million Opportunities for error (DPMO)
DPMO = DPU X 1,000,000
No. of opp. for error

11. Calculating Sigma
Step 3: Correlate the DPMO to the chart showing correlation between “defects per million opportunities” and sigma levels.

12. SIGMA CONVERSION CHART
Sigma and it’s DPMO
SIGMA CONVERSION CHART
Sigma (σ) value
Defects per million opportunities
(+/-) 2
308, 537.0
(+/-) 3
66, 810.0
(+/-) 3.5
22, 750.0
(+/-) 4
6, 210.0
(+/-) 4.5
1,350.0
(+/-) 5
233.0
(+/-) 5.5
32.0
(+/-) 6
3.4

13. Tolerance
UCL
USL
LCL
LSL X
+3σ
+6σ
-3σ
-6σ

14. N number of CTQs (Critical To Quality parameters)
Case Example
STEP
ACTION
EQUATION
CALCUL. 1.
How many units were put through the Process? --
1283 2.
How many came out error free?
1138 3.
Compute the yield of the process.
step 2/ step 1
0.8870 4.
Compute the defect rate.
1 – step 3
0.113 5.
Compute the number of potential things that could create a defect.
N number of CTQs (Critical To Quality parameters) 24

15. Slightly above average performance
Case Example
STEP
ACTION
EQUATION
CALCUL. 6.
Calculate the defect rate per CTQ characteristics
Step 4/ step 5
0.0047 7.
Compute the defects per million opportunities
Step 6 X 1,000,000
4709 8.
Convert the DPMO into sigma value using the sigma conversion chart --
4.1 sigma 9.
Draw conclusions
Slightly above average performance

16. Six Sigma Tools: There are two six sigma methodologies:
DMAIC (define, measure, analyze, improve, control)
DMADV (define, measure, analyze, design, verify)

17. Six Sigma Tools: For existing processes D Define M Measure A Analyze
I Improve
C Control

18. Six Sigma Tools: For new processes D Define M Measure A Analyze
D Design
V Verify

19. The Journey
Six Sigma aims at continual improvement through the journey starting from the existing sigma level, gradually moving towards six sigma level and beyond.