1. Why/When is Taguchi Method Appropriate?
A new tip Every Friday
Friday, 22nd June 2001

2. Tip #10
Taguchi Method Performs Process “centering” or “fine tuning” (next 6 slides)
Friday, 22nd June 2001

3. Taguchi Method Performs Process “centering” or “fine tuning”
“centering” or “fine tuning” of a process
MEANS DETERMINING :
THE CENTRAL VALUES OF CONTROL FACTORS TO ACHIEVE
REPEATABLE PERFORMANCE even when THE LEVELS OF
CONTROL FACTORS HAVE SOME “VARIATIONS” AROUND ITS
CENTRAL VALUES
Please note that this is different than making the process
ROBUST against NoIsE in general
”Centering” or “Fine Tuning” covers only the CONTROL FACTORS

4. Taguchi Method Effect of Internal/External noise on the output Y
Noise Factors X
EXTERNAL NOISES
Process / Product
Diagram Y
VARIATIONS
INTERNAL NOISE Z
Control Factors

5. THE FACTOR EFFECT PLOT using S/N RATIO INDICATES
THE RATE AT WHICH A PARTICULAR CONTROL FACTOR LEVEL AFFECTS THE S/N RATIO i.e. VARIANCE
BEST SETTINGS ARE SELECTED (AS SHOWN BT )
FOR EACH CONTROL FACTOR
EACH SELECTED SETTING IMPLIES reduced VARIANCE
S / N RATIO 
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3

6. THE FACTOR EFFECT PLOT using Mean INDICATES
THE RATE AT WHICH A PARTICULAR CONTROL FACTOR LEVEL AFFECTS THE Mean (AS INDICATED BY SLOPE)
BEST SETTINGS ARE SELECTED (AS SHOWN BY )
BY using S/N RATIO PLOT
EACH SELECTED SETTING IMPLIES reduced VARIANCE
BUT COULD AFFECT THE Mean SIGNIFICANTLY
SLOPE AT A1 IS LARGE
SLOPE AT B2 IS MEDIUM
SLOPES AT C3 AND D2 ARE SMALL
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3
Mean 

7. THE FACTOR EFFECT PLOTS (S/N RATIO AND Mean)
CLEARLY INDICATE THAT
CONTROL FACTOR ‘B’ HAS small EFFECT ON S/N RATIO
and A LARGE EFFECT ON Mean
‘B’ IS AN ADJUSTMENT FACTOR AND CAN BE USED
FOR ADJUSTING MEAN-ON-TARGET
S / N RATIO 
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3
Mean 

8. Taguchi Method Internal noise in control factor B and its effect on output Y
B – Variation in B
Y – Large variation in Y Y B Y
Shape of this curve depends on the control factor settings
Increasing S/N ratios
Best Settings
Nominal Settings
Y – small variation in Y

9. More Tips Links below Tips 12, 11, 10  Taguchi Method
Friday, 3rd Aug 2001
Friday, 27th July 2001
Friday, 20th July 2001
Friday, 13th July 2001
Taguchi Method
1st Priority : Variance Reduction 2nd Priority : Factor Effects
15. “inner” L9 array with “outer” L4 and L9 NoIsE arrays
“inner” L18 array with “outer” L4 and L9 NoIsE arrays
Taguchi Method Why/When is Taguchi Method not Appropriate?
Tips 12, 11, 10 

10. More Tips Links below Taguchi Method
Friday, 6th July 2001
Friday, 29th June 2001
Friday, 22nd June 2001
Taguchi Method
“inner” L8 array with “outer” L4 and L9 NoIsE arrays
Useful at ALL Life-stages of a Process or Product
Performs Process “centering” or “fine tuning”
Tips 9, 8, 7 

11. More Tips Links below Tips 6, 5, 4 
Taguchi Method Identifies the “right” NoIsE factor(s) for Tolerance Design
Taguchi Method
Finds best settings to optimize TWO quality characteristics Simultaneously
7. Taguchi Method
When to select a ‘Larger’ OA to perform “Factorial Experiments”
Friday, 15th June 2001
Friday, 8th June 2001
Friday, 1st June 2001
Tips 6, 5, 4 

12. More Tips Links below Tips 3, 2, 1 
Friday, 25th May 2001
Friday, 18th May 2001
Friday, 11th May 2001
Taguchi Method Using Orthogonal Arrays for Generating Balanced Combinations of NoIsE Factors
Taguchi Method Signal-to-Noise Ratio for Quality Characteristics approaching IDEAL value
4. Taguchi Method improves " quality “ at all the life stages
at the design stage itself
Tips 3, 2, 1 

13. More Tips Links below
Friday, 4th May 2001
Friday, 27th April 2001
Friday, 6th April 2001
3. Taguchi Method Appropriate for Concurrent Engineering
2. Taguchi Method can study Interaction
between Noise Factors and Control Factors
1. Taguchi’s Signal-to-Noise Ratios are in Log form

14. end