1. Why/When is Taguchi Method Appropriate?
A new tip Every Friday
Friday, 3rd August 2001

2. New Tip #16
Taguchi Method 1st Priority : Variance Reduction 2nd Priority : Factor Effects (next 4 slides)
Friday, 3rd August 2001

3. 1st Priority : Variance Reduction 2nd Priority : Factor Effects
Symbols :  
Taguchi Method
1st Priority : Variance Reduction 2nd Priority : Factor Effects
Variance Reduction : USE Factor-Effect Plot for S/N Ratio :
Select ‘dominant’ Control Factor (and their Levels) such that “variance” is minimized
Neutral Factor
S / N RATIO 
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3
“put” the “mean-on-target” : USE Factor-Effect Plot for Mean :
Select one of the ‘neutral’ Control Factors as the “adjustment factor”
Mean 
Adjustment Factor
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3

4. 1st Priority : Variance Reduction
Symbols :  
Taguchi Method
1st Priority : Variance Reduction
S/N Ratio (Objective Function)
Taguchi methods are experimental statistical methods to optimize a given process technology with respect to an objective function defined as
 = =
 useful
 Harmful
Mean Square
Variance
The Ideal Value of the S/N Ratio is  (infinity).
Since the ideal value of the Ratio is  (infinity),
 the primary importance is shifted to “reduction in Variance” to 0 (zero)
 making “improving mean” a secondary objective
(which is primary in conventional approach)

5. Symbols :  
Taguchi Method
1st Priority : Variance Reduction and “put” the “mean-on-target”
Variance is, in fact, reduced in presence of NoIsE
and thus the product/process becomes “ROBUST”
Identify an “adjustment factor” that has little or no effect on the variance but has a large effect on the mean
 use the ‘adjustment factor’ to “put” the “mean-on-target”

6. 1st Priority : Variance Reduction 2nd Priority : Factor Effects
Symbols :  
Taguchi Method
1st Priority : Variance Reduction 2nd Priority : Factor Effects
Factor-Effect Plot for S/N Ratio :
Select ‘dominant’ Control Factor (and their Levels) such that “variance” is minimized
Neutral Factor
S / N RATIO 
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3
Factor-Effect Plot for Mean : A, C, D Levels are selected from S/N ratio plot
Select one of the ‘neutral’ Control Factors as the “adjustment factor”
 use this ‘adjustment factor’ to “put” the “mean-on-target”
Do not select from this plot
Mean 
Adjustment Factor
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3

7. Earlier Tips Links below
Friday, 27th July 2001
Friday, 20th July 2001
Friday, 13th July 2001
Taguchi Method
“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 

8. Earlier Tips Links below
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 

9. Earlier Tips Links below
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 

10. Earlier Tips Links below
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 

11. Earlier 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

12. end