1. Why/When is Taguchi Method Appropriate?
A new tip Every Friday
Friday, 15th June 2001

2. Tip #9
Taguchi Method Identifies the “right” NoIsE factor(s) for Tolerance Design (next 8 slides)
Friday, 15th June 2001

3. Taguchi Method Identifies the “right” NoIsE factor(s) for Tolerance Design
OPTIMIZING A DESIGN MEANS DETERMINING :
(A) THE BEST ARCHITECTURE ( " CONCEPT " DESIGN )
USE "AVAILABLE" and "ASSURED DESIGN “ else “A NEW CONCEPT”
(B) THE LEVELS OF CONTROL FACTORS ( " ROBUST " DESIGN )
MAIN OBJECTIVE " OPTIMUM SETTINGS " , " NOISE INSENSITIVITY “
ON " EXISTING / OLD " EQUIPMENT AND PROCESSES
NO COST FOR " NEW SETTINGS " ON " OLD EQUIPMENT
(C) TOLERANCES OF CONTROL/ NoIsE FACTORS ("TOLERANCE" DESIGN )
REDUCING THE " VARIATIONS " IMPLIES BETTER
RAW MATERIAL / EQUIPMENT / LABOUR / USER ENVIRONMENT
EXPENSIVE AND HENCE IT IS TO BE AVOIDED

4. Taguchi Method Identifies the “right” NoIsE factor(s) for Tolerance Design
OPTIMIZING A DESIGN MEANS DETERMINING :
(A) THE BEST ARCHITECTURE ( " CONCEPT " DESIGN )
BY USING "AVAILABLE" and "ASSURED DESIGN “
with certain modifications
else
BY USING “A NEW CONCEPT”
that works in a entirely different manner
In either of above concepts,
the new implementation of the concept needs “parameter optimization”

5. Taguchi Method Identifies the “right” NoIsE factor(s) for Tolerance Design
OPTIMIZING A DESIGN MEANS DETERMINING :
(B) THE LEVELS OF CONTROL FACTORS ( " ROBUST " DESIGN )
MAIN OBJECTIVES ARE TO
DETERMINE THE " OPTIMUM SETTINGS "
ACHIEVE " NOISE INSENSITIVITY “
“BEST RESULTS” ON " EXISTING / OLD " EQUIPMENT AND PROCESSES
AT NO ADDITIONAL COST FOR " NEW SETTINGS " ON "OLD EQUIPMENT”

6. Taguchi Method Identifies the “right” NoIsE factor(s) for Tolerance Design
OPTIMIZING A DESIGN MEANS DETERMINING :
TOLERANCES OF CONTROL and/or NoIsE FACTORS
("TOLERANCE" DESIGN )
REDUCING THE " VARIATIONS " IMPLIES BETTER
RAW MATERIAL
EQUIPMENT
LABOUR
USER ENVIRONMENT
EXPENSIVE AND HENCE IT IS TO BE AVOIDED

7. Taguchi Method Identifies the “right” Control Factor(s) for Tolerance Design
THE FACTOR EFFECT PLOT INDICATES
THE RATE AT WHICH A PARTICULAR CONTROL FACTOR LEVEL AFFECTS THE S/N RATIO
A1  HIGHER SLOPE IMPLIES ‘VARIATIONS’ IN PARAMETER A AT A1 WILL AFFECT THE S/N RATIO ADVERSELY
C3  SIMILAR ADVERSE EFFECT ON S/N RATIO (AS FOR A1)
B2 AND D2  HAVE THE LEAST EFFECT ON S/N RATIO
S / N RATIO 
A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3

8. Taguchi Method Identifies the “right” Control Factor(s) for Tolerance Design
THE FACTOR EFFECT PLOT INDICATES the effects of internal NoIsE (I.e. variations in the control factors themselves)
THE RATE AT WHICH A PARTICULAR CONTROL FACTOR LEVEL AFFECTS THE S/N RATIO
Tolerance Design :
 Priority #1 : Choose Control Factor A
as it has a very steep slope near Level A1
 Priority #2 : Choose Control Factor C
as it has a substantial slope near Level C3
NOTE : Control Factors B and C ought not to be used for
tolerance design

9. Taguchi Method Identifies the “right” NoIsE Factor(s) for Tolerance Design
 CONDUCT the experiment with best settings of Control Factors wherein NoIsE is included as
factorial combinations
or as noise-combinations based on orthogonal array
 THE effects of all external NoIsE factors can be calculated in a manner similar to the ANOVA analysis for Control Factors
From the NoIsE factor effect plot
Choose the dominant noise factor(s)
for Tolerance Design
NOTE : Insensitivity may have been achieved for some NoIsE factor(s)

10. Taguchi Method Identifies the “right” NoIsE for Tolerance Design
CONCLUSIONS
REDUCING THE "VARIATIONS" IN “SELECTED” CONTROL / NoIsE FACTORS IS CALLED “TOLERANCE DESIGN”
“SELECTING” NoIsE FACTORS (FOR TOLERANCE DESIGN)
INTERNAL NoIsE FACTORS (FROM MAIN-ARRAY)
SETTABLE/ADJUSTABLE EQUIPMENT PARAMETERS
EXTERNAL NoIsE FACTORS (FROM NOISE-ARRAY)
RAW MATERIAL
LABOUR SKILL
USER ENVIRONMENT
Friday, 15th June 2001

11. 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 

12. 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 

13. 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 

14. 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 

15. 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

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