This document summarizes Taguchi's views on quality engineering and analysis. It discusses Taguchi's definition of quality as the total loss incurred by society due to product failure or deviation from desired performance levels. This includes costs of poor performance, operating costs over the product lifespan, and harmful side effects. The document also explains Taguchi's loss function approach, which quantifies quality losses based on the product's deviation from the target value. It provides an example showing how to calculate annual losses and how improving the process mean and reducing variation can significantly reduce quality losses. Finally, it outlines the key aspects of Taguchi's approach, including designing quality in at the system, parameter, and tolerance levels to produce robust products and processes insensitive to variability

1. TAGUCHI’S QUALITY ENGINEERING &
ANALYSIS
Presentation Given By
Vishal Sachdeva
3611758
Submitted To
Er.Rahul Singla
A.P DME

2. BIBLIOGRAPHY

3. TAGUCHI’SLOSSFUNCTION
What were Taguchi’s views about quality??
•Taguchi defines Quality Level of a
product as the Total Loss incurred by
society due to failure of a product to
perform as desired when it deviates
from the delivered target performance
levels.
•This includes costs associated with
poor performance, operating costs
(which changes as a product ages) and
any added expenses due to harmful
side effects of the product in use

4. EXPLORINGTHETAGUCHIMETHOD
The Loss Function
Considering the Loss Function,
it is quantifiable
Larger is Better:
Smaller is Better:
Nominal is Best:
2
1( )L y k
y
    
2
( )L y ky
 
2
( )
:
m is the target of the
process specification
L y k y m
where
 

5. 0
2
0
0
0
is cost of repair or replace
a product and must include
loss due to unavailability
during repair
is the functional limit on
y of a product where it would
fail to perform its function
half the
A
k
A



time
THECOSTOFLOSS
Considering The Cost Of Loss (K)
k in the L(y) equation is found from:

6. LOSSFUNCTIONEXAMPLE
Nominal Is Best
We can define a processes average loss as:
s is process (product) Standard Deviation
y(with bar) is process (product) mean
 
2
2
L k s y m   
  

7. EXAMPLECONT.
•A0 is $2 (a very low number of this type!) found by
estimating that the loss is 10% of the $20 product cost
when a part is exactly 8.55 or 8.45 units
•Process specification is: 8.5+.05 units
•Historically: ybar = 8.492 and s = 0.016

8. EXAMPLECONT.
•Average Loss:
•If we make 250,000 units a year
•Annual Loss is $64,000
     
2 2
2
2 0.016 8.492 8.500
.05
800 .00032 $0.256
L
L
   
 
  

9. FIXINGIT
Shift the Mean to
nominal
Reduce variation
(s = 0.01)
Fix Both!
 
22
800 .016 0 $0.2048
Annual Loss is $51200 about 20% reduction
L    
 
 
22
800 .010 .008 $0.1312
Annual Loss is $32800 about 50% reduction
L    
 
 
22
800 .010 0 $0.08
Annual Loss is $20000 about 66% reduction
L    
 

10. TAGUCHIMETHODS
Benefits To Companies
•Help companies to perform the Quality Fix!
Quality problems are due to Noises in the product or
process system
Noise is any undesirable effect that increases variability
•Conduct extensive Problem Analyses
•Employ Inter-disciplinary Teams
•Perform Designed Experimental Analyses
•Evaluate Experiments using ANOVA and Signal-to
noise techniques.

11. TAGUCHIAPPROACH
Defining The Taguchi Approach
•The Point Then Is To Produce Processes
Or Products The Are ROBUST AGAINST
NOISES
• Don’t spend the money to eliminate all noise,
build designs (product and process) that can
perform as desired – low variability – in the
presence of noise!
Here:
ROBUSTNESS = HIGH QUALITY

12. TAGUCHIAPPROACH
Defining The Taguchi Approach
Noise Factors Cause Functional Variation
They Fall Into Three “Classes”
1. Outer Noise – Environmental Conditions
2. Inner Noise – Lifetime Deterioration
3. Between Product Noise – Piece To Piece Variation

13. STEPBYSTEPTAGUCHIMETHOD

14. TAGUCHIAPPROACH
Defining the Taguchi Approach
•TO RELIABLY MEET OUR DESIGN GOALS
MEANS: DESIGNING QUALITY IN!
•We find that Taguchi considered THREE
LEVELS OF DESIGN:
level 1: SYSTEM DESIGN
level 2: PARAMETER DESIGN
level 3: TOLERANCE DESIGN

16. TAGUCHIAPPROACH
SYSTEM DESIGN
•All About Innovation – New Ideas,
Techniques, Philosophies
•Application Of Science And
Engineering Knowledge
•Includes Selection Of:
Materials
Processes
Tentative Parameter Values

18. TAGUCHIAPPROACH
Parameter Design
•Tests For Levels Of Parameter Values
•Selects "Best Levels" For Operating Parameters
to be Least Sensitive to Noises
•Develops Processes Or Products That Are
Robust
•A Key Step To Increasing Quality Without
Increased Cost

20. TAGUCHIAPPROACH
Tolerance Design
•A "Last Resort" Improvement Step
•Identifies Parameters Having the greatest Influence
On Output Variation
•Tightens Tolerances On These Parameters
•Typically Means Increases In Cost

21. OVERALLCONCLUSION
Taguchi methods summary
•Taguchi methods (TM) are product or process improvement
techniques that use DOE methods for improvements
•A set of cookbook designs are available – and they can be
modified to build a rich set of studies (beyond what we have
seen in MP labs!)
•TM requires a commitment to complete studies and the
discipline to continue in the face of setbacks (as do all quality
improvement methods!)

22. Thank You