31-12-2010, 03:37 PM
SUBMITTED BY:
RAKESH KUMAR
ME103111
[attachment=7811]
History & Background
High quality product or service and the associated customer satisfaction is key for enterprises survival
In traditional method of quality improvement during pre-production experiment only one factor is adjusted.
This method is costly and unreliable
R.Fisher developed method using statistical design of experiments(SDE)
Taguchi uses off-line quality control to make a design robust against variability in both production and user environment
Taguchi philosophy
In a competitive market environment, continual quality improvements and cost reductions are necessary for business survival.
An important measurement of the quality of a manufactured product is the total loss generated by that product to the society.
Change the pre-production experimental procedure from varying one factor at a time to varying many factors simultaneously (SDE) , so that quality can be built into the product and the process.
The customer's loss due to poor quality is approximately proportional to the square of the deviation of the performance characteristic from its target or nominal value.
A product (or service) performance variation can be reduced by examining the non-linear effects of factors (parameters) on the performance characteristics. Any deviation from a target leads to poor quality.
Taguchi methods
Taguchi methods are statistical methods developed by Genichi Taguchi to improve the quality of manufactured goods, and also applied to, engineering , biotechnology, marketing & advertising.
Taguchi work includes 3 principal contribution to statistics:
Taguchi loss function
The philosophy of offline control
Innovations in the design of experiments
Taguchi’s definition of quality
"quality is the loss a product causes to society after being shipped, other than losses caused by its intrinsic functions.“
two categories:
(1) loss caused by variability of function
(2) loss caused by harmful side effects.
4 quality concepts devised by Taguchi:-
Quality should be designed into the product from the start, not by inspection and screening.
Quality is best achieved by minimising the deviation from the target, not a failure to confirm to specifications.
Quality should not be based on the performance, features or characteristics of the product.
The cost of quality should be measured as a function of product performance variation and the losses measured system- wide.
TAGUCHI'S LOSS FUNCTION
For every product quality characteristic there is a target value which results in the smallest loss; deviations from target value always results in increased loss to society
small deviations from the target value result in small losses.
These losses, however, increase in a nonlinear fashion as deviations from the target value increase.
Taguchi specified three situations:
Larger the better (for example, agricultural yield);
Smaller the better (for example, carbon dioxide emissions); and
On-target, minimum-variation (for example, a mating part in an assembly).
RAKESH KUMAR
ME103111
[attachment=7811]
History & Background
High quality product or service and the associated customer satisfaction is key for enterprises survival
In traditional method of quality improvement during pre-production experiment only one factor is adjusted.
This method is costly and unreliable
R.Fisher developed method using statistical design of experiments(SDE)
Taguchi uses off-line quality control to make a design robust against variability in both production and user environment
Taguchi philosophy
In a competitive market environment, continual quality improvements and cost reductions are necessary for business survival.
An important measurement of the quality of a manufactured product is the total loss generated by that product to the society.
Change the pre-production experimental procedure from varying one factor at a time to varying many factors simultaneously (SDE) , so that quality can be built into the product and the process.
The customer's loss due to poor quality is approximately proportional to the square of the deviation of the performance characteristic from its target or nominal value.
A product (or service) performance variation can be reduced by examining the non-linear effects of factors (parameters) on the performance characteristics. Any deviation from a target leads to poor quality.
Taguchi methods
Taguchi methods are statistical methods developed by Genichi Taguchi to improve the quality of manufactured goods, and also applied to, engineering , biotechnology, marketing & advertising.
Taguchi work includes 3 principal contribution to statistics:
Taguchi loss function
The philosophy of offline control
Innovations in the design of experiments
Taguchi’s definition of quality
"quality is the loss a product causes to society after being shipped, other than losses caused by its intrinsic functions.“
two categories:
(1) loss caused by variability of function
(2) loss caused by harmful side effects.
4 quality concepts devised by Taguchi:-
Quality should be designed into the product from the start, not by inspection and screening.
Quality is best achieved by minimising the deviation from the target, not a failure to confirm to specifications.
Quality should not be based on the performance, features or characteristics of the product.
The cost of quality should be measured as a function of product performance variation and the losses measured system- wide.
TAGUCHI'S LOSS FUNCTION
For every product quality characteristic there is a target value which results in the smallest loss; deviations from target value always results in increased loss to society
small deviations from the target value result in small losses.
These losses, however, increase in a nonlinear fashion as deviations from the target value increase.
Taguchi specified three situations:
Larger the better (for example, agricultural yield);
Smaller the better (for example, carbon dioxide emissions); and
On-target, minimum-variation (for example, a mating part in an assembly).
