1. Why/When is Taguchi Method Appropriate?
Tip #7
Taguchi Method : When to Select a ‘larger’ OA to perform “Factorial Experiments”
Friday, 1st June 2001

2. Tip #7
Taguchi Method : When to Select a ‘larger’ OA to perform “Factorial Experiments”
We always ‘think’ about ‘reducing’ the number of experiments (to minimize the ‘resources’ – equipment, materials, manpower and time)
However, doing ALL / Factorial experiments is a good idea if
Conducting experiments is ‘cheap’ but measurements are ‘expensive’
The experimental facility will NOT be available later to conduct the ‘verification’ experiment
We do NOT wish to conduct separate experiments for studying interactions between Control Factors

3. Taguchi Method : When to perform ALL / “Factorial Experiments”
Conducting ALL / Factorial experiments is a good idea if
Conducting experiments is ‘cheap’ (and in-house)
but measurements are ‘expensive’ (and elsewhere)
When an apparatus is fully set-up, it may be rather easy to conduct the experiments quickly (if we are not hampered by measurements in between the experiments)
Just collect all samples (that have ‘captured’ the effects of NoIsE factors)
Send samples (elsewhere) for measurements (make sure that these will capture the effects of NoIsE)

4. Taguchi Method : When to perform ALL / “Factorial Experiments”
Conducting ALL / Factorial experiments is a good idea if
The experimental facility will NOT be available LATER to conduct the ‘verification’ experiment
A typical case when experiments are done
On Production equipment
On Borrowed equipment
In presence of visiting ‘experts’

5. Taguchi Method : When to perform ALL / “Factorial Experiments”
Conducting ALL / Factorial experiments is a good idea if
We do NOT wish to conduct separate experiments for studying interactions between Control Factors
Analyze without considering interactions, Predict best combinations of control factors as well as Best results. Check this out – we already HAVE the results of the best experiment
If the results do not match, Evaluate the “key” interactions – again check results
If the results ‘still’ do not match, Evaluate “all” interactions – again check results

6. Control Factors and Levels Factorial Combinations
Taguchi Method : How to Select a ‘larger’ OA to perform “Factorial Experiments”
Control Factors and Levels
Factorial Combinations
Suitable OA
2 CF / 2-levels 4 L4
3 CF / 2-levels 8 L8
4 CF / 2-levels 16
L16
5 CF / 2-levels 32
L32

7. Control Factors and Levels Factorial Combinations
Taguchi Method : How to Select a ‘larger’ OA to perform “Factorial Experiments”
Control Factors and Levels
Factorial Combinations
Suitable OA
2 CF / 3-levels 9 L9
1 CF / 2-levels 18
L18
3 CF / 3-levels 27
L27 54
L54

8. 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 

9. 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 

10. 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 

11. 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 

12. 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

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