4.3 Design of Experiments

Question 1

What is the goal of DOE?

Answer 1

DOE can help to identify vital factors in complex systems where the interaction between variables is important. It can also help to optimize the factors in a complex system.

Question 2

What is the difference between DOE and OFAT experiments?

Answer 2

One factor at a time (OFAT) experiments only test one variable. They can be time consuming and miss interactions between variables. DOE experiments test multiple variables at once, saving time and detecting interactions.

Question 3

How does DOE relate to Y=f(x)?

Answer 3

DOE is the last step in the Y=f(x) funnel, identifying and optimizing key variables that other tools missed.

Question 4

What is inference space?

Answer 4

Inference space is the parameters within which it is safe to make inferences. Generally this defined by the high and low settings of variables in a DOE. Making inference about settings outside of what has been tested is unreliable in a complex system.

Question 5

How do you select the levels for the testing variables in DOE?

Answer 5

Use process knowledge. The levels should be the high and low points for normal operation of the process.

Question 6

RSM is an example of what kind of DOE?

Answer 6

Response Surface Methodology (RSM) is a type of Optimization DOE that charts non-linear interactions between variables.