Design for Six Sigma: In Technology and Product Development

Appendix B. Glossary

A

absolute zero

A property of a quality characteristic that allows all measurements to begin from the number zero and go up the rational number line from that point. Many designs have an absolute zero scale of measurement and should have their data measured relative to that scale.

additive model

A mathematical function that expresses a dependent variable, y, in terms of the sum (simple addition) of functions of relatively independent variables represented by the control factors in an optimization experiment. The additive model assumes mild-to-moderate interactivity between the control factors and assigns the numerical contribution to the response for this interactivity to the error term in the model: y = f(A) + g(B) + h(C) ...