Interpretation of Harringtons Desirability

Harrington proposes the following interpretation:

desirability 1 as "ultimate satisfaction" or "improvement beyond this point has no value";
desirability 0.8 - 1 as "excellent" or "well beyond anything available";
desirability 0.63 - 0.8 as "good" or "slight improvement over industrial quality";
desirability 0.4 - 0.63 as "acceptable, but poor";
desirability 0.3 - 0.4 as "borderline";
desirability 0 - 0.3 as "unacceptable to completely unacceptable".

Advantages: closed form, differentiable for even n, useful interpretation
Disadvantages: always symmetric, different functions for target value and maximisation problems

Dipl.-Stat. Detlef Steuer
1999-10-04